{"id":637518,"date":"2026-04-30T01:15:15","date_gmt":"2026-04-30T01:15:15","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/637518\/"},"modified":"2026-04-30T01:15:15","modified_gmt":"2026-04-30T01:15:15","slug":"omnivorous-rodent-like-mammal-lived-in-dinosaurs-shadow-on-pacific-coast","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/637518\/","title":{"rendered":"Omnivorous, Rodent-Like Mammal Lived in Dinosaurs\u2019 Shadow on Pacific Coast"},"content":{"rendered":"

Paleontologists have descibed a new species of the multituberculate mammal genus Cimolodon<\/a> based on a fossil found in Baja California, Mexico.<\/p>\n

\"An<\/a><\/p>\n

An illustration of Cimolodon desosai on the tree with a fruit in its mouth. Image credit: Andrey Atuchin.<\/p>\n

The newly-described mammal species lived in what is now Mexico about 75 million years ago (Cretaceous period).<\/p>\n

Named Cimolodon desosai, the ancient creature was about the size of a golden hamster and weighed 100 g.<\/p>\n

The animal likely scampered on the ground and in trees and ate fruits and insects.<\/p>\n

\u201cThe genus Cimolodon was a pretty common mammal during the Late Cretaceous, the last epoch of the Age of Dinosaurs,\u201d said Professor Gregory Wilson Mantilla, a paleontologist at the University of Washington and curator of vertebrate paleontology at the Burke Museum.<\/p>\n

\u201cCimolodon fossils have been found throughout western North America, from western Canada down through Mexico.\u201d<\/p>\n

\u201cThis new species, Cimolodon desosai, was ancestral to the species that survived the extinction event.\u201d<\/p>\n

\u201cIt and its descendants were relatively small and omnivorous \u2014 two traits that were advantageous for surviving.\u201d<\/p>\n

The fossilized remains of Cimolodon desosai \u2014 teeth, a skull, jaws and parts of the skeleton, including a femur and an ulna \u2014 were found in 2009 in the El Gallo Formation of Baja California.<\/p>\n

The specimen represents the most complete mammal known from the Mesozoic of M\u00e9xico and one of the best known cimolodontan multituberculates<\/a> from North America.<\/p>\n

\u201cIt\u2019s very hard to find fossils at this site compared to other areas,\u201d Professor Wilson Mantilla said.<\/p>\n

The fact that the paleontologists uncovered more than just teeth for Cimolodon desosai means that they can better understand its size and shape and how it likely moved.<\/p>\n

It also helps fill out the picture of this genus and the habitat in which it lived, and contributes to a better understanding of the multituberculate group in general.<\/p>\n

\u201cThe El Gallo mammalian local fauna is now known from 16 specimens referred to three multituberculate species, one metatherian, and one eutherian,\u201d the researchers said.<\/p>\n

\u201cAlthough further sampling is needed, the mammalian local fauna presently shows greatest biogeographic affinities with the Terlingua local fauna of western Texas.\u201d<\/p>\n

The team\u2019s paper<\/a> was published this month in the Journal of Vertebrate Paleontology.<\/p>\n

_____<\/p>\n

Gregory P. Wilson Mantilla et al. Cranial and postcranial remains of a new species of Cimolodon (Mammalia, Multituberculata, Cimolodontidae) from the Upper Cretaceous (Campanian) El Gallo Formation of Baja California, M\u00e9xico. Journal of Vertebrate Paleontology, published online April 22, 2026; doi: 10.1080\/02724634.2026.2641109<\/p>\n","protected":false},"excerpt":{"rendered":"Paleontologists have descibed a new species of the multituberculate mammal genus Cimolodon based on a fossil found in…\n","protected":false},"author":2,"featured_media":637519,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[155967,49,48,238164,238165,238166,48227,238167,16433,238168,31922,1072,238169,238170,1671,238171,66,84270,27781],"class_list":["post-637518","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-baja-california","tag-ca","tag-canada","tag-cimolodon","tag-cimolodon-desosai","tag-cimolodontidae","tag-cretaceous","tag-el-gallo-formation","tag-fossil","tag-jaw","tag-mammal","tag-mexico","tag-multituberculata","tag-multituberculate","tag-north-america","tag-omnivory","tag-science","tag-skull","tag-teeth"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/637518","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=637518"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/637518\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/637519"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=637518"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=637518"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=637518"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}