CTENODACTYLINAE HINTON, 1933

Vianey-Liaud, Monique, Rodrigues, Helder Gomes & Marivaux, Laurent, 2010, A new Oligocene Ctenodactylinae (Rodentia: Mammalia) from Ulantatal (nei Mongol): new insight on the phylogenetic origins of the modern Ctenodactylidae, Zoological Journal of the Linnean Society 160 (3), pp. 531-550 : 533

CTENODACTYLINAE HINTON, 1933

Type genus: Ctenodactylus, Gray, 1828 .

Included genera: Sayimys , Prosayimys , Metasayimys , Africanomys , Sardomys , Pireddamys , Irhoudia , Pellegrinia , Pectinator , Massouteria , Felovia , Helanshania gen. nov.

The genus Testouromys was erected by Robinson & Black (1974) for one complete m3, one broken m1, and one eroded M1, from a Tunisian Miocene locality (Testour). The m3 has a pattern close to that of some species of Sayimys , with open – V shaped mesosynclinid and metasynclinid, like in Sayimys baskini ( López-Antoñanza & Sen, 2004) . For that reason, Testouromys could be synonymized with Sayimys . Akzharomys , erected by Shevyreva (1994) on the basis of a few teeth from the lower Miocene Akhzarian Formation, has not been further used. From its trilobate pattern, the lack of a trigonoid structure on the m3, and the M2 with a sinus relatively longer than in molars of Helanshania or Prosayimys , as in the species of Sayimys , this genus is possibly a junior synonym of Sayimys .

Geological range and geographical distribution: Late early to early late Oligocene in Central Asia (Inner Mongolia), from early to late Miocene (North China, Mongolia, Kazakhstan, North India, Pakistan, Greece, Turkey, Libya, Morocco, Sardinia), Pleistocene (Sicily), Recent (arid zones of North Africa, from Morocco to Libya, Saharan Africa from Mauritania, Algeria, Chad to Ethiopia and Somalia).

Emended differential diagnosis

Ctenodactylinae differ from Tataromyinae in:

Skull and mandible: ‘reduction’ of the temporal masticatory apparatus, which includes a small temporal fossa and a weak temporal crest, low condyle and low to absent coronoid process; sciurognathous mandible showing a great development of the masseter -pterygoid masticatory apparatus, with a single horizontal heavy masseteric crest.

Cheek teeth: reduction of the premolars (in size and eventually in number) compared to the Tataromyinae ; dental formula 1/1, 2-1/1-0, 3/3. DP4/dp4 may be retained a more or less long time; then P4/p4 may be lost early in life.

Cheek teeth from unilaterally hypsodont to hypsodont; cementum occasionally filling the sinus (sinusid) and synclines (synclinids).

Entolophid displaced forward, to the middle of the lower molars; possible reduction of the mesosynclinid; anterocone absent on the upper cheek teeth; hypocone as strong as the protocone; reduction of the anterior and posterior synclines on the upper molars; tendency to produce a bilobate pattern, first on upper, then on lower, molars.