h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Maybe I should write a proper entry about this.

Rhinos are among my favourite kinds of mammals. There are currently only two remaining species in Africa - the White and the Black - and three more in Asia - the Indian, the Javan and the Sumatran. ALL of them are highly endangered.

These species are an extremely tiny remnant of a group of creatures that in the past were numerous and diverse. I would like to tell those of you who don't know, just how many interesting species of rhino lived in the past so you can have a better idea of just what biodiversity means when considered over the course of the history of our planet. And also get an idea of what 'evolution' can accomplish!

The very first rhinos appeared about 55 million years ago and were small - about three feet or less at the shoulder. They were hornless, lightly built fast-running animals, most resembling small horses. From there, a number of different groups developed. The Hyracodonts started out similar to the small running original rhinos but some became larger - spectacularly larger. The Indriciotheres in fact became the largest known land mammals of all: an overall head-and-body length of 8 m, standing 5.5 m at the shoulder and with a mass of perhaps up to 20 tons (a big African bull elephant is about 6 tons). They were still hornless and long-necked, not looking rhinoceros-like at all.

Rhinoceroses lived in Europe and America as well as Africa and Asia. American rhinos included the large hornless swamp-living Amynodonts, that were hippo-like with large tusks in upper and lower jaws; the long-bodied short-legged Teleoceratines, that might be called 'dachshund rhinos' - they had only a single short horn on the snout tip; and the Diceratherium that had two small nose horns side by side. Some rhinos became modern-rhino-like in proportions and lifestyle but without developing horns.

In Europe and Asia rhino diversity was highest. Apart from the huge Indricotheres, there were the almost-as-huge elasmotheres. These rhinos lived on the Asian steppe and became rather long-legged. Their heads were short and they had a thick boss on the forehead - indication of a single horn like that of a Unicorn, that must have been huge. Unfortunately the horn itself is not preserved. Rhino horns aren't actually bone, they're made of keratin the same stuff as makes hair and nails, and thus don't preserve well.

There were numerous rhinos even living in Europe - some related to the modern Sumatran rhino. An impressive species living in Europe and also Asia was the Chilotherium. This one was hornless but had very long curved tusks in the lower jaw - it must have looked like a cross between a rhino and a hippo!

Another impressive Eurasian species was the Woolly Rhino. This one lived all over northern Europe and Asia during the ice ages and developed a long shaggy woolly coat to preserve it in the cold. The woolly rhino left some excellent fossils including preserved horns. It had two long curved horns one behind the other like the African white rhino. It was about the same size as well.

There were many other species of Asian and European rhinos. Strangely, there are few rhino fossils from Africa! I'm not sure when they got into this continent.

Rhinos died out in America about 5 million years ago, and in Europe only during the ice ages - quite likely at the hand of Man.

I'd see about drawing some pictures and perhaps making a proper entry of this.

Maybe you should. There are lots of articles on hootoo, but nothing up to date or sufficiently detailed.

Websailor

OK Websailor I'll see about getting a few ancient rhino drawings done! Then I'll write them up.