A report released in 2007 showed that a set of
ancient footprints had provided compelling evidence that some
dinosaurs were able to swim.
A fifteen metre trackway (fifty feet long)
revealed one animal's underwater odyssey. It was discovered in
the Cameros Basin in Spain, which was once a vast lake. The s-shaped
prints suggested the beast clawed at sediment on the lake floor as
it swam in something like three metres of water (ten feet).
The marks were about 125 million years old,
dating to the Early Cretaceous, according to the team of scientists
who detailed the exploration and examination in the journal 'Geology'.
They were left by a large, bipedal, carnivorous dinosaur.
Dr Loic Costeur, a palaeontologist at the University
of Nantes, France, and a co-author of the paper explained that
they had come across them about three or four years before the
report was published. The Cameros Basin has thousands of walking
footprints from diverse dinosaur fauna, but when the team saw
these particular prints it was obvious straight away that this
was a swimming dinosaur.
The underwater trackway, which is well-preserved
in sandstone, is made up of twelve consecutive prints each
consisting of two to three scratch marks. The footprints are
quite peculiar in their shape and morphology - they are not at
all like walking footprints. In walking footprints, the shape of
the foot can be recognised; but here it is not at all the case:
the marks are sets of grooves on the sediment surface.