A couple of weeks ago Brian Switek’s blog Laelaps included a
post on transitional fossils (those things that some
creationists will tell you simply don’t exist… ) Brian’s post
was sparked by this story (OK, maybe the writer of was aiming
for ‘balance’, but really!) & he suggested that others might
like to emulate him & write something about their own favourite
transitional fossil. The idea’s been simmering away in my mind
since then. Brian’s challenge required some pause for thought –
what is my favourite transitional fossil? I do like the whales,
but he beat me to it on that one. And then I thought, what about
Diarthrognathus??? Diarthrognathus lived back in the Triassic
(ie while the dinosaurs were the dominant land mammals) & was a
‘mammal-like reptile’ - as the name suggests, a reptile with
some mammal-like features of its anatomy. These include things
like the presence of different types of teeth in the mouth;
development of a secondary bony palate that separates the nasal
passage from the mouth – thus a