Cronopio dentiacutus
provided by EOL authors
Cronopio dentiacutus was a dryolestoid mammal that lived in the woodlands of Argentina in the Middle Cretaceous, about 100-96 million years ago . Paleontologist Guillermo Rougier said it superficially resembled the fictional Scrat the sabre-toothed squirrel in the 'Ice Age' films (2,5). This mouse-sized mammal was a few inches long and weighed about 1 oz (28 g). It had a narrow snout and 2 long canines and ate insects.
Cronopio spent most of its time high up in trees, where it was less likely to be eaten or unintentionally squashed by dinosaurs (5).
It was named by Rougier, Apesteguía and Gaetano in 2011 after fictional characters in the work of Argentinian writer Julio Cortázar (1,3); 'dentiacutus' derives from the Latin for "sharp-toothed" (1). It belonged to the Meridiolestida branch of the Superorder Dryolestoidea, which survived from from the Late Cretaceous to early Paleocene (100–60 million years ago) in South America. It is the earliest dryolestoid mammal discovered in South America. Cronopio and Necrolestes patagoensis are the only known mammals with single-rooted molars; most mammals have double-rooted molars. Necrolestes was thought to be a marsupial, but further analysis shows that it belonged to a separate group that was believed to have died out 45 million years after Cronopio. Wible (4) said Necrolestes’s supreme burrowing adaptations helped it survive longer than its relatives.
