Palaeoryx majori Schlosser, 1904
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publication ID |
https://doi.org/ 10.5281/zenodo.4650779 |
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persistent identifier |
https://treatment.plazi.org/id/9636CE11-B46B-FF8F-FD30-D988FEDEFE3E |
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treatment provided by |
Felipe |
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scientific name |
Palaeoryx majori Schlosser, 1904 |
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Palaeoryx majori Schlosser, 1904
Palaeoryx majori Schlosser, 1904: 38 , pl. VII, fig. 5.
Palaeoryx laticeps Andree, 1926: 161 , pl. XIII, figs 4, 6.
MATERIAL EXAMINED. — Frontlet: AK3-130; P3-M3: AK5-643 (LM1-M3 = 60.7); P4-M3: AK5-426 (LM1-M3 = 62.0); P3-P4: AK4-191; P3: AK5-609; M2: AK5-369; m2-m3: AK4-199.
DESCRIPTION
Skull
The braincase is wide (Appendix: Table 10) and the cranial roof slightly convex ( Fig. 23A View FIG ). The opisthocranium is short and moderately low. The mid-frontal suture is raised slightly and is rather open ( Fig. 23B View FIG ). The frontals are not elevated between the horn-cores. Ahead of them the frontals incline smoothly, forming an angle of about 105° with the cranial roof. The orbits are rather round- ed and well projected laterally. The width of the skull at the dorsal orbital rims accounts 155 mm. The supraorbital foramens are sunken into elongated and narrow pits. There are no postcornual grooves. The anterior tuberosities of the preserved basioccipital are strong, widely separated and slightly oblique comparatively to the sagittal plane. Between them and the posterior tuberosities a wide furrow runs along the basioccipital axis. The oval foramen is large, placed well in front of the anterior tuberosities. The horn-cores are elongated (≈ 300 mm along the anterior surface) and placed just above the orbits and laterally ( Fig. 23A, B View FIG ). Their basal part forms an angle of about 80° with the cranial roof. They are placed well apart at the base (internal basal distance at about 57 mm) and widely divergent toward the apexes. In their uppermost part they re-curve inwards ( Fig. 23 View FIG ). In lateral view they appear strongly inclined backwards and curved posteriorly ( Fig. 23A View FIG ). Thin discontinuous longitudinal grooves run along their surface. They do not bear any keel. Their cross-section is elliptical with weak mediolateral compression at the base, becoming stronger towards the tips (Appendix: Table 10).
Dentition
The few dental specimens assigned to this form, cannot give a complete idea on the tooth morphology. They differ from the previously described dentition of Miotragoceus valenciennesi and Tragoportax aff. amalthea in the longer molar row and the stronger hypsodonty. The P3 is lingually bi-lobed, while both the P3, 4 bear a hypoconal spur. The upper molars are wide with well developed basal pillar, which in some specimens (mainly in M2) appears double. The lobes fuse slowly together, giving rise to a strong central islet. The m3 has a clear goat fold, a strong “ectostylid” and a well developed-rounded talonid.
COMPARISON
The morphological characters of the skull AK3- 130 leave no doubts about its attribution to the genus Palaeoryx Gaudry, 1861 , according to the diagnoses given by Pilgrim F Hopwood (1928) and Gentry (1971). Although early authors dis- tinguished several species into this genus ( Schlosser 1904; Andree 1926; summarized and reviewed by Pilgrim F Hopwood 1928), later authors simplify its taxonomy and recognize a single species Palaeoryx pallasi (Wagner, 1857) ( Gentry 1971; Solounias 1981; Bosscha-Erdbrink 1988). Solounias (1981) accepts the monospecificity of the genus, but he also recognizes four varieties based on some dental and horn-core differences.
My observations on the Palaeoryx material from Pikermi (BMNH, MNHN) and Samos (MGL, BMNH, AMNH, PIM, AeMNH) allow a slightly different approach, recognizing Palaeoryx majori Schlosser, 1904 as a valid species. Indeed, the differences between Palaeoryx pallasi (W a g n e r, 1 8 5 7) a n d P a l a e o r y x w o o d w a r d i Pilgrim F Hopwood, 1928 do not merit a species value, since they do not exceed population variability observed in other late Miocene bovids. It seems that these two forms are correctly regard- ed as conspecific, meaning that P. pallasi is equally present in Pikermi and Samos. Nevertheless, the fossil record of Samos offers strong evidences on the occurrence of a second species on the island.
Recent excavations in Samos ( Koufos et al. 1997) brought into the light two skull specimens of Palaeoryx from the middle Turolian fossiliferous horizons, labeled MTLA-113 and MTLB- 160 (AeMNH) ( Fig. 24 View FIG ). Although similar in their general morphology, these two skulls differ in a large set of secondary characters summarized in the appendix ( Table 14). These differences obviously exceed those of intraspecific variability. The cranial and dental characters of MTLA- 113 are very close to those of other specimens from Samos and Pikermi attributed to Palaeoryx pallasi ( Fig. 24 View FIG ). MTLB-160 seems however identical to the specimen figured by Schlosser (1904: pl. VII, fig. 5) under the name Palaeoryx majori . Most of the characters observed in MTLB-160 reappear in the holotype of Palaeoryx laticeps Andree, 1926 stored in the Münster collection with the serial number PIM- 121 ( Fig. 24 View FIG ). The braincase structure of this specimen also differs from that of another specimen in the same collection PIM-118, attributed to Palaeoryx pallasi . NHMW A4779 ( Solounias 1981: fig. 61D, E) looks very similar to the specimen MTLB-160 and to the type skull of P. majori Schlosser, 1904 and it should be included into this species.
Most of the features distinguishing P. majori from P. pallasi can also be observed in the skull AK3-130, which therefore is placed in the former species. The single significant difference that can be observed concerns the setting of the horncores on the frontals, which appears wider in the Akkaşdagwı form, reflecting probably intraspecific variation.
The dentition of P. majori is not certainly known. Schlosser (1904) ascribed to his new species some isolated dentitions that however could belong to P. pallasi as well. Since both species are present in Samos, the dental characters of each form need a more careful approach. The Akkaşdagwı data are also poor to solve the issue. Judging from the Akkaşdagwı toothrows it seems that P. majori has a shorter molar row than P. pallasi . The available M1-M3 lengths from Akkaşdagwı range from 60.7 to 62 being smaller than that of MGL S200, MGL S199, PIK 2456, PIK 2459, BMNH M10831 (range: 65.5-69.5). Similar values occur on the specimens MGL S327 (61.8 mm) and BMNH M10832 (61.3 mm) that, however, cannot be distinguished from P. pallasi .
The coexistence of two Palaeoryx species is also manifested in Halmyropotamos, Greece ( Melentis 1967), where both P. pallasi (= P. woodwardi ) and P. majori are present. On the contrary, the presence of the genus in Turkey is badly documented. Köhler (1987) refers some isolated teeth from Kayadibi and Eski Bayırköy and a few horn-core fragments and a mandible from Mahmutgazi to Palaeoryx pallasi . Bouvrain (1994a) describes from KTA some dentitions and one horn-core as x Palaeoryx sp. The morphology of the described toothrows is quite similar to that from Akkaşdagwı, certifying the presence of the genus in this locality.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
