On the metatherian nature of the Deltatheroida, a sister group of the Marsupialia
Article first published online: 9 OCT 2007
Volume 23, Issue 1, pages 1–10, January 1990
How to Cite
KIELAN-JAWOROWSKA, Z. and NESSOV, L. A. (1990), On the metatherian nature of the Deltatheroida, a sister group of the Marsupialia. Lethaia, 23: 1–10. doi: 10.1111/j.1502-3931.1990.tb01776.x
- Issue published online: 9 OCT 2007
- Article first published online: 9 OCT 2007
- 20th December, 1988.
A lower molar of Sulestes sp., a deltatheridiid from the Coniacian of Uzbekistan, is described. The Deltatheroididae new fam. is erected. The Deltatheroididae and Deltatheridiidae are assigned to the order Deltatheroida Kielan-Jaworowska 1982 and it is argued that the Deltatheroida are metatherians, a sister group of Marsupialia. The Deltatheroida have at least an incipient alisphenoid bulla, three premolars sharply differentiated morphologically from four molars, a very large stylar area and the protoconid higher than the metaconid. They differ from known Cretaceous marsupials in having a tendency to lose the last molar, in having a small protocone, a narrow and short talonid, and a hypoconulid and entoconid not approximated. Known deltatheroidan taxa are compared. Relationships of the Deltatheroida and Aegialodontia are discussed. The place of metatherian origin is still not known with certainty. □Mammalia, Metatheria, Deltatheroida, Marsupialia, Cretaceous, Asia, Paleobiogeography.