Cainotheriidae

The bizarre anatomical features of the cainotheriids denote them as primitive artiodactyls. Previous research placed them near to Tylopoda, more recent research places them closer to Ruminantia. Robiacina of the middle/upper Eocene was previously classified as a member of this family, but has been more recently split into a separate family as the sister taxon to Cainotheriidae. In the course of the Upper Eocene primitive genera such as Oxacron and Paroxacron developed, considered the first true cainotheriids as sister taxa in the subfamily Oxacroninae. Subsequently, in the course of the Oligocene, the subfamily Cainotheriinae underwent a discrete evolutionary radiation, with the rabbit-sized genera Plesiomeryx and Caenomeryx. The most specialized genus, Cainotherium, was also the last to disappear, during the middle Miocene. Even at the beginning of the Miocene, these animals were quite common in various parts of Europe, with numerous species (e.g. C. laticurvatum, C. miocenicum, C. bavaricum). The cainotheriids died out definitively when, during the Miocene, the climate became colder. == Paleoecology ==

These small ungulate animals possessed exceptionally long hind legs; this characteristic, combined with small size and large auditory bulla, has led many scholars to consider cainoterids a sort of ecological parallel of rabbits. It was therefore assumed that these animals proceeded to leap thanks to the long hind legs, but the discovery of fossil traces of the lower Miocene found in the locality of Salinas de Anana in Spain, clearly left by Cainotherium, showed that the locomotion of these animals had to be very different from that of rabbits, and quite similar to that of the current small ruminants. ==References==