👉 Musseromys is a genus of extinct mammals that lived during the Cretaceous period, about 68-65 million years ago. These creatures were known for their large, massive teeth and the presence of a unique skull shape, which was not found in other species from this time frame. Musseromys is distinguished by its long, slender bodies with bulbous heads, and it had an elongated snout and short legs that allowed them to move across the ground easily.