[1] The earliest and most primitive pantodonts, Bemalambda (with a 20 cm (7.9 in) skull probably the size of a dog) and Hypsilolambda, appear in the early Paleocene Shanghuan Formation in China.

[3] The pantodonts varied considerably in size: the small Archaeolambda, of which there is a complete skeleton from the Late Palaeocene of China, was probably arboreal, while the North American, ground sloth-like Barylambda was massive, slow-moving ("graviportal") and probably browsed on high vegetation.

Asian families can typically be distinguished from the American because their paracone and metacone (bottom of W on side of tongue) tend to be closer together.

[1] The pantodonts were previously grouped with the ungulates as amblypods, paenungulates, or arctocyonids, but since McKenna & Bell 1997 they have been allied with the tillodonts and considered to be derived from the cimolestids.

[1] Some dental features can possibly link the most primitive pantodonts to the palaeoryctids, a group of small and insectivorous mammals that evolved during the Cretaceous.