DENIZENS OF MADRID’S MIOCENE WOODS: THE PALAEOMERICIDS
During our “time-travel safari” through the Miocene woods and plains of Madrid, many of the herbivores we could come across would look vaguely familiar. Small three-toed horses, deer with simple antlers, running rhinos… all these animals belonged to the same families as their modern counterparts. But one of the ungulates we were likely to encounter was an animal with no living relatives.
Triceromeryx pachecoi, as this creature is named, was built like some sort of stocky deer, but on its head it had three bony appendages: the two smaller ones, placed over the orbits, were ossicones, bony structures similar to those of modern giraffes. The third, larger appendage, was forked and grew directly from the back of the skull. The weaponry of this bizarre animal was completed with a pair of small dagger-like canines protruding beyond the upper lip.
The reconstruction of the life appearance of Triceromeryx pachecoi was one of my first professional challenges as a hopeful young paleoartist, back in the early nineties. Fossil remains of this species were first recognized back in the 1940s at the fossil site of Hidroeléctrica in Madrid, and they were enough to show that it was a pretty weird animal, but they were so fragmentary that reconstructing its life appearance was a tricky business. In fact, the appendages were not found attached to a complete skull, and even the fact that they belonged to the same animal could seem open to question. Fortunately, at about that time discoveries were made in other Spanish fossil sites which added important pieces to the palaeomericid puzzle.
At the site of Els Cassots in Catalonia, paleontologists discovered a complete, crushed skull of a new palaeomericid which they named Ampelomeryx ginsburgi. Although the shape of its appendages was different, having a complete skull further confirmed their arrangement in the animal’s head and provided new information about palaeomericid evolution and function.
Closer to Madrid, a collection of palaeomericid fossils were found at the site of La Retama, in Cuenca. Again, the new fossils were so different from the ones from Madrid and Catalonia that they clearly belonged to a new species, and the shape of the appendage at the back of the skull was probably the weirdest. I was commissioned to create a life reconstruction of the new palaeomericid for the local museum at Cuenca, and even I was surprised at the strange appearance of the creature.
Here is my first reconstruction of the palaeomericid from la Retama, created for the Museum of Cuenca back in 1991. The illustration showed several males in a dispute over a female, reflecting the hypotheses that the appendages were exclusive of the males
When I started working on the reconstruction of Madrid’s T. pachecoi it had seemed a strange enough animal, but the findings of palaeomericid fossils that were taking place were showing the remarkable diversity of this family: almost each new finding corresponded to a new species, each of them wierder than the previous one!
More recently, those palaeomericid fossils keep contributing to our knowledge of that strange family. A recent study has finally given a name to the species from la Retama: Xenokeryx amidalae. A detailed analysis of its anatomy and that of the other palaeomericids has clarified the affinities of the family, which is revealed as closely related to the giraffids, rather than to the American dromomerycids as some previous studies had suggested. You can check the new study here:
Triceromeryx pachecoi was the right size to fit in the diet of the large amphicyonids that were so common in Madrid at the time. Here a nice male has come to a sad end and its remains are disputed by a pair of quarrelsome Amphicyon
The palaeomericids disappeared in the Miocene leaving no living descendants, but they were a succesful and diverse group, with a wide Eurasiatic distribution from Spain to China. We have come a bit closer to understanding their evolution and their place in Nature, but they remain one of the most mysterious ungulate groups and much remains to be known about them. Having worked in their reconstruction since so early in my a career, I find them especially endearing. And certainly, the finding of a complete skull of Madrid’s Triceromeryx pachecoi would be high on my wish list. New Miocene fossil sites keep appearing in Madrid as works uncover sediments here and there. So let us not give up hope!