Antarctosaurus
Name:
Antarctosaurus
(Southern lizard).
Phonetic: An-tarc-toe-sore-us.
Named By: Friedrich von Huene - 1929.
Classification: Chordata, Reptilia, Dinosauria,
Saurischia, Sauropodomorpha, Sauropoda, Titanosauria,
Antarctosauridae.
Species: A. wichmannianus
(type).
Possibly also A. giganteus, A. jaxarticus and A. brasiliensis.
Diet: Herbivore.
Size: Uncertain due to incomplete and uncertainty of
attributable remains. Lower estimates however have suggested a size
of around 18 meters long for the type species, while other
material indicates an upper size of up to 30 meters long if the
classification is correct. Refer to main text for details.
Known locations: Argentina, possibly Brazil.
Time period: Coniacian to Campanian of the
Cretaceous.
Fossil representation: Several remains but of
incomplete individuals and scattered bones.
Sometimes
when people hear the name Antarctosaurus they
assume that this dinosaur
lived in Antarctica where in actuality it lived in Argentina.
Antarctosaurus means ‘southern lizard’ and here
it is a reference
to being found on a southern continent. However the real problem with
Antarctosaurus is that it is known from very
incomplete remains, not
all of which may actually be attributable to the genus.
Today
only the type species A. wichmannianus is
considered valid by
everyone, however A. giganteus, also from
Argentina, might
represent a second although possibly much more massive species. The
problem here is that A. giganteus is known from
very incomplete
remains that are not easy to compare with the type species, so many
regard it as a nomen dubium. A. brasiliensis
from Brazil is also
considered a nomen dubium because it is only known two limb bones and a
partial vertebra. One former species from India called A.
septentrionalis has now been separated and named as its own
genus
Jainosaurus.
Another species, this time from Kazakhstan called A.
jaxartensis is also considered unlikely to be part of the
genus.
Aside from difference and being unable to compare more remains of all
species, the main argument against including the Indian and
Kazakhstani material with the South American fossil is that South
America is thought to have been isolated from the other continents of
the world during the late Cretaceous.
The
scant remains and confusion regarding just what is and is not
attributable to the genus make it’s hard to establish an accurate
figure for the size of Antarctosaurus. Study of
the type species has
indicated a size of up to eighteen metres long; however without
knowing the full body shape and proportions for certain, this figure
is really only a best guess. If the material for A.
giganteus is
valid them an upper size approaching thirty meters may be more
appropriate, at least for this species of the genus. This would
also make Antarctosaurus a size rival for
Argentinosaurus,
but
again, with the validity of the inclusion of these fossils with the
Antarctosaurus genus in doubt, it is impossible to
reliably attribute
this size with this dinosaur.
Further reading
- Short review of the present knowledge of the Sauropoda. Memoirs of
the Queensland Museum 9(1):121-126. - F. von Huene - 1927.
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