understand all the terminology? visit the Glossary)
which are all fused. Viewed laterally, the sacrum is slightly arched,
with continuous neural blade formed by the neural spines. A platform
projects from the bases of the neural spines and links with the
diapophyses. There is a shallow sulcus along the ventral surface
of the fused sacral vertebrae and the first two vertebrae have pleurocoels,
set in deep excavations.
of history, as this entry's a bit short. Ornithodesmus was
originally described as a bird,
was then re-described as a pterosaur,
was then discovered to be a dinosaur, was classified as a troodontid
(although the material it was compared to eventually turned out
to be misidentified itself), then a dromaeosaur.
Basically, no-one really knows what it is, although most palaeontologists
agree it is a dromaeosaur. Even if it is, it is not the same as
the large velociraptorine(s)
which is known from the island.
do I know if I've found a bone?