Early Pliocene Porcupine (Mammalia, Rodentia) from Perpignan, France: a New Systematic Study
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Early Pliocene porcupine (Mammalia, Rodentia) from Perpignan, France: a new systematic study Sevket SEN Laboratoire de Paléontologie, Muséum national d’Histoire naturelle, UMR 8569 du CNRS, 8 rue Buffon, F-75231 Paris cedex 05 (France) [email protected] Sen S. 2001. — Early Pliocene porcupine (Mammalia, Rodentia) from Perpignan, France: a new systematic study. Geodiversitas 23 (2) : 303-312. ABSTRACT The relatively rich porcupine remains from the early Pliocene locality of Serrat d’en Vacquer, near Perpignan, have been restudied. They were previ- ously determined as Hystrix primigenia (Wagner, 1848) by Depéret (1890) and maintained in this species by later students. The bulk of the material KEY WORDS Mammalia, represents in fact a new species, H. depereti n. sp., larger in size than H. primi- Hystricidae, genia and different from it in its higher crowned cheek teeth and reduced Rodentia, third molars. Among the Perpignan material, there are two molars, different Pliocene, France, in colour and possibly mixed, that fit better in size and morphology with new species. H. primigenia. RÉSUMÉ Les porc-épics (Mammalia, Rodentia) du Pliocène inférieur de Perpignan, France : une nouvelle étude systématique. Les restes de porc-épics sont relativement abondants dans le gisement plio- cène de Serrat d’en Vacquer, près de Perpignan. Ils ont été attribués à Hystrix primigenia (Wagner, 1848) par Depéret (1890) et d’autres paléontologues qui ont étudié les Hystricidae fossiles d’Europe. L’examen du matériel montre MOTS CLÉS Mammalia, que la plupart des spécimens représente une nouvelle espèce, H. depereti Hystricidae, n. sp., qui se distingue de H. primigenia par sa plus grande taille, la couronne Rodentia, plus élevée de ses dents jugales et ses troisièmes molaires plus réduites. Deux Pliocène, France, dents incluses dans ce matériel, différentes en couleur et peut-être provenant nouvelle espèce. d’un autre niveau, possèdent des caractères similaires à ceux de H. primigenia. GEODIVERSITAS • 2001 • 23 (2) © Publications Scientifiques du Muséum national d’Histoire naturelle, Paris. www.mnhn.fr/publication/ 303 Sen S. anterior H. primigenia. Finally, because of the strong simi- A mesoflexus mesoloph larities of the dental pattern, they all considered mesostyle posterior the Perpignan sample within the morphological mesoflexus pa variability of H. primigenia, but slightly larger. proto- mt I have to note that porcupine remains are gener- lophule post- fossette ally rare in late Miocene and Pliocene localities, and the reduced number of specimens from each posteroloph para- locality does not allow an accurate observation of fossette metalophule morphological and size variabilities in fossil por- pr hy cupines. This is also the case of H. primigenia, anteroloph although its remains are found in a large number of Turolian localities from Spain to Turkey (see hypoflexus map in Sen 1996), but always with a few speci- B mesolophid mens from each locality. In this matter, the newly anterior discovered material from Hadji Dimovo in mesoflexid posterior mesoflexid ed Bulgaria and referred to H. primigenia is excep- metalo- phulid postero- tional since it represents at least seven individuals flexid and the specimens are well-preserved. For the md comparison of the Serrat d’en Vacquer porcu- antero- lophulid postero- pine, the sample from Hadji Dimovo together lophid with that of Pikermi provides a good basis, allow- central pd conid ing the observation of individual variations of size hd and dental morphology in H. primigenia. hypolophulid hypoflexid The material from Serrat d’en Vacquer is rela- tively rich and represents at least five individuals FIG. 1. — Nomenclature to describe cheek teeth structures of according to the number and the degree of attri- Hystricidae, from the left side; A, upper cheek teeth; B, lower tion of p4. All specimens are illustrated as if cheek teeth. Abbreviations: ed, entoconid; hd, hypoconid; hy, hypocone; md, metaconid; mt, metacone; pa, paracone; they are from the left side; if inverted, their pd, protoconide; pr, protocone. numbers on the illustrations are underlined. INTRODUCTION METHODOLOGY Depéret (1890: 45) referred to Hystrix primigenia There is no special nomenclature to describe (Wagner, 1848) the porcupine remains from the cusps, crests and synclines of Hystricidae cheek locality Serrat d’en Vacquer near Perpignan teeth. The most commonly used terms are that of (Pyrénées orientales, France), and noted that the the classical Cope-Osborn terminology for cusps Perpignan porcupine is morphologically quite and that of Stehlin & Schaub (1951) for crests similar to H. primigenia from Pikermi in Greece, and synclines. Indeed, the last authors used the however with “dimensions à peine plus fortes” pentalophodont Theridomys dental pattern, num- and “la forme un peu plus triangulaire de la bering the lophs from 1 to 5 and the synclines dernière molaire inférieure”. Hugueney & Mein from I to V; they applied this terminology to a (1966), restudying the specimens from the Lyon large number of rodent families, including the collections, accepted this determination. Hystricidae. At present, based on the homologies Later on, several students referred to this material of the Hystricidae dental structures, it is possible emphasizing the differences already mentioned to provide a more understandable nomenclature by Depéret, and questioning its attribution to to describe these structures (Fig. 1). This nomen- 304 GEODIVERSITAS • 2001 • 23 (2) Early Pliocene porcupine from Perpignan clature uses the common terms already utilised in in the present study to estimate the degree of other groups of rodents as well as in many mam- hypsodonty of cheek teeth. malian orders. A similar adaptation has also been proposed for Castoridae by Hugueney (1999). The cusps are named according to their homolo- SYSTEMATICS gies in other mammals. It is a little more difficult to postulate the homologies of lophs and synclines Family HYSTRICIDAE Fischer de Waldheim, 1817 since the occlusal pattern in Hystricidae is compli- Genus Hystrix Linnaeus, 1758 cated by the occurrence of new crests and by the subdivision of synclines. However, in most cases, Hystrix depereti n. sp. it is quite easy to compare hystricid homologies (Figs 2A, B; 3B; 4A-C) with those of more classical dental pattern of HOLOTYPE. — Right lower jaw with p4-m3 (PR-25), Theridomyidae or Ctenodactylidae, for example. collection of the Muséum d’Histoire naturelle of Length and width measurements of teeth corre- Perpignan, Pyrénées orientales, France (Fig. 4A). spond to the maximum values along the longi- PARATYPES. — In the collections of Muséum tudinal and transverse axes of teeth. The d’Histoire naturelle of Perpignan: M1-2 sin (PR- measurement of the crown height (= maximum 154), M1-2 dex (PR-155), M1-2 dex (PR-27), enamel height) presents some difficulties, mainly mandible sin with p4-m3 (PR-24), mandible dex with d4-m2 (PR-147) and five lower incisors (PR-24, when cheek teeth are still in their sockets. 26, 148, 149, 151). In the collections of the Muséum Moreover, some specimens may not have clearly d’Histoire naturelle (Musée Guimet) in Lyon: P4 sin defined enamel/dentine boundary at the base of (Pp-58d), mandible sin with p4-m2 (Pp-55), the crown. toothrow p4-m2 dex (Pp-58a), m3 sin (Pp-58b) and m3 dex (Pp-58c). In the collections of the Muséum Fossil and living porcupines have semi-hypsodont national d’Histoire naturelle, Paris: P4 sin (PE-1a), to hypsodont cheek teeth. Their hypsodonty is P4 dex (PE-1d), M1-2 sin (PE-1b) and M3 sin unequal: the lingual portion of upper cheek teeth is (PE-1c). These four specimens probably belong to the higher crowned than the labial portion, with the same individual. inverse being the case in lower cheek teeth, al- TYPE LOCALITY. — Serrat d’en Vacquer, Perpignan, though the enamel height difference is less between Pyrénées orientales, France. the labial and lingual faces of lower cheek teeth. ETYMOLOGY. — In honour to Prof. Charles Depéret The hypsodonty is usually estimated on mam- who studied the geology of the area and the whole fauna from this locality. malian cheek teeth as the ratio of the maximum enamel height/the maximum occlusal length on MEASUREMENTS. — See Table 1. the freshest teeth possible. However, Van Weers DIAGNOSIS. — Large sized porcupine with semi hyp- (1993) proposed to use “the crown height” which sodont cheek teeth. The third molars reduced and almost triangular in occlusal outline. Sinus and is, according to him, the height of the tooth body sinusids are shallow on upper and lower molars but without the roots (anteriorly, from the interroot deep on p4. area to the occlusal surface), instead of the enamel DIFFERENTIAL DIAGNOSIS. — Size larger than in height. First, this measure does not correspond to H. primigenia. The crown of cheek teeth is propor- the true crown height, and second such a parame- tionally higher than in H. primigenia but much lower tre is difficult to use for fossil Hystricidae because it than in H. refossa Gervais, 1852. The sinus of upper needs isolated teeth whilst the fossil remains are and lower molars is less deep than in H. primigenia. The third molars are almost square in shape in often jaw fragments with teeth stuck into alveoli. H. primigenia, but rather triangular and posteriorly Handling fossil samples, I came to the conclusion reduced in the new species. that the parametre “enamel height” is easier to be measured than the measurement proposed by Van DESCRIPTION Weers (1993). Therefore, only the measurements From the upper jaw, only isolated teeth are of the enamel height (= crown height) are used preserved. The size of the upper cheek teeth GEODIVERSITAS • 2001 • 23 (2) 305 Sen S. A A B B B’ C C C’ FIG. 3. — Comparison of mandibles in lateral view, from the left side; A, Hystrix primigenia (Wagner, 1848) from Pikermi (PIK-3089); B, Hystrix depereti n. sp. from Serrat d’en Vacquer (PR-24); C, Hystrix cristata Linnaeus, 1758 from Italy (MNHN 1990-662).