Dietotenhosen hupeanus (Philippi, 1887)
PHILIPPI, R. A. 1887. Die tertiären und quartärem Versteinerungen Chiles. Leizpig. Brockhauss. [p. 211, pl. 47, fig. 4]
1854 Pecten propinquus Hupé in Gay, 1854
1887 Pecten hupeanus Philippi, 1887
1887 Pecten vidali Philippi, 1887
1887 Pecten hupeanus Philippi, 1887
1887 Pecten vidali Philippi, 1887
R. A. Philippi, 1887, plate 47.
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«Testa ovato-rotundata, depresso-convexa, subaequivalvis; costls radiantibius, inaequalibus [circa 26], alternantibus minoribus ornata; auriculis magnis, inaequalibus, transversim [i. e. radiatim] striatis.
Hupe. — Longit. 55, altit. 58 mm. Pecten propinquus Gay non Münster, Gay, Hist. Chil. Zool., VIII, 291, Taf. V, Fig. 3. Von Coquimbo. Das Museum besitzt ein noch von Gay gesammeltes Exemplar, welches die Bezeichnung hat: "Pecten propinquus" da aber der Name propinquus schon vom Grafen Münster für eine andere Art gebraucht war, konnte ich ihn nicht beibehalten. Das von Hupe abgebildete Exemplar ist ein Avenig grösser als das unserige, welches aber besser erhalten zu sein scheint; in diesem sind die Streifen der Ohren wenig hervortretend.» RUDOLPH AMANDUS PHILIPPI, 1887
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«Type specimens.— Syntypes of Pecten propinquus Hupé, 1854, MNHN.F.A26549, two left valves from “Coquimbo,” Coquimbo Formation. Syntypes of Pecten vidali Phillippi, 1887, SGO.PI 656a, one right valve from Mejillones, paratype of Pecten vidali Phillippi, 1887, SGO.PI 656b, one left valve from Mejillones, Antofagasta region, La Portada Formation.
Diagnosis.— Shell flabelliform, thick, right anterior auricle high and entirely sculptured with ribs. Plicae with flat crest unequally sulcated by a shallow groove and covered with ribs from 45 mm to 70 mm; interspaces smooth, up to 20–35 mm, then sculptured with a central primary rib and two secondary ribs from 50 mm to 61 mm height. Some plicae of adult right valves are trisulcate. Shagreen microsculpture present on auricles, grooves on plicae and interspaces from 3 mm or 5 mm height.
Occurrence.— Late Miocene–middle Pliocene (as discussed below) from Playa Chorillos, La Piña, Totoral, Caldera (Atacama Region, Bahía Inglesa Formation); “Mejillones,” Cuesta del Burro, (Antofagasta Region, La Portada Formation); Punta Teatinos, La Serena, Quebrada de Tongoy, Quebrada Romeral, Quebrada Lagunillas, Quebrada Honda, (Coquimbo Region, Coquimbo Formation); Horcón (Valparaíso Region, Horcón Formation).
Description.— Shell of large size, attaining up to 120 mm in height, thick, flabelliform, higher than long in juvenile, equidimensional or longer than high in adult specimens, slightly opisthocline, posteriorly elongate and antero–dorsal margin more concave than the postero–dorsal one; right valve flat, left one strongly convex. Hinge dorsal margin straight, 49–59% of total disc length. Umbonal angle 99–116°. Auricles almost symmetrical, large, narrow, with the anterior one slightly longer, and with free margins sloping anteriorly; left anterior one with vertical free margin on few specimens; right anterior auricle with dorsal margin slightly projected upwards and free margin straight; byssal notch rounded, short and shallow, functional ctenolium throughout ontogeny, with 5–6 strong teeth; byssal fasciole with convex corrugations towards the umbo; posterior and left anterior auricles with free margin straight or slightly convex, with a shallow byssal sinus. Right anterior auricle sculptured with 6–12 radial ribs, left anterior with 12–16, and posterior auricles with 7–12; ribs on auricles of homogeneous width, ribs on left anterior auricles fine for the tribe, dorsal ribs of right anterior auricle coarser than ventral ribs. Resilifer moderately deep, triangularisosceles, upright in some specimens and oblique in a few ones. Discs sculptured with wide plicae of sub-equal width, rectangular in cross section, with flat grooved crests, smooth or sculptured with three or four scaly ribs appearing between 45 mm and 70 mm. Ribs covered with low scales ventrally directed. Plicae separated by flat interspaces and sculptured with amiddle primary rib that arises between 20 mmand 35 mmshell height on both valves that is flanked by two secondary ribs arising between 50 mm and 60 mm shell height. Right valve sculptured with 20–24 unpaired plicae, sulcated by one groove that commence at 30–40 mm height, in adults, some plicae are trisulcated with grooves that split the plicae in similar widths. Usually the bifurcation on right plicae is incomplete, with the remaining sub-plicae joined throughout ontogeny; few plicae may be entirely and unequally bifurcated or equally trifurcated in late ontogeny; right interspaces twice as narrow as left ones. Left valve with 17–22 simple plicae and interspaces of equal or narrower width; plicae sulcated by grooves that commence between 45 mm and 55 mm height and splitting the plicae unequally, some of them with two grooves. Entire disc surface sculptured with antimarginal ridgelets from beginning of radial stage, developed on plicae and interspaces before the appearance of shagreen microsculpture; commarginal microsculpture of fine lirae restricted to beginning of initial radial stage up to 13 mm height on right valve; shagreen microsculpture developed on interspaces and grooves on plicae from 2.5–5 mm from beaks and extended to ventral margin, and present on entire auricles.
Materials.— 52 right valves and 63 left valves: MACN-Pi 2479; GNS WM 9614, 9615; SGO.PI 208, 1032a–h, 1034a–f, 1053a, b, 1058a–c, 1071a, b, 1101a–e, 1108a–d, 1113a, b, 1211a–c, 1222a, b, 1244, 1247a, b, 1248a, b, 17525, 17526, 5854a–g, 5860a, b, 5910, 5911a, b, 5915a–e, 5919a–c, 5920, 5928a–c, 5930a–c, 5934a–d, 5943, 5946a, b; SNSB-BSPG 1966 IV 11–13, 155–165, 170–172, 174–182, 186–189, and UNISTRA 52735.
Dimensions (mm).—MNHN.F.A26549 syntype of Pecten propinquus L = 40.2, H = 44.4; SGO.PI 656 holotype of Pecten vidali, an articulated specimen, L = 75.0, H = 75.3; SGO.PI 208 L = 55.8, H = 55.1; SGO.PI 1058, L = 89.0, H = 84.0.
Remarks.— This species was originally named as Pecten propinquus by Hupé in Gray, 1854 based on two left valves (syntype MNHN.F. A26549, set of two specimens available online, Fig. 3.1) from Coquimbo, whose illustration corresponds to a reconstruction of both valves. However, this name was preoccupied by a crinoid (Pecten propinquus Münster, 1833). Subsequently, Philippi (1887) proposed Pecten hupeanus as a replacement name for P. propinquus, based on a left valve from Coquimbo (SGO.PI 208). Later, Herm (1969) erroneously believed that P. vidali, instead of P. hupeanus, would correspond to the replacement name for P. propinquus, stating that the holotype of P. hupeanus was housed at Museo de Historia Natural (Chile), although this specimen is not part of Hupé’s material. Recently, Griffin and Nielsen (2008) illustrated the syntype of Pecten propinquus Hupé, stating that the only valid type material of P. hupeanus Philippi, 1887 corresponds to the type material available to Hupé (MNH Gg 2002/91, an old catalogue numbering). Then, the specimen selected by Philippi in 1887 to name P. hupeanus would not be a type specimen (according to the International Commission of Zoological Nomenclature, 1999, Art. 72.7). The syntypes of P. vidali (SGO.PI.656a, b) correspond to the two valves originally mentioned as “upper and lower valves” by Philippi (1887), who illustrated the right valve (Philippi, 1887, pl. 47, fig. 5).
Dietotenhosen hupeanus n. comb. is the most common species of the Chilean Chlamydini representatives and it is widely distributed from Punta Mejillones southwards to the area of Caleta Horcón. This taxon has been mentioned by Herm (1969) from the La Portada, Cuesta del Burro and Hügel Creek sections, but when he labelled and described the species, he referred it to “Mejillones” sensu lato. Its oldest occurrences are at Playa Chorrillos, a section dated as late Miocene (Bahía Inglesa Formation) (Achurra et al., 2009), and in the area of Bahía Tongoy, where this species is contained in a specific section of the Coquimbo Formation assigned to the latest Miocene–earliest Pliocene (Le Roux et al., 2006). It extended its stratigraphic range into the early Pliocene, an age proposed by Marchant et al. (2000) for exposures at Caldera (Coquimbo Formation). Certainly, D. hupeanus n. comb. is recorded at Cuesta del Burro and in the area “Mejillones” (La Portada Formation, Cuesta del Burro Member) where the exposures were assigned to the early middle Pliocene by Ragaini et al. (2008). This species was also found in exposures at Horcón (Horcón Formation), referred to the late Pliocene based on the molluscan content by Carrillo-Briceño et al. (2013), an age herein dismissed due to its circular argument. Herm (1969) mentioned many other localities where this species comes from Puerto Viejo (Bahía de Copiapó, Caldera) (Bahía Inglesa Formation), Quebrada Chañaral de Azeitunas, Quebrada Culebrón (in Coquimbo), Quebrada Salinita, Quebrada Pachingo (Bahía de Tongoy), (Coquimbo Formation) and Horcón (Horcón Formation). Also, D. hupeanus n. comb. probably is present in Barranquilla (Caldera, Bahía Inglesa Formation), Estero Culebrón (Coquimbo) and Quebrada Salina (Bahía de Tongoy), (Coquimbo Formation), but unfortunately the repository of that material remains unknown. Chlamys vidali was mentioned in southern Peru at Sud-Sacaco (Sacaco Basin, 100 km southwards, Nazca, Pisco Formation) (Muizon and DeVries, 1985), where the isotopic ages of the exposures were referred to the latest Miocene by Ehret et al. (2012). This species was also mentioned for the late Pliocene in southern Peru at cerro Huaricangana (surroundings of Nazca, “Huaricangana Formation;” DeVries, 2017) where it would reach the early Pleistocene at the highest terrace of the hill (T. DeVries, personal communication, 2019) and, for the late Pliocene in northern Peru for the Hornillos Formation (DeVries, 1986, 1988, unpublished). If those relative ages are accepted, the youngest occurrence for this species and genus would expand from latest Miocene to the early Pleistocene. Additional studies are necessary for understanding themigratory routes taken by the studied taxa. Herm (1969) was the only author who provided a short diagnosis of the species, which has been emended herein. Jonkers (2003) assigned C. vidali and C. hupeanus to Zygochlamys, described specimens housed at SNSB-BSPG (among others repositories) and stated that Z. hupeanus would be the youngest species of the genus, and that Z. vidali and Z. hupeanus would have never been sympatric. That author recognized morphologic differences that constitute a matter of degree between both taxa, arguing that: (1) the adults of Z. hupeanus have shells longer than high, whereas in Z. vidali they are higher than long; and (2) Z. hupeanus has more-convex left valves and less-convex right ones, a wider umbonal angle, less-asymmetrical auricles, fewer ctenolium teeth, and more delicate radial sculpture. In his study, D. hupeanus n. comb. and D. vidali n. comb. (both types of them illustrated in Fig. 3.1, 3.2) are considered synonymous because they have shells and auricles of similar shape and size, shells that are large and flabelliform, and auricles that are almost symmetrical and narrow.Moreover, the shell surface of both taxa is entirely covered with shagreen microsculpture (Figs. 3.2, 3.10, 3.11, 4.1), ornamented with an equal number of rectangular and grooved plicae (Figs. 3.10–3.12, 4.1), bearing fine ribs that appear beyond 30 mm from beaks and separated by interspaces that are smooth in much of the shell, but ornamented with a central primary and two secondary ribs in the advanced ontogeny. It must be highlighted that the collection of D. Herm has been split between two institutions. Part of the material is housed at SNSB-BSPG and the images provided by W. Werner are included herein. Another part, which includes most of the studied specimens of D. hupeanus n. comb., is currently housed at the National Museum of Natural History of Chile, a repository visited by MB.» SANTELLI, M. B. & C. J. DEL RÍO. 2019. New Neogene taxa of the tribe Chlamydini Teppner, 1922 (Pectinidae, Bivalvia) of southern South America. Journal of Paleontology, 93 (6): 1088-1104, figs. 1-7. [p. 1092-1094, 1096]
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Dietotenhosen hupeanus (Philippi, 1887); M. B. Santelli & C. J. del Río, 2019, New Neogene taxa of the tribe Chlamydini Teppner, 1922 (Pectinidae, Bivalvia) of southern South America, figures 3.1 (syntype of Pecten propinquus Hupé, 1854), 3.2 (holotype of Pecten vidali Phillippi, 1887), 3.3-3.12, 4.1, and 4.2 (syntypes of P. vidali Phillippi, 1887), 4.3. (paratype of Pecten vidali Phillippi, 1887).
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«TYPE MATERIAL. Two syntypes in the Typothèque of the Laboratoire de Géologie under catalogue number MNHN-Gg2002/91.
TYPE LOCALITY. ‘Altos de los Faluns de Coquimbo’ (Top of the cliffs at Coquimbo, Chile).
REMARKS. Philippi (1887: 203) introduced Pecten hupeanus clearly as a replacement name for Hupé’s species, as the name was preoccupied by Pecten propinquus Münster, 1833. He also stated (and figured in pl. 47, fig. 4) that he had one additional specimen that was left in the Museum by Gay. According to Philippi its preservation seems to have been very poor in comparison to Hupé’s original figured material, but Philippi was correct in identifying both species. Möricke (1895: 578, pl. 13, figs 2-4) described and figured material he also correctly placed under Pecten hupeanus Philippi. Herm (1969: 103), who never saw Hupé’s type material, included Pecten propinquus (apparently only Hupé’s types) as a synonym of Pecten vidali Philippi, 1887. However, he also described Pecten hupeanus from Caldera and Coquimbo, stating that the holotype of Pecten hupeanus Philippi was in the ‘Museo Nacional de Historia Natural’ in Santiago, Chile. However, the specimen there is the one mentioned by Philippi and labelled Pecten propinquus and left behind by Gay. As Pecten hupeanus is clearly a replacement name for Pecten propinquus Hupé, the type material is the type material available to Hupé, and not Philippi’s additional specimens (ICZN 1999: Art. 72.7). In any event, Herm (1969: 106) compared Pecten vidali and Pecten hupeanus as closely related species, only separable by means of slight differences in the ornamentation. The shell outline and geminate ribs indicate this species belongs in Zygochlamys Ihering, 1907.»
GRIFFIN, M. & S. N. NIELSEN. 2008. A revision of the type specimens of Tertiary molluscs from Chile and Argentina described by d’Orbigny (1842), Sowerby (1846), and Hupé (1854). Journal of Systematic Palaeontology, 6 (3): 251-316, pls. 1-24. [p. 283]
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Zygochlamys hupeanus (Philippi, 1887), syntype of Pecten propinquus Hupé, 1854; M. Griffin & S. N. Nielsen, 2008, A revision of the type specimens of Tertiary molluscs from Chile and Argentina, plate 14, figure 4.
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«Stratigraphical age and distribution. Known from Late Pliocene deposits in central Chile (Caldera, Coquimbo, Tongoy); apparently nor as common and widespread as Z. vidali.
Herm (1969) assigned almost similar age ranges to Z. hupeana and Z. vidali (wíth the latter starting somewhat earlier in the Pliocene), but he claimed that the two species were allopatric. However, in the lot of Z. hupeana that he collected at La Piña (650823/11) there are nine valves of small Argopecten, a genus which occurs abundantly (and with much larger specimens) in the Pleistocene of central and northern Chile, and which were never seen in samples of Z. vidali. This suggests that Z. hupeana is a stratigraphically younger species than Z. vidali, which would explain why these scallops never occur together. Z. hupeana is here assumed to be the youngest species of Zygochlamys (Fig.25). Remarks. Shagreen microsculpture was observed only in material from Salina Grande (Tongoy) and Quebrada Chañaral de Azeitunas (two valves from each locality); in the large sample (46 valves) from La Piña (northern Caldera) no trace of microsculpture was found, but otherwise the fossils from there are identical to shells from the other localities. Zygochlamys hupeana is very similar to Z. vidali in maximum shell size (VH 100.7 mm and 105.0 mm, respectively), outline of the disc, and relative length of the hinge (Fig. 30). Similarities in sculpture between these species make separation of juveniles rather difficult, but in adults radial sculpture is stronger in Z. vidali. Adult specimens of Z. hupeana can further be distinguished from those of Z. vidali by valves that are longer than high (the only species of Zygochlamys to have such valves), a more convex LV and a RV that is very much flatter (Fig. 33); other differences are a wider umbonal angle, less asymmetrical auricles, and a significantly lower number of byssal teeth in the functional ctenolium (3.8 ± 0.4 [n = 17] in Z. hupeana versus 5.3 ± 0.2 [n = 38] in Z. vidali.» JONKERS, H. A. 2003. Late Cenozoic-Recent Pectinidae (Mollusca: Bivalvia) of the Southern Ocean and neighbouring regions. Monographs of Marine Mollusca, 5: i-viii + 1-125 pp, 17pls. Backhuys Publishers, Leiden [p. 42]
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Zygochlamys hupeana (Philippi); H. A. Jonkers, 2003, Late Cenozoic-Recent Pectinidae (Mollusca: Bivalvia) of the Southern Ocean and neighbouring regions, plate 7, figures d-f.
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