{"id":647529,"date":"2026-05-03T19:50:12","date_gmt":"2026-05-03T19:50:12","guid":{"rendered":"https:\/\/www.newsbeep.com\/au\/647529\/"},"modified":"2026-05-03T19:50:12","modified_gmt":"2026-05-03T19:50:12","slug":"this-tiny-creature-survived-a-world-of-dinosaurs-and-changed-what-came-next","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/au\/647529\/","title":{"rendered":"This Tiny Creature Survived a World of Dinosaurs and Changed What Came Next"},"content":{"rendered":"

\"Cimolodon<\/a>An illustration of Cimolodon desosai on the tree with a fruit in its mouth. It was about the size of a golden hamster, the researchers said. It likely scampered on the ground and in the trees and ate fruits and insects. Credit: Andrey AtuchinThis tiny dinosaur-era mammal may hold the secret to surviving Earth\u2019s worst extinction.<\/p>\n

Mammals lived alongside dinosaurs for millions of years until a catastrophic event 66 million years ago wiped out about 75% of life on Earth. Even after this mass extinction, some species endured. Among the survivors were small, rodent-like mammals from the genus Cimolodon. These animals belonged to a group known as multituberculates, which first appeared during the Jurassic Period and survived for more than 100 million years before eventually disappearing. By studying them, scientists gain insight into how early mammals made it through the extinction and later evolved into the wide range of species seen today.<\/p>\n

New Species Found in Baja California<\/p>\n

Researchers led by the University of Washington have identified a previously unknown species within this genus using a fossil discovered at a site in Baja California. The fossil is estimated to be about 75 million years old. The new species, named Cimolodon desosai, was roughly the size of a golden hamster. Scientists believe it moved both on the ground and in trees and likely fed on fruits and insects.<\/p>\n

The findings were published April 22 in the Journal of Vertebrate Paleontology.<\/p>\n

A Common Mammal With Survival Advantages<\/p>\n

\u201cThe genus Cimolodon was a pretty common mammal during the Late Cretaceous, the last epoch of the Age of Dinosaurs. Cimolodon fossils have been found throughout western North America, from western Canada down through Mexico,\u201d said senior author Gregory Wilson Mantilla, a UW professor of biology and curator of vertebrate paleontology at the Burke Museum. \u201cThis new species, Cimolodon desosai, was ancestral to the species that survived the extinction event. It and its descendants were relatively small and omnivorous \u2014 two traits that were advantageous for surviving.\u201d<\/p>\n

Rare Fossil Provides More Complete Picture<\/p>\n

The fossil was first discovered in 2009 by Wilson Mantilla and his team. Unlike many similar finds, which often consist only of teeth, this specimen included a broader set of remains. The researchers recovered teeth, a skull, jaws, and parts of the skeleton, including a femur and an ulna.<\/p>\n

\u201cIt\u2019s very hard to find fossils at this site compared to other areas,\u201d Wilson Mantilla said. \u201cAt first, my field assistant found just a little tooth poking out. If he had just found that, I would have been over the moon. But then when we looked inside the crack of the rock, we could see there was more bone.\u201d<\/p>\n

Because the team uncovered more than just teeth, they were able to better estimate the animal\u2019s size, body structure, and movement. These details also provide a clearer picture of the environment it lived in and improve understanding of the multituberculate group overall.<\/p>\n

Advanced Imaging and Identification<\/p>\n

To study the fossil in detail, the researchers used digital imaging and micro-computed tomography, or micro-CT, to produce high-resolution images. They then compared the teeth of C. desosai with those of related species in the Cimolodon genus to confirm it represented a new species.<\/p>\n

\u201cThat far back in time everything is named based on their tooth characteristics,\u201d Wilson Mantilla said. \u201cIf you find a skeleton that\u2019s missing teeth, sometimes it\u2019s hard to attach it to a name.\u201d<\/p>\n

Naming the Species and Acknowledgments<\/p>\n

The new species was named after Michael de Sosa VI, the field assistant who first noticed the fossil. De Sosa died while the team was still analyzing the specimen.<\/p>\n

\u201cHe was a great field assistant, and he was like a little brother to me,\u201d Wilson Mantilla said. \u201cIt\u2019s a great specimen to be associated with.\u201d<\/p>\n

Reference: \u201cCranial 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\u201d by Gregory P. Wilson Mantilla, Isiah R. Newbins, David E. Fastovsky, Yue Zhang, Marisol Montellano-Ballesteros, Dalia Garc\u00eda Alc\u00e1ntara and Meng Chen, 22 April 2026,\u00a0Journal of Vertebrate Paleontology.
DOI: 10.1080\/02724634.2026.2641109<\/a><\/p>\n

Additional co-authors are Isiah Newbins, UW doctoral student in biology, David Fastovsky at the University of Rhode Island; Yue Zhang, who completed this research as a UW postdoctoral fellow in biology; Meng Chen, who completed this research as a UW doctoral student in biology; and Marisol Montellano-Ballesteros and Dalia Garc\u00eda Alc\u00e1ntara at the Universidad Nacional Aut\u00f3noma de M\u00e9xico.<\/p>\n

This research was funded by UC MEXUS-CONACYT, Direcci\u00f3n General de Asuntos del Personal Acad\u00e9mico PAPIIT IN111209-2, the UW College of Arts and Sciences, the UW Department of Biology and the American Philosophical Society.<\/p>\n

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Follow us on Google<\/a> and Google News<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"An illustration of Cimolodon desosai on the tree with a fruit in its mouth. It was about the…\n","protected":false},"author":2,"featured_media":647530,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[64,63,2931,313304,32501,9867,128,99811,87182],"class_list":["post-647529","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-au","tag-australia","tag-evolution","tag-extinction-event","tag-mammals","tag-paleontology","tag-science","tag-university-of-washington","tag-vertebrates"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/647529","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=647529"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/647529\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/647530"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=647529"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=647529"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=647529"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}