Name:
Brachytrachelopan
(Short necked Pan).
Phonetic: Brak-e-trak-el-o-pan.
Named By: O.W.M. Rauhut, K. Remes, R.
Fechner, G. Cladera & P. Puerta - 2005.
Classification: Chordata, Reptilia, Dinosauria,
Saurischia, Sauropodomorpha, Sauropoda, Dicraeosauridae.
Species: B. mesai (type).
Diet: Herbivore.
Size: Estimated to be 10 meters long.
Known locations: Argentina, Chubut Province -
Ca�ad�n C�lcero Formation.
Time period: Tithonian of the Jurassic.
Fossil representation: Cervical (neck),
dorsal (back) and sacral (hip) vertebrae, ribs and partial
elements of the hip and hind limb.
Dicraeosaurid
sauropods
(as typified by Dicraeosaurus)
are noted for having
proportionately shorter necks, but even out of all these
Brachytrachelopan has the shortest. This is in
stark contrast to
other sauropod types in other parts of the world such as Mamenchisaurus
and Sauroposiedon
which all show a progression towards a longer neck
specialisation. The key explanation for the short neck of
Brachytrachelopan is that it must have evolved to
fill a niche in the
late Jurassic ecosystems of South America that was not being filled by
other dinosaurs. Specifically ornithopod dinosaurs such as Iguanodon
that are were common in other parts of the world during the end of the
Jurassic are largely unknown from South America, and it may have been
their absence that allowed short necked dicraeosaurids like
Brachytrachelopan to thrive. Therefore the short
length of the neck
suggests that Brachytrachelopan would have
specialised in low to medium
height vegetation.
Although
the type specimen remains are only those of a partial skeleton,
palaeontologists have estimated the length of Brachytrachelopan
to be
towards ten meters. Additionally the fusion evident in the fossil
remains indicates that this was a fully grown individual. The
skeletal remains were also found articulated which means they are in
the same arrangement that they would have been in life, something
which helps to establish the short proportions of the neck.
Unfortunately the remains were found already exposed and it’s quite
possible that there was once more to this specimen but with the
additional remains being lost to erosion. Perhaps the most
interesting area which is still missing is the skull as without this it
is impossible to infer any specific dietary preference which may be
connected to the short neck.
The
remains of Brachytrachelopan were discovered by
Daniel Mesa, a local
shepherd, and the type species name of B. mesai
is in honour of
him. Also because the remains were discovered by a shepherd it
gave the inspiration for the genus name ending with ‘pan’ which is
actually a reference to the god figure of Pan, who in in Greek
mythology was often depicted as being the patron deity of
shepherd’s. The first part of the genus name translates as ‘short
necked’ so that the full meaning of the name is ‘short necked
Pan’.
Further reading
- Discovery of a short-necked sauropod dinosaur from the Late Jurassic
period of Patagonia - O. W. M. Rauhut, K. Remes, R. Fechner, G.
Cladera & P. Puerta - 2005.
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