Fruitafossor

Fruitafossor is an extinct genus of small mammaliaforms that lived during the Late Jurassic of western North America. It contains a single described species, Fruitafossor parvus. The fossils were recovered from the Fruita Paleontological Area in Colorado, dating to roughly 150–160 million years ago.

The animal was small, roughly mouse-sized, and is known from a limited set of skeletal remains. The forelimbs and shoulder girdle show adaptations for digging, including robust forelimb bones and large claws, indicating a fossorial lifestyle likely aimed at extracting invertebrates from within fruits or soil. The dentition is simple, with small, peg-like teeth that suggest an insectivorous diet rather than a plant-based one; the jaw and postcranial skeleton share features with other early mammaliaforms but lack the full dental complexity of later true mammals.

Fruitafossor is placed among mammaliaforms, a broader group that includes true mammals and their close relatives, but its exact relationship to crown-group mammals is uncertain and subject to ongoing study.

Significance: The discovery of Fruitafossor provides evidence that specialized digging and insectivory evolved early among mammaliaforms in the Jurassic, contributing to understanding of the ecological diversity and morphological experimentation in early mammal evolution.