Paleontological Journal

, Volume 43, Issue 3, pp 237–250

Eotherapsid hypothesis for the origin of Monotremata


    • Borissiak Paleontological InstituteRussian Academy of Sciences

DOI: 10.1134/S0031030109030010

Cite this article as:
Ivakhnenko, M.F. Paleontol. J. (2009) 43: 237. doi:10.1134/S0031030109030010


Comparative study of the cranial structures (lateral wall of the braincase, temporal and tympanic regions) of mammals and theromorphs shows that Monotremata evolved from the eotherapsid stem of theromorphs, while therian mammals are descendants of eutherapsids.

Key words

Monotremata Theromorpha cranial morphology

Copyright information

© Pleiades Publishing, Ltd. 2009