|1st Species||Repenomamus robustus|
|2nd Species||Repenomamus giganticus|
|Time Range||124.6–123.2 mya|
|Name Meaning||Crawling mammal|
|Physical Dimensions||60 centimeters long for R.robustus; 1 meter long for R.giganticus|
|Weight||6 kilograms for R.robustus; 14 kilograms for R.giganticus|
Repenomamus is a gobiconodontid eutriconodont mammal from the Early Cretaceous of China. It was named in 2000 by Jinling Li and his associates. It was one of the biggest Mesozoic mammals to exist, as well as one of the few specialized ones.
Repenomamus bore some resemblance to a badger. It had a stout, relatively long, barrel-shaped body, 4 relatively short, sprawling legs, a moderately long tail, and a mid-sized, conical head with large jaws. Its body would have been covered in fur.
Repenomamus was a predator, preying on lizards, primitive birds, and other small dinosaurs. It had long, sharp canines and incisors for shearing flesh, as well as pointed premolars (teeth placed between the canines and molars) for grasping and piercing prey.
Repenomamus was unique in the sense that it was one of the only Mesozoic mammals to have adapted a hypercarnivorous lifestyle; its relatively large size meant that it could overpower small animals and prey on them with ease, its teeth were adapted for shearing flesh and piercing through prey, and its jaws were strong enough to bite through bone to some extent. More evidence for this kind of lifestyle was found when a specimen of Repenomamus giganticus was found with a baby Psittacosaurus in its stomach region; the baby dinosaur was found in smaller pieces, meaning that the mammal ripped it apart with its mouth before swallowing it in smaller, more digestible chunks. Another interesting thing to note about Repenomamus is that, due to the anatomy of its shoulder and leg bones, it walked with a sprawling gait, similarly to a reptile; as well as this, its pelvic bones were similar to those of marsupials and monotremes, meaning that it either laid eggs or gave birth to undeveloped young that it carried around in a pouch. In all, Repenomamus was one of the first unique and specialized Mesozoic mammalians to exist; recent digs in well-known bone beds would lead way to the discovery and naming of other specialized Mesozoic mammalians, such as Fruitafossor, Castorocauda, and Volaticotherium.