From a very early age, we are taught to place disparate aspects of nature in discrete conceptual boxes. Children’s field guides and Facts on File-type cards tell us that particular animals live in specific places, eat particular foods, and otherwise give simple, easy-to-remember summations of the essence of nature. But the natural world – past and present –  is not so easily simplified. Herbivores, such as hippos, sometimes scavenge meat, and many dinosaurs – traditionally characterized as being “good reptiles” – were marked by a slew of characteristics that we once thought were unique to birds. Among extant organisms, however, there is scarcely a better test of our preconceptions about animals than their