Necrolestes

Necrolestes (from Ancient Greek νεκρός (necrós), meaning "dead", and λῃστής (lēistḗs), meaning "robber") is an extinct genus of mammals, which lived during the Early Miocene in what is now Argentine Patagonia. It is the most recent known genus of Meridiolestida, an extinct group of mammals more closely related to therians (marsupials and placentals) than to monotremes, which were the dominant mammals in South America during the Late Cretaceous. It contains two species, N. patagonensis and N. mirabilis; the type species N. patagonensis was named by Florentino Ameghino in 1891 based on remains found by his brother, Carlos Ameghino in Patagonia. Fossils of Necrolestes have been found in the Sarmiento and Santa Cruz Formations. Its morphology suggests that it was a digging, subterranean-dwelling mole-like mammal that fed on invertebrates.

== Description == thumb|right|230px|Lower jaw About one-third of the skeleton of N. patagonensis—including most of the skull— has been found as disassociated bones of several individuals. The snout bends upwards at its end. The opening of the nasal fenestra has a septomaxilla separating the nasal and premaxilla bones, which is unknown in therian mammals, with the nasal fenestra also appearing to have ossified external nasal cartilage. The forelimbs have numerous characters in common with those of fossorial mammals, including a medially curved olecranon process of the ulna, and a mediolaterally compressed head of the humerus.