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

Re: Coelurus a maniraptoran (for how long?)

----- Original Message -----
From: "Mickey_Mortimer" <Mickey_Mortimer11@email.msn.com>
To: <dinosaur@usc.edu>
Sent: Monday, June 11, 2001 6:20 AM
Subject: Re: Coelurus a maniraptoran (for how long?)

I've re-read

Fernando E. Novas: Anatomy of *Patagonykus puertai* (Theropoda,
Avialae, Alvarezsauridae), from the Late Cretaceous of Patagonia, JVP 17(1),
137 -- 166 [unfortunately I don't have the last page with the character
matrix] (March 1997).

It says "Alvarezsauridae and Ornithothoraces share the following cranial and
postcranial synapomorphies supporting the monophyly of Metornithes: quadrate
articulates with prootic and squamosal;"
As you wrote --

> 9.  Quadrate articulating only with the squamosal (0), or with both
> and squamosal (1).
> This is a fine metornithine character, although oviraptorids have it too.

Unfortunately, the cladogram only includes Ornithomimidae, Tyrannosauridae,
*Deinonychus*, *Archaeopteryx*, *Alvarezsaurus*, *Mononykus*, *Patagonykus*
and Ornithothoraces.

"vertebral neural canal dorsoventrally wide relative to centrum depth;"
Is this the same as

> 18.  Wide vertebral foramen in thoracic vertebrae, vertebral
> foramen/articular cranial facies ratio (vertical diameter) larger than
> 0.40: absent (0), present (1).
> This is a valid metornithine character too, though it is also present in
> Avimimus and Rahonavis.

, and is it connected to the wide foramen magnum of *Shuvuuia*?

"prominent ventral processes on cervicodorsal vertebrae;"
As you wrote --

> 16.  Prominent ventral processes on cervico-dorsal vertebrae: absent (0),
> present (1).
> Again, Chiappe et al. code this as unknown in Alvarezsaurus, when the
> first three dorsals of that genus have very small hyapophyses, if any
> (Bonaparte,
> 1991).  The authors code it as absent in dromaeosaurids, as the processes
> in Deinonychus are only moderate in size.  The hypapophyses of Nomingia,
> Chirostenotes, Sinornithoides, Avimimus and Rahonavis are at least as
> large as Mononykus, while Ornitholestes, Caudipteryx, Saurornitholestes,
> Velociraptor and oviraptorids are also said to have prominent processes.

"ossified, longitudinally oriented rectangular sternum;"
As you wrote --

> 39.  Sternum subquadrangular to transversally rectangular (0) or
> longitudinally rectangular (1).
> [...] As can be seen from the following list, this does not support
> Metornithes. The numbers indicate width divided by length.
> [...]
> Indeed, it can be seen that Mononykus has an exceptionally narrow sternum,
> while the proportions in basal pygostylians are similar to those in
> dromaeosaurs.  I think you'll agree there is no support for Metornithes
> here.

Additionally, in *Eoalulavis* nearly only the keel is ossified.

"ossified sternal carina;"

> 40.  Ossified sternal keel: absent (0), present (1).
> Confuciusornis only occasionally has a faint keel (two specimens), while
> the keel is caudally restricted in Protopteryx and absent in
> So whether this is a good metornithine character or not is very debatable.

"ulnar distal condyle present;"
Is this the same as

> 51.  Distal end of ulna subrectangular and transversely compressed (0), or
> subtriangular in shape (1).
> This is fine.  Also known in Rahonavis by the way.

"Carpometacarpus present;"
As you wrote --

> 54.  Distal carpals and proximal portion of metacarpals unfused (0), or
> fused forming a carpometacarpus (1).
> An extremely variable character.  Mononykus has all metacarpals and the
> semilunate completely fused.  Confuciusornis only fuses metacarpal I with
> the semilunate.  Jibeinia, Protopteryx, possibly Longipteryx, Sinornis,
> "Archaeoraptor", Cathayornis? caudatus and Longchengornis have unfused
> metacarpi.  Thus, I think Mononykus developed this in parallel to the
> partial development in confuciusornithids, the development within
> enantiornithines and the development in euornithines.

Does anyone have an idea as to what a carpometacarpus is good for in
flightless animals, and why only some pygostylians and alvarezsaurids have

"Prominent antitrochanter on ilium;"
As you wrote --

> 64.  Prominent antitrochanter: absent (0), caudally directed (1), or
> dorso-caudally directed (2).
> This is fine, though also present in Avimimus.

Is the famous book "Mesozoic Birds: Over the Heads of Dinosaurs" or whatever
its title was already published? Can someone give me the complete ref?

"pubic apron reduced;" (in *Patagonykus* the pubes just touch, despite being
long, mesopubic and having a big boot, and aren't sutured)

> 75.  Pubic apron more than one-third the length of the pubis (0), shorter
> or absent (1).
> This is fine too, although present in Avimimus and Bagaraatan too.

What's the condition in oviraptorosaurs?

"obturator process of ischium absent; terminal process[es?] of ischia not in
True of *Mononykus*; oviraptorosaurs and segnosaurs have obturator
processes; only the acetabular portion of the ischium is known for
*Patagonykus*. Is an ischium of *Alvarezsaurus* known? And wasn't there an
ornithothoracine whose ischia touched, or is this false memory?

> 19.  Hyposphene-hypantrum accessory intervertebral articulations in dorsal
> vertebrae: present (0), absent (1).
> Although Chiappe et al. code Patagonykus as having this character, it is
> absent in this genus(Novas, 1997).

*Patagonykus* has indeed character state 0, like *Rahonavis* and nearly all
other saurischians, but unlike *Mononykus* and AFAIK all pygostylians. The
illustrations are unambiguous.

Does the sentence "A deep postspinal depression exists in each proximal
caudal" refer to pneumatic fossae? (Depressions that look like pneumatic
fossae are present on proximal caudal centra below the transverse

The carpometacarpus seems to indicate that the hands could only swivel to
the ulna from a neutral position, but not to the radius. Birds have the same
condition, other theropods AFAIK not...