Mammuthus columbi
(Columbian mammoth)
Name:
Mammuthus columbi
Phonetic: Mam-mu-fus ko-lum-be.
Named By: Hugh Falconer - 1857.
Synonyms: Elephas maibeni, Elephas
washingtonii, Mammuthus jeffersonii, Parelephas eellsi,
Parelephas floridanus, Parelephas jacksoni, Parelephas
progressus, Parelephas roosevelti.
Classification: Chordata, Mammalia,
Proboscidea, Elephantidae, Mammuthus.
Species: M. columbi.
Diet: Herbivore.
Size: Up to 4 meters tall at the shoulder.
Known locations: Canada, USA, Mexico &
Nicaragua.
Time period: Calabrian through to Tarantian of the
Pleistocene. Possibly survived into the early Holocene.
Fossil representation: Multiple specimens.
Mammuthus
columbi is better known as the Columbian mammoth, although
it is not
actually named after the country Colombia that is in South America,
but after the province of British Columbia in Canada. The Columbian
mammoth appears to have been one of the most common mammoths roaming
North America during the Pleistocene, and is thought to have come
from mammoths that crossed the Bering land bridge from Asia into North
America during the early Pleistocene at the latest. This would have
been possible by fluctuating sea levels that would have been constantly
rising and falling in connection with decreasing and increasing
glaciations.
M.
columbi is often
confused with M.
imperator, better known as the imperial
mammoth,
that also lived in North America at the same time as M.
columbi.
M. imperator is generally considered as being
even larger than M.
columbi, with tusks that are curved so much that the tips
actually
overlap one another. Palaeontologists regard this as enough reason to
keep these two species of mammoth separate, an analysis that is
currently supported by the consistent nature of remains attributed to
both species.
Compared
to other mammoths,
the Columbian mammoth is generally thought to have had a reduced
covering of hair from those that were active in Eurasia. This is
based upon the fact that North America is generally considered to
have been warmer and less frozen than Europe during the Pleistocene,
and an extensive covering of hair would have actually hindered the
Columbian mammoths ability to cope with the warmer conditions.
One
species of mammoth called
M.
exilis is thought to be descended from M.
columbi. Better
known as the pygmy mammoth, M. exilis is
currently only known from
the Californian channel islands where a population of Columbian
mammoths are thought to have travelled to when the sea levels were much
lower, and land masses larger, only to be cut off from the mainland
when sea levels rose again.
As
with most of the North
American megafauna, the disappearance of the Columbian mammoth
remains an uncertain and controversial subject. Hunting by humans is
considered to have been a contributing factor, with fossil sites
indicating that mammoths were killed and processed by human hunters,
although in seemingly insufficient numbers to wipe out the whole
population. Climate change has also been taken to be another
contributing factor, and combined with increased hunting the stress
may have been too great for the population to survive. Other current
theories put forward include new diseases brought in from Asia by new
migrants such as the first people, but these diseases would have to
be so specialised that they would have affected all of the large
megafauna while largely having little effect if any upon the smaller
animals that exist to this day. Another is that an air burst from a
comet exploding in the upper atmosphere similar to the Tunguska event
of 1909 caused continent wide devastation that starved the larger
animal species into extinction. To further complicate matters some
Columbian mammoth remains are claimed to have come from the early
Holocene period several thousand years after all of these events are
supposed to have wiped out the megafauna. The only thing that remains
fairly stable to say at this time is that populations of Columbian
mammoths as with other megafauna at this time seem to have declined
rapidly to a point that they could not recover from.
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