Fruitafossor windscheffeli

Fruitafossor was a tiny Late Jurassic mammal from the Morrison Formation of Colorado. Small even by Mesozoic mammal standards, it had powerful forelimbs that were adapted for digging burrows. The open-rooted, peg-like teeth may have been an adaptation to insect-eating. Fruitafossor was so close to the base of Mammalia that the group (theriomorphs) that it has been most commonly put into are not always found to be true mammals. An alternative phylogenetic placement suggests Fruitafossor was instead at the base of the mammal lineage that includes the egg-laying monotremes.