Pannoniasaurus
Name:
Pannoniasaurus
(Hungarian lizard).
Phonetic: Pan-no-ne-ah-sore-us.
Named By: L. Mak�di, M. W. Caldwell
& A. Osi - 2012.
Classification: Chordata, Reptilia, Squamata,
Mosasauridae, Russellosaurina, Tethysaurinae.
Species: P. inexpectatus
(type).
Diet: Carnivore/Piscivore.
Size: Roughly about 6 meters long.
Known locations: Hungary - Csehb�nya Formation.
Time period: Santonian of the Cretaceous.
Fossil representation: Almost complete skull and
post cranial skeleton.
The
holotype specimen of Pannoniasaurus was first
discovered in 1999,
and finally described to science as a new genus of mosasaur
in
2012. This description made history in the field of mosasaur
research as it marked the first time that a mosasaur had been found in
a freshwater deposit. Before this discovery, mosasaurs had only
ever been found in marine (salt water) deposits.
This
discovery confirmed an idea that many people had already had about
mosasaurs. Being reptiles, they were air breathers with lungs,
and not gills like fish, and so moving from salt to freshwater
should have offered no problems in terms of respiration. The only
real difference between fresh and salt water is that fresh water does
not offer as much buoyancy as salt water, so a Pannoniasaurus
(and
other marine reptile) in freshwater may have had to expend a little
more energy in swimming and reaching the surface.
The
Pannoniasaurus holotype was found in an area that
during the late
Cretaceous was a river basin, and while this confirms that this
individual Pannoniasaurus was in freshwater at the
time of its death,
it does not necessarily mean that this genus of mosasaur was
restricted to this river system. This individual may have been an
occasional visitor, or attracted upstream by the smell of a carcass
of a dinosaur that had drowned upstream, or perhaps have been washed
into the river by a storm surge, we simply do not know yet how. It
is still quite probable however that Pannoniasaurus
could have also
ventured into the sea, perhaps hopping along coastlines from one
river system to the next. This is not that farfetched an idea, in
modern times the saltwater crocodile (Crocodylus porosus)
is
documented as venturing cross Southeast Asia, swimming across
hundreds of miles of open sea to reach new hunting grounds.
Further reading
- The first freshwater mosasauroid (Upper Cretaceous, Hungary)
and a new clade of basal mosasauroids. - PLoS ONE
7(12):e51781. - L. Mak�di, M. W. Caldwell &
A. Osi - 2012.
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