Ptilodus is a genus of mammals from the extinct order of Multituberculata, and lived during the Paleocene in North America.
Ptilodus was a relatively large multituberculate, being 30 to 50 centimetres (12 to 20 in) in length, which is about the same size as a modern day squirrel. Its feet, legs and long tail suggest it was a good climber, so it very possibly led a squirrel-like lifestyle.
The genus was named by paleontologist Edward Drinker Cope in 1881. Cope also mistakenly assigned some material belonging to this genus to Chirox in 1884. Elements from Ectypodus (Jepsen, 1940) and Neoplagiaulax have also been reassigned to this genus.
In The Land Before Time
A Ptilodus appears in The Land Before Time XIV: Journey of the Brave, where an individual runs in front of the Yutyrannus pair and indirectly distracts them from attacking Littlefoot and the others. Its fate is unknown, though it is implied to be eaten.