Bemalambdidae

The bemalambdids are, along with Harpyodus and Alcidedorbignya, the most primitive pantodonts. Hypsilolambda is known only from a skull and teeth, but Bemalambda is known from complete cranial and postcranial specimens and the best preserved mammal from Shanghuan. It was dog-sized (a large animal for its era) and omnivorous.[2]

Both genera have dilambdodont upper premolars (W-shaped crests on the crowns), one of the characteristics of pantodonts, but their upper molars, unlike in later pantodonts, are almost zalambdodont (V-shaped crests) and transversely elongated with the paracone and metacone (cusp) appressed or connated. On p³-M³, there is a large buccal platform on the crowns, the stylar shelf. An exterior indentation on the buccal side, the ectoflexus, is very deep. The lower cheek teeth are easily recognizable as pantodont.[3]

The bemalambdids had a low and short skull with a very small braincase; a prominent sagittal crest and deep temporal fossae, a broad snout; and flaring zygomatic processes. The high coronoid process on the mandible suggest the chewing musculatures was more developed than in later pantodonts. The postcranium was robust, and, judging from a single massive humerus, adapted for digging.[3]

• the Early Paleocene (65.5 to 58.7 Ma) of Guangdong, China (type) (25.1°N 114.3°E / 25.1; 114.3, paleocoordinates 26.0°N 109.4°E / 26.0; 109.4)[4]
• the Early Paleocene (65.5 - 58.7 Ma) of Shaanxi, China[5]
• the Middle Paleocene (61.7 - 58.7 Ma) of Jiangxi, China[6]