Deinotherium
Name:
Deinotherium
(Terrible beast).
Phonetic: Dy-noe-fee-ree-um.
Named By: Johann Jakob Kaup - 1829.
Classification: Chordata, Mammalia,
Proboscidea, Deinotheroidea, Deinotheriidae, Deinotheriinae.
Species: D. giganteum (type),
D.
bozasi, D. indicum.
Diet: Herbivore.
Size: Larger individuals up to 4 meters high at the shoulder, though some fossils suggest that rare individuals may have been larger.
Known locations: Africa and Eurasia.
Time period: Early Miocene through to mid
Pleistocene.
Fossil representation: Multiple specimens.
Although
the
name Deinotherium translates to mean 'Terrible
beast’, this
definition somewhat belies the true nature of Deinotherium
as a
prehistoric elephant. Compared to today’s living elephants
however, Deinotherium is the type genus of the
more distantly related
group called the deinotheres. Deinotherium
remains one of the largest
elephants in the fossil record, rivalling even the big mammoths such
as the huge M.
imperator (Imperial mammoth) and being only
just
beaten by M.
sungari. However the latter mammoth species has
since
been questioned and may yet be shuffled over to M.
trogontherii
(Steppe mammoth). The only terrestrial mammal confirmed to have
been definitively larger than Deinotherium was the
gigantic
Paraceratherium.
The
two things that make
Deinotherium stand out from amongst other elephants
is the two downward
pointing short tusks that are recurved in an arc that sees the tips
pointing towards the front feet when the head is carried horizontally
level. Not only is this a different direction from the forward
pointing tusks of other elephants but the tusks themselves actually
emerged from the lower jaw as opposed to the upper of other elephants.
The reason and function of this arrangement has baffled
palaeontologists since the discovery of this animal, in fact early
reconstructions often had the jaw placed upside down so that the tusks
looked like they were pointing in the ‘right’ direction.
In
elephants and mammoths the
tusks are usually used as tools for the purpose of obtaining food.
Some popular theories concerning how Deinotherium
could use their
tusks include digging in the ground for nutritious roots and tubers,
hooking the tusks around tree branches where they joined the trunk and
snapping them down for easier access to the leaves, to running the
tusks down the trunks of trees to strip off the bark. It’s quite
possible that the tusks were also display devices where the distinctive
shape allowed Deinotherium to recognise others of
their genus at a time
when many other elephants with exotic tusk arrangements were roaming
the land. The thing to remember is that the purpose of the tusks does
not necessarily have to be restricted to just one of these functions,
and that all of the above are probably more likely than just one.
However with the tusks being mounted in the lower jaw, Deinotherium
would have likely had a finer degree of control over them.
Deinotherium
was not just
different in the tusks but had a skull that was short with a flattened
top. The nasal opening is enlarged and further back which strongly
suggests that the trunk was strong and well developed. Although it is
still uncertain how this trunk would appear in life, these
adaptations do also suggest that Deinotherium had a
greater reliance
upon it for manipulating things. The main teeth inside the mouth of
Deinotherium were also suitable for both shearing
and grinding food
which possibly suggests a varied diet.
The
type species of
Deinotherium, D. giganteum,
was first discovered in Europe, but
the later discoveries of D. bozasi have revealed
an African origin.
From here Deinotherium radiated out towards Europe
and Asia where it
became one of the most successful mammals until the end of the
Pliocene. By the start of the Pleistocene the Deinotherium
populations of Europe and Asia seem to have disappeared, quite
probably as a result of the changing habitats which were brought about
by a global change towards a colder climate. The last populations of
Deinotherium held out in Africa where they survived
until around one
million years ago (middle Ionian of the Pleistocene).
Further reading
- Evolution of feeding mechanisms in the family Deinotheriidae
(Mammalia: Proboscidea) - J. M. Harris - 1976.
- On a Deinotherium (Proboscidea) finding in the Neogene of Crete. - A.
Athanassiou - 2004.
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