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R: Status of _Caudipteryx_



----- Original Message -----
From: Mickey_Mortimer <Mickey_Mortimer@email.msn.com>
To: <dinosaur@usc.edu>
Sent: Friday, December 29, 2000 3:56 AM
Subject: Re: Status of _Caudipteryx_

> The postacetabular process of Microvenator actually isn't preserved in
> either ilium (Makovicky and Sues, 1998).

Yes in the Makovicky's paper on Microvenator the postacetabular region is
not preserved, but I've downloaded two photos of the ilium of Microvenator
in the AMNH search-Site in which the preacetabolar region is present, but in
this case however I don't known - and I don't have such good eye to see - if
the postacetabular region are reconstructed in plaster, however from this
photos the preacetabular region is shorter than the postacetabular region.

>Using the postacetabular estimate
> in that paper gives a preacetabular/postacetabular ratio (measured from
>the
> anterior and posterior edges of the pubic and ischial peduncles
> respectively) of .76.  This compares to .98 in Caudipteryx, 1.11 in
> Nomingia, .73 in Ingenia

I'm very interesting in the Ingenia's ilium because within the Oviraptoridae
only Ingenia has a shallow ilium with a straight dorsal margin not a deep
ilium with a convex dorsal margin. For my comparison I use the illustration
pubblished in "The Dinosauria" but I don't know if it is affidable, could
you tell me when I can found some good photos or illustrations of the
Ingenia's ilium?

>Deinonychus (MCZ 4371)
> has a ratio of 1.39 (note AMNH 3015 is "fragmentary and poorly >preserved"
>with an "unknown anterior margin").

Yes, the anterior margin of the AMNH 3015's ilium is unknown, but based on
the illustration of Ostrom (1969, and 1976) there are some difference in the
ilium of the two specimens of Deinonychus, expecially in the deep of the
preacetabular region, in the dorsal margin of the ilium and in the
orientation of the pubic peduncle.

> Actually, the ventral tip of Microvenator's preacetabular process is
>broken
> off.  Following the outline of the bone to a point (as is shown in
>Makovicky
> and Sues 1998) shows that it extends ventrally about halfway (51%) past
>the
> pubic peduncle, as in Nomingia.  Ingenia's extends a third of the way,
>while
> "Rinchenia's" and Caudipteryx's extend past the pubic peduncle.

For Caudipteryx I'm agree with you, but in Rinchenia the extension of the
ventral tip of the preacetabular region could have related to the shortness
of the pubic peduncle, infact in Rinchenia the pubic peduncle is as deep as
the ischiatic peduncle, while in Caudipteryx the pubic peduncle si deeper
than the ischiatic peduncle

By
____________________________________________
Marisa Alessandro
"Volounteer of Paleontological Museum of Monfalcone"
Via Achille Grandi n°18
38068 ROVERETO (TN) ITALY
Tel:039-0464-434658 Email amaris@tin.it
____________________________________________