Triisodontidae is an extinct, probably paraphyletic, or possibly invalid family of mesonychianplacentalmammals. Most triisodontid genera lived during the Paleocene in North America, but the genus Andrewsarchus (if it is a mesonychian, and not an artiodactyl) is known from the middle Eocene of Asia.[2] Triisodontids were the first relatively large predatory mammals to appear in North America following the extinction of the non-bird dinosaurs.[3] They differ from other mesonychian families in having less highly modified teeth.[4]
Because of their comparatively simpler teeth, the triisodontids are regarded as basal mesonychids. A recent study found them to be a paraphyletic assemblage of stem-mesonychians.[5]
^Matthew, W.D. (1937). "Paleocene faunas of the San Juan Basin, New Mexico". Transactions of the American Philosophical Society. 30 (3532). American Philosophical Society: 1–510. Bibcode:1937Natur.140...46C. doi:10.2307/1005521. JSTOR1005521.
^Sarah L. Shelley, Thomas E. Williamson, Stephen L. Brusatte, Resolving the higher-level phylogenetic relationships of “Triisodontidae” (‘Condylarthra’) within Placentalia, October 2015, Society of Vertebrate Paleontology (abstract)