Tetralophodon longirostris ( Kaup, 1832 )

Geraads, Denis, Kaya, Tanju & Mayda, Serdar, 2005, Late Miocene large mammals from Yulafli, Thrace region, Turkey, and their biogeographic implications, Acta Palaeontologica Polonica 50 (3), pp. 523-544 : 529-530

Tetralophodon longirostris ( Kaup, 1832)

Material from Yulafl I.—TTMEU−CY−23, left dentary, with m2–m3 and alveoli of m1; TTMEU−CY−202a, right dentary with m2 and alveoli of m1 ( Fig. 4A); TTMEU−CY−202b, isolated right m3 ( Fig. 4B); TTMEU−CY−111, right dentary with heavily worn m1; TTMEU−CY−112, right dentary with heavily worn m2, and anterior part of m3; TTMEU−CY−48 isolated left M2.

Description.—TTMEU−CY−23 and TTMEU−CY−202 belong to adult individuals. The corpus of each specimen is robust and broadens posteriorly. The interalveolar crest and the mandibular foramina are missing in TTMEU−CY−23, but the interalveolar crest of TTMEU−CY−202 is straight, long and mesio−ventrally sloping. It is deflected downward at ~45 ° relative to the alveolar border, while the ventral margin of the symphysis exhibits a downward deflection of 15 °. These measurements for TTMEU−CY−112 are 40 ° and 17 °, respectively. There are four mandibular foramina on TTMEU− CY−202. The largest one is positioned below the alveoli of m1, the others are positioned anteriorly on the symphysis. TTMEU−CY−111 belongs to a juvenile individual with a slender corpus exhibiting three mandibular foramina.

The m2 of TTMEU−CY−202 has four lophids, plus a small and low distal cingulum. The anterior margin of the tooth is broken. The pretrite half−lophids 2 and 3 preserve large posterior accessory conules while the fourth one has a smaller one. All other intermediate molars have four loph(id)s, but due to the wear stage in all specimens, it is impossible to determine their precise composition.

All m3s are morphologically similar. They each have five lophids and a bituberculate talonid, which could also be considered as a lophid. Each half−lophid is composed of a large main cone, a smaller mesoconelet and anterior and posterior accessory conules on the pretrite half−lophids and a posterior accessory conule on the first posttrite half−lophid. The pretrite half−lophids 4 and 5 of TTMEU−CY−23 do not exhibit any accessory conules. The anterior cingulum is well developed in all teeth. There are no traces of labial and lingual cingula except a thick basal one on the labial side of the last lophid of TTMEU−CY−23. There is a trace of cement at the base of the interlophids.

Comparisons.—Tetralophodont records are scarcer in Turkey than those of choerolophodonts, but they are more numerous in other Eurasian localities. Tetralophodon longirostris ranges from the late middle Miocene to the late Miocene. It is well known from Eppelsheim, Dorn−Dürkheim 1, Belvedere in Austria, and Nombrevilla in Spain ( Tobien 1978; Gaziry 1997; Göhlich 1999). The genus Tetralophodon has also been recorded in Istanbul ( Viret 1953).

The materials from Yulafli are very similar in size and morphology to those of Tetralophodon longirostris from Eppelsheim ( Tobien 1978: pl. 10: 1) and Dorn−Dürkheim 1 ( Gaziry 1997: pl. 1: 2). The m3s have five lophids and a talonid, a simple crown pattern without anancoidy, a slight cement cover in the posterior interlophids, and the symphysis is down−turned. The fossils from Yulafli are distinguished from other tetralophodonts (“ Mastodon ” longirostris forma gigantorostris and “ Mastodon ” grandincisivus ) ( Tobien 1978; Mazo and Montoya 2003) by having a simple crown pattern, a weak cement cover, and smaller cheek teeth. The material from Yulafli falls within the size range of T. longirostris from late Miocene localities (Eppelsheim, Esselborn, Mannersdorf), which is clearly distinct from that of “ T. longirostris −grandincisivoid form”–“ Mastodon” grandincisivus (Fig. 8).