Size and Weight:
Thanks to its long, narrow snout capped by two prominent canines, the newly discovered Cronopio has been likened to Sqrat, the "saber-toothed squirrel" of the Ice Age movies. However, one shouldn't take this comparison too seriously: whereas the fictional Sqrat is an adorable, reasonably intelligent, squirrel-sized furball, Cronopio was about the size of a mouse and ate insects rather than nuts.
Its similarity to Sqrat aside, Cronopio is important because it's the earliest "dryolestid" mammal ever to be discovered in South America, dating to the middle Cretaceous period, about 100 million years ago. Because it coexisted with enormous theropod and titanosaur dinosaurs, Cronopio spent most of its time high up in trees, where it was less likely to be gobbled up for lunch or unintentionally squashed by these larger animals.
Unusually for a Mesozoic mammal, Cronopio is represented in the fossil record by not one, but two, near-complete (albeit tiny) skulls--more often, these tiny mammals are survived only by scattered teeth and pieces of jawbone. Hopefully, this will allow paleontologists to flesh out the course of early mammalian evolution in South America, direct evidence for which has, up to now, been severely lacking.