Adcrocuta eximia (Roth F Wagner, 1854)

Bonis, Louis de, 2005, Carnivora (Mammalia) from the late Miocene of Akkaşdağı, Turkey, Geodiversitas 27 (4), pp. 567-589 : 568-570

Adcrocuta eximia (Roth F Wagner, 1854)

Hyaena eximia Roth F Wagner, 1854: 396 . — Wagner 1857: 120. — Kittl 1887: 332.

Hyaena hipparionum Gervais, 1859: 242 .

Hyaena sp. – Schlosser 1903: 33.

Hyaena variabilis Zdansky, 1924: 93 .

Hyaena honanensis Zdansky, 1924: 103 .

Crocuta eximia – Pilgrim 1931: 116. — Şenyürek 1958: 1.

Crocuta gigantea latro Pilgrim, 1932: 146 .

Crocuta mordax Pilgrim, 1932: 150 .

Adcrocuta eximia – Kretzoi 1938: 118. — Ficcarelli F Torre 1970: 25. — Schmidt-Kittler 1976: 59. — Koufos 1980: 83. — Solounias 1981: 91. — Bonis F Koufos 1981: 79. — Howell F Petter 1985: 460. — Werdelin F Solounias 1991: 24. — Bonis 1994: 20.

Adcrocuta praecursor Kretzoi, 1938: 118 .

Adcrocuta variabilis – Kretzoi 1938: 118.

Crocuta (Percrocuta) eximia – Kurtén 1957: 397.

Crocuta miriani Meladze, 1967: 31 .

MATERIAL. — Upper carnassial of an old individual (AK7-131), two right lower carnassials of two cubs (AK6-x and AK6-y), two right mandibles of probably the same young individuals as the cubs (AK3-128 and AK3-203), piece of maxilla with D3 and broken D4 (AK6-z), right mandible of a young adult (AK7-68), both rami of an adult mandible (AK3-82 and AK3- 129), lower canine (AK3-83), left lower canine (AK5- 251), lower p3 (AK5-317), lower i2 (AK5-571), right M1 (unnumbered), broken left M1(unnumbered), piece of distal humerus, phalanges.

DESCRIPTION ( FIGS 1-4 )

The large sized Adcrocuta eximia (size of the extant Crocuta crocuta (Erleben, 1877) the spotted hyena) is certainly the most common late Miocene hyaenid, having been found from China to Spain. The powerful jaws and crushing premolars are allied to an elongated carnassial and the presence of a well developed anterior accessory cusp on p4 which indicate a quite high shearing power. This animal was probably a carrion eater and bone crusher as well as a skill hunter. The species was first attributed to the genus Hyaena Linnaeus, 1758 (Roth F Wagner 1854), then to the genus Crocuta Kaup, 1828 by Pilgrim (1931) and finally to the new genus Adcrocuta Kretzoi, 1938 . It is the most common hyaenid of Akkaşdagwı with a minimum number of individuals of five with a piece of upper carnassial of an old individual (AK7-131), two right lower carnassials of two cubs (AK6-x and AK6-y) and the two right mandibles of probably the same young individuals (AK3-128 and AK3-203), a right mandible of a young adult (AK7-68), both rami of an adult mandible (AK3-82 and AK3-129) and some isolated teeth or bones.

The adult mandible AK3-129 and AK3-82 ( Fig. 1 ) is quite complete on the left side except for the incisors, the canine and the p1 which are all represented by their alveoli. The ascending ramus is tall with very well marked muscular insertions which indicate a very powerful masseter muscle. The corpus is deep and there are two mental foramina, one below p2 and another one below the anterior root of p3. The premolars are slightly worn on their tips, especially p3. The shape does not differ from the numerous specimens described in the literature. The carnassial, m1, is elongated. There is a tiny cingulum at the base of the anterobuccal part of the paraconid. The protoconid is a little taller than the paraconid. The metaconid is very small and there is only one visible small cuspid on the talonid (hypoconid) with a low lingual crest in the place of the entoconid. There is no trace of a m2. An isolated right lower canine probably belongs to the same individual.

The right mandible AK7-68 has the alveolus of p1 and a very fresh dentition from p2 to m1 without any trace of m2 ( Fig. 2 ). The corpus is a little less deep than that of the previous specimen but also has two mental foramina. The premolars are quite similar but the m1 differs in that its buccal cingulum is more developed, in the absence of a metaconid and in the presence of a very small but distinct entoconid on the talonid. The other mandibles, with very fresh premolars, are similar to AK7-68. They have the same degree of development as a very fresh left lower canine (AK5-251). Two right milk lower carnassials (AK6-x and y) have quite low and elongated paraconids and protoconids, the latter being a little higher, but no metaconids ( Fig. 3 ). This is a derived state which differs from the more plesiomorphic deciduous carnassial of Percrocuta Kretzoi, 1938 (see Chen F Schmidt-Kittler 1983). On AK6-x the talonid is less worn and there are three cuspids, a high entoconid, a hypoconulid and a very worn hypoconid.

A piece of maxilla with D3 and broken D4 could belong to one of these individuals ( Fig. 4 ). The D2 is low, simple and elongated. The piece of milk carnassial has a well developed parastyle and a lingually elongated protocone.

The piece of upper carnassial is very worn on the lingual face of the metastyle and it belongs to an individual older than those described above. An upper worn left M1 (5.7/ 29.2 mm) and a broken right M1 may belong to this individual.

A piece of distal humerus and a very uncomplete femur are quite similar to, although a little larger than the bones of A. eximia from Pikermi ( Gaudry 1862 -1867: pl. XIV, fig. 3). The distal humerus reaches a total distal breadth of 62.9 mm against 54.7 mm for the specimen figured by Gaudry (1862 -1867: pl. XIV, fig. 3); on both bones, the epitrochlear foramen is absent, replaced by a small bony process. Some phalanges, especially phalanges of immature individuals, probably belong to Adcrocuta eximia .

Figures

FIG. 1. — Adcrocuta eximia (Roth & Wagner, 1854), mandible AK3-83, AK3-129, Akkaşdağı, late Miocene (Turolian), Turkey, occlusal view. Scale bar: 5 cm.

FIG. 2. — Adcrocuta eximia (Roth & Wagner, 1854), right hemimandible AK7-68, p2-m2, Akkaşdağı, late Miocene (Turolian), Turkey, buccal view. Scale bar: 5 cm.

FIG. 3. — Adcrocuta eximia (Roth & Wagner, 1854), lower right d4 AK6-x, Akkaşdağı, late Miocene (Turolian), Turkey; A, buccal view; B, lingual view. Scale bar: 3 cm.

FIG. 4. — Adcrocuta eximia (Roth & Wagner, 1854), upper left D2-D3, Akkaşdağı, late Miocene (Turolian), Turkey; A, buccal view; B, lingual view. Scale bar: 3 cm.