Miotragocerus and Tragoportax: Grandfather Boselaphines
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
Back we go to the Miocene! If you've been keeping up, you'll remember that the Miocene was a transitional period in the history of life on Earth, marking a change from more ancient to more recent types of living being. Today we look at two important ones of those. Miotragocerus and Tragoportax were some of the earliest of the representatives of the group of herbivorous mammals that is at present the most numerous and diverse in the world, the bovids. Bovids are cows, goats, sheep, buffaloes, wild oxen, antelopes, gazelles, and their kin. The bovids turned up in the world in the early Miocene, about 23 million years ago, as small, short-horned types very similar to the modern Duikers. Somehow in their build and physiology they already held the keys to their later success. They diversified and soon evolved into spectacular types. These two, Miotragocerus, and Tragoportax, were the best known of the very earliest large and impressive bovids. Technically speaking, they belonged to the tribe Boselaphini, which today only has two survivors, the Chousingha and the Nilgai, which I hope to feature here soon. The two are extremely different from each other, and extinct boselaphines included ones that were different still. The boselaphines might be the group that was ancestral to many or most of the later bovids.
Miotragocerus, sometimes called the 'European Eland', was the earlier of the two genera. It appeared at least 12 million years ago, perhaps even as much as 16 or 17 million years ago. It is known from abundant fossils from Europe and Asia, and some likely ones from Africa also. Because many of these fossils are very fragmentary, it's not clear how many species of the genus existed; some may turn out to have belonged to different genera, 'Miotragocerus' just being a convenient 'bin' to put them all in. At any rate, this was a medium-sized antelope, but for the time, pretty much the largest antelope in existence. It reached 80 kg/176 lbs in weight, but many kinds were somewhat smaller than this. The name 'eland' is thus a bit of a misnomer, as modern elands are very much larger than this (up to a ton in weight). Its limbs were comparatively long and slender. It had (at least from the skeletal reconstruction I used as reference for my picture) quite a long face. Its horns were backward-curving and somewhat diverging. It had a keel on the front of the horn, but no trace of transverse ridges. Its horns also were only slightly twisted outwards along their length, not spiralled. I reconstruct it here with a striped-and-spotted body similar to that of the modern Bushbuck which is an antelope that is conservative in build and lifestyle and thus might be a good model for what these early antelopes looked like. Miotragocerus likely evolved in Europe or Asia Minor, from where it dispersed far and wide. Its dentition shows it to have mainly been a browser, living in lush habitats such as riverine woodlands. It survived to about 8 million years ago, and likely left many descendants.
Indeed, Tragoportax might have evolved from some species of Miotragocerus. It was a larger, more imposing animal, reaching a weight of 200 kg/440 lbs. The one I depict here is based on fine fossils of Tragoportax cyrenaica, found in Libya, North Africa. The manes and fur fringes I give it here are features today widespread in the bovid family, meant to make male individuals look more imposing seen in profile. Tragoportax had well-developed horns, also with a keel or flange on the front, diverging a bit more than those of Miotragocerus. Females also had horns, though they were smaller and more slender than those of the males. These animals likely lived in herds, with males establishing dominance through posing and occasional fighting. They apparently could survive in drier, harsher, more open regions than Miotragocerus, and could deal better with tough grasses, though they likely browsed also. Tragoportax existed from at least 11 million years ago, the middle Miocene, to perhaps as recent as 2.5 million years ago, the early Pliocene. Several species are recognized, mostly from Europe and western and southern Asia, but also in Africa as far down as South Africa, where they perhaps survived the longest, though these ones are sometimes ascribed to a different genus, Mesembriportax.
These two very early antelopes, both being as successful and widespread as they were, are good candidates for being the ancestors of a whole slew of later antelopes and other bovids. But it's not clear just how the evolution happened. If you're keeping up with my articles, you'll have seen that even at this very early time, so many different kinds turned up so quickly and with so many different specialized features, many that are strikingly different from anything that survives today, and also from anything else in the fossil record, that it's very difficult to determine just what was related to what and what evolved from what. There are also certainly a very large number of 'gaps' in the fossil record. The prehistoric beasts that we do know, mostly come from specific fossil locales, each providing just a 'snapshot' of life existing at a particular time and particular place; the big picture varied very much both in terms of place and in terms of time. All that we can say for sure, is that life is incredibly inventive, and our planet Earth, over the billions of years that it has existed, has proven to be a welcoming home for quite a staggering array of physical types, even while every basic 'kind' only has a short period (though we're still speaking of millions of years) in which to flourish before being replaced by something different. As for our bovids, I surely hope that the years to come turn up even more weird fossils for us to try to fit into their family tree.