[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Reversed Hallux in Theropods: a query
Hello again. More questions :o)
It seems that the reversed hallux of theropods figures prominantly in
discussions about arboreal theropods and the evolution of birds. However,
from every illustration and skeletal reconstruction I have seen, this
"reversal" is not so reversed as to create a grasping toe! More often than
not, it seems, it points backward (like a much reduced normal toe would), not
forward (like a digit specialized for grasping would). In some cases, it
appears that it might be directed to the side a bit, but still faces more
backward than forward.
Now the questions:
1) Is the "reversed" hallux really reversed after all? If so, why isn't it
reconstructed that way? If not, why is it such a big deal?
2) If the hallux were to be used as a grasping tool (e.g., for perching),
wouldn't it have to be at least as large as the main toes (digits II-IV)?
The purpose of a backwards pointing toe would be to keep the animal from
falling forward, but the dismally small digit I's of theropods seem
ill-suited for such a task - even for the small critters!
I must say that (gulp) on this point (and this point only), I agree with
Larry Martin. I just don't see how the this little toe could be of much use,
whether the animal was arboreal or not.
Any clarifications would be most appreciated!