Name:
Megacerops
(Large horned face.).
Phonetic: Meg-ah-seh-rops.
Named By: Joseph Leidy - 1870.
Synonyms: Ateleodon, Brontops,
Brontotherium, Haplacodon , Menodus peltoceras,
Oreinotherium, Teleodus, Titanops , Titanotherium ramosum.
Classification: Chordata, Mammalia,
Perissodactyla, Brontotheriidae.
Species: M. coloradensis
(type), M. curtus, M. hatcheri, M.
kuwagatarhinus, M. osborni, M. platyceras, M. riggsi.
Diet: Herbivore.
Size: Larger individuals up to 2.5 meters tall
at the shoulder.
Known locations: Canada, Seskatchewan. USA,
Colorado, Montana, South Dakota, Wyoming.
Time period: Priabonian of the Eocene to Rupelian of
the Oligocene.
Fossil representation: Numerous individuals allowing
for accurate reconstructions of the whole animal.
Since
the early days of palaeontology many genera of brontotheres have been
named from North America, though now after over one hundred and fifty
years of continuous study and discovery, many of these have now been
perceived to be synonymous with the genus Megacerops.
Some of these
names include genera such as Brontops and Atelodon,
but by far the
most famous of all these is Brontotherium, a
genus that has received
a large amount of publicity due in part to the name which translates
as ‘thunder beast’. However, now that Brontotherium
is
synonymous (the same) with Megacerops, it
must be remembered that
older sources mentioning Brontotherium, are
actually referencing
Megacerops, even if they did not intend to.
The
inclusion of Brontotherium as a synonym to
Megacerops may actually also
have wider implications for the classification of these animals since
Brontotherium was also the type genus of the
Brontotheriidae, the
group that all related animals including Megacerops
were included
within. Usually a group of animals is named after the first to be
named and already it is unusual that a group should be named after an
animal that was named after a genus that was named a few years after
others (Brontotherium was named in 1873,
whereas Megacerops was
named in 1870). In addition to this now, it would be highly
unusual for a group of animals to continue to be named after a genus
now widely declared to be synonymous to another genus. Therefore it
is not inconceivable for the Brontotheriidae to become something like
the Megaceropsidae, unless of course Brontotheriidae can somehow
obtain protected status.
Now
talking about Megacerops as an animal, Megacerops
was one of the
larger herbivorous animals known to have lived upon the North American
continent during the Late Eocene/Early Oligocene. When compared to
modern day animal forms, Megacerops would have
been superficially
similar to a rhinoceros; So far all individuals of Megacerops
are
noted for having a pair of blunt horns that rise upwards from the front
of the snout, with individuals thought to be males having larger
horns.
There
is a popular theory about Megacerops in that males
would fight each
other with their larger horns for dominance within a group. There is
even some fossil evidence which might support this since at least one
male has been found with partially healed ribs, the injuries
seemingly caused by a tremendous blow from the side. The only animals
known to have rivalled large Megacerops in North
America at this time
were other large Megacerops. None of the
predators around at the same
time as Megacerops such as nimravids
like Holplophoneus
and Eusmilus,
as well as creodonts such as Hyaenodon
came close to the size of an
adult Megacerops; it is fair to say that a fully
grown adult
Megacerops would have been immune from attack by any
predator of the
time in that location.
Megacerops
was an animal adapted for browsing low growing vegetation, an
analysis brought about by the observation that the teeth of Megacerops
were much better for slicing leafy vegetation rather than grinding
grass. Skull analysis also suggests attachment points for a long
tongue and flexible lips which would have been ideal for stripping
vegetation from branches. Ultimately however it was probably this
specialisation combined with the large body size that caused the
downfall of Megacerops. At this time, the
world’s climate was
drying out, and all over the world the lush forests that had
dominated the planets ecosystems during the early Eocene were already
being replaced by grassy plains. This shift in ecosystem caused a
dramatic loss in available food bearing habitats as well as the
development of new herbivores better able to survive in this changing
world that enabled created greater competition for food sources. With
the huge size now a hindrance since there was no longer enough food to
support a large population, Megacerops were slowly edged out to the
fringes of survival before finally going extinct.
Further reading
- Contributions to the Stratigraphy and Palaeontology of the Goshen
Hole Area, Wyoming. III. A New Basal Oligocene Formation. -
Bulletin of the Museum of Comparative Zoology 76(3):71-93. -
E. M. Schlaikjer - 1935.
- The holotype specimen of Menodus giganteus,
and the
"insoluble" problem of Chadronian brontothere taxonomy. -
Paleogene Mammals. Bulletin of the New Mexico Museum of Natural
History 26. pp. 129–136. - M. C. Mihlbachler, S.
G. Lucas & R. J. Emry - 2004.