Ictitherium viverrinum Roth F Wagner, 1854

Bonis, Louis de, 2005, Carnivora (Mammalia) from the late Miocene of Akkaşdağı, Turkey, Geodiversitas 27 (4), pp. 567-589 : 571-572

Ictitherium viverrinum Roth F Wagner, 1854

Ictitherium viverrinum Roth F Wagner, 1854: 392 . — Kretzoi 1938: 113. — Solounias 1981: 61. — Kurtén 1982: 1009. — Werdelin 1988: 101. — Beaumont 1988: 28. — Semenov 1989: 45. — Werdelin F Solounias 1991: 24.

Ictitherium robustum – Gaudry 1862 -1867: 52. — Arambourg F Piveteau 1929: 65.

Thalassictis gracilis Hensel, 1862: 566 .

Thalassictis viverrina – Hensel 1862: 566.

Ictitherium gaudryi Zdansky, 1924: 67 .

Ictitherium sinense Zdansky, 1924: 72 .

Palhyaena x gaudryi – Kretzoi 1938: 113.

Sinictitherium sinense – Kretzoi 1938: 114.

MATERIAL. — Left half mandible (AK5-209) with p4-m1, right p3, distal part of hind limb.

BACKGROUND

This is one of the smallest hyaenid recovered in Akkaşdagwı. A mandible with p4-m1 ( Fig. 5 ) is the sole specimen belonging to this species. Although the species was perfectly defined by Roth F Wagner (1854)for specimens coming from the late Miocene locality of Pikermi ( Greece) which is the type locality of the species, Ictitherium viverrinum has a complicated history. Some years before the work of the two Austrian palaeontologists, Gervais (1850) named a species Thalassictis robusta for specimens recovered in the locality Kishinev ( Ukraine) from figures in a manuscript written by von Nordmann. Some years later (1862-1867), Gaudry went back to the genus Ictitherium Wagner, 1848 and he called Ictitherium robustum the sample from Pikermi ( Greece) nowadays housed in the Muséum national d’Histoire naturelle, Paris ( MNHN). So the two species viverrinum and robustum were confused.The latter species was even considered as the type species of Ictitherium in so far as viverrinum and robustum (or robusta ) were synonyms ( Pilgrim 1931: 83) or attributed to other genera (see Werdelin F Solounias 1991). The question was revisited by Kurtén (1954) when redescribing and refiguring the type collection from Kishinev housed in the Museum of the Geological Institute of Helsinki University ( Finland). Leaving these specimens in the genus Ictitherium Wagner, 1848 , he compared the collection with other species and he also considered in the genus Ictitherium the following species: I. wongii Zdansky, 1924 , I. hipparionum (Gervais, 1846) whose type specimen is lost, I. sivalense (Lyddeker, 1877) , I. hyaenoides Zdansky, 1924 , I. gaudryi Zdansky, 1924 , I. indicum (Pilgrim, 1910) and I. tauricum Borissiak, 1915 but strangely he did not take into account I. viverrinum because he probably believed that it was really a synonym of I. robustum . Solounias (1981),in revising the hyaenids and bovids from the late Miocene of Samos ( Greece), stressed clearly the differences between the species viverrinum and robusta , the first belonging to the genus Ictitherium and the second to the genus Thalassictis Gervais ex. Nordmann, 1850, with both being the type species of their genera. He gave a detailed description of I. viverrinum principally from the specimens of Samos. Shortly afterwards, in a parallel work, Kurtén (1982) reached the same conclusion that these species are not congeneric and that the two genera have different evolutionary trends and adaptations. He figured both lower and upper carnassials of these species to show the differences ( Kurtén 1982: fig. 1) and nowadays this conclusion is generally accepted. One mandible from Akkaşdagwı has the characters of Ictitherium viverrinum .

DESCRIPTION ( FIG. 5 )

The corpus is shallow with two mental foramina, the anterior under p2 and the second one under the anterior root of p3. The masseteric fossa is not very deep. The corpus bears the alveolus of c, p1 (single rooted), p2 and p3 (both double-root- ed). The p4 is elongated with traces of buccal and lingual cingula. The anterior accessory cuspid is quite small and bulging. The main cuspid (“protoconid”) has a faint vertical anterior crest and is as high as the paraconid of m1. The talonid is long and broad with a large buccal accessory cuspid (“hypoconid”) and a smaller but well distinct lingual accessory cuspid (“entoconid”) and a distal crest which ends the talonid basin. This talonid looks a little like that of a molar. This premolar is very close to that of I. viverrinum from Pikermi. The m1 is long especially because of the long talonid ( Fig. 5 ). The trigonid is low but the metaconid is well developed. The hypoconid is linked by a low crest to the distal base of the protoconid. The entoconid is well developed and clearly separated from the metaconid. The hypoconulid exists as a distal crest which terminates the trigonid basin, separated by two notches from the other cuspids of the talonid. There is a single quite large alveolus for m2. There is a well developed cingulum along the base of the buccal face. There is a single quite large alveolus for m2. All these characters are present in the m1 of Ictitherium viverrinum from Pikermi. The size of the teeth lies among that of the smallest specimens of this species measured in the MNHN (Appendix: Table 1). An isolated third lower premolar matches this species.

A distal portion of a hind limb with astragalus, naviculum (tarsal scaphoid), ectocuneiform, mesocuneiform, metatarsals II to V and some phalanges are quite similar to the foot figured by Gaudry (1862 -1867: pl. 9, figs 5, 6) under the name Ictitherium “ robustum ”.

Figures

FIG. 5. — Ictitherium viverrinum Roth & Wagner, 1854, left hemi-mandible AK5-209, p4-m1, Akkaşdağı, late Miocene (Turolian), Turkey; A, buccal view; B, lingual view. Scale bar: 5 cm.