Re: Dinosauricon Phylogeny: in progress

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

I wrote-

> >I don't think velociraptorines as currently thought of (Velociraptor,
> >Deinonychus, Saurornitholestes) have a good chance of being monophyletic.
> >I
> >wrote a long piece on this offlist, and could find it if anyone's
> >interested.

Tim Williams expressed interest, so I searched through my university's
terrible e-mail system to find it-

Currie (1995) lists the following synapomorphies of Velociraptorinae-

1. High DSDI.
The DSDI of dromaeosaurs is as follows-
Sinornithosaurus 1.13-1.43 (Xu and Wu, 2001)
Bambiraptor 1.40-1.51 (Burnham et al., 2000)
Deinonychus 1.31-2.33 (Rauhut and Werner, 1995)
Saurornitholestes 1.19-2.00 (Rauhut and Werner, 1995)
Velociraptor 1.46-1.60 (Rauhut and Werner, 1995)
Dromaeosaurus .81-1.18 (Rauhut and Werner, 1995)
Utahraptor .85-1.00 (Kirkland et al., 1993)
Achillobator 1.11-1.13 (Perle et al., 1999)
Bambiraptor has a velociraptorine ratio, while it varies between teeth of
Sinornithosaurus.  Microraptor and Cryptovolans lack anterior serrations, so
cannot have their DSDI's measured.

2. Second premaxillary tooth much larger than third and fourth premaxillary
teeth.
0- Deinonychus (Ostrom, 1978)
Dromaeosaurus (Currie, 1995; the second tooth is not preserved, but the
third and fourth are large)
1- Sinornithosaurus (Xu et al., 1999)
Velociraptor (Barsbold and Osmolska, 1999)
IGM 100/1015 (anonymous 1997)
Utahraptor (Kirkland et al., 1993)
Sinornithosaurus has the velociraptorine state, while the
velociraptorine-like Deinonychus lacks it and the dromaeosaurine-like
Utahraptor has it.

3. Nasals dorsally depressed.
This varies in Velociraptor (Osmolska and Maryanska, 1999) and is probably
due to the flexibility of the element in life.  Furthermore, Deinonychus
lacks the condition, and it is unknown in Saurornitholestes.  It seems to be
present in Sinornithosaurus, but not in Bambiraptor.  Of dromaeosaurines,
only Utahraptor preserves a nasal, but this is undescribed.

Currie also lists the following ways velociraptorines differ from
Dromaeosaurus-

4. Shallower premaxilla.
Only the posterior portion of the premaxilla is known in Dromaeosaurus.  The
length/height ratio of Utahraptor's premaxilla is intermediate between
Deinonychus and Velociraptor (Kirkland et al., 1993).

5. More slender quadratojugal.
Also in avialans, Sinornithosaurus and Bambiraptor.

6. Postorbital process of frontal less sharply demarkated from frontal
orbital margin.
Also in troodontids, Sinornithosaurus, Bambiraptor and almost all other
coelurosaurs.  Primitive.

7. More robust posteromedial palatine process.
True in Deinonychus, but not Velociraptor.

8. Dorsal fossa on ectopterygoid.
Present in Deinonychus and Saurornitholestes, but not Velociraptor.

9. More maxillary and dentary teeth.
Microraptor- ?/~19
Sinornithosaurus- 12+/13+
Bambiraptor- 9/13
Velociraptor- 11/14or15
Saurornitholestes- ?/16
Deinonychus- 15/16
Dromaeosaurus- 9/11
Achillobator- 11/?
Deinonychus has more maxillary teeth than dromaeosaurines and Bambiraptor,
but Velociraptor does not.  Saurornitholestes may have, given the large
number of dentary teeth, but the same is true for Microraptor.
"Velociraptorines" have more dentary teeth than Dromaeosaurus and
Bambiraptor,
but so might Sinornithosaurus.  Microraptor's total is much larger.
Remember too that dromaeosaurs' outgroup, troodontids, have very large
numbers of teeth.

10. Vertical process on posteromedial articular smaller.
Plesiomorphy.

So in conclusion, there are no valid suggested synapomorphies for a
Velociraptorinae including Deinonychus but not Sinornithosaurus, Bambiraptor
and Microraptor.  Deinonychus and Saurornitholestes appear closer
morphologically to each other than either is to Velociraptor.  They may be
closer to Dromaeosaurus than Velociraptor.

Mickey Mortimer