Denizens of Madrid’s Miocene woods: the Bear-Dogs
For most of the early and midlle Miocene, cat-like carnivorans had to play a subordinate role in the predator guild of Madrid’s woodlands and prairies. The dominant hunters and scavengers in those ecosystems belonged to the Caniformia (which is the “dog half” of the order Carnivora), and they included two groups known with the confusing popular names of “Bear-Dogs” and “Dog-Bears”. The “Dog-Bears” or hemicyonines, were close relatives of today’s bears, and will be discussed in a different post.
The “Bear-Dogs” or Amphicyonids, were neither dogs nor bears, but a separate family distantly related to both. Most of them had a rather unspecialized dentition with a nearly complete set of premolars and molars, resembling in some ways the dentition of dogs, and suggesting a similarly varied diet. But their skeleton was not especially dog-like in most cases, and instead it resembled a mixture between a bear and a big cat in terms of body proportions and locomotor adaptations.
One of the most common and well-known members of this family was Amphicyon major, an animal similar in size to a modern brown bear and whose remains are found in several fossil sites in Madrid. Well adapted to a life as an active hunter, scavenger and omnivore, it would keep the modest cats of the time (the largest of which was leopard-sized) easily at bay.
Here is a reconstruction of Amphicyon major in the middle Miocene environments of Casa de Campo, an area that today is covered with mediterranean bush and woodland, but which during the Aragonian was part of a savannah-like floodplain with gallery woods near water. These two individuals are disputing a carcass of Triceromeryx.