Elasmotherium
Name:
Elasmotherium
(Thin Plate Beast).
Phonetic: E-las-moe-fee-ree-um.
Named By: Gotthelf Fischer von Waldheim - 1808.
Synonyms: Elasmotherium inexpectatum,
Elasmotherium peii.
Classification: Chordata, Mammalia, Eutheria,
Perissodactyla, Ceratomorpha, Rhinocerotoidea, Rhinocerotidae.
Species: E. sibiricum (type),
E.
caucasicum, E. chaprovicum, E. peii.
Diet: Herbivore.
Size: The type species E. sibiricum
is known to
have approached 4.5 meters long, and 2.5 meters high at the
shoulder. E. caucasicum slightly larger at
around 5 meters long.
Known locations: China, Kazakhstan, Russia,
Turkmenistan, Ukraine and Uzbekistan.
Time period: Piacenzian of the Pliocene through to
the late Pleistocene. Extinction date usually estimated to around
fifty thousand years ago, though evidence now exists that indicates
that Elasmotherium existed for at least many
thousands of years after
this.
Fossil representation: Hundreds of individuals
ranging from nearly complete skeletons to partial remains of teeth and
jaws.
Elasmotherium
is one of the a typical animals that represents Pleistocene era fauna,
though there has been a lot of debate over not only how it lived but
what it really looked like One problematic area concerning the study of
Elasmotherium is the actual morphology of the
genus. Some
reconstructions consider Elasmotherium to have been
similar to modern
rhinos and be set quite low to the ground, while other
reconstructions give Elasmotherium a more
horse-like appearance, in
part due to the long legs of the animal.
A
second area of contention about Elasmotherium is
the not only the shape
and size of the horn. But whether one even existed. No horn core is
known to exist despite multiple cranial remains, yet the best
preserved individuals d show a boss (round dome) growth on bone on
the skull where the horn would be expected to be. If Elasmotherium
did not have a horn then they still would have had a low round
protuberance on their heads. If Elasmotherium
however did have
horns, and it’s quite likely that they did, then these horns would
have been made out of keratin, the same material that your
fingernails are made of. Unfortunately keratin does not preserve like
bone, and in time decomposes like flesh, which means that even with
a best guess by comparison to other similar animals, we still do not
know what shape or size this horn could have been. Modern
reconstructions that you see today are therefore based upon comparison
to other Pleistocene era rhinoceroses.
To
further complicate the matter about horn form, it should be
remembered that there are at the time of writing three recognised
species of Elasmotherium. The first Elasmotherium
species appeared in
the late Pliocene, popularly believed to have been descended from
Sinotherium.
The oldest species of Elasmotherium are E.
caucasicum
and E. chaprovicum, both going back as far as
the late Pliocene,
meaning that both species existed at the same time as one another.
Two separate species would denote a need to recognise members of their
own kind including physical, though slight, variation. Had horns
been present, then is quite probable that the horns of the two
species would have had differences in form and size, in a similar
manner to the ceratopsian
dinosaurs of the late Cretaceous. This is
not to imply that E. caucasicum and E.
chaprovicum coexisted on the
same landscapes, merely that they may have occasionally encountered
one another and needed to tell the difference. The type species
E. sibiricum is better known from the late
Pleistocene, but if this
species coexisted with an older or as yet undiscovered species, as
well as having many more hundreds of thousands of years of evolutionary
development, then it’s plausible that a keratinous horn, if
present, would again be slightly different from other Elasmotherium
species horns.
Another
area of debate regarding Elasmotherium is whether
they were hairy or
not. Again different species of the same genus may require different
answers, but so far only teeth and bones of these animals are known,
soft tissue and skin material is several lacking. It could be though
that there is simply no one good answer and that suggestions that
Elasmotherium did or did not have hair may be
correct. The
Pleistocene period was not one long ice age as it is sometimes
incorrectly depicted, but a series of glacial periods when world
temperatures dropped and ice sheets spread from the poles, and
interglacial periods when world temperatures increased and ice sheets
receded back to the poles. All mammals have the ability to grow
hair; even rhinos alive in Africa today still have hair though very
sparse. During the interglacial periods when temperatures were
warmer, Elasmotherium may have had less and/or
thinner hair.
Conversely, during the glacial periods when world temperatures were
cooler, Elasmotherium may have been more hairy
than their
interglacial ancestors and descendants.
Elasmotherium
have been depicted as living in a wide variety of environments,
though today most palaeontologists agree that Elasmotherium
probably
lived on open grass plains in mixed scrub, probably switching between
the two as they wandered. Elasmotherium are
usually depicted as being
grazers of grass and low growing vegetation. This is mainly derived
from the observation that the teeth are large and have high crowns, a
form that is very common to grazing animals that experience high tooth
wear from their diets. Grassy plains featuring the occasional area of
sparse woodland would have also been very common during this period of
the Earth’s history, and most of the successful herbivores of this
time evolved to exploit these environments.
Quickly
returning to the subject of whether Elasmotherium
were hairy or not,
living in areas that were exposed to environmental elements may have
meant a greater need to develop hair growth. One reason is the
obvious that such environments offer very little protection from
prevailing winds which can add a significant wind chill factor to
existing temperatures in an environment. Another factor, especially
during glacial periods is that the air is not just colder, but drier
because a much greater proportions of the world’s water is frozen solid
as ice. This means a greatly reduced cloud cover which in turn does
not trap the warm air that had built up during the day, not only
causing a reduction in air temperatures, but freezing what little
moisture is on the ground as frost. This would have been particularly
true for inland areas such as central Eurasia, which may have
furthered the need for Elasmotherium to be hairy.
There
are a few areas over which we are a little more certain about
Elasmotherium. The front feet of Elasmotherium
were larger than the
rear. This is significant as the form of the fore quarters shows that
the fore legs would have had a greater weight bearing responsibility
than the rear legs. Larger fore feet would have reduced ground
pressure due to the greater weight being spread over a larger surface
area, something that may have helped Elasmotherium to deal with snowy
and other soft surface conditions. Cave art that is many thousands of
years old also depicts beasts like Elasmotherium
that show them to have
more bison-like poses than those of horses, something that lends a
little of support to modern reconstructions of Elasmotherium
being a
bit more low slung with their heads held closer to the ground for
browsing. One cave in particular at Rouffignac in France shows a
primitive drawing of a rhinoceros-like beast that some have interpreted
to possibly be an Elasmotherium.
Studies
of the limbs of Elasmotherium also suggest that
they would have been
quite like modern day rhinos in terms of their locomotion. Although
it is uncertain how fast they could run given their size and weights,
which are variable according to interpretation, it has been
recognised that Elasmotherium were at least
skeletally capable of an
airborne phase during running as in a gallop.
Further reading
- About the Hyroideum, Sternum and Metacarpale V Bones of
Elasmotherium sibiricum Fischer (Rhinocerotidae)
- Journal of the
Palaeontological Society of India 20: 10–15. - E. I.
Belyaeva - 1977.
- Diversity and evolutionary trends of the Family Rhinocerotidae
(Perissodactyla) - Palaeo (141): 13–34 - Esperenza
Cerde�o - 1998.
- Middle Miocene elasmotheriine Rhinocerotidae from China and
Mongolia: taxonomic revision and phylogenetic relationships -
Zoologica Scripta (The Norwegian Academy of Science and Letters)
32 (2): 95–118 - Pierre-Olivier Antoine - 2003.
- Limb Bones of Elasmotherium (Rhinocerotidae,
Perissodactyla)
from Nihewan (Hebei, China) - Vertebrata Palasiatica (in
Chinese with English translations) (4): 110–121 - Tao
Deng, Ming Zheng - 2005.
- On the fossil rhinoceros Elasmotherium
(including the collections
of the Russian Academy of Sciences) - V. Zhegallo, N.
Kalandadze, A. Shapovalov, Z. Bessudnova, N. Noskova,
E. Tesakova - 2005.
- Relict Mammal Species of the Middle Pleistocene in Late Pleistocene
Fauna of the Western Siberia South - Quaternary stratigraphy and
paleontology of the Southern Russia: connections between Europe,
Africa and Asia: Abstracts of the International INQUA-SEQS
Conference (Rostov-on-Don, June 21–26, 2010).
Rostov-on-Don: Russian Academy of Science. pp. 78–79 -
2010.
- On the importance of the representatives of the genus Elasmotherium
(Rhinocerotidae, Mammalia) in the biochronology of the Pleistocene of
Eastern Europe. - Quaternary International. 379: 128–134. A. K.
Schvyreva - 2015.
- Evolution and extinction of the giant rhinoceros Elasmotherium
sibiricum sheds light on late Quaternary megafaunal
extinctions. -
Nature Ecology & Evolution. 3 (1): 31–38. - Pavel Kosintsev,
Kieren J. Mitchell, Thibaut Devi�se, Johannes van der Plicht, Margot
Kuitems, Ekaterina Petrova, Alexei Tikhonov, Thomas Higham, Daniel
Comeskey, Chris Turney, Alan Cooper, Thijs van Kolfschoten, Anthony J.
Stuart & Adrian M. Lister - 2018.
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