[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Support for Enigmosauria



>   (1) A "true" semilunate is still the most complex and promising.

Isn't it too complex to be promising? :-)

>   (2) coracoid glenoid convex.

AFAIK that's true of crocodiles, but I can hardly imagine that in a
dinosaur. Does it exist?

>   (3) a characteristic digit 2 of the pes is another that could be very
> promising.

This consists of several apparently independent characters:

- digit II markedly shorter than IV
- claw II bigger than III and IV
- claw II much bigger than all others
- digit II hyperextensible

Troodontidae, Dromaeosauridae, *Bambiraptor*, *Sinornithosaurus*,
*Microraptor* and *Rahonavis* have all 4. At least some specimens of
*Confuciusornis* have the 2nd and to a slight extent the 3rd, but with the
claw not the first and AFAIK neither the last character. *Archaeopteryx* has
the first and probably the last, but no others. Several recent birds have
the 2nd alone. And so on.

>   (4) and with the primitive eggshells of segnosaurs out of the way,

Segnosaur eggshell is so "primitive" that it _must_ be derived. *Troodon*
and *Lourinhanosaurus* have dinosauroid-prismatic eggshell, while
?segnosaurs have dinosauroid-spherulitic one like sauropods and
ornithischians!!! Morphological long-branch attraction :-)

> Sorry, but for the
> time being the segnosaurs remain rejected, although they do appear to be
the
> nearest outgroup to the true maniraptor-bird clade.

Unless you tell us of more characters that _positively_ place segnosaurs
somewhere else, and not just _negatively_ place them _not_ as sister to
Oviraptorosauria sensu lato, even the 2 characters you mentioned would hold
"Enigmosauria" together in cladistic analyses AFAIK. Bootstrap support etc.
might be very weak, but it still would be most parsimonious.