Pantolambda

Pantolambda (Greek: "all" (pantos), "lambda" (lambda), in a reference to the shape of upper premolars, similar to the Greek letter lambda) is an extinct genus of Paleocene pantodont mammal. Pantolambda lived during the middle Paleocene, and has been found both in Asia and North America.

Cretaceous mammals, which had to compete with dinosaurs, were generally small insect eaters. Pantolambda was one of the first mammals to expand into the large-animal niches left vacant by the extinction of the dinosaurs. Pantolambda and other early pantodonts would quickly evolve into heavy animals such as Barylambda and Coryphodon. These were the first large browsers, pioneering styles of life later followed by many unrelated groups of mammals: rhinos, tapirs, hippos, ground sloths, and elephants. Pantodonts such as Pantolambda were definitely not tree dwellers.