<img src="http://www.fotango.com/p/eba00019870f00000026.jpg" align=left vspace=20 hspace=20 alt="Sivatherium">
<i>Sivatherium</i> is the name given to a genus (that is, group) of extinct giraffes.
It means "Siva beast" -
named after the god Siva (or Shiva), the Destroyer, one of the principal three Hindu deities.
There were a number of different species in this genus, with the one most plentifully
represented in the fossil record being <i>Sivatherium maurusium</i>. All of these kinds
are generally called sivatheres in English. My illustrations show reconstructions of a couple of different kinds.
Sivatheres lived from around five million years ago until comparatively recently. As giraffes
go they were unusual in appearance, and are often placed in a separate family from the rest.
They were heavy-bodied, short-necked and carried horns (called ossicones) that
were much more elaborately developed than those of other giraffes. They originated in Africa
and later extended their range into Eurasia. The genus was first discovered on the Indian
subcontinent, though. There are indications that sivatheres survived well into civilized
times. They were common over large areas of the Earth right up to the last worldwide glacial
period. Also, a small Sumerian statue was found showing a man with a bridled creature that
strongly suggests a sivathere - it has a short, bulldog-like face, compact but broad palmate
antlers, and most tellingly, two stubby horns projecting forwards over the eyes. Also
there is an illustration made about 5 000 years ago in what is now the Sahara desert depicting
a creature that might have been a </i>Prolibytherium</i>, a relative of the sivatheres. It is
possible that humans contributed to the extinction of these strange mammals.
How is it possible to tell that sivatheres were giraffes? After all, they don't look as if
they were. But bones tell a lot. The defining characteristic of giraffes are their horns.
Giraffes are classified between the deer and the antelopes. Deer usually have elaborate
antlers that grow from the skull and are shed annually. Giraffes have bony protrusions
called ossicones that grow from the skull and are covered by skin in life. Antelopes have
bony cores projecting from the skull that are covered by a distinct horny sheath, and these
are never shed. Each kind of horn or antler has a particular, distinctive pattern of bone
growth and deposition that can be distinguished in fossils. From this it is clear that the
sivatheres' "antlers" were in fact of the ossicone kind.
<img src="http://www.fotango.com/p/eba00019870f00000019.jpg" align=right vspace=20 hspace=20 alt="A Sivathere">
The structure of the rest of the skeleton is also giraffe-like. The biggest sivatheres
stood about seven feet tall at the hump of the shoulder.
The neck attaches high on
the shoulders, and the back slopes downwards to the rump. The shoulder blades are
long and the forequarters more strongly devoloped than the hindquarters. The ribcage
is short but deep. This and many other small details point out the relationship. By keeping
track of these details it is possible to see how the different kinds were related to one
another. It is even possible to track the giraffe lineage back to a time when they did not
have any ossicones. This development occurred later in an Okapi-like ancestor from which the three
modern lineages - long-necked giraffes, Okapis and sivatheres - developed.
The sivathere's skull was unusual. Especially in the most recent species,
it is deep and robust, but with a very short facial region.
Some paleontologists have concluded that the sivathere must have had a long, proboscis-like
snout, similar to those of modern tapirs. It is generally true that mammals with shortened
nasal bones have large fleshy noses and lips. Personally I don't think that the sivathere had
a proboscis, though. Its nasal bones are too robust for that, and extend an equal amount above
and below the nasal opening. In animals with long snouts the nasal bones are usually slender
and end well behind the bone supporting the front teeth. My own guess is that, at most, the
sivathere would have had thick, fleshy lips and a bulbous snout. Giraffes have strongly
reduced frontal facial bones, but this reduction has been compensated for by a development of the lips
rather than of the nose. In the head illustrations I reconstructed the sivathere with an ordinary muzzle, while in the
full body illustration I gave it a somewhat distended snout.
<img src="http://www.fotango.com/p/eba00019870f00000027.jpg" align=left vspace=20 hspace=20 alt="Sivatherium maurusium">
Evolution is also evident in the fossil record of the sivathere line. One of the earliest-
living species was <i>Sivatherium maurusium</i>, depicted here. Its fossils were found all over Africa, including
the remains (mostly broken off ossicones) of more than 5 000 individuals at Langebaanweg in
South Africa. This sivathere looked much like an Okapi. It
was smaller, had a longer face and less developed ossicones than later species. However the very first
clues of the elaboration of the ossicones were present in a backwards curve and a few
protrusions of the bony ridges along the front edge. Later species had the ossicones extended and branched
to form antler-like structures. Some were ridged, others were twisted,
and the most impressive kinds had flattened, flared, palmate tips like those of the modern
fallow deer (but shorter and thicker). A distinctive feature of these later sivatheres is that,
just above and in front of the eyes, there was a straight, stubby pair of ossicones sticking
In modern giraffes the ossicones are used in ritual head-knocking fights where the winner gets the
right to mate with females in the territory. Giraffes stand shoulder to shoulder facing in the
same direction and swinging their necks sideways. Sivatheres, because of their shorter necks, would
more probably have knocked heads standing face to face, and using mostly the short front pair of
ossicones. The rear, flaring ones might have been more for display. In the modern male horned ungulate the
size of the horns increase according to its health and testosterone levels. So an animal with
larger horns displays that it has an advantage over a smaller-horned rival, and in this case
the weaker animal might decide not to fight rather than fight a battle it is likely to lose. This
saves the animals from needless confrontations. Only when the opponents are more or less evenly matched
externally do they go ahead to fight it out to determine who is <i>truly</i> the fittest. Sivatheres very
probably did all of this in exactly the same way as modern animals do. But if they did not, we
would have no way of knowing it!
In their time the principal enemies of sivatheres were probably the then-still-existing sabretooth
tigers. These cats were adapted to killing large, slow-moving herbivores, most probably by an
ambush attack aimed at the soft underparts such as the throat and the entrails. But these big beasts
would also have been easy prey for humans armed with spears and arrows and the know-how to dig
pits and set traps. Sivatheres were probably savannah dwellers, depending on the mixture of trees
and open grassy spaces for feeding and shelter coupled with the ability to spot danger. The ice
ages led to a cycling from dense forests to dry grasslands and back, which meant that savannah
mammals had to move regularly as their habitats changed position. They would also have been put
under pressure by humans who, especially in the savannahs, used fire to drive out animals and also
to convert wooded areas to open grassland for the cultivation of crops or as pastures for domestic
animals. All in all, these different pressures all put together were probably responsible for
driving the sivatheres over the brink of extinction. Because the largest mammals need the most food they
are typically affected the worst by environmental pressures.
As I said earlier, giraffes and deer have a common ancestry. Deer often have white spotting on
a brownish background. The giraffe has dark, geometric patches on a white background. The Okapi
has a dark brown body with white legs striped horizontally with black.
In my full-body reconstruction I gave the
sivathere a coat pattern that might be considered intermediate to all of these three strikingly
different patterns. It starts out with light spotting on a dark ground, with the light patches
gradually merging together to leave the dark patches either standing on their own or merging
into horizontal stripes. Of course it is by no means certain that all of these stages would have
been present in any single animal, so my reconstruction is speculative. But I hope that it at
least demonstrates how both the giraffe and Okapi pattern might have developed from a deer-like
spotted coat. And, because the sivathere had qualities intermediate between those of deer and
modern giraffes, it is likely that at least one of the species might have had such an intermediate
coat pattern. Of course some sivatheres would very probably have evolved their own, different,
distinctive color patterns. But because the hair and skin are not preserved by the fossilisation
process, we will never know for sure - unless someone someday manages to clone a sivathere from
ancient genetic material! At least it would be easier to do with sivathere DNA than with that of
a dinosaur, not to mention that it would probably not lead to the same kind of problems!
Sivatheres are gone, and that is sad. But when we consider how a creature such as a sivathere
could have evolved from something resembling an Okapi, we start to get a grasp of the huge
evolutionary potential inherent in mammals and their interactions with each other and their
environments. If we humans take good care of the species we have left, and guard their habitats
and ecosystems wisely, who knows, it might not be too long before new and even stranger creatures
evolve out of our present day giraffes, Okapis and other large mammals!