Temporal range: Jurassic–Oligocene
160 to 35 million years ago
|Skull of Ptilodus|
They were eventually outcompeted by rodents, becoming extinct during the early Oligocene.
At least 200 species are known, ranging from mouse-sized to beaver-sized. These species occupied many ecological niches, ranging from burrow-dwelling to squirrel-like tree-dwelling.
Multituberculates are usually placed outside both the two main groups of living mammals, the Theria (placentals and marsupials), and monotremes. Some cladistic analyses put them closer to Theria than to monotremes.
The multituberculates had a head anatomy similar to rodents. They had cheek-teeth separated from the chisel-like front teeth by a wide tooth-less gap (called the diastema). Each cheek-tooth displayed several rows of small cusps (or tubercles, hence the name) which worked against similar rows in the teeth of the jaw. It was an efficient chopping device.
Images for kids
Ectypodus eating a contemporary rodent. Some multituberculates are known to have had omnivorous or animalivorous habits.
Multituberculate Facts for Kids. Kiddle Encyclopedia.