Djadochtatheriidae Kielan−Jaworowska and Hurum, 1997

Kielan-Jaworowska, Zofia, Hurum, Jørn H. & Lopatin, Alexey V., 2005, Skull structure in Catopsbaatar and the zygomatic ridges in multituberculate mammals, Acta Palaeontologica Polonica 50 (3), pp. 487-512 : 489

Family Djadochtatheriidae Kielan−Jaworowska and Hurum, 1997

Revised diagnosis.—Well−defined family, which includes the largest Djadochtatherioidea . Differ from all other multituberculates (and from all other mammals) in having a subtrapezoidal snout in dorsal view, with wide anterior margin and lateral margins confluent with zygomatic arches rather than incurved in front of the arches. Djadochtatheriidae differ from other members of Djadochtatherioidea in having the snout extending for almost 50 percent or more of the skull length. They have very long postorbital processes directed postero−laterally and downwards, and parietal ridges extending from them postero−medially. The parietal apparently sends a lateral process along the upper margin of the orbit (character well−documented in Kryptobaatar , but is less certain in other genera). The nuchal crest is very prominent, incurved anteriorly in the middle, so that the skull in dorsal view is shorter in the middle than laterally. They share with Chulsanbaatar , Kamptobaatar , and Taeniolabididae lack of palatal vacuities.

Genera assigned.— Djadochtatherium Simpson, 1925 , Kryptobaatar Kielan−Jaworowska, 1970 , Catopsbaatar Kielan−Jaworowska, 1994 , and Tombaatar Rougier, Novacek, and Dashzeveg, 1997 .

Distribution.—Late Cretaceous (?early and?late Campanian) formations Djadokhta, Bayan Mandahu, Baruungoyot, and their stratigraphic equivalents in the Gobi Desert.