Colbertia
extinct genus of mammals
Colbertia is an extinct genus of oldfieldthomasiid notoungulate. It lived from the Early to the Middle Eocene, and its fossilized remains were discovered in Argentina and Brazil.
Description
This animal was roughly the size of a Virginia opossum, reaching approximately 50 centimeters in length excluding its tail. Its weight has been estimated to have been around 2 to 3 kilograms.
Colbertia had a relatively elongated skull, with low-crowned (brachydont) molars; the cusps of the molars were joined to form ridge-like structures called lophs, and are therefore considered lophodont. The paracone and the metacone had notable folds. The ankle bones of Colbertia indicates that it was a plantigrade, an ancestral condition within Notoungulata. The bone morphology at the base of the skull was very similar to other basal Notoungulates, although the petrous bone had distinct characteristics also found in similar but slightly more recent notoungulates, such as Dolichostylodon.
Classification
The genus Colbertia was first described in 1952 by Carlos de Paula Couto, as a new genus for a species of notoungulate described two years earlier and attributed to the genus Oldfieldthomasia as O. magellanica. The type species of the genus is Colbertia magellanica, from the Early Eocene Itaboraí Formation of Brazil.
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This entry incorporates text from “Colbertia” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.