Also found in the same rocks were Dinnebitodon amarali and Nearctylodon broomi, but the latter was later considered to be a juvenile specimen of Kayentatherium, and so was synonymised.

[2] Some researchers think it might have been semi-aquatic, with adaptations formerly thought to indicate digging habits now interpreted as specialisation towards limb-powered swimming.

A find in 2000 of Kayentatherium wellesi from the Kayenta formation of Arizona was examined by microCT scan, and revealed an adult with at least 38 perinates, a number considerably higher than any living mammal litter.

Perinates had similar skull proportions to adults, with well-developed teeth, and may have been able to fend for themselves at birth.

[5] Allometric study shows that tritylodontids had proportionally smaller brains at this stage than mammal perinates, which supports the hypothesis that the evolution of larger brain size in early mammals was associated with changes in reproductive strategy to invest more parental energy in a smaller number of offspring.