[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
MARINE REPTILE EGGS, & CONSTRAINTS
Regarding my thoughts on constraints in turtle evolution related to
their retention of ovipary (I said that embryo turtles derive their
calcium from the eggshell), Leslie Noe wrote...
> I see a break in the logic here; let me add a rider, eggshells derive
> their calcium from the mother. Therefore can the embryo not
> derive calcium from the mother instead of the (secondary source)
> of the eggshell?!?
Yeah... I don't know. It would be a good idea to find out about
calcium budgets and skeletal embryology in turtles and other
reptiles. I'm very poorly informed in this subject and cannot pretend
to understand it. Anyone?
On possible terrestrial locomotion in metriorhynchid crocs, Leslie
> Danny Grange (then a research student, at Bristol University), at
> the SVPCA (1996, University College London) presented a paper
> entitled 'Locomotion in metriorhynchid crocodilians' (no idea if
> this was ever published) in which he concluded met. crocs. could not
> walk on land (based on limb girdle morphology)
Grange's stuff on metriorhynchid locomotion was not published, and
I'm afraid he's now out of the palaeo business, sorry to say. I know
that Dino Frey and a few other people who have worked on/are familiar
with metriorhynchids did not agree with Grange's views and his
contention that metriorhynchids were immobile on land was one point
of disagreement. Note that Dino Frey and Steve Salisbury are doing an
SVPCA '98 presentation entitled 'Locomotion in metriorhynchid
crocodiles: 'no gallop' is the only consensus'.
"You're making a mess"