THE NEOGENE VOLUTIDAE (GASTROPODA: NEOGASTROPODA ...

J. Paleont., 81(1), 2007, pp. 82–102 Copyright 䉷 2007, The Paleontological Society 0022-3360/07/0081-82$03.00

THE NEOGENE VOLUTIDAE (GASTROPODA: NEOGASTROPODA) FROM THE PACIFIC COAST OF CHILE SVEN N. NIELSEN

AND

DANIEL FRASSINETTI

GeoForschungsZentrum Potsdam, Sektion 3.1, Telegrafenberg, 14473 Potsdam, Germany, ⬍[email protected]⬎ and Museo Nacional de Historia Natural, Casilla 787, Santiago, Chile, ⬍[email protected]⬎ ABSTRACT—Fourteen species of Volutidae are recognized from the Neogene of central to southern Chile. Seven species are known from previous descriptions: Voluta triplicata, V. alta, V. domeykoana, V. obesa, V. vidali, Proscaphella taverai, and Adelomelon reconditus. A neotype is designated for Voluta alta. Proscaphella gracilior, type species of the genus Proscaphella, is considered to belong to the genus Miomelon, which places Proscaphella in synonymy with Miomelon. Most species of ‘‘Proscaphella,’’ excluding the type species, form a separate group well distinguished from Miomelon, and for these the new genus Palaeomelon is introduced with Voluta triplicata as type species. Seven new species are reported: Palaeomelon tucapeli, Palaeomelon angoli, Adelomelon colocoloi, Adelomelon caupolicani, Miomelon lautaroi, Miomelon? pelantaroi, and Pachycymbiola? galvarinoi. Voluta triplicata, V. domeykoana, and Proscaphella taverai are included in Palaeomelon n. gen., Voluta obesa and V. alta are referred to Adelomelon, and Voluta vidali is referred to Pachycymbiola. The fossil record of the Recent volute genera Miomelon and Pachycymbiola extends back into the Miocene, Adelomelon is known from the Late Eocene, while Palaeomelon is known in Chile only from the Miocene. Species are morphologically very similar among genera, and from this it is inferred that separation of genera probably occurred in the late Paleogene.

2004; del Rıó and Martıńez, 2006) and those reported here from Chile. Today, about five species of Adelomelon, four species of Miomelon, two species of Pachycymbiola, and five species of Odontocymbiola are recognized (Weaver and duPont, 1970; Leal and Bouchet, 1989; Dell, 1990; Poppe and Goto, 1992), all of which live off southern South America.

INTRODUCTION

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one of the better-known groups of gastropods from the Chilean Neogene because specimens are usually large. For a long time, the only species known were those described by Sowerby (1846) and Philippi (1887, 1897). About a century later, Stuardo and Villarroel (1974) reviewed the genera Miomelon Dall, 1907 and Proscaphella Ihering, 1907 and described a new Recent species of Miomelon and a new fossil species of Proscaphella, both from Chile. These authors, however, did not see the close relationship between Proscaphella gracilior (Ihering, 1896), type species of Proscaphella, and the Recent species of Miomelon. Only recently was a Cenozoic volute from Chile, Adelomelon reconditus Frassinetti, 2000, included in a modern genus. In Argentina, Adelomelon pilsbryi (Ihering, 1899) had been described from the Early Miocene of Patagonia and two additional species of Adelomelon Dall, 1906, A. posei and A. valdesiense, were described recently by Scarabino et al. (2004) from the Patagonian Late Eocene and early Late Miocene, respectively. In Chile, volutes are also known from the formerly Atlantic part of southern Chile near Chile Chico (Frassinetti and Covacevich, 1999). The preservation of this material, however, is not good enough for generic and specific determination [but see del Rıó and Martıńez (2006) for a revision of the fossil South American Atlantic Volutidae]. Modern volutes have been revised at various times (e.g., Clench and Turner, 1964; Weaver and duPont, 1970; Darragh, 1988; Poppe and Goto, 1992), yet relationships between and within different groups remain poorly known. Based on anatomical data, Riedel (2000) considered Volutidae Rafinesque, 1815 in its traditional grouping as paraphyletic and raised the Athletinae Pilsbry and Olsson, 1954 to family status. All South American volutes belong to the subfamilies Zidoninae H. and A. Adams, 1853 and Odontocymbiolinae Clench and Turner, 1964, however. Species of the odontocymbioline Odontocymbiola Clench and Turner, 1964 are often conchologically inseparable from species of the zidonine Adelomelon (see Leal and Bouchet, 1989) and fossil species included in the latter may actually belong in the former genus. Odontocymbiola lives only on the Atlantic side of South America and can be expected to be found in the fossil record of Argentina. The fossil record of the genera discussed here is poorly known and consists of the species reported from Argentina (e.g., Ihering, 1907; Scarabino et al., OLUTES ARE

GEOLOGY OF FOSSIL-BEARING LOCALITIES

Neogene sediments are known from a limited number of basins along the Chilean Pacific coast (see Martıńez-Pardo, 1990). The northern basins very seldom have aragonitic shells preserved, so that the here reported specimens all come from central to southern Chilean localities (Figs. 1, 2). The Navidad, Ranquil, and Lacui Formations are time-equivalent (Finger et al., 2003, in press) and have been synonymized as Navidad Formation by Martıńez-Pardo (1990). However, the regional formation names are maintained here, because the units are geographically well separated. Navidad Formation.⎯Philippi (1887) used the term ‘‘Navidad’’ for a relatively large area around the village of Navidad and it is not clear from where exactly his fossils came. The locality ‘‘Matanzas’’ was given by Philippi (1887) as being 5 km from Navidad, south of a small river which ends at Matanzas. The Matanzas locality, as used here, is situated at the base of coastal cliffs about 1 km north of the village of Matanzas. A fossiliferous bed is exposed on the coastal platform and underlies more than 30 m alternating sandstones and siltstones (Frassinetti and Covacevich, 1981, 1993) (Fig. 2.1.7); another small fossiliferous lens of pale green sandstone is situated about 2 m higher in the same section and contains a similar fauna (Fig. 2.1.6). Punta Alta is situated at the coastal cliff just below the road between Navidad and Matanzas. The fossiliferous lens consists of grey siltstone (Frassinetti and Covacevich, 1982) (Fig. 2.1.5). Altos de Rapel is immediately north of the mouth of the Rapel River. This locality consists of fine-grained sandstone at the base of a coastal cliff (Fig. 2.1.2). Further north, to the north of a granite outcrop, fallen blocks were sampled (Fig. 2.1.1), that probably were derived from different beds within the cliff. Punta Perro has been used by Covacevich and Frassinetti (1986) for sandstone at the base of the coastal cliff immediately south of the mouth of the Rapel River. Nielsen (2003) distinguished several localities at Punta Perro and separated grey siltstone of the coastal platform (Fig. 2.1.3) from overlying orange82

NIELSEN AND FRASSINETTI—NEOGENE VOLUTIDAE OF CHILE

FIGURE 1—Geographic distribution of Chilean Neogene deposits containing volutes and geographic range of Neogene Volutidae. A.: Adelomelon; M.: Miomelon; Pach.: Pachycymbiola; Pal.: Palaeomelon. For localities within shaded areas see details in Figure 2–4.

brown to yellowish sandstone (Fig. 2.1.4). The latter coincides with the locality cited by Covacevich and Frassinetti (1986). South of Matanzas, gray fractured siltstone constitutes the locality Pupuya of Covacevich and Frassinetti (1986).

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All these localities coincide with the coastal cliffs described by Tavera (1979) as belonging to the Navidad Member, the basal Member of the Navidad Formation, which he considered lower to middle Miocene. Encinas et al. (2006) raised the three Members to formation rank, so homonymy between the Navidad Member and Navidad Formation was eliminated. The localities sampled probably represent different stratigraphic levels within the Navidad Formation. Faunas of different ecological environments within the Navidad Formation have been reported by Nielsen (2003) and Nielsen et al. (2003), who distinguished a shallowwater fauna within brown sandstone and a deepwater fauna found in grey siltstone. However, displacement of sediment into a deepwater basin is indicated by sedimentological structures (Encinas et al., 2003) and microfossils of mixed depths (Finger et al., 2003, in press). Some mollusks can be correlated to well-dated latest Oligocene to middle Miocene sequences in southern Peru (DeVries and Frassinetti, 2003) and might have been reworked from older sediments (Nielsen et al., 2003; Finger et al., 2003, in press). The localities presented here represent both shallow-water and deepwater faunas and appear to be contemporaneous as all have been dated as Late Miocene based on planktic foraminifera (Ibaraki, 1992; Finger et al., 2003, in press). The Navidad Formation as used here is the most representative, well-studied, and fossiliferous part of the Navidad Formation sensu Tavera (1979). Ranquil Formation, Arauco.⎯Philippi (1887) noted that his locality ‘‘Lebu’’ is close to the city of this name. However, both Eocene and Miocene sediments are known from that area (Garcıá, 1968; personal obs.) and the exact localities of Philippi’s fossils are largely unknown. Material from the Ranquil Formation, like the Navidad Formation, is Late Miocene in age (Finger et al., 2003, in press) and shows the same sediment-related depth distribution as in the Navidad Formation. The newly found specimens come from Caleta Ranquil and from Punta El Fraile. Caleta Ranquil is the type locality of the formation and specimens come from reddish-brown sandstone with intercalated green glauconitic beds (Fig. 2.2.4) and grey siltstone (Fig. 2.2.3). At Punta El Fraile, two different lithological units can be distinguished. A grey siltstone unit (Fig. 2.2.1) is exposed along today’s intertidal platform but is often covered by sand. Concordantly overlying it is a reddish brown sandstone unit (Fig. 2.2.2). Both lithological units were dated as Late Miocene by Finger et al. (2003, in press). Mocha Island.⎯Mocha Island is located some 84 km south of Lebu, 35 km from the coast opposite the town of Tiruá. Tavera and Veyl (1958) recognized a marine complex, highly fossiliferous in the upper levels, which forms almost the whole island and its coast (Fig. 3.1). This marine complex consists of very fine sandstone with intercalations of mudstone and was assigned to the Miocene Ranquil Formation of the nearby Arauco Peninsula (Tavera and Veyl, 1958). Those authors additionally described a sedimentary sequence of little exposure underlying the sequence just described. This lower unit crops out at Punta Torrecillas (Faro Mocha Oeste) and also was assigned to the Miocene Navidad Formation. A third unit in the southeastern part of the island is composed of marine sandstone and was assigned to the Pliocene. The fauna of Mocha Island is somewhat problematic. Most specimens resemble species known from the Navidad and Ranquil Formations but consistently show minor differences. The fauna in general seems to be slightly younger than that of Navidad-equivalent beds but no reliable dates are available. Lacui Formation, Chiloe´.⎯The localities given by Philippi (1887, 1897) for Chiloe´ are much better defined than those near Navidad or Arauco. He first reported volutid specimens from the Bay of Ancud and Huin˜imo´ at the mouth of the Nal River (Philippi, 1887) and later received material containing volutes from the southwestern part of Chiloe´ (Philippi, 1897).

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FIGURE 2—Volute-bearing fossiliferous localities (appendices 1, 2) of the (1) Navidad, (2) Ranquil, and (3) Lacui Formations; for location of the detail maps see Figure 1. Navidad localities: 1 ⫽ RAP; 2 ⫽ ARA/191077.4; 3 ⫽ PPP; 4 ⫽ PPN/240277.1/140976.6; 5 ⫽ PTA/251080.2/150976.2; 6 ⫽ MAT; 7 ⫽ MAP/150976.8; 8 ⫽ 261080.1. Ranquil localities: 1 ⫽ FRM; 2 ⫽ FRA; 3 ⫽ RQT; 4 ⫽ RAN. Lacui localities: 1 ⫽ CHO; 2 ⫽ PCT; 3 ⫽ CUC.

New material comes from a grey siltstone bed on Chocoi Peninsula (Fig. 2.3.1), opposite the northern coast of Chiloe´, from grey siltstone west of Playa Chaumań (Fig. 2.3.2) on the northern coast, and from a similar siltstone just south of the village of Cucao (Fig. 2.3.3) on the western coast of Chiloe´. Dated localities of the Lacui Formation are Late Miocene in age (Finger et al., 2003, in press), as is the Navidad Formation. Guafo Island.⎯Guafo Island (or Huafo in older literature) is situated to the southwest of Chiloe´ Island at 43⬚37⬘S, 74⬚45⬘W. Frassinetti (1997, 2000) studied the fauna of the fossiliferous coastal platform, which is present mainly in the eastern side of the island. The sampled areas are mainly between Punta Yań˜ez and Punta Caleta and, further to the south, close to Playas Buenas. The deposits consist of grey siltstone in the northern part of Caleta Samuel (Punta Yań˜ez), of yellowish sandstone and siltstone in the southern part (Punta Toro, Estero Chilconal), and of grey siltstone in the area Estero Tres Calles–Punta Caleta. Frassinetti (1997, 2000) suggested a Pliocene age for these deposits based on the gastropods and bivalves encountered, which correlate closely with the molluscan fauna from Guamblıń Island (Frassinetti and Covacevich, 1995) and Tubul (Arauco Peninsula). Stokes, Ipuń, and Lemo islands (Los Chonos Archipelago).⎯The fossiliferous deposits on Stokes Island are situated at the extreme northwestern tip of the peninsula that projects from the western side of the island, opposite the small Lemo Island.

There, fossiliferous silty sandstones and well-cemented finegrained sandstones with concretions crop out in the coastal platform. Ipuń Island is situated opposite Stokes Island (Fig. 3.2). The fossil material comes from grey siltstone and sandstone of the coastal platform at the extreme southeastern tip of the island, the northeastern sector, and the extreme northwest. Lemo Island, like a small promontory, is situated between Ipuń and Stokes islands, closer to the extreme southeast of Ipuń Island. Stokes and Ipuń islands yield a very similar molluscan fauna and their sediments most probably represent the same lithological unit and have the same age. Frassinetti (2001) compared the fauna collected on Stokes Island with that from the Navidad Formation of central Chile. His analysis indicated an Early to Middle Miocene age for the fauna and, therefore, also for the deposits of Ipuń and Lemo islands. The recent study of the fauna of Ipuń Island (Frassinetti, 2004) confirmed the clear similarity of the faunas from Stokes and Ipuń islands. The presence of the nautiloid Aturia sp., ranging from Paleocene to latest Miocene (Kummel, 1964), additionally limits the minimum age of the fauna. Since no studies on Lemo Island are available, we infer a Miocene age for the deposits encountered on the basis of a superficial resemblance of sediments and fauna, and on the geographically intermediate position of this island between Ipuń and Stokes islands.


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FIGURE 3—Volute-bearing fossiliferous localities (appendices 1, 2) on (1) Mocha and (2) Stokes, Ipuń, and Lemo islands; for location of the detail maps see Figure 1. Mocha localities: 1 ⫽ 170693.5/170693.6; 2 ⫽ 170693.7; 3 ⫽ 160693.2; 4 ⫽ 180693.2; 5 ⫽ 170693.8; 6 ⫽ 150693.2. Stokes, Ipuń, and Lemo localities: 1 ⫽ 030984.4; 2 ⫽ 310884.2; 3 ⫽ 041083.4; 4 ⫽ 051083.2/051083.1/310884.1.

Crosslet, Hereford, and Smith islands, San Pablo and Newman fiords (Gulf of Tres Montes).⎯According to Covacevich and Frassinetti (1986), the fossiliferous localities on Hereford Island are situated in the southeastern part of the island (Fig. 4). The lithology of the sediments and their faunal content indicate that it is the same unit as is present in the southeastern part of Crosslet Island. Forsythe et al. (1985) defined the sediments of Crosslet and Hereford islands, the surrounding smaller islands, and the southern coast of Taitao Peninsula to the north of the islands as Chaicayań Group. They studied foraminifera from three samples from this sequence and concluded that the age is Late Miocene. Furthermore, they stated that the foraminifera indicated a temperatewater environment. According to the macrofossils, Covacevich and Frassinetti (1986) proposed a Middle to Late Miocene age for the Chaicayań Group, based on a comparison with the fauna of the Navidad Formation, which they considered as a chronostratigraphic reference section. The upper age limit is given by intruding porphyries which have been dated as Pliocene (Mpodozis et al., 1985). The sediments of the San Pablo and Newman fjords (Fig. 4) are also part of the Chaicayań Group (Forsythe et al., 1985) and have the same lithology and faunal content. The faunal assemblage of the Tres Montes Region resembles that of the Licancheo Member (Navidad Formation) and of a cemented sandstone bed on top of the Ranquil Formation, including species like Oliva rapelensis Tavera, 1979, ‘‘Pyrula’’ exigua Philippi, 1887, Penion macsporrani (Philippi, 1887), and Cancellaria

crossletensis Covacevich and Frassinetti, 1986 (personal obs.). The age is, therefore, slightly younger than that of the typical Navidad Fauna. MATERIAL AND METHODS

Literature is cited in the synonymy lists only if figures are given or new names or combinations are proposed. Pure species lists are not included because it is usually not possible to evaluate whether a name really refers to the respective species. Locality abbreviations of Nielsen (2003) are used as in Figure 2. A list of locality numbers sorted by locality (Appendix 1) and one including the examined specimens housed in the Museo Nacional de Historia Natural, Santiago de Chile, sorted by species (Appendix 2) are given as appendices. Specimens described or mentioned in this study are deposited in the collections of the following museums: BMNH–The Natural History Museum, London, Great Britain; MNHN-LP–Laboratoire de Paleóntologie, Museúm national d’Histoire naturelle, Paris, France; SGO.PI–Departamento de Paleontologıá de Invertebrados, Museo Nacional de Historia Natural, Santiago de Chile; and SMF–Senckenberg Museum, Frankfurt, Germany. Some specimens were coated with MgO prior to photography and presence or absence of coating is indicated in the figure captions. Photographs were taken using a Canon T70 or Leicaflex SL2 camera. Images were scanned from Ilford FP4 125 black and white 35 mm negatives using an Acer ScanWit 2720S film scanner and processed with Adobe Photoshop.

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JOURNAL OF PALEONTOLOGY, V. 81, NO. 1, 2007 by the presence of axial folds and fine spiral sculpture. The species of Palaeomelon are easily separated from those of other genera by their slender shell, spiral threads, and axial ribs, folds, and/ or nodules. The type species of Proscaphella, Voluta gracilior Ihering, 1896 (⫽V. gracilis Philippi, 1887), belongs in Miomelon. Proscaphella has previously been considered a synonym of Miomelon by several authors, including von Ihering himself (Ihering, 1914; Weaver and duPont, 1970; Parodiz, 1996). Since the remaining Chilean species of Proscaphella constitute a well-defined group distinct from Miomelon, a new genus name is required. PALAEOMELON

(Sowerby, 1846) new combination Figure 5.1–5.8

TRIPLICATA

Voluta triplicata SOWERBY, 1846, p. 262, pl. 4, fig. 74; PHILIPPI, 1887, p. 70, pl. 7, figs. 8–10. Adelomelon triplicata (SOWERBY, 1846). DALL, 1907, p. 365. Proscaphella triplicata (SOWERBY, 1846). IHERING, 1907, p. 206; STUARDO AND VILLARROEL, 1974, p. 152–153, fig. 19. Voluta (Proscaphella) triplicata SOWERBY, 1846. TAVERA, 1979, p. 91.

FIGURE 4—Volute-bearing fossiliferous localities of the Tres Montes region (Penas Gulf); for location of the detail map see Figure 1. Locality numbers (appendices 1, 2): 1 ⫽ 060984.4; 2 ⫽ 060984.5; 3 ⫽ 060984.2; 4 ⫽ 060984.1; 5 ⫽ 081083.5; 6 ⫽ 080984.10; 7 ⫽ 081083.4; 8 ⫽ 091083.1/090984.4; 9 ⫽ 031183.10; 10 ⫽ 110984.1; 11 ⫽ 111083.5/110984.2; 12 ⫽ 110984.3; 13 ⫽ 120984.5; 14 ⫽ 091083.3.

SYSTEMATIC PALEONTOLOGY

Family VOLUTIDAE Rafinesque, 1815 Subfamily ZIDONINAE H. and A. Adams, 1853 Genus PALAEOMELON new genus Type species.⎯Voluta triplicata Sowerby, 1846; Miocene, Navidad Formation, Chile. Other species.⎯Voluta domeykoana Philippi, 1887, Proscaphella taverai Stuardo and Villarroel, 1974, Palaeomelon tucapeli n. sp., Palaeomelon angoli n. sp. Diagnosis.⎯Shell fusiform, spire more or less elongate. Protoconch smooth, with calcarella. Teleoconch whorls shouldered. Sculpture of spiral threads and axial ribs or folds, nodules present on or above ribs of some species. Columella with three folds. Etymology.⎯Free combination of palaeo (from the Greek palaios ⫽ old) and the ending of South American volute genus names, –melon. Discussion.⎯The genus Proscaphella was introduced by Ihering (1907) for a group of Argentinian volutes in which also Chilean species were later included (Stuardo and Villarroel, 1974). Ihering (1907) mentioned similarities between Proscaphella and Cymbiola Swainson, 1831 and separated his genus from the latter

Description.⎯Shell fusiform, last whorl and spire of subequal height. Protoconch large, smooth, with tip (calcarella), consisting of about 3.5 whorls, last whorl smaller than previous ones. Teleoconch of about six whorls. Whorls convex, shouldered, broad subsutural ramp shallowly concave. Moderately strong axial ribs beginning on shoulder, becoming obsolete on lower part of whorl. On some specimens, ribs form short stronger folds. Ribs usually forming nodules on shoulderangle. Suture impressed, crenulated by ribs of previous whorl. Sculpture of 16–24 regularly spaced spiral threads on spire whorls, 46–66 flattened spirals on last whorl near aperture. Secondary threads occur very irregularly on some specimens. Interspaces wider or equal to spirals. Last whorl constricted to form short, wide, slightly twisted siphonal canal. Fasciole prominent. Aperture elongate-oval, outer lip thin, smooth on inner side. Columella sinusoidal, with three folds, anterior one, at entrance to siphonal canal, most prominent. Height up to 65 mm. Types.⎯Two syntypes BMNH G.26412 (Navidad, height 53.9 mm, form A, Sowerby, 1846, pl. 4, fig. 74), BMNH G.26413 (Navidad, height 46.4 mm, form A). Type locality is the coast near Navidad, Navidad Formation, Central Chile. Other material examined.⎯SGO.PI.6272 (72 specimens, PPP, forms A and B), SMF 326191 (two specimens, MAT, possibly form B), SMF 326192 (one specimen, MAT, height 31.5 mm, form B), MNHN-LP d’Orbigny collection 10565 (‘‘Fusus subreflexus Sow.,’’ one specimen, Navidad, form not determined), SGO.PI.101, Philippi collection (three specimens, Matanzas, height 62.3 mm, form B), SGO.PI.103, Philippi collection (one specimen, Navidad, height 42 mm, form A), SGO.PI.3725 (one specimen, Matanzas, height 63 mm, form B), SGO.PI.3726 (26 specimens, Matanzas, form B), SGO.PI.5317 (one specimen, Pupuya, form A), SGO.PI.5384 (seven specimens, Punta Alta, form B), SGO.PI.5386 (nine specimens, Punta Alta, form B), SGO.PI.5463 (one specimen, Punta Perro, form B), SGO.PI.5565

→ FIGURE 5—Palaeomelon n. gen. 1–8, Palaeomelon triplicata (Sowerby, 1846). 1, 2, Syntype BMNH G.26412, ‘‘Navidad,’’ Navidad Formation, height 53.9 mm, uncoated. 3, 4, Syntype BMNH G.26413, ‘‘Navidad,’’ Navidad Formation, height 46.4 mm, uncoated. 5, SMF 326192, Matanzas, Navidad Formation, height 31.5 mm, coated. 6–8, SGO.PI.3725, Matanzas, Navidad Formation, height 63 mm, coated. 9–14, Palaeomelon domeykoana (Philippi, 1887). 9, Paralectotype SGO.PI.4556, ‘‘Navidad,’’ Navidad Formation, height 77.5 mm, uncoated. 10, 11, SGO.PI.6038, Pupuya, Navidad Formation, height 13.5 mm, coated. 12, Paralectotype SGO.PI.102, ‘‘Matanzas,’’ Navidad Formation, height 86.5 mm, coated. 13, Lectotype SGO.PI.111, ‘‘Navidad,’’ Navidad Formation, height 86 mm, uncoated. 14, SGO.PI.5426, Mocha Island, probably Ranquil Formation, height 107 mm, coated.


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(two specimens, Rapel Norte, height 58.3 mm, aperture 37 mm, form A), SGO.PI.6349 (nine specimens, RAN, form B). Occurrence.⎯Navidad Formation, Ranquil Formation; Miocene, Central Chile. Discussion.⎯Morphological variability of Palaeomelon triplicata is difficult to estimate. Two forms are apparent, with one (form A) posessing longer, lower ribs and a lower spire than the other (form B). Whether these are morphological endpoints of a variable species or two distinct species could not be resolved with the material available. Palaeomelon triplicata can be distinguished from other species of the genus by its slender shell and elongate axial ribs or folds. PALAEOMELON

(Philippi, 1887) new combination Figure 5.9–5.14

DOMEYKOANA

Voluta domeykoana PHILIPPI, 1887, p. 70, pl. 8, fig. 4. Adelomelon domeykoana (PHILIPPI, 1887). DALL, 1907, p. 365. Proscaphella domeykoana (PHILIPPI, 1887). IHERING, 1907, p. 206; STUARDO AND VILLARROEL, 1974, p. 149–150, figs. 12a–16, 21. Voluta (Proscaphella) domeykoana PHILIPPI, 1887. TAVERA, 1979, p. 91.

Description.⎯Shell fusiform, aperture and spire of subequal height. Protoconch about 2.3 mm high, consisting of 1.75 whorls, smooth, with calcarella. Teleoconch of five to six shouldered whorls. Whorls convex, broad subsutural ramp concave. Blunt nodes on shoulder, 10–13 per whorl, very low ribs below nodes reach lower part of whorls. Suture depressed. Regular flattened primary spiral threads over whole teleoconch, about 22–26 on spire whorls and 65–78 on last whorl. Secondary threads usually not present, appearing very irregularly if present. Interspaces wider or equal to spirals. Last whorl constricted to short, twisted siphonal canal. Fasciole prominent. Aperture elongate-oval, outer lip thin, smooth on interior side. Prominent, well-defined parietal callus on inner lip. Columella sinusoidal, bearing two to three folds, lowermost most prominent, at entrance to siphonal canal. Height up to 110 mm. Types.⎯Lectotype (Stuardo and Villarroel, 1974) SGO.PI.111, Philippi collection (Navidad, height 86 mm), paralectotypes SGO.PI.102, Philippi collection (one specimen, Matanzas, height 86.5 mm), SGO.PI.106, Philippi collection (one specimen, Lebu), SGO.PI.108, Philippi collection (one specimen, Huin˜imo´, Chiloe´), SGO.PI.109, Philippi collection (two specimens, Chiloe´), SGO.PI.110, Philippi collection (one specimen, Quiriquina), SGO.PI.4555 (one specimen, Navidad, transferred here to Pachycymbiola vidali), SGO.PI.4556, Philippi collection (one specimen, Navidad, height 77.5 mm). Type locality is Navidad, Navidad Formation, Central Chile. Other material examined.⎯SGO.PI.6273 (3 specimens, RAP), SGO.PI.4173 (one fragment, Matanzas), SGO.PI.6038 (one specimen, Pupuya), SGO.PI.5266 (six specimens, Mocha Island), SGO.PI.5317 (one specimen, Pupuya), SGO.PI.5420 (one specimen, Mocha Island, height 43 mm), SGO.PI.5426 (one specimen, Mocha Island, height 107 mm), SGO.PI.5434 (three specimens, Mocha Island, height 56.7 mm), SGO.PI.6351 (one specimen, PCT), SGO.PI.6350 (two specimens, RAN). Occurrence.⎯Navidad Formation, Ranquil Formation, Mocha Island, Chiloe´; Miocene, central to southern Chile.

Discussion.⎯Stuardo and Villarroel (1974) mixed up some of the collection numbers for their figures. The lectotype figured (fig. 15) is SGO.PI.111, not 113. Figured paralectotypes are SGO.PI.4555 (fig. 16) and 4556 (fig. 14a, b). SGO.PI.4555 is here transferred to Pachycymbiola vidali. Philippi (1887, pl. 8, fig. 4) apparently figured a composite of lectotype SGO.PI.111 and paralectotype SGO.PI.102. Palaeomelon domeykoana differs from P. triplicata in its larger shell, its wider apical angle and therefore less slender spire, and in its rounded nodes below which low ribs continue onto the lower part of the whorl. Specimens from Mocha Island have generally smaller and more rounded nodes. However, they are here provisionally regarded as a variety. One specimen (SGO.PI.5420), also from Mocha Island, has much bigger nodes on the last half whorl. Whether it represents a different species or an injured specimen is unclear. PALAEOMELON

(Stuardo and Villarroel, 1974) new combination Figure 6.1–6.4

TAVERAI

Proscaphella taverai STUARDO AND VILLARROEL, 1974, p. 153–154, figs. 6a, b, 7a, b.

Description.⎯Shell fusiform, aperture and spire of subequal height. Protoconch unknown. Teleoconch of about five whorls. Whorls shouldered, slightly convex, broad subsutural ramp concave. Strong elongate folds on shoulder, 11 on last whorl. Suture adpressed, crenulated by folds of previous whorl. Spiral threads on early spire-whorls, becoming obsolete, restricted to subsutural ramp on later whorls. Interspaces narrower than spirals. Last whorl constricted to form short, almost straight, very wide siphonal canal. Fasciole prominent. Aperture elongate-subquadrate, outer lip thin. Parietal callus not present, replaced by thin, glazing cover. Columella almost straight, bearing three folds, lower two close. Lowest at entrance to siphonal canal. Height up to 80 mm. Types.⎯Holotype SGO.PI.107, Philippi collection (‘‘Voluta domeykoana Phil.,’’ Ranquil near Ancud, height 80 mm), paratype SGO.PI.112, Philippi collection (‘‘Voluta triplicata Sow. ?n. sp.?,’’ Navidad, height 44.3 mm, possibly Philippi, 1887 pl. 7, fig. 10). Type locality is Ranquil near Ancud, Chiloe´, Miocene, southern Chile. Other material examined.⎯SGO.PI.3727 (one specimen, Matanzas). Occurrence.⎯Navidad Formation, Chiloe´; Miocene, central and southern Chile. Discussion.⎯Palaeomelon taverai is easily separated from other species by the presence of spiral sculpture on the subsutural ramp but its absence from the rest of the whorl. Furthermore, axial sculpture is more prominent and the spire is more steplike than in other species. PALAEOMELON TUCAPELI new species Figure 6.5–6.10, 6.13–6.15 Diagnosis.⎯Shell slender, fusiform. Protoconch of two whorls, large, smooth, with calcarella. Teleoconch whorls shouldered, moderately strong nodes on shoulder, low ribs developed on some specimens. Sculpture of rounded spiral cords and secondary →

FIGURE 6—Palaeomelon n. gen. 1–4, Palaeomelon taverai (Stuardo and Villarroel, 1974). 1, 2, Holotype SGO.PI.107, ‘‘Ranquil near Ancud,’’ Lacui Formation, height 80 mm, uncoated. 3, 4, Paratype SGO.PI.112, ‘‘Navidad,’’ Navidad Formation, height 44.3 mm, uncoated. 5–10, 13–15, Palaeomelon tucapeli n. sp. 5–7, Holotype SGO.PI.6039, San Pablo Fiord, Chaicayań Group, height 76.3 mm, coated. 8, 9, Paratype SGO.PI.6040, San Pablo Fiord, Chaicayań Group, height 34.6 mm, uncoated. 10, Paratype SGO.PI.6043, San Pablo Fiord, Chaicayań Group, height 81.4 mm, coated. 13–15, two specimens from lot SGO.PI.6046, San Pablo Fiord, Chaicayań Group. 13, 15, Height 34.2 mm, coated. 14. Height 96 mm, coated. 11, 12, 16, 17, Palaeomelon angoli n. sp. 11, 12, Holotype SGO.PI.6047, San Pablo Fiord, Chaicayań Group, height 81 mm, coated. 16, 17, Paratype SGO.PI.6049, San Pablo Fiord, Chaicayań Group, height 41.2 mm, uncoated.


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threads. Siphonal canal moderately long, straight. Fasciole prominent. Columella almost straight, bearing three folds. Description.⎯Shell slender, fusiform, moderately large. Aperture slightly higher than spire. Protoconch of two whorls, large (height 4 mm), smooth, with calcarella. Teleoconch of about six shouldered whorls. Broad subsutural ramp concave to convex. Moderately strong nodules on shoulder, sometimes reaching as low ribs onto lower side of whorl. Suture slightly depressed and clearly below periphery of previous whorl. Regular, rounded spiral cords over whole teleoconch, 30–40 on last whorl, secondary threads occur on some specimens. Interspaces wider than spirals. Last whorl constricted to form moderately long, straight siphonal canal. Fasciole prominent. Aperture elongate-oval, outer lip unknown. Parietal callus moderately developed. Columella relatively straight, bearing three folds, uppermost fold weak. Height up to 100 mm. Etymology.⎯After Tucapel, chief of the Mapuche during the war against the Spaniards under the command of Pedro de Valdivia. Types.⎯Holotype SGO.PI.6039 (San Pablo Fiord, height 76.3 mm), paratypes SGO.PI.6040 (San Pablo Fiord, height 34.6 mm), SGO.PI.6041 (San Pablo Fiord, height 22.5 mm), SGO.PI.6042 (San Pablo Fiord, height 74.1 mm), SGO.PI.6043 (San Pablo Fiord, height 81.4 mm). Type locality is San Pablo Fiord, Tres Montes region, ?Miocene, southern Chile. Other material examined.⎯SGO.PI.6044 (three specimens, San Pablo Fiord), SGO.PI.6045 (two specimens, San Pablo Fiord, height 65 mm), SGO.PI.6046 (four specimens, Newman Fiord, height 96 mm). Occurrence.⎯Tres Montes region, ?Miocene, southern Chile. Discussion.⎯Palaeomelon tucapeli can be differentiated from most other species by its high, slender spire. It differs from P. triplicata by its shorter nodes, and the suture of P. triplicata runs across the ribs or folds of the previous whorl, while in P. tucapeli it clearly runs below them. PALAEOMELON ANGOLI new species Figure 6.11, 6.12, 6.16, 6.17 Diagnosis.⎯Shell elongate-oval to fusiform. Protoconch of 2.5 whorls, large, smooth, with calcarella. Teleoconch whorls shouldered, moderately strong, with short ribs on shoulder. Spiral sculpture of rounded cords and secondary threads. Siphonal canal presumably short and wide. Fasciole weak. Columella slightly bent, bearing three folds. Description.⎯Shell elongate-oval to fusiform, aperture clearly higher than spire. Protoconch of 2.5 whorls, large (height 5 mm, diameter 4 mm), smooth, with calcarella. Teleoconch of about 5.5 whorls. Whorls shouldered, moderately strong, with short ribs on shoulder that reach lower part of whorl of some specimens. Suture slightly depressed. Regular, rounded spiral cords over whole teleoconch, 44–57 on last whorl, secondary threads present on some specimens. Interspaces wider than spirals. Last whorl constricted to form presumably short, slightly twisted, wide siphonal canal. Fasciole weak. Aperture elliptical. Columella slightly bent, bearing three folds, uppermost obsolete on some specimens. Height up to 85 mm. Etymology.⎯After Angol, chief of the Mapuche during the war against the Spaniards under the command of Pedro de Valdivia. Types.⎯Holotype SGO.PI.6047 (San Pablo Fiord, height 81 mm), paratypes SGO.PI.6048 (San Pablo Fiord, height 68 mm), SGO.PI.6049 (San Pablo Fiord, height 41.2 mm). Type locality is San Pablo Fiord, Tres Montes region, ?Miocene, southern Chile. Other material examined.⎯SGO.PI.6050 (two specimens, San Pablo Fiord), SGO.PI.6051 (two specimens, San Pablo Fiord). Occurrence.⎯Only known from type locality.

Discussion.⎯Palaeomelon angoli differs from P. tucapeli n. sp. and P. triplicata by a less slender shell and its less prominent axial sculpture. Palaeomelon domeykoana has more convex whorls, and has rounded nodes instead of ribs or folds. Genus ADELOMELON Dall, 1906 Adelomelon DALL, 1906, p. 143; CLENCH AND TURNER, 1964, p. 151– 167; WEAVER AND DUPONT, 1970, p. 102–107; POPPE AND GOTO, 1992, p. 23, 108–114. Janeithoe PILSBRY AND OLSSON, 1954, p. 295 (type species Voluta beckii BRODERIP, 1836).

Type species.⎯Voluta ancilla Lightfoot, 1786 by original designation; Recent, southern Chile to Argentina. ADELOMELON

OBESA

(Philippi, 1887) new combination Figure 7

Voluta obesa PHILIPPI, 1887, p. 69, pl. 8, fig. 3. Proscaphella obesa (PHILIPPI, 1887). STUARDO AND VILLARROEL, 1974, fig. 9.

Description.⎯Shell elongate-oval to barrel-shaped, aperture about twice height of spire. Protoconch unknown. Teleoconch of about six whorls. Whorls convex, broad subsutural ramp slightly concave. Moderately strong, elongate nodes on shoulder present, hinted at, or absent. Suture slightly depressed. Numerous rounded spiral cords present over whole teleoconch, secondary threads present on some specimens. Interspaces equal or narrower to spirals. Last whorl constricted to form slightly twisted, wide siphonal canal. Fasciole prominent. Aperture elongate-oval. Columella slightly bent, bearing three folds. Well-defined parietal callus present. Height up to 140 mm. Type material.⎯Six syntypes. SGO.PI.858 (Huin˜imo´, internal mold), SGO.PI.859 (Ancud, internal mold, catalogued as type of Serpula chiloensis Philippi, 1887), SGO.PI.866 (Ancud, internal mold), SGO.PI.869 (Ancud, internal mold), SGO.PI.870 (Ancud, internal mold), SGO.PI.871 (Fondo del Estero Nal, Huin˜imo´, Chiloe´, height 125 mm). Because attribution of internal molds is difficult to impossible, SGO.PI.871 is here designated as lectotype. Type locality is Huin˜imo´, Chiloe´, Miocene, southern Chile. Other material examined.⎯SGO.PI.6275 (two specimens, PCT, heights 114 mm and 112 mm), SGO.PI.5566 (one specimen, Rapel Norte), SGO.PI.6021 (one specimen, Mocha Island), SGO.PI.6022 (one specimen, Lemo Island, height 90 mm), SGO.PI.6023 (one specimen, Lemo Island), SGO.PI.6024 (one specimen, Lemo Island). Occurrence.⎯Navidad Formation, Mocha Island, Chiloe´, Lemo Island; Miocene, central to southern Chile. Discussion.⎯Adelomelon obesa is easily recognized due to the distinctive nodes on its shoulder and the barrel-shaped shell. ADELOMELON COLOCOLOI new species Figure 8.1–8.9 Diagnosis.⎯Shell elongate-oval. Spire concave, whorls weakly shouldered. Low elongate nodes present or absent. Sculpture of rounded spiral cords. Straight, wide siphonal canal. Fasciole weak. Upper half of columella concave, straight below, with two columellar folds. Description.⎯Shell elongate-oval, aperture more than twice as high as spire. Protoconch always eroded, seems to be scaphelloid. Teleoconch of about five whorls. Spire concave, whorls weakly shouldered, slightly convex. Low, elongate nodes on shoulder present or absent. Suture slightly depressed. Rounded spiral cords on early spire-whorls, becoming obsolete, restricted to subsutural ramp on later whorls. Interspaces equal to wider than spirals. Last whorl weakly constricted, passing into straight, wide siphonal canal. Fasciole weak. Aperture high, elliptical. Upper half of columella concave, straight below, bearing two folds. Parietal callus layer present. Height up to 120 mm.


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FIGURE 7—Adelomelon obesa (Philippi, 1887). 1, 2, Lectotype SGO.PI.871, ‘‘Fondo del Estero Nal, Huin˜imo´, Chiloe´,’’ Lacui Formation, height 125 mm, coated. 3, 4, SGO.PI.6022, Lemo Island, height 90 mm, coated.

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FIGURE 8—Adelomelon Dall, 1906. 1–9, Adelomelon colocoloi n. sp. 1–3, Holotype SGO.PI.6025, Crosslet Island, Chaicayań Group, height 52.5 mm, coated. 4, Paratype SGO.PI.6027, Crosslet Island, Chaicayań Group, height 54.4 mm, coated. 5, 9, Paratype SGO.PI.6030, Crosslet Island, Chaicayań Group, height 59.2 mm, coated. 6, 8, Paratype SGO.PI.6029, Crosslet Island, Chaicayań Group, height 114.5 mm, coated. 7, Paratype SGO.PI.6026, Crosslet Island, Chaicayań Group, height 34 mm, uncoated. 10–13, Adelomelon reconditus Frassinetti, 2000. Holotype SGO.PI.5844, Guafo Island, height 56.7 mm, uncoated.

NIELSEN AND FRASSINETTI—NEOGENE VOLUTIDAE OF CHILE Etymology.⎯After the Mapuche-chief (Toqui) Colo-Colo. Types.⎯Holotype SGO.PI.6025 (Crosslet Island, height 52.5 mm), paratypes SGO.PI.6026 (Crosslet Island, height 34 mm), SGO.PI.6027 (Crosslet Island, height 54.4 mm, aperture 41 mm), SGO.PI.6028 (Crosslet Island, height 96 mm), SGO.PI.6029 (Crosslet Island, height 114.5 mm, aperture 92 mm), SGO.PI.6030 (Crosslet Island, height 59.2 mm, aperture 46 mm). Type locality is Crosslet Island, Miocene, southern Chile. Other material examined.⎯SGO.PI.6031 (one specimen, Crosslet Island), SGO.PI.6032 (two specimens, Crosslet Island), SGO.PI.6033 (one specimen, Crosslet Island), SGO.PI.6034 (two specimens, Crosslet Island), SGO.PI.6035 (one specimen, Smith Island, height 58 mm), SGO.PI.6036 (one specimen, Hereford Island), ?SGO.PI.6037 (one specimen, San Pablo Fiord, height 94.2 mm). Occurrence.⎯Crosslet Island, Smith Island, ?San Pablo Fiord; Miocene, southern Chile. Discussion.⎯Adelomelon colocoloi most resembles A. obesa, but differs from it by its more slender shell, concave spire, less well-defined siphonal canal, higher aperture, and generally lessdeveloped axial sculpture. However, some specimens of A. obesa also have reduced axial sculpture. Adelomelon colocoloi resembles species of Ericusa H. and A. Adams, 1858, but differs in having well-developed spiral sculpture. Species of Ericusa bear three well-developed columellar folds and some species have an additional one or weaker folds (Darragh, 1988) while A. colocoloi consistently has only two columellar folds. ADELOMELON

ALTA

(Sowerby, 1846) new combination Figure 9.1, 9.2

Voluta alta SOWERBY, 1846, p. 262, pl. 4, fig. 75; PHILIPPI, 1887, p. 69, pl. 7, fig. 6 (from Sowerby).

Diagnosis.⎯Shell large, elongate, slender. Spire and aperture of equal height. Protoconch of 2.5 smooth whorls, with calcarella. Teleoconch of six strongly convex whorls. Sculpture of 25–30 rounded primary spiral cords and additional subequal secondary threads. Siphonal canal not well defined. Fasciole weak. Aperture long, narrow. Columella subsinusoidal with three to four folds. Description.⎯Shell large, elongate, slender. Aperture and spire of subequal height. Protoconch of 2.5 whorls, relatively small (height 3 mm, diameter 2 mm), smooth, with calcarella. Last whorl smaller than previous ones. Teleoconch of six strongly convex whorls. Subsutural ramp adpressed, moderately wide, beginning below periphery. No axial sculpture. Spiral sculpture of rounded cords, 36–44 on late spire whorls, and secondary threads over whole teleoconch. Interspaces narrower than spirals. Threads slightly displaced by growth increments in some specimens. Last whorl constricted to form poorly defined siphonal canal. Fasciole weak. Aperture high, narrow. Upper half of columella convex, below almost straight, bearing three folds, a weak additional fold present on some specimens. Parietal callus moderate. Height up to 230 mm. Types.⎯The only remaining specimen, G.25287, labeled as Voluta alta in the Darwin collection, Department of Palaeontology, The Natural History Museum, London, has no type status as it is one of the specimens from Argentina that Sowerby (1846, p. 262) mentioned as ‘‘apparently belonging to this species, but considered by M. d’Orbigny as different.’’ The ‘‘only one specimen of this very remarkable shell’’ (Sowerby, 1846, p. 262) must be considered to be lost. A more extensive discussion on the type material of Sowerby (1846) will be published elsewhere. To define Voluta alta in comparison with the new species and also to define its type locality, designation of a neotype seems to be required, following ICZN Article 75.3. SGO.PI.6274 (PPP, height 195 mm; Fig. 9.1, 9.2) agrees well with Sowerby’s composite drawing and description, it comes from

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the type area, ‘‘Navidad,’’ and is here designated as neotype of Voluta alta. The type locality is ‘‘Navidad’’ and is here confined to the intertidal platform at Punta Perro. Navidad Formation, Miocene, central Chile. Other material examined.⎯SGO.PI.6276 (one juvenile specimen, PPN), SGO.PI.6277 (one spire, FRM), ?SGO.PI. 5394 (one specimen, Mocha Island, height 57 mm), ?SGO.PI.5442 (one specimen, Mocha Island, 227 mm). Occurrence.⎯Navidad Formation, Ranquil Formation, ?Mocha Island; Miocene, central Chile. Discussion.⎯According to Sowerby (1846), Voluta alta was introduced for a specimen from Navidad, but only one of the two internal molds from Santa Cruz, Argentina, is present in the collection of The Natural History Museum, London (J. Cooper, personal commun., 2001). This specimen (G.25287), with some adherent shell material preserved, however, was one of those on which Sowerby’s composite and somewhat stylized original drawing was based (Sowerby, 1846, pl. 4, fig. 75). The two specimens from Santa Cruz have no type status under ICZN Article 72.4.1, as Sowerby had doubts that they were conspecific. Philippi (1887) reproduced Sowerby’s figure and reported two more internal molds from Navidad (SGO.PI.868, Nal, Bahıá de Ancud and SGO.PI.872, Navidad), of which one is labeled as coming from Chiloe´. Because of this confusion and the resulting uncertainty about the identity of Voluta alta, a neotype is designated here. Whether the specimens from Mocha Island really belong to the same species remains unclear. The large specimen from Mocha Island is an internal mold, with most characters not visible. Adelomelon alta differs from other species chiefly by its large size, slender shell, and distinctive spire. It is similar to the Recent type species A. ancilla (Lightfoot, 1786), from which it differs in having spiral sculpture also on large adults, while only A. ancilla juveniles show spiral ornament (see Reid and Osorio, 2000, fig. 4f). ADELOMELON CAUPOLICANI new species Figure 9.3–9.8 Diagnosis.⎯Shell slender, fusiform. Whorls weakly shouldered. Ribs moderately strong, absent on last whorl. Spiral sculpture of rounded cords and secondary threads, restricted to ramp on late whorls. Siphonal canal short, almost straight, wide. Fasciole sharply bent, very prominent. Columella slightly concave, bearing three folds. Description.⎯Shell fusiform, moderately large, slender. Aperture slightly higher than spire. Protoconch eroded, probably of about 2.5 whorls. Teleoconch of about 4.5 whorls. Whorls weakly shouldered, convex, subsutural ramp slightly concave. Moderately strong, rounded ribs on shoulder, becoming obsolete to absent on last whorl. Interspaces slightly wider than spirals. Suture adpressed. Regular rounded spiral cords on early whorls, secondary threads present on some specimens, becoming weaker on lower part of later whorls, finally restricted to subsutural ramp. Growth increments on last whorl sometimes prominent and forming lamellae. Last whorl constricted, passing into almost straight, short, wide siphonal canal. Fasciole very prominent, sharply bent, forming pseudumbilicus. Aperture elongate-oval, posterior notch present. Columella slightly concave, bearing three folds, uppermost obsolete in some specimens. Height up to 90 mm. Etymology.⎯After Caupolicań, historical chief of the Mapuche. Types.⎯Holotype SGO.PI.6052 (San Pablo Fiord, height 61 mm), paratypes SGO.PI.6053 (San Pablo Fiord, height 72 mm), SGO.PI.6054 (San Pablo Fiord, height 61 mm), SGO.PI.6055 (San Pablo Fiord), SGO.PI.6056 (San Pablo Fiord), SGO.PI.6057 (San Pablo Fiord, height 48 mm). Type locality is San Pablo Fiord, Tres Montes region, Miocene, southern Chile.

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FIGURE 9—Adelomelon Dall, 1906. 1, 2, Adelomelon alta (Sowerby, 1846). Neotype SGO.PI.6274, Punta Perro, Navidad Formation, height 195 mm, coated. 3–8, Adelomelon caupolicani n. sp. 3, 4, Holotype SGO.PI.6052, San Pablo Fiord, Chaicayań Group, height 61 mm, coated. 5, Paratype SGO.PI.6053, San Pablo Fiord, Chaicayań Group, height 72 mm, coated. 6, Paratype SGO.PI.6057, San Pablo Fiord, Chaicayań Group, height 48 mm, coated. 7, 8, Paratype SGO.PI.6054, San Pablo Fiord, Chaicayań Group, height 61 mm, coated.

NIELSEN AND FRASSINETTI—NEOGENE VOLUTIDAE OF CHILE Other material examined.⎯?SGO.PI.6058 (two specimens, San Pablo Fiord), SGO.PI.6059 (one specimen, Crosslet Island). Occurrence.⎯San Pablo Fiord, Crosslet Island; Miocene, southern Chile. Discussion.⎯Adelomelon caupolicani can be separated from other species by its sharply bent, very prominent fasciole. Adelomelon reconditus Frassinetti, 2000 has fewer whorls, a larger protoconch, and weaker axial sculpture. Adelomelon alta is much larger and has spiral sculpture on the whole whorl, also developed in adults. ADELOMELON

RECONDITUS Frassinetti, 2000 Figure 8.10–8.13

Adelomelon reconditus FRASSINETTI, 2000; p. 144, pl. 2, figs. 11, 12.

Diagnosis.⎯Shell elongate-oval, moderately large, spire relatively low. Spire whorls slightly angled. Spiral ornamentation of numerous rounded threads, regularly distributed on shell surface. Small, low, inconspicuous nodes on middle of spire-whorls, continuing on last whorl, corresponding with slight angulation of whorls. Siphonal canal short, straight. Fasciole moderate. Columella straight, with two to three folds. Description.⎯Shell of moderate size, elongate-oval. Protoconch of 2.5 whorls, relatively large (height 5.5 mm, diameter 5 mm), smooth, with calcarella. Aperture and spire of subequal height. Whorls slightly angled, bearing small, low nodes on angulation, on last whorl reduced to swellings. Numerous regularly spaced rounded spiral cords over whole teleoconch surface. Interspaces narrower than or equal to spirals. Aperture high, narrow. Columella straight, bearing two to three folds. Height up to 60 mm. Types.⎯Holotype SGO.PI.5844 (Guafo Island, height 56.7 mm). Type locality is Guafo Island, Pliocene, southern Chile. Other material examined.⎯SGO.PI.5845 (Guafo Island), SGO.PI.5846 (Guafo Island). Occurrence.⎯Only known from type locality. Discussion.⎯This is the smallest species of Adelomelon in Chile. Since most species of Adelomelon have relatively large shells, the specimens may not represent adults. Adelomelon reconditus has a larger protoconch than A. caupolicani n. sp. and bears spiral sculpture also on later whorls, whereas it is only present on spire whorls on A. caupolicani. Adelomelon alta also has spiral sculpture on later whorls, but differs from A. reconditus in having a clearly smaller protoconch and no axial sculpture. Genus MIOMELON Dall, 1907 Adelomelon (Miomelon) DALL, 1907, p. 365. Proscaphella IHERING, 1907, p. 100, 202, 205 (type species Proscaphella gracilior Ihering, 1896); STUARDO AND VILLARROEL, 1974, p. 148– 154. Miomelon DALL, 1907. WENZ, 1943, p. 1350, text-fig. 3823; PILSBRY AND OLSSON, 1954, p. 289; WEAVER AND DUPONT, 1970, p. 131–133; STUARDO AND VILLARROEL, 1974, p. 140–146; DELL, 1990, p. 212– 216; POPPE AND GOTO, 1992, p. 26, 122–125.

Type species.⎯Volutilithes philippiana Dall, 1890 by original designation; Recent, Chile. MIOMELON GRACILIS (Philippi, 1887) Figure 10.2–10.3 Voluta gracilis PHILIPPI, 1887, p. 70, pl. 7, fig. 13 not of Dillwyn, 1823, nor of Swainson, 1824, nor of Wood, 1828. Voluta gracilior IHERING, 1896, p. 96 nom. nov. Proscaphella gracilior (IHERING, 1896). IHERING, 1907, p. 206. Adelomelon gracilior (IHERING, 1896). DALL, 1907, p. 365. Cymbiola (Miomelon) gracilior (IHERING, 1896). IHERING, 1914, p. 110. Miomelon gracilior (IHERING, 1896). PARODIZ, 1996. p. 227. Miomelon gracilior (IHERING, 1896). DEL RıÓ AND MART´ıNEZ, 2006. p. 934, figs. 11.1–11.14, 12.7, 12.8, 15.2, 15.3.

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Material examined.⎯Lectotype (Stuardo and Villarroel, 1974) SGO.PI.105, Philippi collection (Santa Cruz, Argentina, height 37 mm). Discussion.⎯Miomelon gracilior comes from Argentina and has been revised by del Rıó and Martıńez (2006). However, the types are figured here for comparison because it is the type species of Proscaphella. The name Voluta gracilior was introduced by Ihering (1896) as a replacement name for the several times preoccupied V. gracilis Philippi, 1887. Voluta dorbignyana (Figure 10.1, 10.4) has shown by del Rıó and Martıńez (2006) to be a separate species distinct from V. gracilior. Voluta dorbignyana is not preoccupied by V. dorbigniana Mu¨ller, 1851 (p. 40, pl. 5, fig. 27 a, b) due to difference in spelling. MIOMELON LAUTAROI new species Figure 10.8–10.13 Diagnosis.⎯Shell biconical. Protoconch of two whorls. Teleoconch whorls convex. Ramp reaching high onto previous whorl. Sculpture of blunt nodes or short axial ribs and flattened spiral cords. Siphonal canal straight, wide. Fasciole weak to prominent. Columella slightly concave, bearing three folds. Description.⎯Shell moderately large, biconical. Spire lower than aperture. Protoconch of two whorls, eroded, small, presumably with calcarella. Teleoconch of five to six whorls. Whorls convex, broad subsutural ramp convex to concave. Subsutural ramp reaching high onto previous whorl, producing an almost straight-sided spire. Prominent blunt nodes or short ribs on periphery, 12–13 per whorl. Regular flattened spiral cords on whole teleoconch surface, about 39–47 on last whorl, secondary threads occur on some specimens. Interspaces narrower than spirals. Last whorl constricted to form straight, wide siphonal canal. Fasciole weak to prominent. Aperture elongate-oval. Parietal callus moderately developed. Columella slightly concave, bearing three folds, lowest strongest, at entrance to siphonal canal. Height up to 70 mm. Etymology.⎯After Lautaro (1535–1557), important toqui (warchief) of the Mapuche who defeated Pedro de Valdivia in the battle of Tucapel in 1553 and remains a symbol of the struggle for freedom of the indigenous peoples of Chile. Types.⎯Holotype SGO.PI.6060 (Crosslet Island, height 45 mm, aperture 27.7 mm), paratypes SGO.PI.6061 (Crosslet Island, height 60 mm), SGO.PI.6062 (Crosslet Island), SGO.PI.6063 (Crosslet Island, height 63 mm), SGO.PI.6064 (Smith Island, height 32 mm). Type locality is Crosslet Island, Miocene, southern Chile. Other material examined.⎯SGO.PI.6065 (one specimen, Hereford Island), SGO.PI.6066 (three specimens, San Pablo Fiord, one of these with eroded protoconch, height 12.7 mm), SGO.PI.6068 (one specimen, San Pablo Fiord, height 26 mm). Occurrence.⎯Crosslet Island, Hereford Island, Smith Island, San Pablo Fiord; Miocene, southern Chile. Discussion.⎯Miomelon lautaroi differs from the Recent type species M. philippiana (Dall, 1890) by having stronger nodes on the periphery. The Recent M. alarconi Stuardo and Villarroel, 1974 has stronger spiral sculpture and axial ribs rather than nodes. Miomelon eltanini Dell, 1990 also has ribs, and M. turnerae Dell, 1990 has an unusual steplike spire. The latter two species live between South America and Antarctica (Dell, 1990). MIOMELON? PELANTAROI new species Figure 10.5–10.7 Diagnosis.⎯Shell oval. Whorls straight-sided, ramp reaching high onto previous whorl. Axial sculpture of elongate nodes with ribs below. Spiral sculpture of flattened primary cords and secondary threads. Fasciole moderately prominent. Columella slightly bent.

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FIGURE 10—Miomelon Dall, 1907. 1, 4, Miomelon dorbignyana (Philippi, 1887), Holotype of SGO.PI.104, ‘‘Santa Cruz,’’ Argentina, height 117 mm, coated. 2, 3, Miomelon gracilior (Ihering, 1896). Lectotype of Voluta gracilis Philippi, 1887, SGO.PI.105, ‘‘Santa Cruz,’’ Argentina, height 37 mm, uncoated. 5–7, Miomelon? pelantaroi n. sp. Holotype SGO.PI.6069, Lemo Island, Chaicayań Group, height 60 mm, coated. 8–13, Miomelon lautaroi n. sp. 8, Paratype SGO.PI.6061, Crosslet Island, Chaicayań Group, height 60 mm, coated. 9, 10, SGO.PI.6068, San Pablo Fiord, Chaicayań Group, height 26 mm, coated. 11–13, Holotype SGO.PI.6060, Crosslet Island, Chaicayań Group, height 45 mm, coated.

NIELSEN AND FRASSINETTI—NEOGENE VOLUTIDAE OF CHILE Description.⎯Shell moderately large, oval. Spire half of aperture height. Protoconch and early whorls unknown. Whorls straight-sided, subsutural ramp concave to straight, reaching high onto previous whorl. Spire almost straight-sided. Prominent, elongate nodes on periphery, about 15 per whorl, continuing below as ribs. Regular flattened spiral cords over whole teleoconch, secondary spiral threads occur irregularly. Total number of spirals near aperture about 118. Interspaces narrower than spirals. Fasciole moderately prominent. Aperture elongate-oval. Parietal callus moderately developed. Columella slightly bent, bearing at least two folds. Outer lip and siphonal canal unknown. Height about 45 mm. Etymology.⎯After Pelantaro, cacique (chief) of the Mapuche, who drove the Spaniards out of southern Chile in 1598. Types.⎯Holotype SGO.PI.6069 (Lemo Island, height 38 mm). Type locality is Lemo Island, ?Miocene, southern Chile. Occurrence.⎯Only known from type locality. Discussion.⎯Miomelon? pelantaroi differs from other species of this genus by its globose shell and a combination of nodes and ribs. Due to the hard matrix only one to two columellar folds of the presumed three present are visible. Genus PACHYCYMBIOLA Ihering, 1907 Pachycymbiola IHERING, 1907, p. 209; POPPE AND GOTO, 1992, p. 24, 115–117. Adelomelon (Pachycymbiola) IHERING, 1907. WEAVER AND DUPONT, 1970, p. 107–108.

Type species.⎯Voluta brasiliana Lamarck, 1811 by original designation; Recent, eastern South America. Emended diagnosis.⎯Shell medium to large (up to 185 mm) and heavy, subglobose with depressed spire. Protoconch rather small with blunt apex. Teleoconch smooth or with spiral cords. Nodules to heavy spines present in some species. Last whorl large, with elongate-oval aperture. Columella with two or more folds. Discussion.⎯The diagnosis has been emended to include species with spiral sculpture. PACHYCYMBIOLA

(Philippi, 1897) new combination Figure 11.1–11.5

VIDALI

Voluta vidali PHILIPPI, 1897, p. 366–367, pl. 3, fig. 1. Voluta (Cymbiola) ameghinoi var. TAVERA, VALDIVIA, AND VALENZUELA, 1985, pl. 3, fig. 23. Alcithoe vidali (PHILIPPI, 1897). FRASSINETTI, 2001, p. 83–84, figs. 14– 17.

Description.⎯Shell massive, biconical to subglobose. Aperture about twice as high as spire. Protoconch unknown. Teleoconch of five to six shouldered whorls. Broad concave subsutural ramp. From third teleoconch whorl onwards very strong, long nodes are developed, seven to nine per whorl. Suture adpressed, on early whorls often on nodes of previous whorl. Regular flattened spiral cords over whole teleoconch, 22 to 31 on spire whorls, on later whorls becoming restricted to subsutural ramp, secondary threads occur irregularly. Interspaces equal to slightly narrower than spirals. Aperture elongate-oval. Outer lip thickened, interior smooth, lower half flaring. Posterior notch present. Columella straight, on lower end slightly twisted to the right, bearing two to three folds. Thin to heavy parietal callus present. Last whorl constricted, forming a short, straight, wide, open siphonal canal. Fasciole very prominent, restricted above by ridge. Height up to 125 mm. Types.⎯One syntype SGO.PI.5077 (ex 4848, Chiloe´, height 82 mm). This is the juvenile specimen mentioned by Philippi (1897). The second syntype seems to have been lost. Type locality is Chiloe´, Miocene, southern Chile. Other material examined.⎯SMF 326193 (one specimen, PPN, height 91 mm), SMF 326194 (two specimens, CHO),

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SGO.PI.6278 (seven specimens, CHO), SGO.PI.6279 (five specimens, CUC), SGO.PI.4231 (one specimen, Ipuń Island), SGO.PI.4555 (one specimen, paralectotype of Voluta domeykoana, Navidad), SGO.PI.5233 (one specimen, Punta Alta, height 123 mm), SGO.PI.5234 (two specimens, Punta Perro), SGO.PI.5235 (one specimen, Punta Perro), SGO.PI.5236 (one specimen, Punta Perro, height 101.6 mm), SGO.PI.5237 (one specimen, Stokes Island, height 40 mm), SGO.PI.5238 (one specimen, Stokes Island, height 66.7 mm), SGO.PI.5239–41 (four specimens, Stokes Island), SGO.PI.5242–43 (five specimens, Stokes Island), SGO.PI.6067 (one specimen, Lemo Island, height 30.8 mm), SGO.PI.6348 (two specimens, RAN). Occurrence.⎯Navidad Formation, Ranquil Formation, Chiloe´, Stokes Island, Ipuń Island, Lemo Island; Miocene, central to southern Chile. Discussion.⎯This species is easily recognized by its long, strong nodes and characteristic shell shape. It differs from the type species Pachycymbiola brasiliana (Lamarck, 1811) in the presence of spiral sculpture and much longer nodes. The Tertiary Voluta ameghinoi Ihering, 1896 from Argentina has been included in Pachycymbiola by Parodiz (1996), and differs from P. vidali chiefly by having a much lower spire. Pachycymbiola vidali resembles species of the Australian-New Zealand genus Alcithoe H. and A. Adams, 1853 (see Darragh, 1988). However, species of Alcithoe have four or more columellar folds (Weaver and duPont, 1970), whereas P. vidali has only two to three. PACHYCYMBIOLA? GALVARINOI new species Figure 11.6, 11.7 Diagnosis.⎯Shell massive, fusiform to globose. Whorls shouldered. Nodes with ribs on shoulder. Spiral sculpture of flattened cords. Columella straight, bearing three folds. Description.⎯Shell massive, fusiform to slightly globose. Aperture about twice as high as spire. Protoconch unknown. Teleoconch of about four shouldered whorls. Subsutural ramp concave. Moderately strong nodes on shoulder, reaching as ribs down to half of whorl. Regular flattened spiral cords over whole teleoconch, secondary threads occur irregularly. Interspaces narrower than spirals. Last whorl constricted. Aperture elongate-oval, posterior notch appears to be present. Columella straight, bearing three strong folds. Parietal callus thin, expanded. Outer lip and siphonal canal unknown. Height about 60 mm. Etymology.⎯After Galvarino, chief of the Mapuche. Galvarino fled from Spanish captivity after both his hands were severed, to continue his struggle against the invaders. Type material.⎯Holotype SGO.PI.6070 (Smith Island, height 52 mm). Type locality is Smith Island, ?Miocene, southern Chile. Occurrence.⎯Only known from type locality. Discussion.⎯Pachycymbiola? galvarinoi differs from P. vidali and P. ameghinoi through the absence of strong nodes and the presence of moderately long ribs. DISCUSSION

The disjunct geographic distribution of the Neogene Chilean Volutidae (Fig. 1) resembles that of the Cancellariidae (Covacevich and Frassinetti, 1986) and permits two different interpretations: 1) that an environmental barrier, possibly a high gradient in water temperature, existed between the Penas Gulf and the more northern localities, which made migration for volute species impossible, and 2) that the age of the Penas Gulf deposits differs significantly from that of the northern Miocene localities and no species survived from one time interval to the other. Currently no scenario is favored, because significant differences in sea surface temperature may have been produced by upwelling. Based on faunal similarities, the deposits of Ipuń and Stokes islands can be correlated with those of the Navidad, Ranquil, and Lacui Formations, which would

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FIGURE 11—Pachycymbiola Ihering, 1907. 1–5, Pachycymbiola vidali (Philippi, 1897). 1, 2, Syntype SGO.PI.5077, ‘‘Chiloe´,’’ Lacui Formation, height 82 mm, coated. 3–5, SGO.PI.5236, Punta Perro, Navidad Formation, height 101.6 mm, coated. 6, 7, Pachycymbiola? galvarinoi n. sp. Holotype SGO.PI.6070, Smith Island, Chaicayań Group, height 52 mm, coated.


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TABLE 1—Key to the Chilean Neogene Volutidae. A.: Adelomelon; M.: Miomelon; Pach.: Pachycymbiola; Pal.: Palaeomelon; PW: protoconch whorls; S/A: spire/aperture; S/I: spirals/interspaces. PW

Shell shape

S/A

Whorl profile Axial sculpture

Pal. triplicata

3.5

fusiform

1

convex, shouldered

Pal. domey koana

1.75

fusiform

1

Pal. taverai

?

fusiform

1

Pal. tucapeli

2

fusiform, slender

⬍1

convex, shouldered slightly convex, shouldered shouldered

Pal. angoli

2.5

elongate-oval to fusiform

⬎0.5

shouldered

A. obesa

?

elongate-oval to barrelshaped

⬍1 0.5

convex

A. colocoloi

?

elongate-oval

⬍0.5

A. alta

2.5

elongate, slender

1

A. caupolicani

2.5?

fusiform

A. reconditus

2.5

elongate-oval

M. lautaroi

2

biconical

M.? pelantaroi

?

oval

0.5

straight

Pach. vidali

?

massive, biconical to fusiform

0.5

shouldered

massive, fusiform to slightly globose

0.5

shouldered

Pach.? galvari- ? noi

⬍1

1 ⬍1

slightly convex, weakly shouldered strongly convex convex, weakly shouldered slightly angled convex

S/I

moderately S ⱕ I strong ribs, nodules on shoulder 10–13 blunt S ⱕ I nodes

Siphonal canal

Columella

flattened

Spirals

prominent

Fasciole

short, wide, slightly twisted

sinusoidal, three folds

flattened

prominent

short, slightly twisted

sinusoidal, two to three folds

11 strong elongate folds

S⬎I

?

prominent

short, almost almost straight, straight, three folds very wide

moderately strong nodules moderately strong, short ribs

S⬍I

rounded

prominent

S⬍I

rounded

weak

moderately relatively long, straight, straight three folds short, slight- slightly bent, ly twisted, three folds wide

moderately S ⱖ I strong elongate nodes low elongate S ⱕ I nodes

rounded

prominent

slightly twisted, wide

slightly bent, three folds

rounded

weak

straight, wide

upper half concave, straight below, two folds

absent

S⬎I

rounded

weak

moderate ribs, becoming absent small low nodes 12–13 prominent blunt nodes or short ribs prominentelongate nodes very strong long nodes

S⬍I

rounded

very prominent, pseudumbilicus

long, straight upper half convex, below straight, three folds short, slightly constraight, cave, three wide folds

SⱖI

rounded

moderate

S⬎I

flattened

weak to prominent

S⬎I

flattened

moderately prominent

SⱖI

flattened

very promishort, nent, restrictstraight, ed by ridge wide

S⬎I

flattened

?

nodes and ribs

indicate a latest Miocene age (Finger et al., 2003, in press). However, the mollusk fauna is thought to have an early Miocene age (DeVries and Frassinetti, 2003), which has been confirmed by Finger et al. (in press) and Nielsen and Glodny (2006). The accompanying fauna of the Penas Gulf contains species which are well known from the basal part of the Navidad Formation (Covacevich and Frassinetti, 1986), but some are only known from the superjacent Licancheo Member. The sediments of the Penas Gulf were dated by Forsythe et al. (1985) based on small foraminiferal assemblages. However, the results of a more detailed study by Finger et al. (2003, in press) showed that larger samples are needed to reduce the possibility of dating of reworked foraminifera. A detailed investigation of age-diagnostic foraminifera is needed for the Licancheo Member as well as for the Chaicayań Group of the Penas Gulf to confirm if these units can be correlated. The generic composition of Recent and fossil South American

short, straight straight, wide

straight, two to three folds slightly concave, three folds

?

?

slightly bent, at least two folds straight, slightly twisted, two to three folds straight, three folds

volutes suggests that, unlike in other gastropod groups (Nielsen and DeVries, 2002; Nielsen et al., 2004), no interchange with the Australian-New Zealand Region has taken place since at least the Miocene. This can be best explained by the direct development of most Volutidae; planktonic larvae are usually lacking (Leal and Rios, 1990; Maxwell, 2003). Scarabino et al. (2004) separated Adelomelon and Pachycymbiola through shell outline and protoconch morphology. However, none of their specimens had the protoconch preserved. The Miocene species of Palaeomelon n. gen., Adelomelon, and Miomelon are morphologically very similar to each other (Table 1), leading to the inference that separation of these genera occurred during the late Paleogene. Pachycymbiola, however, is easily distinguished from the other South American volutes. Apart from Volutospina araucana (Tavera, 1942, foto 3, figs. 1–3), the status, age, and taxonomic position of which are not known, there are no other possible Eocene

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volutes known from Chile. However, even though some Eocene faunas or species have been described (Philippi, 1887; Nielsen and Frassinetti, 2003), they remain poorly known. Adelomelon posei has been described by Scarabino et al. (2004) from sediments of Late Eocene through Middle Miocene age. While A. posei certainly has the elevated spire of typical Adelomelon, its strong nodes resemble those of some species of Pachycymbiola. If A. posei should prove to be Eocene it could belong to a group ancestral to species of both genera or an early representative of true Adelomelon. Species of the genus Palaeomelon are known only from the Miocene, suggesting that this genus became extinct when water temperatures became colder during the Miocene. ACKNOWLEDGMENTS

We are indebted to K. Bandel (Universita¨t Hamburg, Germany) for providing working space and facilities to SNN after finishing his doctoral thesis, for a good time in the field, and for fruitful discussions. E. Vinx (Universita¨t Hamburg) and H. Nun˜ez (Museo Nacional de Historia Natural, Santiago, Chile) made photographs of most of the specimens. Special thanks are due to A. G. Beu (Institute of Nuclear and Geological Sciences, New Zealand), who significantly improved the content and language of an earlier version of the manuscript. SNN thanks P. S. Va´squez (Technische Universita¨t Berlin, Germany) for company during field work, her hospitality, and for processing most of the maps. Thorough reviews by J. A. Todd (The Natural History Museum, London, Great Britain), T. A. Darragh (Museum Victoria, Australia), and L. C. Anderson (Louisiana State University, USA) are gratefully acknowledged. Work of SNN during the years 2000 to 2003 was financially supported by the University of Hamburg and grants Ba 675/25 and Ni 699/1 of the Deutsche Forschungsgemeinschaft (DFG). REFERENCES

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1

Locality numbers of the Covacevich–Frassinetti Collection. Bold numbers within one locality indicate the same locality visited on different field trips. Matanzas: 150976.8. Pupuya: 261080.1. Punta Alta: 251080.2; 150976.2. Punta Perro: 240277.1; 140976.6. Rapel Norte: 191077.4. Mocha Island: 150693.2; 170693.5; 170693.6; 170693.8; 170693.7; 160693.2; 180693.2. San Pablo Fiord: 110984.2; 110984.3; 111083.5; 120984.5; 110984.1. Newman Fiord: 091083.3. Lemo Island: 041083.4; 310884.2. Crosslet Island: 080984.10; 081083.5; 091083.1; 081083.4; 060984.1; 060984.2. Smith Island: 060984.4; 060984.5. Hereford Island: 031183.10. Guafo Island: 290884.1; 031083.1; 280884.3. Ipuń Island: 030984.4. Stokes Island: 051083.2; 051083.1; 310884.1. APPENDIX

2

Locality numbers of specimens housed in SGO.PI. Palaeomelon triplicata (Sowerby, 1846) 101—Matanzas: Coll. Philippi. 103—Navidad: Coll. Philippi. 3725—Matanzas: 150976.8. 3726—Matanzas: 150976.8. 5317—Pupuya: 261080.1. 5384—Punta Alta: 251080.2. 5386—Punta Alta: 251080.2. 5463—Punta Perro: 240277.1. 5565—Rapel Norte: 191077.4. 6272—Punta Perro: PPP. 6349—Ranquil: RAN. Palaeomelon domeykoana (Philippi, 1887) 111—Navidad: Coll. Philippi. 102—Matanzas: Coll. Philippi.

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JOURNAL OF PALEONTOLOGY, V. 81, NO. 1, 2007 106—Lebu: Coll. Philippi. 108—Chiloe´: Coll. Philippi. 109—Chiloe´: Coll. Philippi. 110—Quiriquina: Coll. Philippi. 4556—Navidad: Coll. Philippi. 4173—Matanzas: 150976.8. 6038—Pupuya: 261080.1. 5266—Mocha Island: 150693.2. 5317—Pupuya: 261080.1. 5420—Mocha Island: 170693.5. 5426—Mocha Island: 170693.6. 5434—Mocha Island: 170693.8. 6273—North of Rıó Rapel: RAP. 6350—Ranquil: RAN. 6351—Playa Chaumań, Chiloe´: PCT.

Palaeomelon taverai (Stuardo and Villarroel, 1974) 107—Ranquil, Ancud: Coll. Philippi. 112—Navidad: Coll. Philippi. 3727—Matanzas: 150976.8. Palaeomelon tucapeli n. sp. 6039—San Pablo Fiord: 110984.2. 6040—San Pablo Fiord: 110984.2. 6041—San Pablo Fiord: 110984.2. 6042—San Pablo Fiord: 110984.2. 6043—San Pablo Fiord: 110984.3. 6044—San Pablo Fiord: 110984.2. 6045—San Pablo Fiord: 111083.5. 6046—Newman Fiord: 091083.3. Palaeomelon angoli n. sp. 6047—San Pablo Fiord: 6048—San Pablo Fiord: 6049—San Pablo Fiord: 6050—San Pablo Fiord: 6051—San Pablo Fiord:

111083.5. 120984.5. 110984.3. 110984.2. 110984.3.

Adelomelon obesa (Philippi, 1887) 858—Huin˜imo´: Coll. Philippi. 866—Ancud: Coll. Philippi. 869—Ancud: Coll. Philippi. 870—Ancud: Coll. Philippi. 871—Estero Nal: Coll. Philippi. 5566—Rapel Norte: 191077.4. 6021—Mocha Island: 170693.7. 6022—Lemo Island: 041083.4. 6023—Lemo Island: 310884.2. 6024—Lemo Island: 310884.2. 6275—Playa Chaumań, Chiloe´: PCT. Adelomelon colocoloi n. sp. 6025—Crosslet Island: 080984.10. 6026—Crosslet Island: 081083.5. 6027—Crosslet Island: 081083.5. 6028—Crosslet Island: 081083.5. 6029—Crosslet Island: 081083.5. 6030—Crosslet Island: 091083.1. 6031—Crosslet Island: 081083.4. 6032—Crosslet Island: 060984.1. 6033—Crosslet Island: 060984.2. 6034—Crosslet Island: 080984.10. 6035—Smith Island: 060984.4.

6036—Hereford Island: 031183.10. ?6037—San Pablo Fiord: 120984.5. Adelomelon alta (Sowerby, 1846) ?5394—Mocha Island: 160693.2. ?5442—Mocha Island: 180693.2. ?6007—Pupuya: 261080.1. 6274—Punta Perro: PPP. Adelomelon caupolicani n. sp. 6052—San Pablo Fiord: 110984.1. 6053—San Pablo Fiord: 111083.5. 6054—San Pablo Fiord: 111083.5. 6055—San Pablo Fiord: 111083.5. 6056—San Pablo Fiord: 110984.2. 6057—San Pablo Fiord: 110984.2. ?6058—San Pablo Fiord: 110984.2. 6059—Crosslet Island: 080984.10. Adelomelon reconditus Frassinetti, 2000 5844—Guafo Island: 290884.1. 5845—Guafo Island: 031083.1. 5846—Guafo Island: 280884.3. Miomelon dorbignyana (Philippi, 1887) 104—Santa Cruz (Argentina): Coll. Philippi. 105—Santa Cruz (Argentina): Coll. Philippi. Miomelon lautaroi sp. nov. 6060—Crosslet Island: 081083.5. 6061—Crosslet Island: 080984.10. 6062—Crosslet Island: 080984.10. 6063—Crosslet Island: 080984.10. 6064—Smith Island: 060984.5. 6065—Hereford Island: 031183.10. 6066—San Pablo Fiord: 110984.2. 6068—San Pablo Fiord: 120984.5. Miomelon? pelantaroi n. sp. 6069—Lemo Island: 041083.4. Pachycymbiola vidali (Philippi, 1897) 5077—Chiloe´: Coll. Philippi. 231—Ipuń Island: 030984.4. 4555—Navidad: Col. Philippi. 5233—Punta Alta: 150976.2. 5234—Punta Perro: 140976.6. 5235—Punta Perro: 140976.6. 5236—Punta Perro: 140976.6. 5237—Stokes Island: 051083.2. 5238—Stokes Island: 051083.2. 5239—Stokes Island: 051083.1. 5240—Stokes Island: 051083.1. 5241—Stokes Island: 051083.1. 5242—Stokes Island: 310884.1. 5243—Stokes Island: 310884.1. 6067—Lemo Island: 041083.4. 6278—Chocoi Peninsula: CHO. 6279—Cucao, Chiloe´: CUC. 6348—Ranquil: RAN. Pachycymbiola? galvarinoi n. sp. 6070—Smith Island: 060984.5.