multituberculate
noun
mul·ti·tu·ber·cu·late ˌməl-tē-ˌtü-ˈbər-kyə-lət 
: any of an order (Multituberculata) of relatively small extinct mammals of the Mesozoic and early Cenozoic that typically resembled rodents, had many-cusped molars, and have no known living descendants
Example Sentences
Recent Examples on the Web But Adalatherium’s anatomy suggests a connection with another group of mammals called multituberculates, which lived in the northern hemisphere. 
Theresa Machemer, Smithsonian Magazine, 1 May 2020 Jeholbaatar belonged to a now extinct lineage of mammals called the multituberculates that endured for well over 100 million years. Jim Daley, Scientific American, 5 Dec. 2019
Theresa Machemer, Smithsonian Magazine, 1 May 2020 Jeholbaatar belonged to a now extinct lineage of mammals called the multituberculates that endured for well over 100 million years. Jim Daley, Scientific American, 5 Dec. 2019 Word History
Etymology
New Latin Multituberculata, ultimately from Latin multi- + New Latin tuberculatus tuberculate
First Known Use
1884, in the meaning defined above