👉 The term "Nannosciurus" is an extinct genus of mammals that lived in the Late Cretaceous period, approximately 68 million years ago. These animals were characterized by small, round heads, a thick, black fur coat, and short limbs that allowed them to move quickly across the ground. Nannosciuruses are known for their distinctive skull features, including large, rounded ears and a narrow, curved jaw that may have been used for hunting.