MORE BASAL ORNITHISCHIAN STUFF

[Tetanurae@aol.com]

Philidor11 writes (quoting Dave Norman):
<< However, since then this animal has undergone a name change!  It is now
claimed that the original material of Fabrosaurus, since it is only a small
piece of jaw with a few teeth, cannot be closely compared to the newer
skeleton so it is impossible to know exactly how similar these animals really
were.  To be safe, the new skeleton was renamed Lesothosaurus australis. >>

This is a typo on Norman's part.  The combination L. australis has never been
used in a scientific paper, and never can be.  When Galton named the genus
Lesothosaurus, he named he species diagnosticus to go with it.

This led Thulborn to write in the 1992 ref I gave out in the last email:

"Perhaps he most eloquent symptom of the prevailing confusion appeared in the
work of Norman (1985: 100) 'It is now claimed that the original material of
Fabrosaurus, since it is only a small piece of jaw with a few teeth, cannot be
closely compared to the newer skeleton so it is impossible to know exactly how
similar these animals really were.  To be safe, the new skeleton was renamed
Lesothosaurus australis.' (sic)"

George Olshevsky wrote (quoting me):
PB<<It was not a heterodontosaurid because it didn't have
 the fangs, and also had none of the other specializations of
heterodontosaurs.>>

GO<<Had pretty much the same kinds of cheek teeth.>>

George, this is really not for certain.  All of the preserved teeth of
Pisanosaurus are worn, so their original un-worn shape isn't known.
Heterodontosaurid cheek teeth are only really distinctive in their un-worn
newly errupted form.  All we know for sure from the teeth is that it a) wasn't
an iguanodontian and b) wasn't a ceratopid, aside from that, the worn cheek
teeth don't help much.

Again though, the primitive ankle and propubic pelvis, as well as the lack of
fangs and an arched diastema, demonstrate that Pisanosaurus probably is not a
heterodontosaurid, but instead the most basal ornithischian known.

Peter Buchholz
Tetanurae@aol.com