-,.
PHYLOGENY AND RELATIONSHIPS OF THE ELAPID SNAKE GENUS SIMOSELAPS JAN, 1859: THE EVOLUTION OF A GROUP OF BURROWING SNAKES
by
John David Scanlon School of Biological Sciences University of Sydney
Submitted in partial fulfilment of the requirements for the degree of Bachelor of Science with Honours
•
,
November 1985
TABLE OF CONTENTS
ABSTRACT
CHAPTER 1:
.. . . . . . . . . . . . . .
I
•
•
I
•
•
•
•
•
•
,
•
•
•
•
•
•
iv
General Introduction
1.1
The Australian elapid snaKes • • • • •
1.2
Simoselaps, _Neelaps and Vermicella •
3
1.3
Choice of methods
7
1.4
Outline of thesis
CHAPTER 2: 2.1
•
• 9
Morphology and Geographic Distribution of Species Operational definitions of morphological terms and measurements • . . • • • • • • • . • • • • .11 2.1.1
E>:ternal: body and tail morphology and colour pattern
2.2
• .11
2.1.2
Head scales: 'topology' and measurements •
2.1.3
Internal features
Species accounts: morphology and distribution Simoselaps
~
•• 14 • .19 .25
• .25 .29
S. fasciolatus S. bertholdi S. littoralis •
~
• .31
.
.31
S. anomalus • S. minimus
• .35
. ." . .
S. australis S. semifasciatus S. approximans
.§.. roped and similar forms • • • • 'INA roped' •
.36
. . . . · .37 · .38 .42
. . . . · .44 · .45
NT roperi •
.45
'incindus' •
· .49
campbelli •
.49
CHAPTgR 3: 3.1
3.2
woodjonesi
.50
Status of Queensland roperi forms • •
.50
Neelaps calonotus •
.51
N. bimaculatus
.54
Vermicella annulata ••
• .57
Furina and Glvphodon
• .60
Phylogeny and Relationships Introduction: principles and methods of cladistics • 3.1.1
gvolutionary polarity of character states
• .69
3.1.2
Phylogenetic inference from the data. •
· .72
3.1.3
Other concepts relevant to this study
· .74
Relationships of Simoselaps 3.2.1
Furina and Glyphodon •
3.2.2
Inclusion of Vermicella in the
. . . . . . . . . . . 79
.81
Furina group 3.2.3 3.3
3.4
. . . 69
g}(clusion of Toxicocalamus •
.. .
.83
Definition and polarity of cladistic characters 3.3.1
Size, body scalation and pattern •
3.3.2
Head scales: topology
3.3.3
Head scales: ratios
.91
3.3.4
Dentition and features of sKull
.93
3.3.5
Ratios of sKull measurements •
• .95
.86
• .89
Phylogeny .97
3.4.1
Analysis of data •
3.4.2
Character weighting and fossoriality •
3.4.3
Phylogenetic hypotheses
3.4.4
Summary of proposed phylogeny: the characters and groups.
· .98 101
. . .' . . . . . . . 105
CHAPTB:R 4:
Discussion
4.1
Review of pr'evious hypotheses and points of inter'est , • , , 10'1
4,2
This analysis as a test of previous hypotheses. •
4,3
4.4
CHAPTER 5:
4,2.1
Relationships
, itO
4.2.2
Phylogeny
$
112
Biogeography and adaptation in Simoselaps 4,3.1
Historical biogeography
4.3.2
Dentition and diet , • . .
, 113 116
Taxonomic implications of the phylogeny
• 118
Scale-row Reduction in Australian Pr'oteroglyphs
5,1
Introduction.
5.2
Hethods
5.3
Results
, 123
5.3.1
Hode of reduction
124
5.3.2
Occurrence of posterior reduction
5.3.3
Number of reductions, and 'depr'ession',
5.3.4
Cases: Simoselapsi Pseudechisi
• 125 .'
. .
125
, 12:3
Notechis gr'oup
5,4
, i 10
, i33
Discussion.
APPENDICES
Ai
Technique for' clearing and staining snakes
A2
Key figur'es: skull and head scales
A3
Survey of skulls of some elapids
A4
Cladistic data matri>: •
"
136 i 3:::
· 141 144
IV
ABSTRACT
The Australian genera of small fossorial snaKes Simoselaps, Neelaps and Ver-micella (Elapidae: the 'Simoselaps group'), together comprising fifteen currently recognised species, have been the subject of disaegreement in taxonomy, with several different generic systems currently in use . Conflicting hypotheses concerning relationship to other groups have been proposed, based on morphology, and a number of recent studies based on ecological and genetic data also have implications for phylogeny and relationships.
The present worK redescribes the edernal morphology of the species, and gives the first detailed descriptions and figures of sKull morphology for Simoselaps and Neelaps, including the first description of the modified dentition of the Simoselaps semifasciatus species-group, which is associated with a specialised diet. The sKull of Vermicella annulata is redescribed, including some features not previously observed. In addition, the geographic distribution of most of the species is mapped in detail from literature and museum records.
Based on the shar-ed possession of a number of derived features of morphology, a probable monophyletic group is defined including the Simoselaps group and two genera of terrestrial elapids, Furina and Glyphodon: these other genera are also described in the same terms as the Simoselaps group. The species of the Simoselaps group are analysed cladistically, using Furina as an outgroup and a large set of characters based on edernal and cranial morphology, and a phylogenetic hypothesis proposed. This taKes into account the liKelihood of convergence in the morphology of fossorial snaKes by weighting against characters functionally associated with burrowing.
The proposed phylogeny is compared with previous hypotheses, and is considered to resolve some problems while redefining others., The historical biogeography of the group is considered, using the data on phylogeny and distribution, but insufficient worK M S been done on directly comparable groups, so no conclusions are reached. The functional aspects of dentition as related to dietary specialisation are
" discussed br-iefly, and the ta>~cmomic implica:tions of the proposed phylogeny are s.ummar·ised.
In addition, a r'eport is made of a prelimina.ry investigation of 's;.cale-ro'tl reduction't an aspect of the edemal morphology which has been neglected by previous workers on Australian snaKes; this feature provides comple}( char'acter's with irnpor·tant implications for the phylogeny of snaKes.
CHAPTER i:
1.1
GENERAL INTRODUCTION
THE AUSTRALIAN ELAPID SNAKES
Australia, with New Guinea, the Solomon Islands and Fiji, contains over a hundred species of terrestrial proteroglyphou5 (front-fanged) venomous snaKes; these are currently assigned to about thirty genera (Cogger et aI, 1983; McDowell, 1967,i 969.1.1 970), The family-level classification of snakes is somewhat fluid (see. Smith et
aI, 1977; Cogger, i 985), but the Australasian proteroglyphs have usually been placed in the family Elapidae (see Cogger et aI, i 983), and they are here regarded as elapids. The Elapidae also includes the African and Asian cobras, mambas and Kraits and the coral snakes of South and Central America.
Biochemical (Schwaner et aI, 1985) and morphological (McDowell 1967 ,1970d 985) evidence support a hypotheSis that the Australasian elapids are a natural group of all the descendants of a single ancestral species (that is, a monophyletic group); 'molecular' clocK' dating of divergence times within this group suggests an appro::1: of this thesis consists of two parts, one (Chapter's i -4) being the study Df the relationships and phylogeny of the fossorial elapid snaKe genus Simoselaps, the other (Chapter' 5) an investigation of a set of mor'phological features providing phylogenetic characters of wider potential.
Appropriate morphological terms are defined and the methods of measurement are described in Section 2.1 of Chapter 2, and the morphology and distr'ibution of the species are summarised in 2.2. Redescription could not be avoided, since familiarity with the many published sources of data cDuld not be assumed as a frameworK for' the new data presented here.
Chapter 3 contains the investigation of the r'elationships of this. group Df snaKes within the Australasian elapid radiation. The first section introduces the concepts and methods of cladistics, the method used here for constructing phylogenetic hypotheses from the morphological data. Then (3.2) the available evidence on this and other' groups of snaKes is e>:amined in Drder tD find a close relative outside trfe SimoselaRs group, as a suitable outgroupi the composition of the ingroup for the analysis is also justified her·e. Section 3.3 defines the unit characters used in the analysis, and infers polarity (the data math:·: obtained is included as Appendi:·:
4),
Section 3.4 uses the cladistic data to construct a hypothesis of phylogeny within the ingrouPi characters are weighted because of the particular problems of convergence and parallelism in lineages of fossorial snaKes, reviewed br-iefly her·e. The proposed phylogeny is summarised with refer-ence to the groups and the characters defining them.
Chapter 4 discusses the phylogenetic hypothesis in terms of the previous conflicts and suggestions outlined above (1.2), including some suggestions for furtherworK on this group, and concludes the study of Simoselaps and relatives with a summary of the ta:·:onomic implications of the phylogeny t and proposed changes.
A number of the morphological char-ader-s used here have not previously been used for the Australian elapids, or have received only scant attention. One of these was itself of limited use for the Simoselaps gr-oup, but is consider-ed of significance for other- groups including the viviparous Notechis lineage. This charactel' is the dor-saJ scale-r-ow pattern, a.nd is investigated for a number- of Aus-tralian snaKes in Chapter 5, which is otherwise independent of the Simoselaps study.
CHAPTER 2: MORPHOLOGY AND GEOGRAPHIC DISTRIBUTION OF SPECIES
2.1
OPERATIONAL DEFINITIONS OF MORPHOLOGICAL TERMS AND MEASUREMENTS
This study is based on specimens in the collections of the Australian Museum, Sydney (AM) and Western Australian Museum, Perth (WAM), the latter obtained on loan and e>:amined at Sydney University or the AM Department of Herpetology. Specimens examined are listed in the species accounts (section 2.2). Data were obtained by observation and measurement of both external and internal structures.
2.1.1
External: body and tail morphology and colour pattern
Ventral scale count (VS)
On the ventral surface of most snaKes, there is a single row
of overlapping scales, also Known as ventral plates or scutes, which are much wider than long. Each ventral generally corresponds to a pair of ribs and a dorsal vertebra, so the total number is an important characteristic of an individual; there is a widely used standard method of defining the first (most anterior) and last (most posterior) ventrals to ensure consistency of counts on an individual and comparability between species : 2, showing left lateral, dorsal and ventral aspects 1\
of the sKull of S.warro, AM R 19017; all bones mentioned in the text are identified. All sKull dr-awings were made using a binocular microscope with a camera lucid a attachment. The convention in this and other drawings is that structures not clearly visible in the specimen due to over'lying tissue (transparent, but still refractive) ar'e omitted, or' an outline dashed. 8:dges of adjacent bones shown as overlapping or double are drawn as seen; the bones of the braincase may be translucent in small
specimens. Mandibles are
shown in situ, displaced or are omitted; repetition is avoided by omitting some views of some species which are well represented by similar species.
Dimensions of some bones, such as those of the ventral wall of the braincase and of the septoma>:illae and vomers, were not measured because the cleared tissue surrounding them did not allow application of the calipers to the structures. Optical micr'ometer' measurement would be difficult in these cases too, due to the refractive properties of the cleared tissue.
Total sKull length (TSU
Str'aight-line length in the midline fr'om the tip of the
prema>:illa (or the point between the tips when the prema>:illa is concave anteriorly) to
21 ~
the real' of the contact or' apprD}:ima:tion of the e::illa
classified as smooth but concave anteriorly! smoothly conve:·:,
01'
with an angular central
section distinctly offset from the lateral processes. This bone is formed by the fusion clf two later'al elements in the embryo (Romer, 1956), so the concavity presumably represents a 'scar' when present. Two measurements were also taKen: length of prema>:illa visible from above, measured in midline in the plane of the upper sur'face of nasals; and ma>:imum width, between tips of lateral processes.
Nasal length
Length, parallel to midline, of nasal bones as seen from above. Because
the upper lobe of the premaxilla usually edends bacK between the anterior nasal tips, the sum of these lengths may e:{ceed the combined length of the bones.
Frontal (bone) length
PostOl'bita~
(po)
Ha>:imum length of the frontal bones seen from above.
McDowell (1969a) defined the Rhynchoelal2s group (see section 3.2) on
the basis of several characters including the fact that the postorbital bone is loosely attached to the parietal in such a way that it can move in an antero-posterior plane around its point of attachment. The po is connected by a ligament to the upper surface of the ma>:illa, and HcDowell proposed a functional e>(planation for the Kinesis related to the mode of feeding. The presence of a functionally jointed po was tested by manipulating the maxilla with forceps so that it rotated around its articulation with the prefrontal, and looKing for corresponding motion of the po (directly probing the po was avoided when possible, as it is often delicate and easily detachable in small snaKes), Other features of the po's shape and position were also noted; contact or overlap with the frontal, and whether the bone was pointed or had an expanded distal end. The nature of the postorbital attachment was investigated in some other Australian elapids (Appendi}: 3}.
Parietal
This is the major' bone of the braincase, enclosing the brain dorsally and
laterally. Hidline length (not generally a maximum because of the lateral anterior
2
t.. processes); and ma>:imum width posterior to the postorbital processes. Depending on continuous variation in shape, this ma>;imum may be immediately behind these vertical ridges (which fOf'm attachment surfaces for the muscles of the venom glands), or' at the posterior suture with the periotic, or at an intermediate bulge.
Supraoccipital
E:xoccipitals
Midline length.
Length of median contad, or apprm;imation, of the two bones.
Supratemporal
This bone is called the tabular by Bogert (1943) and McDowell :imum straight-line length, from
anterior of dentary to tip of retroarticular process. Other structures of the mandible such as lengths of dentary t splenial or articular or type of MecKelian canal, which have been discussed by 14cDowell (1969a, 1970), were not used here. Dentary tooth numbers were not recorded in all cases but were estimated from drawings for a number of specimens.
24
In addition to the clear-ed and stained specimens, tooth counts. were per-for-med on several other specimens by opening the mouth and dearing tissue from around the teeth of one or- more bones (only the lar·ger anKylosed teeth are visible without removing tissue, and socKets cannot be counted). These specimens and data are listed with other data. on the species concerned.
L 2.2
SP8:CI8:S ACCOUNTS: HORPHOLOGY AND DISTRIBUTION
The following descriptions refer to qualitative characteristics of the species of Simoselaps, Neelaps and Vermicella, and also the gener-a Furina and Glyphodon, whose relationship to the Simoselaps group is discussed in the following chapter- (3.2.1). G.uantitative data including scale-counts, ratios and frequencies of some variants are summarised in Tables 2.1-2.3; these are not referred to edensively in the ted, and are placed at the end of this chapter.
Simoselaps
~
Haterial e:-:amined
AH R i4395d 901 7 (cleared and stained) AM R i4394,i4396ti6697 ,1826 i A6024,74459 ,114087 ,and an unregistered 'no data' specimen
Description Colour pattern
Colour photograph in life: Cogger (1983), fig 204. Dorsal scales with
yellow base (basal spot) and orange lateral and posterior edges, forming reticulate pattern: with or without narrow darK edges to dorsals as well. DarK head and nape patches present. Head scalation
Fig 2.1. Hoderately enlarged, sharp-edged rostral (Storr, 1979, states
that the sharp edge is absent, but it is at least as distinct as that of fasciolatus in the larger- sample e>:amined here). Nasal and preocular widely separ-ated. 2nd labial and preocular separated, or sometimes in point or narrow contact. Preocular may contact frontal. Temporals 2+2+3 (in this and the following descriptions, only the 'basic' temporal formula is given. Refer to Table 2. SKull
for occurrence of other conditions).
Fig 2.2. Subsequent species. are compared to S. warro and tCI each other, so r'efer
to other descriptions for comparative information on warro.
Distribution
Hap, Fig 2.3. Sources of data: Localities of AH specimens; Storr
Cagger et al (1983).
(i 979);
L
26
___---------------------=~-----L---Fig 2.1 Heads of Furina ornata and two species of Simoselaps in dorsolateral aspect. Topt F. ornata (AM R 110357) drawn with camera lucid a; middle, S. ~ (AM R 19017) and lower S. fasciolatus (WAM R 5936) drawn 'freehand' from specimens under binocular microscope. Adult specimens; not to scale.
L
7
Fig 2.2 SKull of S. ~, AM R 14395. Top to bottom: left lateral, dorsal and ventral views. TSL (total sKull length) = 9.4mm. All sKulls drawn using a camera lucida.
t:r)
,,; Or ......
Lx..
• •
co)
'o"
.~ V)
•
'-
§ •
~
~
.
c:...r,
...
••
•
~
j .-
~v "+-!
'-:::l
L
•
: is cer-tainly shar-per than a right angle, although the edge itself is not as distinct as in the specimens of other- species shown, SKull
Fig 2,1 L Similar to semifasciatus but without the featur-es listed above as
r-estricted to that species. 8:ash nasal bone is distinctly bilobed anteriorly, the fangs tend even further to longitudinal rather- than tr-ansverse alignment, solid maxillary teeth absent in both specimens e>:amined; the teeth appear to be even mor-e modified than in semifasciatus.
Distribution
Hap, Fig 2.9. Sc,ur-ces: Storr- (1967,1979); Storr and Johnstone (1988); AM
localities.
One specimen fr'om WA, WAM R 28699, could not be definitely assigned to semifasciatus or- apprm:imans. The locality (26" 24'S, 114D 29'8:, 10 miles sCluth of SharK Bay) iE. further' north than any near-coastal recor-ds of semifasciatus, and hundreds of Kilometres from any of appro>:imans, as which it was identified in the museum r-egister. This specimen has 5th and 6th labials fused (not Known in approximans), and 2nd labial and preocular separated on one side and in 'point contact' on the other (always contacting in other- semifasciatus); the tempor-olabial is distinct. The pale inter-spaces are discontinuous, consisting of 'tear--dr-op'-shaped centr-al spots the full length of a
4
Fig 2.11 SKull of S. approximans, WAH R 73478, and maxilla of australis, AM R 98197. Top to bottom: dorsal and ventral views of appro>:imans (TSL = 10.2mm), ventral view of left maxilla of australis (TSL = 10.0mm, not to scale).
4
scale, on single transver'se rov/s so that iidjacent spots are separated by darK later'al edging on each scale. The number of darK brown bands (:::1 on body, 10 on tail) is higher than any other Si.moselap=. Known.
S. roperi and similar forms.
The r'emaining members of the S. semifasciatus group are distr'ibuted in northern and north-centra.l Australia. All are very similar in scalation, a.lthough fr'equencies of var-iants appear tel differ between recogni!:.able for·ms. All of these snaKes may have either i 7 (as in the rest of the semifasciatus group) or 15 scale-rows, with the possible
e>~ception
of 'campbelli' in which both specimens e>lamined have 17.
The nasal scale is usually divided in each of these forms.
This group (which is not assumed here to be monophyletic) includes the named forms S. roped (Kinghorn), S. campbelli
(Kinghorn)t~ woqdjo~
(Thomson), S. incinctus
~amined
tel groups to which these names may be
applied:
More than 50 solid bands on body and tail: 'WA r'operi' Fewer- than 50 solid bands on body and tail: NT roperi Unbanded: 'incinctus'
F ewer than 40 bands, head patch solid: campbell! (G.ueensland)
Fewer than 40 bands, head patch greatly reduced or absent: woodjonesi Unbanded: 'incinctus'
4
'WA rClperi'
WAM R 20349 (cleared and stained): WA specimen.
Material e}: amined
\.JAH R 17127,70025,70449,78134
Western Australia
AM R 41151,47402,92525,101411 Northern Territory
AM R 51952
Locali ty unKnown
AM R 4107S'
Description Colour pattern
This for'm is similar in pattern to S. semifasciatus (see Cogger, i 983,
fig. 203). Head and nape patches, and dorsal bands, darK brown, interspaces lighter brown. In addition, the lower later'al scales may be edged with the darKer colour. Head scalation
Fig 2.8. As noted above, the nasal is usually divided below (that is,
the nasal gr-oove joins the nostr-il to the lower- edge of the scale), In this and other respects, the head scalation is mor-e similar- to australis than semHasciatus. Fusion of 5th and 6th labials occur-s as a var-iant (Storr, 1967). SI-:amined.
Too few specimens have been examined to be certain that the two forms
compared here represent separate populations, rather than morphs within one species. The var-iation is not clinal (StDrr, i 967 t neglected the difference in longitude to interpret differences between Roper River, NT, Kimberley, WA t and Tennant CreeK, NT t as clines), for both forms occur at sever-al localities, including Jabiru in the Alligator Rivers region (C. James, pers. comm.; and compare Cogger, i 983, fig. :330, and AM R 104934 with 74 and 29 bands respectively). Wells and Wellington (1985) reported sympatry of broad- and narrow-banded forms 'in the rocKy r-anges sDuth of Adelaide River township' (they also misidentified the narrow-banded form as roperi and descr-ibed the other- as a new species 'Brachyurophis murra'Li',
which is thus a synonym of
roperi). They distinguished the two forms by ventral count as well as pattern; in addition, 'roperi' was assumed to always have i5 scale-rows, and the two were supposedly distinguished by labials L2 and 3 contacting the nasal in 'roperi' (equivalently, 2nd separated from preocular): this condition did not occur in any NT specimens of either for-m that I have e:-:amined.
9
S. 'incindus'
Haterial e){amined
AH R 12012,51951 (Alice Spr-ings) 64014,64336 (Ht. Iso.) 40919 (LaKe [vella, NT)
(~;
-
Description Colour gattern
Distinguished from the previous two forms by lacK of bands other than
head and nape blotches. Photographs in Cogger (1983), fig. :328 (blacK and white) and in Horton and Stammer- (1976) (colour). Body pinKish brown irl life, and dorsal scales sometimes edged narrowly with darK pigment. Head scalation
Distribution
As for previous forms.
Storr
(i 967);
AH localities. The locality in the far north of the NT is
new, based on an AM specimen.
Status
This form was described as a subspecies of 'Vermicella semifaciata, by Storr
(1967), but is regarded by Cogger
(i 975,
Cogger et a1 i 9:::3) as a species. Few specimens
are Known (Storr e>:amined four), but the unbanded populations appear not to be homogeneous. The specimen from the northern NT in particular suggests that lacK of bands may be a convergent feature of several distinct populations of 'rogeri', and that if species barrier-s are involved, more char-acters and more specimens are r-equir-ed to demonstr-ate them. However-, for- the analysis carried out here, 'incinctus' is assumed to represent a single t.l>(on.
S.
~ampbelli
Material examined
AM R
93~:7
(holotype),20578
Description Colour pattern
Similar to broad-banded roperi of the norther-n NT; colour- in life not
50 Known. The holatype is now colour·less. Head scalation
Distr-ibution
Similar' to other- 'r'oper-i' for·ms.
Map, Fig 2.13. Sour-ce: AH localities (including type locality; !(inghor-n,
1929).
S. woodjonesi
Mater-ial e>:amined
AM R 17015,18262,30337
Descr-iption Colour- gattem
Similar to broad-banded NT r-operi but the head patch is r·educed. In the
holotype (not seen, but with a compar-atively detailed descr-iption by Thomson, i 934) ther-e ar'e white spots within the darK brown patch on the pr'eoculars and supraoculars, while the AM specimens e>:amined have no solid patch, only a few darK marKs on the edges of the frontal scale. Colour of pale parts of dar-sum 'pale grey-brown to pinK' in life (Thomson, 1934). Head scalation
Similar' to other 'roperi', An e>:cellent set of drawings of the holotype
is in Thomson (1934) which includes one of the ventral aspect, SKull
Not examined, but in AH R 30337 the maxillae wer'e exposed and the teeth
e>:amined; there were two solid teeth on each, but on one side the anterior' one was immediately behind the fangs, before the diastema. The significance of this variant is not Known.
Distribution
Map, Fig 2.13.
Sour-ces: P.!>! localities; Thomson (1934).
Status of G.ueensland 'roper-i' forms
S. woodjoneg is accepted here as a valid ta>:on because of its char-acteristically pale head (confir-med by G. Czechura., pers. comm.), a feature consistent over its geogr'aphical range. S. campbelli is thought to be distinct from YLoodjonesi for'
1
this reason, and also appears to have higher ventral and lower subcaudal counts. than either' woodjonesi Dr NT roper-i. It is, however, possible that the specimens €%3.mined were females, in which case the scale-count differences would be e>:pected within a population. The tails of the campbelli e>:amined were long and cylindr-ical, so they ar'e assumed to be males. Clarification of the status of these, lil:i1la and nasal ar-e broadly e>:panded, forming a par-tial tube (closed by softer tissue, appar-ently cartilage) opening to the nostr-i}; this is less edensive in the other- species e>:amined. The nasals do not have the more-op-less
o
',J'ey'"
......
~~~)(
Fig 2.18 SKull of Vermicella annulata, AM I no data' specimen. Top to bottom: lateral, dorsal, ventral views. TSL = 16.3mm.
tr-ansver-se pos-ter-ior- edge, appr-m:imating or- contacting the fr-ontals, seen in all Simoselaps and Neela!;2s.• The pr-efr-ontals e>dend well for-war-d, so that the ma;dlla (and consequently the fangs) have a position anterior to those seen in Simoselaps and Neelaps, and more like other-, terrestr-ial, elapid!:- (see Boulenger-, lE:96). Perhaps par-tly as a consequence of this, the anter-ior tip of the palatine is well posterior- to that of the ma:dlla. Boulenger- did not detect a lateral (maxillary) pr-ocess of the palatine articulating with the anter-ior median process of the maxilla, as reported and figured by McDowell (1969a); this structure was not present in either specimen I e>(amined. There is a posterior lateral process representing an expanded surface for articulation with the pterygoid; this is similar to Fur-ina but no Simoselaps or Neelaps e:-:amined. The anterior median process of the maxilla in the specimen figured was apparently connected by a ligament to the ectopter-ygoid. There ar-e one or two solid ma:dl1ar-y teeth on a straight or- slightly downcurved ma>dllai the pterygoid teeth are small in size and number-, The postorbital may be absent, as in R 21345 and Boulenger-'s specimen, or tiny and in contact with the frontal (McDowell, i 969a), but in the lar-ger specimen there is a small, triangular- po firmly attached to the par-ietal and separ-ated from the fr-onta1. Ontogenetic change in skull shape, especially of the parietal, is indicated by comparison of the specimens and figures available (r-elated both to slow or completed growth of the brain, and to changes in the musculature imposed by scale; see Gould, 1977). The large specimen has a narrow parietal with a very prominent lateral 'shelf' anteriorly t which is less prominent in the other species e:-:amined and in the V. annulata. figured by Boulenger and McDowell. Whether the presence of the postor-bital in the same specimen is related to this allometry is not known.
Distribution and status of forms
The distr-ibution of Vermicella is not mapped here,
but see Cogger (1983) and the list of localities in Storr
(i 967).
The only taxonomic
revision of of Verrnicella was Storr.!!:- (1967), which did not consider eastern Australian representatives and was therefore unable to analyse geographic and other variation over most of the range of these snakes. Two subspecies were recognised in WA and NT (snelliJ multifasciata r-espec'tively) as distinct from !! annulata of eastern Australia, and
60 the second of these was recognised as· a distinct species by Cogger (1975), Hany specimens of annulata are :amined at those institutions in i 979, These genera are described in this section because they are pr-obably the closest relatives of Simoselaps and Neelaps, as argued in the following chapter- (3.2),
Description Colour and b.attern
Fur-ina have a similar colour' patter·n to SimoselaRs warro and
Neelaps spp.; a colour photogr'aph of F. diadema is in Cogger (1983), fig i 92, and also blacK and white pictures of the thr'ee species (figs 7E:7-789), There is a blacK patch covering the top of the head, and another on the nape, separated by a pale (orange-red) bar', The dor'sum has a reticulated pattern, each scale reddish with a yellowish basal spot and darK lateral and posterior margins. The sKin between the scales is white e}(cept within 'solid' darK marKings, and the ventral surface is unpigmented e:·:cept for a darK streaK on the anterior chin scales sometimes present. Fur-ina ornata and especially
L bar'nardi undergo ontogenetic change in the
e:dent and density of (presumed) melanin, with larger specimens becoming darKer and losing the r'eticulate patter·n; the pale occipital bar' also gr'adually darKens and in some large specimens of barnardi is distinctly darKer than the head and nape. This loss of the characteristic patem has resulted in ta.:-:onomic confusion, with barnar'di being described as a. Glyphodon (Kinghorn, i 939) and retained as G. barnardi by Cogger
(i 975,
61
Cogger' et aI, 19:::3). Hany larger· specimens of barnardi in museum collecticms have been identified as G. tristis, and smaller ones often as F. diadema. Glyphodon (Cogger, 1983, figs 790,791) do not have the pale basal spot of Furino. even when young; instead, the white sKin between the scales is prominent, or the scales are narrowly pale-edged, creating an inverse f·eticulation. G. dunmalli appears not to have a pale occipital bar, though 'inconspicuous lighter marKings on the necK' in a small specimen (Worrell, i 955) may be remnants of it. Head scalation
'Fig 2...1. !\ Rostral
small and smooth; nasal small, single in Fur-ina (including
barnardi; Kinghorn, 1939), divided by the nostril in Glyphodon, and widely separated from the preocular. Pre ocular is also separated from the 2nd supra labial by contact of the prefrontal and 3rd labial. Pre ocular may contact frontal in Furino.: this contact occurs in 4 of 150
L diadema, 3 of 50 barnardi, and 30 of 40 ornata e:·:amined at the
AM; 81 of 97 ornata reported by Storr (19E:1). It is not Known for Glyphodon dUfrmalli (3 specimens e>:amined including holotype, AH R 14809) or tristis (21 AH specimens), or for any other elapids but Furina, Simoselaps or Neelaps. Tempor'als 2+2+3 in Furina (pel's. obs.), sometimes £+2+3 (especially in barnardi, e.g. holotype figured in Kinghorn, 1939); Glyphodon tristis. 2+2+3, G. dunmalli 2+2+4 (figs in Cogger, 1983; also Worrell, 1955). No regular fusions Known. SKull
The sKull of Furina (Fig 2.19) is overall most similar to that of Simoselaps
warro of the species already considered, but differs in a number of features. The prema>:illa is narrow, without the edended lateral processes, and with the upper' lobe not e>:i:ending bacK between the anterior tips of the nasals; the posterior edge of the nasal on each side is more oblique rather than transverse, and with an acute-angled posterolateral corner; there is thus a larger space between the nasal and the frontal and prefrontal, even though the prefrontal is diagonally jointed to the frontal and e>:tends further anteriorly. This appears to be a functional joint, with the bones loosely interlOCKing to for'm a hinge so the prefrontal can swing forward and laterally. Prefrontal Kinesis was not investigated specifically in Simoselaps. and Neelapst but from the figur-es these bones appear' to be similarly jointed in all but & bimaculatus and the S. semifa.sciatus gr-oup, in an anterolateral plane even though the prefrontal is attached to the lateral edge of the frontal rather' than diagonally, The Kinesis in Ver-micella, if present, would appear to be lateral, without much of a.n anterior component.
62
/
~~/~ ---------~
- ~~... ~...~~~
Fig 2.19 SKull of Furina diadema, AM R 98165. Top to bottom: lateral, dorsal, ventral views. Because the eye and venom gland were incompletely cleared, much of the sKull structure was obscured in lateral view. TSL = 9.4mm.
63 The postorbital is 5.imilar to that of S. bertholdi, and has a fundional pivot around its ar·ticulation with the edreme anterior tip of the parietal, The figure shows the ma>dlla and pr'efrontal in 'rapier-stabbing' position (McDowelll 1969a.)1 with the pr'efrontal swung out and forward and the ma>:illa tilted down posteriorly to 'erect' the fang. McDowell suggested for' the 'Rhynchoelaps group' that the postorbital Kinesis allows the ma>:illa to be returned to horizontal by the contradion of the venom-gland muscles; some of these muscle fibr'es inser·t on the postorbital, which is in turn conneded to the ma:dlla by a ligament. The palatine e:dends further forwar'd than the maxilla (when in normal rela>:ed position), as in warro; the posterior end of the palatine is I:?>:panded as in Vermicella but none of the other species examined. The supra temporals ar'e much shorter than warro or fasciolatus, but similar to bertholdi; quadrates a little longer than these Simoselaps, and the dentaries quite deep as in Vermicella but unliKe the other·s. The sKull of Glyphodon tristis is figured by Boulenger (1896, fig 22), It is similar to Furina, but the prefrontals and postorbitals are in contad, and shown as being tightly connected to the frontals and parietal; this may be a stylistic effect, however, and the presence and edent of Kinesis should be investigated further in Glyphodon as well as the other snaKes discussed here.
Distribution
Not mapped here; see Cogger (1983) and Storr' (19:::1) for 'area' maps and
WA locality lists respectively. F'. diadema, NSW and south-east G.ld; barnardi north-east and north-west G.ld and northern NT; ornata north-west G.ld, NT and most of WA. Ther'e is sympatry between diadema and barnardi in central eastern G.ld t and e>:tensively between barnardi and ornata in the northern NT (including Darwin and Groote Eylandt, for e;-:ample). G. tristis is found on Cape Yor'K peninsula, Torres Str'ait islands and souther'n New Guinea. G. dunrnalli has a restricted, and probably fragmented, distribution in the r-anges of south-eastern G.ld. Sour-ces: AM localities; G.H localities; Wor'rell (1955); Storr' (1981); Czechura and Covacevich Ii 985),
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Table 2.3 Length measurements (this page) and tooth counts (continuation next page) of sKulls examined. Abbreviations: TSL = total sKull length (see 2.1>; 1.= length; w.= width; pmx = premaxilla; nas = nasal; frt = frontal; prU = parietal; mand.= mandible; s 'occ.= supraoccipital; ex occ.= e}: occipi tal; quad.= quadrate; max.= max ilIa; pal.= palatine; pter.= pterygoid; ecto.= ectopterygoid; sU = supratemporal. G"-
,
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:a are assumed, as a null hypothesis, to be equally closely related. The object of the method is essentially to use available data on the distribution of charadeI' states to restrict attention from the class of combinatorially possible phylogenies to a smaller set of the most probable (which might still include the null).
This procedure is complicated by homoplasy, the 'reversal' of characters to the primitive state or 'convergence' on the 'same' derived states in different lineages. Types of homoplasy are discussed in the next section. In interpreting each character, there is an Ho which states that the taxa possessing the derived state form a monophyletic group, and Ho/s specifying taxa which must be added or e>:cluded due to reversal or convergence. If all Ho's for the data set are consistent, the approach of Hennig (1966) is well defined and produces a single most parsimonious hypothetical phylogeny,and this will be accepted as the result of the analysis (see Felsenstein, 1982, for a review of these methods which includes discussion of a similar, but distinct, application of the idea of statistical hypotheses to the problem). If not all are consistent, a number of different methods of revising the data have been proposed and used, but no single one stands out as having such advantages as to be regarded as 'the correct answer', These approaches (reviewed by Felsenstein, i 982) are: (a)
compatibilitYi selecting largest suites of consistent characters and using
the resulting phylogenies. This approach worKs on the assumption that there are 'good'
73 and 'bad' characters, and attempts to e>:dude those characters that give a misleading version of the phylogenYi homoplasy is eHplicitly e:·:duded (both reversal and convergence). The disadvantage of this method is the simplicity of the dichotomy assumed; intermediate amounts of homoplasy may occur in many cases, in which case the residue of compatible characters will e:·(dude most of the available information. This method is not considered further here. (b)
parsimony. Parsimony-based analysis is most consistent with the
hypothetico-deductive approach outlined above. There are other assumptions which may be made which will generally produce different results : (i)
no reversals (Camin-SoKal parsimony), and
(ii)
no convergence overall (Wagner) parsimony, unlimited multiple origins and reversals; the
total length of the tree, measured in unitary character state changes, is minimized. (iv)
polymorphism parsimony, based on the coe>:istence of two or more
states of a character in ancestral taH ai discussed below.
Character weighting
Clear-Iy, in a par·ticular- case, some char-acters may be pr-one to homoplasy, while others, even by chance, are not; for this reason characters are often 'weighted' according to some estimate of their reliability. Weight will be related to unequal probability of change in different characters: fielsenstein (1982) states that 'A character whose probability of change in a segment of the phylogeny is H has half the weight of one whose probability of change is }( 2,. The most appropriate weights for· characters in a particular case would reflect their actual correspondence to the true phylogeny, but this of course is not Known. There is no way of weighting characters
~
priori, and thus no precise application of statistical probability to this problem. fi arris (1969) described a 'succeSSive-approximations approach' to character weighting, but found for· simulated data sets that "it is most expedient to treat suspicious characters as if they were unreliable", and his method thus seems to mimic a 'compatibility' scheme, (a) above. There are few if any applications of his method in the literature,
74
not even by Farris himself, so it has presumably been found unsuccessful with real data, where most charaders are neither absolutely reliable nor completely random.
Farris' algorithm weights characters according to an arbitrary measure of consistency with the overall dadogram generated from the whole set (initially unweighted), and repeats this procedur'e until the same results are obtained in ~ccessive
iterations. I suggest that such a method might be more applicable if the
character weight is allowed to vary betvJeen parts of the cladogram according to a more local measure of consistency. One reason for this is that the actual edent of the ingroup is arbitrary, and the reliance placed on a character in one lineage should not be dominated by the possible 'misbehaviour' of the 'same' character in other lineages.
3.1.3
Other- concepts r-elevant to this study
Operational homology and the character concept
Homology is a basic and neceE.sar-y concept in biology. The use of all anatomical and morphological terms, for instance, depends on the assumption that the 'sameness' recognized in structur-es of different individuals and taxa is 'real'; this 'reality' is usually understood as meaning inher-itance of the structure from a common ancestor-, and homology may be defined in these terms (see Cade, 1979).
There is thus an apparent circularity in attempting to deduce common ancestry from the shar-ed possession of 'homologous' character- states; however, this is the same as that involved in assigning polarity, and resolvable in the same way. Oper-ational homology can be defined in ter-ms of similarity - for- instance, SoKal and Sneath (1963) 'call two character states the "same" whenever they are indistinguishable' (p.69). Designations of char-acter- state ar'e then, liKe those of polarity, hypotheses, subject to falsification or r-efinement by further observations.
A 'unit character' (equivalent to the binary char-acter-s used her-e) was defined by SoKal and Sneath (1963) as 'an attribute about which one statement can be made,
7
thus yielding a single piece of information ... Wher-e a character can vary continuously, such as the length of an organ, this character of length is broKen down into as many steps as the observational method will allow with good r-eUability' (p.63). This is the approach to defining characters taKen here.
The object of defining characters for- cladistic analysis is to detect synapomorphies which in turn reflect relationships; divergence of single species (autapomor-phy) is not informative. Therefore character states which distingUish only single species are not used in the analysis: on assessing the various ta){a, any states found in only one ingroup taxon are rejected unless intermediate to other-s also represented. Moreover, where similar derived states are found in two species but the distribution of the 'synapomorphy' conflicts with a sufficient number of other characters, the change is considered convergent; it thus consists of two separate autapomorphies, and is e>:cluded from fUr-ther consideration. E:xamples are discussed in the definitions of characters 26 and 40 (where the putative character conflicts with the suite of synapomorphies defining the Simoselaps semifasciatus group. Wher-e similar derived states occur in more than two species the character is tested for consistency in the same way, but all such characters are retained here.
The practice folowed in this study is to define character states only for conditions actually obser-ved in the ta>:a considered. Potentially an intermediate state would be postulated if three observed states (A,B,C) were radially related to an inferred intermediate (H) which could be described but was not observed (as shown below); this situation did not arise with the characters used. B A
-(H)
/
~C Parsimony methods and polymorphism
Clear-ly the 'best' characters in cladistic analysis should be those where the states are clearly distinct, and all instances of each advanced state are similar enough
76 for no doubts of homology to arise. In any gr-oup of species, probably several such char-acter-s can be found; an e:·:ample is number 44 in the character set defined below (modification of the pterygoid for egg-eating), What is useful about such charaders il:. not only that states can be clearly distinguished, but that variation within species can be ignored: the derived state is fi>:ed when it occurs. But in all sexually reproducing diploid species, any character state must occur first as a variant before becoming fi}:ed by selection or drift, and if both primitive and advanced states occur in one population, others derived from it may possess either state and both independent fixation and reversal are obviously possible. This tends to invalidate the use of either Camin-SoKal or Dollo assumptions, particularly for characters where polymorphism is liKely to be tolerated in a population.
F elsenstein (1982) reviews a phylogenetic parsimony method using polymorphism, which was originally devised for chromosomal characters, but need not be limited to them. In this method, an intermediate 'state' of coexistence of pr'imitive and derived states is assumed to have e>:isted in an ancestral taxon, even when no such polymorphism is seen in modern species.
Polymorphism is commonly seen, in snaKes, in characters of head-scale topology, which liKe chromosome marKers are concerned with fusion, fission and the relative pOSitions of homologous structures. Thus the use of an intermediate state does not requir·e particular assumptions about the mode of evolution of the character (as it may for chromosome marKers). The existence of intermediate variants is a useful guide to homology; for example, see the discussion of charaders 18-19 in S. semifasciatus (Section 3.3),
Categories of homoplasy
Homoplasy is the set of phenomena resulting in the lacK of correspondence between a character' of Known polarity and the true phylogeny. There are essentially two categories, reversal (or reversion) and convergence. Whereas for· a non-homoplastic character the derived state defines a monophyletic group, that of a reversing character
77 defines a group including some, but not all, of the descendants of the ancestor' in which the 'forward' change occurred; such a group is l2araphyletic. A convergent chara.cter defines a polyphyletic group, an aggregate of clades whose common ancestors did not possess the defining character state.
The term parallelism is often used to denote the or'igin of similar- der-ived states in closely related groups, as distinct from convergence states in mor'e distantly r-elated groups. Cade
(i 979)
'~
stricto' on similar
states that 'ther-e is no, shar-p
distinction to be made between convergence and par-allelism', bll't
~fUS
distinction can be
made mor-e pr-ecise in terms of unit char-acters: I shall use par-allelism to refer to independent origins of a character state from a single primitive state, and convergence for origins of similar states from distinct ancestral states. This avoids subjective categories liKe 'close' and 'distant', and is based only on the distribution of the character in question (along with a phylogenetic hypothesis of polarity),
A further distinction can be made within parallelism, if required. If the genetic condition corresponding to the derived state was already pr-esent in the common ancestor, its e}:pression in two descendants may actua.lly be homologous. This may occur-, for instance, if either- the primitive state or a hypothetical intermediate corr-eponds to a polymorphic condition (see previous section). Otherwise, the similar advanced states may evolve separ'ately de
llQYQ.,
and ar-e analagous (as in convergence).
Similarly, reversals may be of two Kinds. In one, liKely to be associated with polymorphism but also possible by loss of a recenUy evolved structure, the final state is homologous to the primitive one. The alternative, apparent or non-homologous reversal, occurs not by the loss of the advanced state but its further' modification by another mechanism to resemble the ancestral state.
Note on allometr'Y and the use of ratios
Allometry t or the change in shape with growth due to di Herential local growth rates, can be e}:pected to be a rule r-ather than an exception for snaKes as in eIther
7
animals (Gould, i 977). However-, it may be difficult to take into account; it may be masked by natur'al var-iability in samples, especially if differ·ent gr'owth stages ar-e not adequately r-epr-esented. I consider this to have been the case for- this study; juveniles were unavailable for- several species, and where specimens for measurement were selected from a larger number (Simoselaps australis, S. bertholdi, S, littoralis, Vermicella annulata and Furina ornata), adult specimens were preferred. Therefor·e, since the best morphometric descriptions (detailed growth curves for a large set of measurements) were unavailable for' comparison, it was decided to use r'atios to construct characters for- analysis. Ratios are generally considered to be poor as characters, particularly for a method like cladistics
(Ii.
Carolin, pers. comm.), due to
their failure to distinguish increase in one character from decrease in the other. Thus, they may be an uncertain guide to homology. However, r'atios have previously been used to characterize ta>:a by storr and L.A. Smith (numerous papers, most importantly in this conted Storr, 1967>t and in phenetic analysis of Australian snakes (Mengden et 0.1., in press). Further, in a morphological study of several whipsnake species :imately 20 e>:amined had this feature. This state is considered derived for the same reason as the previous one, on the reasonable assumption that the condition in the 'small-eyed' genera is not homologous.
Pre ocular-frontal contact occurs in the Australasian elapids only in Furina, Simoselaps and Neelaps, and is thus another synapomorphy.
Furina, Neelaps and Simoselaps
~
share the reticulate dorsal pattern and
head and nape blotches described in Section 2.2, and the other Simoselaps patterns can be interpreted as homologous (Storr, 1967; Section 3.3.1 above). Similar dorsal patterns occur in Pseudechis and Cacophis, but with only two pigments distinguishable, and similar head blotches are seen in Pseudonaja. All these other genera have the ventral surface pigmented: it is white in Simoselaps, NeelaJ;)s, Furina and Glyphodon.
I cons;lder that the evidence is sufficient to define a 'Furina group' as a probable monophyletic lineage, containing the following genera: Furina, Glyphodon, Simoselaps, Neelaps and (probably) Vermicella.
Within this group, Glyphodon lacKs the advanced states of colour pattern, and pre ocular-frontal contact. This suggests that these two species are 'basally' related to the rest of the group: whether they are closely f-elated to each other is considered unresolved. Simoselaps and Neelaps share these derived states with Furina, so Furina is adopted here as an appropriate outgroup for analysis of the 'Simoselaps group'.
81 3.2.2
Inclusion of Vermicella in the Furino. group
There have been two conflicting recent suggestions as to the relationships of the bandy-bandies (Vermicella). Storr (1967) considered V. annulata (including three subspecies) to be closely related to 'V. bertholdi' (the SimoselaQs ber·tl"'tOldi group); these were said to 'comprise a group somewhat apart from the other species of Vermicella'. This group is characterised by annuli, 'a deep primary temporal and relatively long frontals and parietals', as well as the 'generic' chara.ders of short tail, moderate or great enlargement of the rostral, and basic 1+1 +2 tempor'al formula.
McDowell, while considering Simoselaps and Neelaps (as Rhynchoelaps) to be close to To>:icocalamus of New Guinea
(i 9690.;
see ned section), placed Vermicella with
the Solomon Islands Salomonelaps and loveridgelaps and Fijian Oqmodon. Of these, Vermicella and Loveridgelaps were thought to be sister gr'oupst showing similar blad< bands (in Loveridgelaps, forming annuli only on the taill, pterygoid teeth r'educed in number and size, and the inclusion of blind snaKes dllary proce:.s of the palatine; vertebr'al zygapophyses, musculature of the venom gland, and contact between temporolabial and lip. The palatine process, and position of the TL, ar'e primitive features shared with Asian elapids, and McDowell suggested that the Vermicella group was basal to the rest of the Australo-Papuan radiation (in which the advanced states are found in most species).
Having e>:amined cleared and stained specimens of V. annul at a and other Australian snaKes, I do not find McDowell's Ii 970) evidence for relationship of Vermicella with specifically non-Australian species to be compelling. The palatinepterygoid articulation appears to be similar to that of Simoselaps, or particularly Furino. (Figs 2.18 and 2.19); the length of the palatine relative to the ma:dlla is variable within Simoselapst and reduction of palatine teeth occurs in other burrowing snaKes such as Oligodon (Wall, 1923), Pros'Lmna (Loveridge, 1958) and Calamaria. (Inger and Mar>:, 1965), so convergent decrease in length would not be surprising. I did not
82 detect a pointed later'al pr'ocess of the palatine, adjacent tf.) the anter'ior median process of the ma>dlla, in either specimen of Vermicella; nor does Boulenger :amine the vertebrae or musculature specifically, the value of these characters has recently been questioned by HcDowell (1985), who now considers that there has been significant parallelism in the form clf the 'adductor e>:ternus superficiali s I •
The temporal scalation of Ogmodon and Salomonelaps is similar to that of To>:icocalamus (Ogmodon in particular shares similar advanced states of dentition and head scalation with that genus, though these ar'e dismissed by HcDowell); the anter'lor temporal
(if
present) is shallow, giving the impression that the TL is fused with the
poster'ior labial, as HcDowell notes. In addition, variants with seven distinct labials occur in these three genera, supporting the idea that the condition in these species is derived from one where the TL was a normal labial (HcDowell 1969a, l. 970).
Loveridgelaps ha.s f.+2+3 tempor·a.ls (pers. obs.), the probable primitive state fr-om which the common 2+2+3 of the Australian snaKes was derived (see HcDowell, 1967, on the nature and occurrence of the TU. One AH specimen
(R
91228) also shows
fusion of the TL with labial 5. The temporal formula of Vermicella is 1+1+2, indicating fusions, and the form of the scales is very similar to that in Simoselaps bertholdi, as pointed out by Stor-r' (1967). This situation is also similar- to that in S. fasciolatus and some individuals of the S. semifasciatus gr-oup (based on my own e>:aminations: see Figs 2.1,2.8). The pr-imary tempor-al is deep, and fr-om the variants seen in the semifasciatus group I believe that a scale of this shape represents a fusion of the TL with the upper- pr-imar-y t P 1, and is ver-y unliKely to involve the fusion TL=6, as HcDowell supposed. Unfortunately the only fusion-var-iants Known in Vermicella (Storr, 1967; pers. obs.) involve further fusions, not fissions which might indicate the pr-imitive state.
The weight of the dietar-y and dentitional similarity of Vermicella and
83 Loveridgelaps 1:. reduced by 'the fad 'tha't 'similar denti1:icln is found in Hicrurus, with pterygoid teeth reduced or absent (Boulenger, 1896) and Ophiophaqus, with palatine teeth distinctly larger than the few on the pterygoids (Bogert, i 943). These nonAustralian e!api.c!:
"lre
only distantly related (Smith et aI, i 977) but share an
ophiophagous diet and boldly banded pattern (see Shine, 19:::0b). These cor·relation:. suggest that these character's form a functional comple}:, and should not be weighted as if independent.
Thus Vermicella appears usually to lacK the defining characters of the 'Vermicella group' of HcDowell (1970); its specific similarities to Loveridqelaps can also be e:·:plained by conver'gence, and it does possess similar'ities of colour pattern and head scalation to members of Simoselaps, and similar features of the sKull to Furina. For these reasons, Vermicella is retained here as a possible relative of Simoselaps and Neelags, and included in the cladistic analysis of this group.
3.2.3
i3:}:clusion of Tm:icocalamus
HcDowell :a.
28
Fusion of secondary with upper tertiary temporal (2° =3 D ). This has not been
observed in Furino., but occurs as a variant in some species of the ingroup. Two states: State 0 (fusion absent)
29
-1
State 1 (present in some individuals).
Pre ocular-frontal contact. This feature, as described in the previous section, occurs
as an infrequent or common variant in the three species of Furino., and it also occurs in some members of the ingroup. There are other ingroup species in which the two scales may be only narrowly separated but are not Known to contact, but this is not r'ecognised as an intermediate state because of the subjectivity involved in distinguishing 'narrow' from 'broad', Thus: State 0 (contacting in some individuals) State 1 (separated).
-1
91
30 t 31
Upper posterior- angle of rostral. This angle is always obtuse in Furina.t but is
sometimes or always acute in some ingroup species. Three states are recognised: State
o (posterior
angle obtuse)
~
State 1 (less than a right angle in some specimens)
~
State 2 (always acute).
32
Rostral anterior edge. Smoothly rounded in Furina, smooth or with a more or less
'sharp' anterior edge in ingroup ('more or less' meaning shar-p in at lea.st some individuals>. State 0 (smooth)
~
S1:a1:e i (sharp in some or all specimens),
While charac1:ers such as 1:hese may be subjec1: 1:0 allome1:ric or geographic variation, and some of the data collected may be analysable in these terms, this is not done here and it was consider-ed mos1: practical to define states in terms of mean values of observed ratios. Mathematical 1:ransforma1:ion of da1:a was not used; variance was taKen in1:o accoun1: (subjectively) in constructing cladis1:ic charac1:ers by a graphical technique. Means and observed ranges were plo1:ted against an appropriate scale for each ingroup species and 1:he outgroup sample (see fig. 3.1 for an example of this method), and apparent 'clumps' were separated as character states. Thus although states are defined in terms of means, more information was used in deciding their numbers and boundaries.
33,34
Rostral length, % of snout-frontal distance. The range observed was 13.2-20.4 in
Furina ornata, 22.2-73.3 in the ingroup. Three states are recognised: State 0 (mean 50). Fig 3.
shows the mean and r-ange of this
ratio for each species, illustrating the method of constructing characters; these values are also found in Table
35
Ratio of anter-ior to posterior width of frontal. 1.11-1.50 in
the ingroup. Two states recognized: State 0 (mean H.20)
36
~
L ornata,
0.88-1.87 in
State i ({ 1.20).
Ra1:io of length to ma>dmum width of frontal. 1.06-1.42 in Ii. ornata, ingroup 0.95-
'10
.. .. ....... u
C
60
+"
Uk
"1:J
+"
C
o
cUL
50
....I
c...
I
+" :J
o C
....o'"
~
~
5-
I
+" 01
CAL
C
..
....
~i
CA.M
_ .....j -
AlT
.s::.
......
t .- . . -",-L . .
30j -
"'"
J.
Q.A.
JIll,,"
VA.
c...
+" 1ft
o
a:;
1M.
10
t F
10
Fig 3.1 Figure illustrating the method of constructing cladistic characters from data on head scale mea.surements (also for sl
93 2.09. Two states: State 0 (mean . Two states ar-e r-ecognised: State 0 (mean 50.0).
Dentition and features of sl:iends anterior to
the
m~t}:i11a
in L ornata, level with it in F. diadema; in the ingroup the front of the
palatine may be in front or behind that of the maxilla. Two states: State 0 (anterior or level> '"* State 1 (posterior).
46
Anterior par·t of nasal bone on each side single Dr bilobed. Single in Furina, single
or bilobed in ingrouPi so State 0 (single) '"* State 1 (bUobed).
47
Anterior process of prefrontal. Furina and soine ingroup species have a process on
the anterior face of the prefrontal bone, longer than wide when seen from above; in others it is much reduced or absent. These two states are distinguished: State 0 (prefrontal process distinct) '"* state 1 (small or absent).
48
Postorbital-frontal 'contact'. This and the following character describe the
relationship of the pro::tends to the anterior limit of the parietal and may contact the frontal, thus excluding the parietal from the border of the orbit; in the ingroup other than Vermicella the po is "Iell separated from the frontal and the parietal forms part of the orbital border. In Vermicella the po varies, being absent, very small and wholly anterior to the parietal (McDowell, 1970), or in one large specimen well-developed and separated from the frontal. Two states are recognised: State 0 (postorbital reaching frontal, at least sometimes) '"* State 1 (separated, parietal entering orbit anterior to po).
49
Antero-posterior pivot of postorbital. McDowell (1969a) emphasised this character
shared by Toxico>:alamus and 'Rhynchoelaps'. Pivot present in Furina, pr'esent Dr absent in ingroup: State 0 (po pivoting around articulation with parietal) '"* State 1 (postorbital fi>:ed to sKull).
50
State of distal end of postorbital. Narrows to a point in Furina, and in the ingroup
95 either pointed or with the distal end
exp~nded
State 0 (po narrowing to point laterally)
-t
and blunt. Two states were recognised:
State 1 (tip e:{panded).
II Jaw muscles meeting in midline of parietal. In Furina the muscles of the jaw and venom gland meet in the midline posteriorly, leaving a triangle of exposed parietal. This state also occurs in the ingroup, but in some species they do not meet and the posterior edge of the parietal is exposed medially or covered by longitudinal necK muscles. Two states: State 0 (muscles meet in midline)
-t
State 1 (transverse posterior
edge of exposed parietal area).
52,53
Shape of prema>:illa. Convex anteriorly in Furina e}(amined; concave, convex or
angular in ingroup. A concave anterior edge may also occur in Furina ornata (see Worrell, 1961a, figured as 'Lunelaps christieanus'), but as only
~
diadema and barnardi
were examined for this study, the state in these species is assumed to be primitive. State i (smooth anterior edge \vith a median concavity) .,.. State 0 (smoothly conve:.:) State 2 :illa length, 7'0 mandible length. Outgroup 23 (F. diadema) and 31 (F. barnardi>;
23-37 in the ingroup. S.
~,
the least fossorial member of the ingroup, has ma>:illa
length 30-33% of mandible length; therefore the state in L barnardi and S. warro is taKen here to be primitive. State 1 (35-37)
61
t-
State 0 (29-34) .... State 2 (23-28).
Palatine length, % mandible length. Furina 19,20; ingroup 17-21, 23-29. Two states:
State 0 (17-21) .... State i (23-29).
62
Ectopterygoid length, 7'0 mandible length. 27 and 2E: in Furina, 20-32 in ingroup. Two
states are recognised: State 0 (23-32) .... State 1 (20-22).
63,64
Supratemporal length, % mandible length. 18,21 in Furina, 23-32 in ingroup. Three
states a.re recognised: State 0 (18-24) .... State 1 (25-29) .... state 2 (30-32),
65,66
SVLlSTL, a measure of relative head size or elongation. Furina 31.0, 31.9,
ingroup in three non-overlapping ra.nges which a.re recognised as states: State 0 (31.087.0) .... State i (19.8-30.8)....
State 2 :cluding those characters not available for all species, and some those species for- which not all charaders were available; and with the species entered in differ-ent or-der-s for- some combinations.
As a result of e>:per-ience with :-pecimens of the snaKes and the characters used here and in the literature, I had formed intuitively based hypo-theses of their relationships. Some, but not others, of these were suppor-ted by the analy!:-is. In par-ticular-, all but the most r-estr-icted combinations of characters supported the monophyly of the Simoselaps semifasciatus and S. ber-tholdi groups. Ther-efor-e, in later analyses; a division was made between phylogeny internal and exter-nal to these groups. 'Inter-naI' analyses r-equir-ed additional outgr-oup-based polarity decisions, in turon depending on 'external' relationships, so the levels wer-e not isolated for- all charader-s:
Of the 66 binar-y char-ader-s, 1i var-ied within the bertherldi gr-erup and were
thus dependent on comparison for- polarity' decisions; for most, warro was taKen as an outgr-oup (which was the closest group in the analyses e>:cluding all charaders perceived as fossorial-related), but for two H6 t 36) Storr's
(i 979)
suggestion of a recent origin
of minimus from anomalus was adopted to identify states of minimus as autapomorphous reversals. For the semifasciatus group, 26 charaders were dependent; the outgr-oup used initially consisted of warro and fasciolatus, and it was found that a number- of charaders supported early separation of australis and semifascia tus from the rest of the group. These two were then used as a 'functional outgroup'; states present in both australis and semifasdatus as well as other ingroup species were accepted as (locally) primitive even if not present in war-r-o or- fasciolatus.
With these additional assumptions based on consistency of charader-s; the two gr-oups wer-e r-eplaced by hypothetical ta:-:a (Table A4) possessing their- (inferred) primitive states, and the edernal phylogeny was investigated using the ma:dmum number- of char-acter-s and a reduced number- of ta:{a. This should pr-oduce less vadability in computer results and thus better reliability; however, the cladogram presented below as the pr-efer-red result was not produced dir-edly by the progr-am, but by compar-ing numbers and types of changes on several hypothetical trees by hand. One reason for thi!:;- is that computer--pr-oduced tr-ees ar-e not gener-ally the !:;-hor-test available fr-orfl the data, so need not be accepted as the preferr-ed hypothesis in any case; also that the method of char-aeter- weighting was adopted (see ned sedion), and thus the assumption of unit value inherent in the program was e>:plicitly not accepted.
3.4.2
Char-acte!' weighting and fossor-iality
One of the most significant aspects of this analysis is that all the ingroup species ar-e mor-e or- less fossor-ial. l1orphological adaptations to fossor-iality :on to all the other- member·sl,
The similar-ity or Ver-micella and S. ber-tholdi is probably convergent (4,2.3), but as noted in 3.4.4, the position of the ber-tholdi group requires confirmation with otherchar·acter-s,
S, warrols similar·ity to both S, fasc101atus and Fur-ina (Kinghor-n; i 956; Storr·, 198il is consistent; this r·efleds symplesiomor-phy within the Fur-ina gr-ouPt as 'Hell as a number· c!f derived states shared VJith fasciolai:us.,
113
4.3
4,3,1
BIOGEOGRAPHY AND ,A,DAPTATION IN SIMOSET APB
Historical bioqeoqraphy
Histor-ical biogeography is the explanation of the pr-es-ently observed distr-ibutions of organisms by r-eference to known or- inferred events or pr-ocesses occurring in the past (see J-e'liew paper-s in Ar-cher- and Clayton
(i 984),
The inferred
processes are, from the aspect of the populations concerned, of two Kinds: disper-sal (the e};pansion of populations within an area or across pre-existing barr-ier-s such ·as oceans; deserts etc,); and vicariance (the fragmentation of a species range by new bar-rier-s arising thr-ough geological or- climatic change),
Rosen
(i 97::::)
and PlatnicK and Nelson Ii 9(8) have discussed a method of
combining data fr-om cl2.distic phylogenetic analysis with geographical distribution to construct hypotheses of historical vicariance events, This involves the idea of an 'area cladograml; where each ta};on is replaced by its ar-ea of occur-r-enee. This has been done for Simoselaps (Fig 4.1),
As str-essed by Rosen
(i 978),
the vir-tue of such a method i:- that compar-ison
of area cladograms constructed for a number of gr-oups provides a means of testinq biogeographic hypotheses, It is pr-esumed that geological or climatic events will disr-upt populations by breaKing up their habitat; other species associated with the same habitat are liKely to be affected in the same waYt and if speciation follows this may be reflected in equivalent area cladograms, For a given area-classification (such as the number-ed ar-eas in the map; Fig 4,1) and number- of ta;{a; possible patter-ns can be enumerated; and precise statistical tests per-formed (Rosen; i 97:::).
Dispersals; in contra::t i would not be expected to be cor-related between different groups; and there is no way of testing e>;planations based on specific dispersal e--/ents. However, ther-e may be evidence for disper-sal in the for-m of sympatr-y between r-elated
ta>~a
(this can be consider-ed evidence of disper-sal on the assumption
that speci~_tion is allDpatr-ic, which 1:- consider-ed to a.pply in most norma.l cases; White;
J
II+-
">~,I \
\
,,
, "\
\ \
\
\
\
\ I
7
------- ... ,
'-(. i- -,:..
I
J(
x
I \
\
'-
,
-- ,,
,
\
,,-
\
,\
, I
--- .-
- -- ......
r
,
\
""'-
'"-
,I
,
....
-- --
'-
"-
\ \
" "-,
\ I I
\ \
\
"-
,
--
3 '-
, "
" .... ....
\
\
""'- , \
\ I
-
" .... "
\
'- \ \
(
\
5
\
\,
\
4 "
\
,
I \
/
I
",
\
'-
\
,- .-
/
/
X
1
\
'-
!
\
\
\
\
)
I
"-
\
,'-
/
I
".
, ,-
".
/
/ /
Fig 4.1 Example of biogeographic analysis method of Rosen (1978) and PlatnicK and Nelson (1978). The total geogra.phic distribution of the group is divided into areaSt ea.ch inhabited by one or more species; then each species is replaced on the cladogram (see Figs 3.1-3) by the areas corresponding to its range. Splits in the tree between distinct areas then represent possible vicariances. Areas of sympatry may be discounted in some cases (PlatnicK and Nelsont 1978)t as done here for areas 4 and 6.
~.I,1t-a-nJ.t,
~'~E_--'''''4-, -:}-
6
s ....... :~\~ ...... 'S'
2·~~_r,)J ....
R· f..s~: .. tcJ-~ S-t (.
-=t !.!.
l ,dlla seen in Furina; with accessory mobility of prefr-ontal and postorbital; is more highly developed than in most Australasian elapids (2,2 above, and d, McDowell; i 96%, where Furina is not discussed), McDowell
(i 969a)
regarded the
shar-ed featuj-es of the Rhynchoelaos gr-oup as adaptations for soft-bodied prey: Tohcocalamus loriae feeds on earthworms (McDowell, i 969ai confirmed by ,AJ'l specimens, pers. obs.), but Furina feeds on skinks (Shine; i981) like many other- Austr-alian snakes with less mobile maxillae; and Savitzky
(i 983)
classed skinKs as hard-bodied (he
regarded specialised morphc,logies seen in scincivores as cases- of adaptation fori
durophagy!).
The other notable feature of the dentition in Fur-ina is the possession of enlarged anterior dentary teeth; these resulted in Glyphodon being named !fang-tooth'; and ar-e also seen less distinctly in other- members of the group (see Figs, Chapter 2), The most extreme e>:ample of maxillary erection in the Elapidae is Dendroaspis, the arbor-eal mambas (McDowell, i 969a); the anterior dentar-y teeth are alse. gr-eatly enlarged and much more fang-liKe in this group (Boulengert 1:::96). These shared featUres of mor-phology suggest shar-ed specialised aspects of pr-ey capture and handling, pr-obably
III
involving imbedding the anterior teeth relatively deep into the prey (mambas feed on mammals, birods and chameleons; Pitman, i 974), Clearly theroe are more than one ways to eat a skink: snaKes v..;ith small, hinged teeth (Savitzk)l; i 983) have a 'ratchet-like
I
mechanism with the teeth hooKing under the edge of the lizard's scales, very differoent from the method inferred here for the Furina group,
Shine
(i 980b)
has reviewed ecological analogues of Vermicella, To his list can
be added the king cobra Ophiophagus; also a snake-eatero (hence its name), and stroongly banded (when young), The palatine and pteroygoid teeth are similar in this species (Bogerot, i 943) to those of Vermicella in spite of the great size differoence aso adults; the particular functional significance of this specialisation is unknown,
A number of burrm:illary fangs; the pterygoid teeth in such cases are reduced or absent (Oliqodon, wall, i 923; Prosymnat Loveridge, i 958),
The Simoselaos semifasciatus grooup is obviously converogent in diet and roostroal shape with these colubr-ids, Shine (1984) suggested that enIaroged posteroior teeth did occur in this group; but did not describe them in detail, The most significant feature of the dentitional specialisation in this group is that the enlarged teeth, presumably used to slit egg shells, are cln the pteroygoids rathero than the maxillae. It seems generoally true that when teeth become specialised in snaKes, it is the maxillae that change first: whethero the reason foro this is mechanical or developmental seems uncertain, An e:< ample of this is the multiple origins of ma:-:illary fangs in snakes (SavitzkYt i9:33).
These data suggest that the pterygoids aroe modified in the S. semifasciatus group because the ma:o;illae are 'preoccupied' by the specialisation of the anterior
118
maxillar-y teeth as fangs. This r-elationship is potentially testable, if other- oophagous r venomous snaKes ar-e found; however-; in areas outside Australasia, most snaKe species ar-e non-venomous colubr-ids, and it is quite liKely that the semifascia:l:us group ar-e unique in this combination.
This possible uniqueness- ma.Kes a detailed study of the feeding behaviour- and mechanics in these sna.Kes highl;! desir-able. In comparison of diets with phylogeny; several points of interest emer-ge: i)
both types of dentition are able to handle both types of pr-ey: both S. australis and fasciolatus eat both lizar-ds and eggs; but fasciolatus has the pr-imitive mor-phology while austr-alis has the 'squar-e pter-ygoid' condition;
2)
egg-eating behaviour came fir-st; befor-e the major- modification of mor-phology; and
3)
data on the diet of S. warr-o ar-e fe';'/, A mh;ed diet of sKinKs and eggs for- this species, as in fasciolatus, would be consistent with the proposed phylogeny.
4.4
TAXONOMIC IMPLICATIONS OF THE PHYLOGENY
Sever-al questions r-emain to be answer-ed before stability of nomenclatur-e can be assured for- this group; ther-e r-emains considerable uncertainty about the number of origins of fossodal habits and mor-phology fr-om a Furina-liKe ancestor. As anc,theraspect of this same question; it r-emains to be shown whether Furina itself is a monophyletic taxon.
lthley
(i 979);
Platt (1984) and others emphasise that in order- to e};pr-ess
infor-mation about phylogeny in a classification consistently t all ta>:a must be monophyletic. Wiley
(i 979)
has proposed a. set of conventions for use of the Linnaean
hier-archy as a phylogenetic system. This allows any phylogenetic hypothesis to be e;:perience, and Knowledge of liKely species in an areat determinations can often be made from head or tail scalation; but in one case I had only a section of body sKin showing a reduction, from anterior to posterior, from 17 to 15 dorsal rows. Its size and location implied that the snaKe was either a Pseudonaja (brown snaKe) or Pseudechis ('blacK snaKe'), but left species in doubt; published identification Keys refer only to 'midbody' scale row counts.
This case suggested an investigation of dorsal scale patter-ns in snaKes; particularly the a.spect of 'posterior reduction! (PR) in dorsal row number; not only to assist in identification of fragments of sjljn, but as a neglected source of characters of probable phylogenetic significance.
Dowling (1951b) proposed a standar-d method of el:a were not suggested explicitly, but Thompson
(i 9 i
4, cited by Dowling) tabulated ventral number for
successive reductions; Johnson
(i 977)
and Resetar and Man
(i 981>
list successive row-
counts and give examples of complete (Dowling or equivalent) counts for each ta}:on; Thorpe (1975) suggested converting the position of reduction to %VS (percent of ventral scale count), allowing comparison between individuals or taxa with different ventr-al counts; and Thomas (1976) proposed a 'summation formula' to combine data from large samples.
Thomas and Dh:on
{i 976}
briefly reviewed the use of 'abbreviated' dor-sal scale
12 row formulae, noting that complete counts are "frequently comple}; and their construction is time consuming", Complete counts have apparently never been used for Australasian proteroglyphs; abbreviated counts at 'necK't 'midbody! and 'immediately anterior to vent' are used by McDowell (1967;i 969a, i 970), and at necK, midbody and 'tail' by Smith (1981a,b;i 982), Sometimes posterior reduction is referred to as present or absent (Storr-; 1967; l,.Jallach, 1985); but it is common to use only midbody counts in species descriptions (e.g. Storr; 1978; Gillam, 1979; Cogger; 1983>,
This chapter- reports on the application of Dowling-style counts to a number of species; and investigates methods of displaying results for samples of several individuals. Because of limited time available for this investigation, which was in competition with the SimoselaDs project, after an initial survey attention was focussed on a few gr-oups in which posterior- scale-row reduction (hereafter abbreviated to "PR") normally occurs. For the same reason, and because these counts are time-consuming, sample sizes are small.
5.2
METHODS
Two methods of recording data from individual specimens were used, and are described separately.
1.
Determine ventral scale (Dc!wling 1 i 95 i a) and midbody scale row (Cogger-, i 975)
counts; then find position of first posterior row reduction; i.e. the site where the dorsal row count reduces fr-om its midbody value by the fusion of adjacent rows or termination of a row; where reductions on left and right sides are separa.ted by one or mor-e segments, only the more anterior was recorded. The position was recorded as the number of the ventral scale centred nearest the posterior edge of the last scale in the reducing row. In addition, the position of 'last anteriorJ reduction was recorded, as the number of the most anterior- ventral at which the dorsal scale-row count was the same as at midbody. This procedure, and conver-sion of position to %VS, were used before I became aware of Dowling's more complete method, and for all counts in the main Simose laps- study.
r
IL
II.
Method of Dowling (1951b). The method of maKing counts is as in I, but not only
are all changes in scale-row number from first to last ventral identified, but their positions on both sides of the body, and the actual rows involved in fission, fusion orter-mination are also recorded. All complete counts using this method are listed in a later section. In all cases, count:- were made directly around the body at the given ventral.
Thomas
(i 976)
proposed that the 'complete' formula begin with the count at a
deSignated ventral posterior to the "area of rapid reductions" usually found behind the head, and used the tenth in examples. While much of the interest of these counts lies in the pattern on the posterior part of the body, the reductions immediately behind the head may also be of Significance in some groups (e.g. Simoselaps); characters such as count at first ventral, mode of anterior reductions - which rows fuse, etc. - and position of 'stabilization of count. Anterior reductions are more rapid but not l
necessarily less important than posterior, and if not counted their significance can only continue to be overlooKed. Nevertheless, in this chapter the emphaSis is on the occurrence and position of PH without much attention to anterior changes or the scalerows involved, because of limited time and the difficulty of assessing variation in all sets of characters.
Important aids in rapidly reviewing the occurrence, though not the details, of this and other characters, were the photographs and line dral;Jings in Cogger ;plicit by Hengden.
Dorsal scale-row patterns, while not universally applicable or- as immune from adaptive cDnvergence as biochemical or cytological systems; provide a complex and phylogenetically informative char-aci:er- set which has not been used for Austr-alasian elapids in a way approaching its potential. It may be largely independent of other external morpholDgical characters used in the past, SD prc,vides a test of consistency for all characters previously used in constructing phylogenetic hypotheses fDr this lineage of snaKes.
135
ACKNOWL[DG[M[NTS
I thanK Allen Greer (Australian Museum) and Glenn Storr (Western Australian Museum) for permission to e}(amine, and clear and stain; :-pecimens in their- care, and Allen also for advice on cladistics. I am also grateful to Greg Czechura and Greg Mengden for cor-respondence and discussions (respectively) on the status and relationships of the Simoselaps species; to Jeanette Covacevich (Queensland Huseum) for discussion:- of Furina, Glyphodon and Cacophis, and permission to examine specimens at the G.H; and to Ross Sadlier and Debbie Kent for giving me somewhere to sit (as well as continuing assistance with specimens, data and equipment at the AM over the years). Paul Webber inspired my interest in pigmentation by mentioning that the yellow colour of Lover-idgelaps can be wiped off with ether-, and found an undescr-ibed species of Simoselaps (which unfortunately escaped from the beer can it was in),
I have greatly appreciated the friendship as well as the expert advice and assistance of my supervisor Rick Shine, a very busy man who has shar-ed his Knowledge and enthusia:-m for- the elapids with me since we met over a tray of Drysda1ia in i 979. Rob LambecK and Craig James have also helped greatly through the year.
Roger- Carolin taught me to use the Wagner program, and when not to use it. Hark Stevens; Allen Greer and Don Anderson allowed me to use their microscopes and dr-awing equipment at different times, which helped maKe this thesis what it is.
I also thanK my fellow Honours students in Biological Sciences for their friendship; advice and suppor-t throughout the year-, and my family and all my friends for tolerating the antisocial aspects of full-time herpetology. To Linda Zapletalt Dave Slip and especially Helen Johnston, I am gr-ateful for- time spent typing on my behalf.
This work is dedicated to Glenn Storr and Sam HcDowell for their worK on the mor-phology of the elapids.
APPENDIX Ai:
TECHNIQUE FOR CLEARING AND STAINING SNAKES
This method is descl'ibed in labol'atol'Y notes fol' a biology coul'se taught at the Univel'sity of Utah, Salt LaKe City t by DI' John Leglel'. It was found to be vel'y successful with the small snaKes, but in general the double-stain method of Ha.nKen and Wassersug (1981) would be preferred. Tl'ypsin Technique Solutions Bleach: Hydrogen Peroxide 3% KOH 2% aqueous Trypsin Solution: Bora}; t saturated aqueous Water, distilled Trypsin
30cc 70cc 30cc 70cc
1.Q.
Use commercial grade bOl'a:{ (20 Mule Team); allow to settle and decant dear- fluid fl'om top. The following tl'ypsin is adequate: Trypsin, purified, Fisher T-360. Stain, StocK Solution: Glacial acetic acid Glycerin Chloral hydrate (i % aqueous) Alizarine Red S
Sec iOee 60ee to saturate
Stain, WorKing Solution: StocK solution KOH 2%
20-30 drops iOOce
The coloul' of the stain changes from brown or red to purple as it is added to the KOH solution. Avoid contamination of stocK solution. Procedure: 1. Remove s\ljn and eviscer-ate; wash thor-oughly in r-unning water-; 12-24 hour-s for specimens that have been stor-ed in for-malin (no trace of formalin odour should r-emain [only a quicK wash was needed for- the WAM and AM specimens, which had been stor-ed in alcoholJ. 2. Bleach: Place specimen in bleach and e};pose to sunlight or- ultr-a-violet r-adiation: 12-24 hours or until all pigment is bleached [this tooK only a few hours for the snaKes, in dir-ect sunlightJ. 3.
Rinse in water.
4. Clear- in tr-ypsin solution; until sKeleton is dear-ly visible. [The longest step, taKing about 24 hours for the smallest and nearly a weeK for the large Simoselaps. Don't tip Qut the trypsin.] 5.
Rinse in water.
6. Stain until bones ar-e deep red. Some or- a.ll of the osseous tissues will also be coloured at this point. They are destained in the following step. [Staining tooK from a few hour-sf to about 2 days for the largest specimens] 7. Destain in trypsin solution (use solution from Step 4) until all or most of the stain has been removed fr-om non-osseous tissues. [No more than a few
hours for most of the colour to come out.] 8.
Wash away all tr-,:u:!:
9.
Glycerin (USP):Distilled water
w1
trypsin solution (in water Ji 15 minutes. (1:1);
one day or longer (still destaining].
10. Pure glycerin; one day or- longer-, 11. Pure glycerin: final storage; add one or two crystals of Thymol to prevent formation of mould. RemarKs: Final dearing of soft tissues is progressive and occurs in glycerin. Some dense connective tissues (e.g.t fa.scia.l> never clear completely but! in a properly pr-epared specimen, all stained osseous elements should be dearly visible with transmitted light. (The two AM Simoselaps specimens had not been sltinned t and were only partly bleached before clearing and staining. Some of the WAM specimens done this year had the eyes removed t and left in in others: removal is recommended in future; because of the structures obscured even by a completely transparent lens.]
APPENDIX A2: KEY DIAGRAHS FOR SKULL ,t.,ND EXTERNAL HEAD-SCALE MORPHOLOGY
To avoid clutter-ing the many dr-awings in Chapter 2 with labels, these figur-es are designed to fold out to be seen with any page of figures Dr te}:t in the thesis, as a guide to terminology and basic str-uctur-e.
Fig A2.1
Head scales
Head of Fur-ina or-na:ta AM R i 10357 (same as Fig 2.iJ; with all
scales of later-al and dor-sal surfaces which are r-eferr-ed to in the text labelled. Fig A2.2
SKull
SKull of Simoselaps war-roo AM R i4395 (same as Fig 2.2) in lateral,
dorsal and ventral views with all bones r-eferr-ed to in ted labelled.
("0
sfr-o...1
sup ....o..\"'loi!L/s
po..occ.; pit-.,..J.
___- - - - ; r - _.......
e.xocc..ip-,ro...l
mo-xj
I/a.
Fig A2.2
APPENDIX A3:
SURVEY OF SKULLS OF SOME ELAPID SNAKES
A number of sKulls of Australian elapid snaKes had previously been prepar-ed for study by the method of clearing flesh with dissecting instruments and a commercial bleach l and these were examined to assess the suitability of sKull charaders for use in cladistic analyses. These specimens are listed in the accompanying tablet with an identifying number, locality where Known, and the condition of each character recorded as present
(+)
or absent (-h with other- detail:- as appropriate. The first six species in
the table are oviparous, the other eight (with the possible e>:ception of Acanthophis) belong to the 'Notechis lineage' of vivipar-ous, single-subcaudal snaKes (Shine, i 9851.
Summary (refer to table A3)
The quadrate process in Austrelapsl Acanthophis, Demansia and a large specimen of Hemiaspis is a flat structure visible only from the median or posterior aspect I whereas in other small snaKes and juveniles of larger species it is a Knob-liKe projection beyond the posterior edge of the bone. This suggests a relationship to size but no phylogenetic pattern.
Postorbital-frontal contact. There is no clear correlation with body size; this character is consistent within genera (Pseudeclis; Cacophisi and Cr'lptophis nigrescens and 'Urlechis' boschmai which can be considered congeneric - see Mengden, 1985), The 'most fossoria1' of the snaKes examined (Cacophis and 'Unechis' spectabilis) have the postorbital displaced baCKwards and separated from the frontal, as in Simoselaps; but in other terrestrial snaKes either state may occur.
Postorbital joint. In these snaKes the postorbital is either firmly fixed tCI the parietal and/or frontal along an edge (most speciesh or loosely attached to the frontal or parietal at its upper anter-ior tip (Cryptophis, 'Unechis') but as descr-ibed in note (3) it is unliKely that there could be a functional ligamentous connection with the maxilla
Table A3 Number-
44 51 3 63 132
4 30 54 105 ~(I
1.1
1_'
I~
4
'..'
~
61
Elapid sl{ull data Species
Qemanill 2§.ammoghi? E§.eudechis lli:!..i~§.L P. porphyriacus L Ese]ddonaJa i~li~ Cacophis 2..9uamulQ§..!d2. C. 'fla vicoll! 5 ' Acanthophis antil.rctieus 6ustrg,lap2. ~§1i Cryptophis !J.igr.§.§.ce!]§. Dr~lia r::hQdogaster HemiS:.§.Ris §.iqn.S:.~ ~§. seutai!d§."~1J.!lEH:his' bosehmai 'U'! §.pectabili§.
Locality
O.uadr-a. te process
Sydney ar-ea Boggabilla Bendalong Pod Macquarie - (North O.ld) Sydney ar-ea. Bur'r-adoo Gosford area Bendalong Sydney area
_1 + (small) + ( " ) + ( " ) + +
Postorbitalfrontal contact
Postor-bital jointed
- (just sep.) + (just conU + + (point)
+ +
+
+ (small) + + (small)
+ +
_3
_3 3
Notes. (1) 'Absence! of this- cha.r-acter means that when viewed laterally I the process- i=- not visible beyond the pos-terior edge of the quadrate. (2) ,Juvenile specimens of lar-ge species. (3) In these species the postorbital is small and only loosely attached to the parietal; but the madlla is toe. short for there to be a functional connection between the tip of the postorbital and the upper posterior end of the ma:dlla as in the Fur-in§:. group. (4) A specimen much larger than average adult size,
in these cases. This r-educed postorbital may be a synapomorphy defining a CrvptophisiUnechis' group, but it is distinct from the condition seen in Furina, Simoselaps and Neelaps. The manner of attachment of the postorbital is considered a useful phylogenetic character.
,
APPENDIX A4: CLADISTIC DATA MATRIX
Table A4 shows the char-acter- states for- each of the seventeen ingroup taxa, and the outgr-oup Fur-inat and for- the si;dy-si;.; binary char-acters defined in Section 3.3. The gaps in the table indicate chal'aders which were unavailable! in each case because a sKull of the relevant ta};on was not e};amined. Head scale measurement!:- were not made on the single specimen of S. anomalus (the sKin of the head was damaged when removing it before clearing and staining); but some data. were available from Storr (1967), and in other- cases the other- three species in this group had the same state.
The two ta};a at the bottom represent hypothetical ancestors at the points of first divergence within each of the Simoselaps species-gr-oupsi and possess all the charader states proposed as primitive within the groups. By using these taxa in the analysis instead of the separa.te members of the groups; the comple>;ity of each analysis was considera.bly reduced; and the size of the character set effectively incr-e ased,
,
Table A4
Cladistic da.h. set
Taxon
Character
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
Fur-ina spp. Simoselap-s ~ Su fasc:iDlatus S, bertholdi S. Ii Horali 5 -s. anom"du5 §. l!linimus S. austr-alis .§.. semifasciatus S. ~p.f_wo~dmans Su '\f..//1, ~er-i! 2' ! NT rEp-e r-i ,. S. incindus S. woodjonesi 2,. liI12Rbelli Neelap~ calonotLJ.§. N. bimaculatus Vermicella. annula"ta
000000000000000000000000000000000000000000000000000000000000000000 000110000000000000001001000000011001100000000001000100110000111110 100111110001100001101001001101011011100001000001000100100110111110 111110011110000101110000000010001001111101001001101000110000101011 111110011111000101110010000010001001111101001001101000110001101011 111110011101000101110011100010001001111101001001001000100101101011 1111100111010000011100111000100010001111 100111100001100001011000011011111110001111011001011100101110101010 100111101001110001011100011111111110101111011011011001101100110010 100111100001110001010000000111111100001111011111011101101100100010 100111001001110001011100001001111110001110011111001101101100100010 1001110000011110011111000100011111100011 1001110010010000010111000100111111100001 1001110011111110011111000000111111101011 1001111011011110011111000000111111101011 110100001001000011110000010100001000110111000001001010110101000010 000110001101000011110000011110001100110111101001001010100000001010 000110001001000101111100000010001001010101101001100000100000000000
S. bertholdi group S. semifasciatus gp
111110011110000101110000000010001001111101001001101000110000101011 100111100001100001011000011111111110101111011001011100101110111010
----~
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BaverostocK; P.R. and T .D.Schwanero; 1985. Phylogeny of Austroalian elapid snakes: the genetic approach. pp.159-i64 in "Biology of Austr-alasian Frogs and Reptiles" t ed. by G.Gr-igg, R,Shine and H.Ehmann. Roy.Zool.Soc.N,S.w.,Sydney. Bechtel, H.B., i 978. Color- and patter-n in snaKes (Reptilia, Ser-pentes). J .Her-p. 12(4),52 i-
"""
.J ::11:" z
BeHair-s; A.dIA., 1957. "Reptiles: Life Histor-y, Evolution and Strouduroe". Har-per-, New Yor-K, Blairo, l,.J.F., i 960. "The Rusty Lizar-d. A population study", Univ.Te};as Pr-ess, Austin. Bogerot, C.M.; i 943. Dentitiona.l phenomena in cobr-as and other- elapids, with notes on adaptive modifications of fangs. Bull.Amer-.Mus.Nat.Hist. 81,285-340, Boulenger-, G.A., 1896. Catalogue of the Snakes in the Broitish Museum 1cDowell, S.B., i 967. Aspidomor-phust a genus of NevJ Guinea snaKes of the family Elapidae, with notes on related gener-a. J.Zool.Lond. 151,497-543. McDowell, S.B. t i 969a. Toxicocalamus; a New Guinea genus of snaKes of the family Elapidae. J.Zool.Lond. 159;443-511. HcDowell, S.B., 1969b. Notes on the Australian sea-snaKe Ephalophis Qreyii M.Smith (Serpentes: Elapidae: Hydrophiinae) and origin and classification of sea-snaKes. Zool.J .Linn.Soc. 4::; ,333-349. McDowell, S.B., i 970. On the status and relationships of the Solomon Island elapid snaKes. J.Zool.Lond. 161;145-190. McDowell, S.B., 1985. The terrestrial Australian elapids: general summary. pp.26i-264 in "Biology of Australasian Frogs and Reptiles"; ed. by G.Grigg l R.Shine and H.Ehmann. Roy.Zool.Soc.N.S.W.! Sydney. HcKenzie, N.L, A.A.Burbidge, A.S.Geor-ge and A.S.Mitchell, i 983. Envir-onmeni:. pp.7-37 in "1,.Jildlife of the Great Sandy Desert, Western Australia", ed. by A.A.Burbidge and N.LMcKenzie. itJildl.Res.Bull.West. ,A.U=_t. 12.
Marshall, LR. and R.P.Her-mann, i 984. Cross-reactivity of bardick snake venom with death adder- antivenom. Med.J.Aust. 140(9},54i-542. Mather; P.B.; 1979. An examination of the reptile fauna of wyperfeld National Park uE-ing pitfall tr-apping. Vict.Nat. 96;98-101. Mengdent G.A., i 983. The ta;{onomy of Australian elapid snaKes: a review. Rec. Aust.Mus. 35,195-222. Mengdent G.A.; i 985a. Australian elapid phylogeny: a summar-y of the chr-omosomal and electrophoretic data. pp.i 85-192 in "Biology of Austr-alasian Frogs and Reptiles"l ed. by G.Grigg, R.Shine and H.Ehmann. Roy.Zool.Soc.N.S.w., Sydney. Mengdent G.A. t i 985b. A chromosomal and electrophoretic analysis of the genus Pseudonaja. pp.! 93-208 in lIBiology of Australasian Frogs and Reptiles", ed. by G.Grigg; R.Shine and H.Ehmann. Roy.Zool.Soc.N.S.w., Sydney. Mengdent G.A., R.Shine and C.Moritz l in preE-s. Phylogenetic relationships among venomous Australasian snakes of the genus Pseudechis 