Kryptobaatar, Filikomys, Barbatodon, Catopsbaatar and Ptilodus

Barbatodon transylvanicus (Rãdulescu and Samson 1986; Late Cretaceous) is a small multituberculate preserving iron in its incisors as in several living rodents. Originally considered close to Taeniolabis, here it nests with Catopsbaatar. The premolars have been molarized. The sliding joint does not slide much.

Filikomys primaevus (Weaver et al. 2020; NMC 1890; Late Cretaceous) is a Cimolodonta Multituberculata found with others in a burrow/nest. It was originally nested close to Ptilodus but here is related to Catopsbaatar.

Catopsbaatar catopsaloides (originally Djadochtatherium; Kielan-Jaworowska 1974; PM120/107; Late Cretaceous, 72mya; 7cm skull length) the orbits are set far back in the skull. Ankle spurs were present. Derived from a sister to Kryptobaatar, Catopsbaatar has a much reduced lower posterior premolar. Premolars were originally mislabeled above. In dorsal or ventral view, the snout is not constricted. The maxillae extend over the premaxillae, pushing the lateral premaxillary teeth medially.

Kryptobaatar dashzevegir (Kielan-Jaworowska 1970, skull lenth 3cm; Late Cretaceous) is one of the most complete members of the Multituberculata, a clade usually placed outside most mammals, but here nests as a clade within the Rodentia, with Rattus. The mandible slid forward to engage the incisors with each other and back again to grind the molars. A flat cranium also characterizes this clade.

Image above from Digimorph.org and used with permission. Below note the PILs of Kryptobaatar become better aligned when the pes is elevated to the digitigrade configuration.

Ptilodus montanus (Cope 1881; Paleocene; 30-50 cm in length) was similar to a squirrel in many respects but neste with the multituberculates. Note the large fenestra in the palate and the very large lower premolar with cutting ridges.

Below are taxa tested in the LRT that are in the lineage of multituberculates.

Taxa in the lineage of multituberculates

Cope ED 1881. Eocene Plagiaulacidae. American Naturalist 15, 921–922.

Kielan-Jaworowska Z 1970. New Upper Cretaceous multituberculate genera from Bayn Dzak, Gobi Desert. In: Kielan-Jaworowska (ed.), Results of the Polish-Mongolian Palaeontological Expeditions, pt. II. Palaeontologica Polonica 21:35-49.

Kielan-Jaworowska Z 1974. Multituberculate succession in the Late Cretaceous of the Gobi Desert (Mongolia). Palaeontologica Polonica. Results of the Polish-Mongolian Palaeontological Expeditions – Part V. 30: 23–43.

Kielan-Jaworowska Z and Gambaryan PP 1994. Postcranial anatomy and habits of Asian multituberbulate mammals. Fossils & Strata 36:1-92.

Rãdulescu R and Samson P 1986. Précisions sur les affinités des Multituberculés du Crétacé supérieur de Roumaine. C R Acad Sci II: Mec-Phys, Chim, Sci Terre, Sci Univ 303p, p. 1825-1830.

Smith T and Codrea V 2015. Red Iron-Pigmented Tooth Enamel in a Multituberculate Mammal from the Late Cretaceous Transylvanian “Hateg Island”. PLoS ONE 10(7): e0132550. https://doi.org/10.1371/journal.pone.0132550

Weaver LN et al. 2020. Early mammalian social behaviour revealed by
multituberculates from a dinosaur nesting site. Nature ecology & evolution. https://doi.org/10.1038/s41559-020-01325-8

Wible JR Rougier GW 2000. Cranial anatomy of Kryptobaatar dashzevegi (Mammalia, Multituberculata), and its bearing on the evolution of mammalian characters. Bulletin of the American Museum of Natural History 247:1–120. doi:10.1206/0003-0090(2000)247<0001:CAOKDM>2.0.CO;2.

wiki/Kryptobaatar
wiki/Ptilodus
wiki/Catopsbaatar
wki/Filikomys
wiki/Barbatodon