Scientists have now discovered a quirky little creature from this time period, as reported in the journal Nature. It's called Cronopio dentiacutus, and it resembles a mouse-sized squirrel with proportionally long teeth, although technically speaking it is neither a squirrel nor saber-toothed.
The extinct mammal, which lived 94 million years ago, belongs to the lineage that has given rise to the marsupials and placental mammals that we know today. It's related to all living mammals, including humans in a remote way. It has been extinct for about 60 million years. Rougier and colleagues examined its unique skull.
http://lightyears.blogs.cnn.com/2011/11/02/tiny-saber-toothed-squirrel-is-mammalian-ancestor/