Tree shrews are often held up as being living fossils, presumably very similar to our own earliest primate ancestor. The dearth of actual fossils of these small tropical mammals, however, has meant that much of this conclusion has been speculative. Li and Ni describe a new fossil tree shrew that is exceedingly similar to the extant pen-tailed tree shrew (Ptilocercus lowii), yet twice as old as any previously described sister taxa. The fossil suggests that this tree shrew has gone nearly unchanged since the Oligocene (over 34 million years ago). Further, it supports the suggestion that the extant P. lowii gives us a living glimpse of the first ancestor of the Archonta, our own superordinal group.
Sci. Rep. 10.1038/srep18627 (2016).