anatomical questions (mandibule of a basal synapsid)

[Jeff Leach <leachjeff2@hotmail.com>]

I have a few question concerning the skull details of a basal synapsid 
(_Varanosaurus acutirostris_), in particular some details of the articular

I have drawn and labeled (hopefully correctly) a figure((<a 
href="javascript:ol(´'http://server3.pictiger.com/img/257503/other/varanosaurus-skull-figure-1.jpg');">), 
the abbreviations shouldn't cause any problems but just in case

ps.cp = cultriform process of the parasphenoid
pt.tp = transverse process of the pterygoid
pt.qr = quadrate ramus of the pterygoid (the more ventral part is a keel on 
the quadrate ramus or a part of the basisphenoid, it is hard to tell from 
the original unlabeled drawing)
coa = anterior coronoid
cop = posterior coronoid
art.rp = retroarticular process of the articular

The questions concerning the articular are

1) is the retroarticular process the ventral process of the articular (as 
labeled in the figure)? The shape and position differs from therapsids so I 
am somewhat unsure.

2) is the 'cotylus for the quadrate' the posterodorsal corner of the 
articular (about where 'art' points to in the medial view of the mandibule?)

3) The two fossa labeled X and Y, anyone know if they have names? They look 
like the articulating surfaces for the quadrate.


Figure 2 (<a 
href="javascript:ol(´'http://server3.pictiger.com/img/257503/other/varanosaurus-skull-figure-2.jpg');">) 
is a relabeled figure 1

4) the article refers to the 'external mandibular foramen', 'inframandibular 
foramen' and 'meckelian fenestra'. The last two terms are equivalent, at 
least I think so. Have I labeled the mandibular foramen and inframandibular 
foramen correctly.

5) Is the 'coronoid eminence', the portion of the posterior coronoid visible 
in lateral view or does it continue posteriorly along the surangular?


Thanks for the help.

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