Ventastega
Name:
Ventastega
(Venta roof).
Phonetic: Ven-tah-steg-ah.
Named By: Ahlberg, Luksevics & Lebedev
- 1994.
Classification: Chordata, Amphibia, Tetrapoda,
Sarcopterygii.
Species: V. curonica (type).
Diet: Piscivore/Carnivore.
Size: Estimated 1 meter long. Skull 20
centimetres long.
Known locations: Latvia - Katleri Formation.
Time period: Famennian of the Devonian.
Fossil representation: Almost complete skull and a
few parts of the post cranial skeleton, including parts of the
shoulder and pelvis.
'Discovered'
in a museum draw and named after the Venta River, Ventastega
is a
partially preserved amphibian tetrapod. Although very poorly
preserved, there have been enough skeletal elements recovered to show
that Ventastega had legs. These post cranial
elements along with the
quite well preserved skull suggest that Ventastega
was more amphibian
than fish, although it is hard to be certain to just quite how well
developed it was.
Given
its place in the fossil record, Ventastega would
have been a
primarily aquatic predator that specialised in hunting fish, but may
have also included other prey such as very small and juvenile
amphibians. The teeth of Ventastega were mostly
small but numerous,
the largest of which were in the upper jaw at the premaxilla and
forward portion of the maxilla. These teeth were up to roughly double
the size of the others and would have been for primarily seizing prey
whereas the smaller teeth were more for gripping prey. This might
suggest that prey like fish were manipulated in the mouth so that they
were swallowed head first. This would avoid any spines that may have
protruded from the fish getting stuck in Ventastega
throat and
digestive system.
The
limbs although largely unknown would almost certainly have been only
developed to be just good enough to push itself along the ground, and
it is possible that Ventastega may never have left
the water
completely, the limbs evolving more for navigating submerged
obstacles and shallows.
Further reading
- The First Tetrapod Finds from the Devonian (Upper Famennian) of
Latvia. Philosophical Transactions of the Royal Society: - Biological
Sciences 343(1305):303-328. - P. E. Ahlberg, E. Luksevics & O.
Lebedev - 1994.
- Ventastega curonica and the origin of tetrapod morphology. - Nature
453 (7199): 1199–1204. - Per. E. Ahlberg, Jennifer A. Clack, Ervīns
Lukševičs, Henning Blom & Ivars Zupiņš - 2008.
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