A few of these strom bids possess unique morphologies (above .... (1915) as sl ightl y earl ier than the beds of Noax, Rosazzo and Brazzano, classical localities.
N. Jb. Geol. PaHiont.Mh.
Stuttgart, J anuar1989
Orthaulax dainellii n. sp. (Gastropoda, Strombidae) from the Lower Eocene of NE Italy By Enrico Savazzi, Uppsala With1 figure in the text E. (1989): Orthaulax dainellii n.sp. (Gastropoda, Strombidae) from the Lower Eocene of NE Italy.- N. Jb. Geol. PaHiont.Mh., 1989 (1 ): 30- 36; Stuttgart.
SAVAZZI,
Abstract: Orthaulax dainelli n. sp., from the lowermostMiddle Eocene of NE Italy, is the
oldest known representative of Orthaulax (s. s.), and the first reliable record of this genus outside the Americas. Zusammenfassung: Die neu beschriebeneArt ist der altesteVertreter der GattungOrthau
lax (s. str.) und deren einziges zuverlassiges augeramerikanisches Vorkommen.
Introduction
The strombid gastropods of the Paleogene of NE Italy include several endemic species, together with a few genera that are found in other continents, but not recorded elsewhere in Europe (SAvAZZI 1979, 1988, in prep., and refer ences therein). A few of these strombids possess unique morphologies (above references, and unpubl. obs.). The peculiar character of the strombid faunas of NE Italy is now confirmed by the finding of a new species of Orthaulax from the Middle Eocene. This discovery is of particular interest, since it constitutes the first reliable record of this genus outside the Americas. Genus Orthaulax GABB, 1873 (non 1863; cf. WENZ 1940)
T y p e s p e c i e s : 0. inornatus GABB, 1 87 3, from theUpperMiocene ofSanto Domingo.
D e s c r i p t i o n : Shell medium-sized to large, composed of 9-12 whorls (in adult specimens whorls can be counted only in axial section). Spire coeloconoid to cyrtoconoid. Height of spire less than lf2 of shell length. Flanks evenly con vex, or marked by a rounded shoulder near the posterior extremity of the aper ture. Shell smooth or sculptured with growth rugae, occasionally with fine spiral threads. Varices may be present in juvenile whorls. In the last few whorls the posterior end of the outer lip extends into a narrow canal that rises to envelope partially or completely the shell apex. Adult stage: Last whorl usually marked by 3 knob-like projections on shoulder: one more or less dorsal, one at the posterior end of the shell aperture, 0028-3630/89/1989-0030 $ 1.75 © 1989 E. Schweizerbart'sche Verlagsbuchhandlung, D-7000 Stuttgart 1
Orthaulax dainellii
n.
sp.
31
one on the left side of the ventral region. Outer lip in 0. gabbi slightly explanate, thin, with very shallow stromboid notch. Outer lip unknown in other species. Anterior canal short, slightly bent dorsally. R e m a r k s : Tibia, Rimella and related strombid genera often possess a pos terior canal extending onto the previous whorls, but this canal is secreted only after the adult size is attained. In Orthaulax, instead, secretion of the posterior canal continues for several whorls, resulting in the secondary covering that enve lopes the spire. Orthaulax is similar in general proportions to Strombus. Seraphs (family Seraphsidae JuNG, 1974) possesses a secondary covering of the spire com parable to that of Orthaulax. 0. gabbi DALL (Upper Oligocene-Lower Miocene of Panama, Florida and Porto Rico) is the best known species. Shell morphology is extremely variable (see VoKES & VOKES 1968). In certain specimens (VoKES & VoKES 1968: pl. 1, figs.7a-b, pl. 2, fig. 4a-b), the shell proportions and aperture are remarkably sim ilar to those observed in species of Strombus (Oostrombus) from the Paleogene of Europe, likeS. pulcinella BAYAN and S. tournoueri BAYAN. A few specimens of 0. gabbi are convergent with the other species of Orthaulax discussed below. Juve nile specimens of 0. gabbi are virtually indistinguishable from those of Strombus tournoueri. The extension of the posterior edge of the aperture onto the previous whorls takes place progressively, starting from the 9th-1Oth whorl (VOKES & VoKES 1968: pl. 1, fig. 3). 0. inornatus GABB (Lower Miocene of Santo Domingo; see DALL 1915: pl. 11, fig. 4) possesses a tall pointed spire, approaching 1/2 of the total height of the shell. 0. aguadillensisMAURY (Upper Oligocene-Lower Miocene of Puerto Rico, Anguilla(?), St Croix and Santo Domingo; WooDRING 1923: pl. 1, figs. 1-11, pl. 2, figs. 3-6) possesses a short cyrtoconoid spire with rounded apex, and its whorls (including the last one) are devoid of a shoulder. This species also lacks the dorsal and abapertural knobs. A few more species have been described: Orthaulax pug nax (HEILPRIN) (Middle to Upper Oligocene of Georgia, Antigua and Florida; see DALL 1915: pl. 5, figs, 5, 10), 0. caepa COOKE (Upper Oligocene of Cuba), 0. conoides WooDRING (Middle Oligocene of Puerto Rico; WooDRING 1923: pl. 2, figs. 1-2, 7). Most of these species are useful as guide fossils (CooKE 1921, and above references).
"Orthaulax" japonicus NAGAO is a guide fossil of the Upper and Lower 0. ja ponicus Zones (NAGAO 1928b) of the Takashima Group (Upper Eocene), Kyushu, Japan. A few authors (WOODRING 1928, KAMADA 1960, 1980, MIZUNO 1964) have placed 0. japonicus in the genus Pseudo/iva (family Buccinidae). Judging from the published illustrations (NAGAO 1928a: pl. 19, figs. 1-2b, pl. 22, figs. 9-11, 15-15b; NAGAO 1928c: pl. 17, figs. 1-4), it appears unlikely that this form is an Orthaulax. Rather, it seems to be morphologically similar to species of Pseudo /iva from the Eocene of the United States (see HARRIS & PALMER 1947: pls.46, 47).
32
EnricoSavazzi
WENZ (1940) regarded Veatchia MAURY, 1913 as a monotypic subgenus of Or thaulax. 0. (Veatchia) carolinae (MAURY) is recorded from the Eocene of Trinidad
(Caribbean region); According to Wenz (1940), Veatchia is characterized by the spire being completely enveloped in the last whorl, and by the presence of a few nodes or folds at the posterior end of the aperture in the adult. I cannot comment on the status of Veatchia, since I have not been able to inspect material belonging to this taxon. Orthaulax dainellii n.
sp.
Fig. 1 1915 Strombus (Oncoma) tournoueri DAINELLI non BAYAN- DAINELLI: 125,612-613 (pro parte) D i a g n o s i s: Shell medium-sized for the genus,very thick in posterior and columellar regions, thin elsewhere. Spire pointed in juvenile stage (apical angle 25-30'), becoming markedly coeloconoid from 5th-6th whorl (pleural angle in adults 140-160'). Varices sometimes present on first 3-4 whorls (arrow in Fig. 1C). Enveloping of previous whorls begins at 4th-5th whorl (Fig. 1C-D,G-H). Shoulder absent in juveniles,rounded in sub adults and adults. Last whorl with a large,transversally elongated,axially constricted dor sal knob,located at the shoulder (Fig. lA-B,E-F,I). Abapertural knob little developed,in distinct (Fig. 1E-F,I). Parietal callus forming a thick,axially elongated knob in posterior region of aperture (Fig. 1B,E-F,I). Secondary covering of the spire apparently approach ing or reaching the shell apex. Outer lip and anterior canal unknown. D e r i v a t i o n o m i nis: After G. DAINELLI, who studied the Upper Eocene faunas from the province of Udine,NE Italy ( see DAINELLI 1915). T y p e s: Holotype: Fig. 1A-.B (Museo di Geologia e Paleontologia,University of Fi renze,lot n. IGF 2842E),from T orrente Zimor (type locality; see below for details). Para types: Fig. 1G-H (lot n. IGF 2843E),from MonteStella; Fig. 1I (lot n. IGF 2845E),from T orrente Zimor; Fig. 1C-D and Fig. 1E-F (lot n. IGF 2847E), from MonteStella. M a t eri al: Most of the specimens referred by DAINELLI (1915) to Strombus tournoueri BAYAN are stored in the invertebrate collection of the Museo di Geologia e Paleontologia, University of Firenze ( Italy),together with the original labels written by DAINELLI. Of these,12 specimens from Torrente Zimor{ . lots n. IGF 2842E,2945E,2846E),4 from Monte Stella (lots n. IGF 2843E,2847E),and 2 heavily worn fragments from Vedronza (lot n. IGF 2848E) belong to Orthaulax dainelli!. A single specimen from Filanda Cignolini (lot n. IGF
Fig. 1. Orthaulax dainellii n. sp. fromNE Italy ( see the text for a discussion on the age of the specimens). A-B: Adult,dorsal and right lateral views,x 1 (holotype,fromTorrente Zimor near Tarcento in the province of Udine,Museo di Geologia e Paleontologia,University of Firenze,lot n. IGF 2842E). C-D: Juvenile,ventral and right lateral views, x 1 (paratype, from MonteStella near Tarcento,lot n. IGF 2847E). T he arrow indicates a varix on one of the early whorls. E-F: Adult,x 1 (paratype,from Monte Stella,lot n. IGF 2847E). G-H: Ju venile,x 1 (paratype,from MonteStella, lot n. IGF 2843E). I: Adult,x 1 (paratype, from TorrenteZimor,lot n. IGF 2845E). J: Juvenile or subadult,right lateral view,x 1 (from "Ri serva Guidata" of Monte Baldo in the province ofVerona,Institute of Historical Geology and Palaeontology,Uppsala University,n. ITt).
Orthaulax dainellii
3
N. jb. Geol. Palaont. Mh. 1989
n.
sp.
33
Enrico Savazzi
34
2844E), also referred by DArNELL! toS. tournoueri, is a melongenid gastropod. 2 specimens fromVolpins, 1 fromAttimis and 1 fromBuia(no catalog numbers) are too badly preserved to be identifiable.T he remaining material cited by DArNELL! (5 additional specimens from Torrente Zimor, MonteStel l a, Attimis andVedronza) was probabl y deposited at other lo cations, or was subsequently lost. A fragmentary specimen of 0. dainellii (Fig. lJ, Inst. Hist. Geol. Palaeont., Uppsala Univ.,Sweden, n. ITt) was found l oose in an outcrop of Eocene basaltic ashes near the Bar Ristorante Graziani, in proximity of the "Riserva Guidata" of MonteBaldo in the province ofVerona.T he sediment contained inside the shell is a calcarenite, which indicates that the fossil is al l ochtonous. L o c a l i t i e s: The l ocal ity referred to byDArNELL! (1915) as "RioZimor" is locatedjust N of Ponte del l a Reania, al ong Torrence Zimor, in the vicinity of Tarcento ( province of
Udine, NE Ital y). An outcrop is located al ong the right side of Torrente Zimor, and is vis ibl e from the road passing. on the opposite side of the stream. A second outcrop is located about 100 m N of the first, along a smaller stream on the left side of Torrente Zimor, near l ocality Craiaz. Dainel li's locality "MonteStella" is sl ightlyN of the top of M.Stella, at the springs ofRoTasaripariam, E of the l ocality ofTorrente Zimor. In both localities, the sedi ment consists of dark grey marls containing abundant rounded pebbles and gravel , mostly consisting of black fl int. Quartzite and metamorphic pebbles were also observed. Fossil s are scarce, and usually badly worn. A short visit at the first local ity of Torrence Zimor re sul ted in the collecting of 2 specimens of 0. dainellii identical in all respects to DAINELLI's material. According to L. CASSUTTI, who began visiting these localities several years ago, specimens of 0. dainellii were once common atTorrence Zimor and MonteStella, but ex tensive col l ecting has greatly impoverished the outcrops. T he locality of M.Stella could not be visited because of bad weather, butL. CAssurrr donated one specimen of 0. dainel lii he had col l ected there during an earlier visit, together with Velates perversus, "Natica" forojuliensis andStrombus tournoueri. Also this specimen is virtually undistinguishable from DArNELLI's material. A g e : T he l ocalities of Torrence Zimor and MonteStella were regarded by DArNELL! ( 1915) as sl ightl y earl ier than the beds of Noax, Rosazzo and Brazzano, classical localities of the Middl e Eocene of the province of Udine.T he actual age of the sediments atTorrente Zimor and Monte Stel la appears to be uppermost Lower Eocene. DArNELL! (1915: 123- 125) gives l ists of macrofossils from these l ocalities. Many of these species are also found in beds of the Middl e Eocene ofNE Italy, but, as a whole, this fauna appears distinct from those of other, sl ightly younger local ities of the Middle Eocene of the province of Udine. T he locality of the "Riserva Guidata" of M. Baldo lies in the province of Verona, approximately 200 kmW-SW ofTarcento.No other fossils were found at this location, and' the age of the specimen is unknown. However, Middle Eocene calcarenites occur higher up the sl ope, and it seems l ikely that the specimen is Eocene (possibly Lower to Middle Eocene) in age. 0. dainellii is therefore the oldest representative of Orthaulax (s. s.), and the only spe cies known from the Eocene.
Re m a r k s: The closest morphologic affinities of 0. dainellii are .with 0. con and with the most Strombus-like specimens of 0. gabbi (see above). It must be noted, however, that 0. dainellii is very close in size, general proportions, as pect of the columellar callus, and selective thickening of the posterior region of the shell, to Strombus tournoueri �ayan, from the Middle Eocene of southern and ' eastern Europe. This last species;· however, lacks the posterior extension of the aides,
Orthaulax dainellii n. sp.
35
aperture that forms the covering of previous whorls, which is distinctive of Or thaulax. This similarity, together with the geographic and stratigraphic distribu tion of the two species, suggests that Orthaulax evolved in the western Tethys from a species of Strombus close to S. tournoueri. 0. dainellii is similar, in general aspect, to representatives of the fusinid Ther sitea, from the Paleogene of northern Africa. According to CosSMANN (1901), adult Thersitea is characterized by a deep posterior indentation of the outer lip. The available specimens of 0. dainellii are incomplete at the outer lip, but such a deep indentation, if present, should still be partly present, or detectable from the growth lines. In addition, illustrations of Thersitea do not show a secondary en veloping of the spire. The parietal callus of juvenile 0. dainellii has a typical strombid appearance. Therefore, the evidence points to strombid, rather than fusinid, affinities for 0. dainellii.
DAINELLI (1901: 277-278, pl. 33, fig. 1) collected several poorly preserved strombids from the "Lower Miocene" (actually Paleogene) of M. Promina in Dalmatia (now part of Jugoslavia, not far from the province of Udine in Italy). He identified these specimens as Strombus problematicus MICHELOTII, but wrote in their description: "the last whorl envelopes all previous ones". This character (which is not visible in OAINELLI's illustration) suggests that these specimens may belong, at least in part, to 0. dainellii. Acknowledgements
L. DELLE CAVE helped in a search of the invertebrate collections of theMuseo di Geo logia e Paleontologia, University of Firenze. L. CASSUTII provided information on the out crops of Torrente Zimor andMonteStella, and donated fossil specimens. L. CASSUTTI, E. MEZZELANI and N. BUFFARINI (Udine, Italy) arranged a field trip to these localities. Literature
CooKE, C. W. (1921): Orthaulax, a Tertiary guide fossil. - U.S. Geol. Survey Prof. Pap. 129-B: 23-31. CossMANN,M. (1901): Essais de paleoconchologie comparee. - 4: 1- 239; Paris. DAINELLI, G. (1901): II Miocene inferiore delMonte Promina in Dalmazia.- Palaeontogr. Ita!., 7: 235- 286. -
(1915): L'Eocene friulano. Monografia geologica e paleontologica.- 1- 7 21; Firenze (LeMemorie Geografiche).
HARRIS, G. D. & PALMER, K. V.M. (1947): T heMollusca oftheJackson Eocene of theMis sissippi embayment (Sabine River to the Alabama River). Part 2. Univalves.- Bull. Amer. Paleont., 30 (117): 209- 563. ]UNG, P. (1974): A revision of the familySeraphsidae (Gastropoda: Strombacea).- Palaeon togr. Amer., 4 7: 1-72. KAMADA, Y. (1960): On the associated occurrence of Vicarya and Vicaryella in thejapanese Tertiary, with the first description of a Paleogene species of Vicarya from Japan. Sci. Rep. Tohoku Univ.Ser. 2,Spec. 4: 281-295.
36
E. Savazzi. Orthaulax dainellii n. sp. (1 980): Takashiman molluscan fossils.- [In:] Tertiary molluscan fossils from . the coal-fields of Kyushu, 1: PG-1 6.
KAMADA, Y.
MIZUNO, A. (1 964):
Paleogene and earlyNeogene molluscan faunae inWestJapan. -Geol. Surv. Japan Rep., 204:1 - 71 . T . (1 928a): Paleogene fossils of the island of Kyushu, Japan. Part1 .- Tohoku Im perial Univ.Sci Rep.Ser. 2, 9: 97-1 28.
NAGAO,
(1 928b): A summary of thePalaeogene stratigraphy of Kyushu,Japan, with some ac counts of the fossiliferous zones. -Tohoku Imperial Univ.Sci. Rep.Ser. 2, 12:1 -1 0. (1 928c): Palaeogene fossils of the island of Kyushu,Japan. Part 2. -Tohoku Imperial Univ.Sci Rep.Ser. 2, 12:11-1 40. E. (1 979). Revisione sistematica di gasteropodi del Cenozoico delle Venezie.1 -240, I-X; Unpubl. grad. thesis, Univ. Padova.
SAVAZZI,
(1 988): Taxonomic revision of Mauryna bellardi and Chedevillia begiati (strombid gastropods) from theMiddle Eocene of NE Italy. - Palaont. Z. 62. (in prep.): Taxonomic revision of Tibia and related genera (strombid gastropods) from the Paleogene of NE Italy. VoKES,
H. E. & VOKES, E. H. (1 968): Variation in the genus Orthaulax (Mollusca: Gastro poda).- TulaneStud. Geol., 6: 71 -79.
WENZ, W.
(1 940): Gastropoda. Allgemeiner Teil und Prosobranchia. Teil 4.- [In:] SCHIN H. (ed.): Handbuch der Palaozoologie, 6 (1 938-1 944): 721- 960; Berlin.
DEWOLF, 0.
P. (1 923): Tertiary mollusks of the genus Orthaula>; from the Republic of Haiti, Porto Rico and Cuba.- Proc. U.S. NationalMus., 64:1-1 2.
WooDRING, W.
(1 928): Miocene mollusks from Bowden,Jamaica. Part 2: gastropods and discussion of results. - Carnegie Inst. Washington Pub!., 385: 1-564. Bei der Ti.ibinger Schriftleitung eingegangen am 6. J uni1988. A n s c h r i f t d e s V e r f a s s e r s: Dr.EN RI CO SAVAZZI, Paleontologiska Institutionen,Box558,S-751 22Uppsala,Schweden.
