5.2.10 Quadratojugal
A slight ridge on posterodorsal margin of your dorsal processes articulates for the a position towards anteroventral osal. Posterior compared to that you will find a superficial fossa which is overlapped by anterolateral edge of this new quadrate. The newest ventral tip of your fossa is the prior border of brand new quadrate foramen. This new posteroventral part of your own quadratojugal versions a continuing epidermis with the fresh new lateral portion of the quadrate, installing into a great fossa on horizontal margin of second element. The fresh quadratojugal models the fresh new posteroventral spot of your own lateral temporary fenestra from inside the Roentgen. callenderi.
Anteriorly, brand new tapering posterior process of the newest jugal inserts into an effective triangular slot on the horizontal body of your quadratojugal (Figure 4o). This form of articulation is additionally contained in P. kirkpatricki (TTU P-9002; Weinbaum, 2011 : fig. 13). The same articulation style happens in A. ferratus and you will Paratypothorax andressorum (SMNS 19003; Schoch & Desojo, 2016 ), where a sandwich-triangular rear procedure of the newest jugal inserts into an enthusiastic embayment in the anteroventral margin of the quadratojugal ventral on the horizontal temporal fenestra. Throughout these taxa, a little anteroventral procedure of the fresh quadratojugal underlaps the new jugal (Schoch, 2007 ). An equivalent articulation along with happens in new doswelliid archosauriform Rugarhychos sixmilensis (Wynd et al., 2020 ) suggesting so it character county is generally plesiomorphic.
5.dos.eleven Postorbital
Brand new postorbital try an filipino cupid excellent triradiate bone having an ornamented lateral skin and you can about three type of techniques (Rates 4q, r). The fresh new anterodorsal procedure possess a definite lateral slot one gets the ventral and you can rear portion of the postfrontal, the posterodorsal procedure articulates to the anterodorsal osal, therefore the ventral procedure fits toward a position on the prior and you will medial facial skin of your posterodorsal means of new jugal. The dorsal margin is actually broadly rounded and has now a definite ridge that variations this new anterolateral margin of your supratemporal fenestra. Brand new curved prior margin provides a weakened ridge, building new posterodorsal margin of orbit. The brand new good dorsal ridge, and this runs posteriorly on the squamosal, is not utilized in aetosaurs (e.g., Desmatosuchus smalli, TTU P9024-; T. coccinarum, PEFO 38001). It is quite most likely missing during the A. geoffreyi (UCMP 156046), and that will not uphold the fresh postorbital, but does have this new squamosal and you can lacks that it ridge. D. grallator have the same dorsal ridge into the postorbital and you may squamosal (Sues et al., 2003 ).
New anteroventral portion of the squamosal and posterodorsal means of the new jugal nearly fits along the posteroventral edge of the fresh new postorbital, almost leaving out which element away from contribution on horizontal temporal fenestra (Contour 3b). This near exemption is not book so you can Roentgen. callenderi since it plus occurs in P. kirkpatricki (Weinbaum, 2011 ), as well as the involvement is extremely limited for the aetosaurs (e.grams., An excellent. ferratus) and crocodylomorph D. grallator (Nesbitt, 2011 ; Schoch, 2007 ).
The fresh new triangular feature originally interpreted just like the lacrimal because of the Parker ainsi que al. ( 2005 : fig. 2) is largely an isolated postorbital recovered on the head out-of PEFO 33787. Brand new prior portion of the kept squamosal from inside the Parker ainsi que al. ( 2005 : fig. 2b) is basically an articulated postorbital.
5.dos.twelve Quadrate
The latest quadrate was maintained inside PEFO 34561 (Figure 4s, t), while the quadrates is blurred when you look at the PEFO 38609 (Rates 3c, d). The brand new quadrate body is a good, dorsoventrally significant bone one does not have fenestration and hills posteroventrally, varying throughout the condition in shuvosaurids and you will aetosaurs in which the quadrate hills anteroventrally (Nesbitt, 2007 ).
A deep dorsoventrally created fossa is obtainable posterolateral to your horizontal flange (Shape 4s). This new pterygoid flange isn’t better-kept inside the PEFO 34561, nevertheless thickened root of the flange takes place off to the right element merely dorsal to your medial condyle across the medial line of quadrate.