Late Jurassic (Tithonian)

Morrison Formation

Bone Cabin Quarry, Albany County, WY, USA

Ultra-rare 3mm mammal.

Mammal.

The mammals of the Jurassic would have looked like rodents to us but they lived at least 85 million years before the earliest true rodents.  These animals belong to groups not far removed from the earliest mammals of the Late Triassic – animals quite alien relative to anything living today – and they’re less familiar even to researchers who specialize in Late Cretaceous groups.