Cremohipparion nikosi Bernor &amp; Tobien 1989, n. sp.
Creators: name: Bernor, R. L.,
name: Tobien, H.
Publisher: name: Zenodo
Year: 1989
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Perissodactyla
Equidae
Cremohipparion
Cremohipparion nikosi

description: <i>Cremohipparion nikosi</i> n. sp. Fig-2 <i>Hipparion matthewi,</i> T obien, 1938 <i>Hipparion matthewi,</i> G romova, 1952, in part Holotype: Male skull fragment, BSP 1899 VII 31 b. Type Locality: Island of Samos (Greece, without locality). Etymology: Named in honor of Dr. Nikos Solounias as a tribute to his long and exhaustive work on the stratigraphy and paleontology of Samos. Age: Turolian, ca. 8.5—5.7 Ma. Geographic Distribution: Greece. Diagnosis: As for <i>Cremohipparion matthewi</i> except that the nasals are strongly retracted to the mesostyle of P4. Lower jaws are not known for this species. Description: The type specimen of <i>Cremohipparion nikosi</i> n. sp. (Fig. 2) <i>is</i> an old adult male individual including the snout, nasals, maxilla and anteroventral aspect of the orbits, both canines and left P2—M3. As with the holotype of <i>C</i>. <i>matthewi,</i> this <i>is</i> a small <i>species</i>. The <i>specimen</i> preserves an approximately subtriangular, anteroventrally oriented POF with a large anteroventrally placed infraorbital foramen. The POF is less than 10 mm deep medially, has no <i>posterior</i> pocketing, preorbital bar is quite short (19.2 mm) and while not clear, the lacrimal most probably invaded the posterior aspect of the POF because of the POB’s very short length. As with C. <i>matthewi,</i> there is no visible caninus fossa. The nasal notch is clearly very strongly retracted to mesostyle of P4. The dorsal premaxillary tubercles are far less developed in this specimen than in C. <i>matthewi.</i> The canines are large and quite robust, and suggest, that it was a male individual. The cheek teeth are in an advanced stage-of-wear, suggesting that this was an old individual. P2 anterostyle <i>is</i> shortened. Protocones are rounded on all cheek teeth; P2’s protocone is connected with the protoloph due to its late wear-stage. When preserved, pli caballins are short, but either single or double. The pre- and postfossettes are heavily worn, but reveal that the individual had shallow amplitude, moderately complex plications of the cheek teeth. However, wear <i>is</i> too advanced to reliably account for how many plications the younger middle stage-of-wear adults had. The hypoglyphs are essentially obliterated on P2 3, shallow on P4—M2, and deep on M3. Remarks: The only <i>previous</i> citations of the type specimen, BSP 1899 VII 31b, were Tobien (1938: Taf. 1) and G romova (1952), both of whom referred it to <i>Hipparion matthewi,</i> based on its size. This <i>species is</i> remarkably similar to C. <i>matthewi</i> in its size and morphology, except for the strong retraction of the nasal bones. This single contrast <i>is</i> significant, in that the ratio of measurement 30 versus 31 (length of the naso-incisival notch from prosthion to the back of the narial opening versus the length of the narial opening to the anteriormost limit of the orbit; re: <i>Eisenmann</i> et al., 1988: Fig. 3a) is 136.0/74.9 (= 181.6) in <i>Cremohipparion nikosi</i> versus 99.1/ 110.6 (= 89.7) in <i>Cremohipparion matthewi.</i> Moreover, we know of no case where a single species of hipparion exhibits a variability in nasal retraction ranging from anterior limit of P2 to mesostyle of P4. K oufos and M elentis (1984) described an important and previously poorly known collection of Samos hipparions from the PMMS, Samos, Greece. This collection originates from the Stefanidis or Andrianos Ravine, and <i>is</i> believed by the authors to be identical to Quarry 1 of the AMNH collection (B rown, 1927). K oufos and M elentis (1984) describe a smaller horse in this which they referred to <i>Hipparion</i> sp. II; the most complete specimen being a skull, PMMS 9 (Plate II, pg. 69; Plate III, pg. 70). They characterize this taxon as being (K oufos and M elentis, 1984: 66): “ <i>size</i> middle; moderate developed preorbital fossa, situated near the orbit; long muzzle; short tooth series, closed (= close to) <i>H. matthewi;</i> simple enamel plication; protocone connected to the protoloph; moderate protostylid”. The cheek tooth characters are most probably not diagnostic because of their later wear-stage. Length of the cheek tooth series <i>is</i> somewhat greater (P2—M3 length = 122.1 mm), than the type C. <i>matthewi</i> (= 111.8 mm) and <i>C</i>. <i>nikosi</i> (= 105.5 mm). Preorbital bar length for PMMS 9 (= 29 mm; Table 1: 54) falls within the uppermost portion of the range of length for <i>Cremohipparion</i> species (B ernor, 1985: 264, Tab. 14; C. aff. <i>moldavicum</i> from Middle Maragheh has one of the highest ranges for this lineage, = 23.6—29.8 mm). Also, reference to Table 1 here reveals that the values for measurements 30 (= 142 mm) and 31 (= 135 mm) are greater overall than <i>C</i>. <i>matthewi</i> and C. <i>nikosi,</i> while its ratio of these measurements (= 105.2) is somewhat different than C. <i>matthewi</i> (= 89.6 mm), and much different than C. <i>nikosi(=</i> 181.6 mm). This feature of <i>Hipparion</i> sp. II suggests a relatively intermediate snout length/nasal retraction. It <i>is</i> presently difficult to determine what the evolutionary relationships of <i>" Hipparion ”</i> sp. II are. The length of preorbital bar is within the range of variation for <i>Cremohipparion</i> aff. <i>moldavicum</i> from Maragheh, as is the length of the maxillary cheek tooth row (= 120.0—141.3 for <i>C</i>. aff. <i>moldavicum;</i> B ernor, 1985: 264, Tab. 14) especially given the fact that PMMS 9 is an old individual. However, PMMS’s POF would not appear to be as strongly developed in its medial depth and peripheral rim as <i>Cremohipparion moldavicum.</i> Therefore, there is no apparent basis to refer PMMS 9 to either C. <i>matthewi</i> nor C. <i>nikosi,</i> and it may or may not prove to be a member of the <i>Cremohipparion</i> lineage. However, further details on POF, lacrimal and caninus fossa morphology are particularly needed to determine its phylogenetic affinities. The AMNH houses some small horse postcranials from Samos. Measurements for metapodials (Table <b>5</b>), humerus (Table 6) radius (Table 7), ulna (Table 8) and astragalus (Table 9) are given here. Figure 3 compares the proportions of metacarpal III and metatarsal III maximum length (var. 1) versus distal articular width (= DAW; var. 11) in comparison with 95% and 99 % confidence ellipses for the Howenegg hipparions (Bernor et <i>al</i>., in press). This figure illustrates that there were a number of different <i>species</i>, belonging to distinctly different later Miocene equid lineages that decreased size. The two <i>species</i> of <i>Cremohipparion</i> reported here are amongst the more elongate and slender species, and contrast most sharply with <i>“Sivalhippus” platyodus</i> from China (Qiu et al., 1987: 94—95; Tab. 10), which had relatively short and broad proportions (and indeed was not a true dwarf form as is seen from its skull dimensions). These observations reinforce our assertions that size cannot be used alone in defining a hipparion species, nor can it alone support assertions of phylogenetic relationship and time correlation.
description: Published as part of <i>Bernor, R. L., &amp; Tobien, H., 1989, Two small species of Cremohipparion (Equidae, Mammalia) from Samos, Greece, pp. 206-226 in Bayerische Staatssammlung für Paläontologie und historische Geologie 29</i> on pages 215-219, DOI: 10.5281/zenodo.1436534
description: {"references": ["Tobien, H \" (1938): Uber das Gebiss des Hipparion mattbewi Abel. - N. Jb. Min., Beil. - Bd. (B), 80: 279 - 306, 1 Tab., 1 Taf.; Stuttgart", "Gromova, V., (1952): Le genre Hipparion. - Inst. Paleontol. Acad. Sei. l'USSR 36., 12: 1 - 473, 54 Abb., 18 Tab., 13 Taf.; Paris (Translated from Russian by St. Aubin. Bur. Rech. Min. Geol., Ann. C. E. D. P.).", "Eisenmann, V., M. - T. Alberdi, C. de Giuli and U. Staesche, (1988): Studying fossil horses. - eds. M. Woodburne and P. Sondaar, Vol. 1: Methodology, VIII + 71, 29 Abb.; Leiden (Brill).", "Koufos, G. D. and J. K. Melentis, (1984): The late Miocene (Turolian) Mammalian fauna of Samos Island (Greece). - Sei. Ann. Fac. Sei., Univ. Thessaloniki, 24 (47): 47 - 78, 4 Abb., 10 Tab., 8 Taf.; Thessaloniki", "Brown, B., (1927): Samos - Romantic Island of the Aegean. - Nat. Hist., 27: 19 - 32; New York.", "BERNOR,. L., (1985): Systematic and Evolutionary Relationships of the Hipparionine Horses from Maragheh, Iran (Late Miocene, Turolian Age). - Palaeovertebrata, 15 (4): 173 - 269, 19 Abb., 20 Tab., Montpellier", "Bernor,. L., Qiu, Z. and Tobien, H., (1987): Phylogenetic and biogeographic bases for an Old World hipparionine horse geochronology. - Ann. Inst. Geol. Hung. Proc. VUIth Internat. Cong.. C. M. N. S., Budapest: 43 - 53; 4 Abb"]}