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!"

Time for some prehistoric beasties again! Here I present to you three related species from South America, called Interatheriines. What sort of things were they? Well, first of all, these are Notoungulates, hoofed mammals that very early, about during the early Palaeocene, or maybe even in the Cretaceous (when the non-avian dinosaurs were still around) had made it from North America to the continent of South America. I've been fascinated by the notoungulates ever since learning about them as a small child. These early hoofed mammals appear to have been related to the even-toed ungulates, or artiodactyls, as well as to the odd-toed ungulates, the perissodactyls - but perhaps more to the latter. Notoungulates were isolated when South America broke its connections with North America, and thereafter evolved in isolation, achieving great diversity. Early notoungulates were quite small, but soon some grew to large size. The toxodonts, especially, included some rhino-sized creatures. But the other branch of the notoungulate order, the Typotheres, generally remained quite small. Many of them would have looked rather like rodents or rabbits. Our group of the day, the interatheriines, belonged to the typotheres, and among them were some of the smallest, though not quite as rodent-like as most of the others.

First, Miocochilius anomopodus, who lived in the mid-Miocene, about 13.8-11.8 million years ago. This was an animal the size of a large cat, standing about 30 cm at the shoulder. Among these, Miocochilius was one of largest and the most advanced towards running ability. It had fairly long and slender legs on its long body, and ran on only two hoof-tipped toes per foot (although the 'hand' had an additional short 'finger' on the outside that wouldn't have touched the ground). It had high-crowned teeth and likely could graze and/or browse. It seems to have been quite an abundant mammal at the time. It was preyed upon by some of the old Sparassodonts, pouched predators unique to South America, and likely some of the Phorusrhacids or terror birds.

The next little crittur is Interatherium robustum. Interatherium was much more rodent-like than ungulate-like, and had a lengthened body with short limbs. It was about the size of a ferret. It had a short but deep skull with a powerful jaw. Unlike Miocochilius, it had four toes per foot, front and back. It lived in the Early to Mid-Miocene, about 21-11.6 million years ago, and its fossils were found in Argentina. It was likely a herbivore, but we know little else about it - for instance, why did it have the short legs and long body? This is the build of a burrow-living animal, but it doesn't have any other adaptations for digging.

Last, we have a couple of Protypotherium australe! Protypotherium was similar to Miocochilius but differed in having more 'fingers' (four) and 'toes' (three) per hand and foot. It had claws rather than hooves. Its limbs were short but strong and it might have been a capable digger. It attained the size of a cat. It was mainly an herbivore and just might have scavenged on occasion. Its high-crowned teeth would have enabled it to graze, a useful ability in the burgeoning grasslands of the Miocene. Protypotherium originated in the late Oligocene, about 29 million years ago, and lasted to the late Miocene, about 7.8 million years ago. Its fossils were found mainly in Argentina, but also in Uruguay, Bolivia and Chile. I show it here using its tongue to groom itself. It might also have used its forward-angled lower incisors. It lived in diverse communities that included ground sloths, armadillos, rodents, monkeys (in the places with trees such as riversides), other notoungulates, litopterns, astrapotheres, sparassodonts, rhea relatives, and terror birds.

Willem

15.01.24 Front Page

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