Nostiradopsis

Nostiradopsis is a genus of small, extinct mammals that lived during the Late Cretaceous period, approximately 72 million years ago. The genus is known from a single species, Nostiradopsis macropus, which was discovered in the Hell Creek Formation of North Dakota, USA. The name Nostiradopsis is derived from the Greek words "nostos," meaning "return," and "irad," meaning "to run," reflecting the animal's unique running style.

Nostiradopsis was a small, bipedal mammal, with a body length of about 15 centimeters (6 inches) and a weight of around 50 grams (1.7 ounces). It had a long, slender snout and small, sharp teeth, suggesting that it was an insectivore. The most distinctive feature of Nostiradopsis was its unusual hind limbs, which were much longer than its forelimbs. This adaptation allowed the animal to run on its hind legs, similar to a kangaroo, and may have helped it to escape predators.

The discovery of Nostiradopsis has provided valuable insights into the early evolution of mammals. Its unique running style and small size suggest that it was a specialized, early mammal that may have been adapted to a specific ecological niche. The genus is also notable for its early appearance in the fossil record, as it lived during a time when mammals were still relatively rare and small.

In summary, Nostiradopsis is a small, extinct mammal that lived during the Late Cretaceous period. It is known for its unique running style and early appearance in the fossil record, and has provided valuable insights into the early evolution of mammals.