--- title: Scientists Discover New Mammal That Survived the Dinosaurs description: Researchers at University of Nebraska-Lincoln (UNL) have discovered the existence of a new mammal that lived among dinosaurs, and even survived after them. canonical: https://time.com/4061577/mammal-dinosaur-extinction-fossil-discovered/ author: Alexandra Sifferlin article:opinion: false article:content_tier: free article:published_time: 2015-10-05T18:17:52.000Z article:modified_time: 2026-02-22T11:31:25.373Z article:section: Science og:title: This Rat-Like Mammal Survived the Dinosaur Extinction og:description: Fossil was discovered by an undergraduate og:url: https://time.com/4061577/mammal-dinosaur-extinction-fossil-discovered/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt0fcdd5678a6fe478/698866e5f887dc51aae92b72/kimbetopalis-reconstruction.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: Kimbetopalis-reconstruction og:type: article twitter:card: summary_large_image twitter:title: This Rat-Like Mammal Survived the Dinosaur Extinction twitter:description: Fossil was discovered by an undergraduate twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt0fcdd5678a6fe478/698866e5f887dc51aae92b72/kimbetopalis-reconstruction.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # Scientists Unearth Rat-Like Mammal That Survived Dinosaur Extinction by [Alexandra Sifferlin](https://time.com/author/alexandra-sifferlin/) ## Alexandra Sifferlin Oct 5, 2015 6:17 PM UTC  Reconstruction drawing of a Kimbetopsalis-simmonsae. Reconstruction drawing of a Kimbetopsalis-simmonsae.Sarah Shelley—University of Edinburgh by [Alexandra Sifferlin](https://time.com/author/alexandra-sifferlin/) ## Alexandra Sifferlin Oct 5, 2015 6:17 PM UTC Researchers have [discovered](http://onlinelibrary.wiley.com/doi/10.1111/zoj.12336/abstract) the existence of a new, rat-like mammal that existed alongside dinosaurs, and even survived after them. An University of Nebraska-Lincoln (UNL) undergraduate student, Carissa Raymond, discovered the fossil of the species which walked the earth some 65 million years ago. Raymond discovered some peculiar black teeth during a fieldwork trip with UNL paleontologist Ross Secord and other students in the San Juan Basin in New Mexico. A UNL[ press release](http://news.unl.edu/newsrooms/unltoday/article/undergrad-discovers-new-mammal-species/) continues the story: “The teeth had cusps arranged in rows resembling kernels on an ear of corn or the teeth of a meat-tenderizing mallet. “They were characteristic of multituberculate mammals, rodent-like creatures that lived with dinosaurs for more than 100 million years. They survived the dinosaur extinction only to die out about 40 million years ago.” The species, named _Kimbetopsalis simmonsae_, was the first new multituberculate mammal (multiple rows of cusps on an animals’ teeth), to be discovered in the area in over 100 years. [The Washington _Post_ reports](http://www.washingtonpost.com/news/morning-mix/wp/2015/10/05/scientists-discover-furry-new-post-apocalyptic-critter-that-survived-demise-of-the-dinosaurs/) that the mammal grew from “tiny proportions” to about the size of a large beaver over 500,000 years — an extremely rapid growth, in terms of evolution. ‭“It’s rare for anybody to find one of these,” Thomas Williamson, a curator at the New Mexico Museum of Natural History and Science, [said](http://news.unl.edu/newsrooms/unltoday/article/undergrad-discovers-new-mammal-species/). “I wish I had found it.” ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4061577/mammal-dinosaur-extinction-fossil-discovered/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4061577/mammal-dinosaur-extinction-fossil-discovered/"},"headline":"Scientists Unearth Rat-Like Mammal That Survived Dinosaur Extinction","datePublished":"2015-10-05T18:17:52.000Z","dateModified":"2026-02-22T11:31:25.373Z","description":"An undergraduate made the discovery","url":"https://time.com/4061577/mammal-dinosaur-extinction-fossil-discovered/","keywords":["animals"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt0fcdd5678a6fe478/698866e5f887dc51aae92b72/kimbetopalis-reconstruction.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Alexandra Sifferlin","jobTitle":null,"url":"https://time.com/author/alexandra-sifferlin/"}],"articleSection":"Science","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt0fcdd5678a6fe478/698866e5f887dc51aae92b72/kimbetopalis-reconstruction.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Kimbetopalis-reconstruction","caption":"Reconstruction drawing of a Kimbetopsalis-simmonsae.","creditText":"Sarah Shelley—University of Edinburgh","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/science/","name":"Science"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/animals/","name":"animals"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4061577/mammal-dinosaur-extinction-fossil-discovered/","name":"Scientists Unearth Rat-Like Mammal That Survived Dinosaur Extinction"}}]}] ```