This new ventral articular epidermis bears a couple of convex surfaces split up of the good concave skin

5.2.thirteen Squamosal

The fresh morphology and you will sideways against orientation of one’s squamosal is quite similar to that of aetosaurs instance S. robertsoni, A good. ferratus, P. andressorum, and you can D. spurensis (Profile 4u, v; Walker, 1961 : fig. 2; Brief, 2002 : fig. 2; Schoch, 2007 : fig. 8; Schoch & Desojo, 2016 : fig. 4). The new oddly-molded squamosal (called “sword-like” to own A great. ferratus from the Schoch, 2007 ) models the fresh new posterodorsal margin of your own supratemporal fenestra. T. ruthae is served by an effective laterally centered squamosal; yet not, R. callenderi and aetosaurs lack the obvious ventral projection used in one taxon (Ezcurra mais aussi al., 2017 ).

The brand new squamosal contains about three procedure, an enthusiastic anterior techniques, a great posterodorsal processes, and you will an excellent posteroventral processes. The fresh new mediolaterally thin prior techniques ‘s the premier of one’s around three and articulates ventrally toward quadratojugal, versions a small part of the posterodorsal margin of horizontal temporary fenestra, and articulates dorsally toward posteroventral side of the fresh postorbital. A horizontal ridge towards dorsal portion of the squamosal bounds the new supratemporal fenestra sideways and you can continues on anteriorly onto the dorsolateral margin of one’s postorbital. A tiny anteriorly leading apex of the prior procedure of the new squamosal underlies an effective posterodorsal projecting prong of one’s dorsal process of the latest jugal. Which contact excludes the postorbital away from involvement from the margin out-of the fresh new infratemporal fenestra as stated in earlier times, similar to the condition in P. kirkpatricki (Weinbaum, 2011 ), and different about condition in aetosaurs (e.g., P. andressorum, Schoch & Desojo, 2016 ). A little position for the anteroventral skin of your own anterior techniques matches a slimmer dorsal procedure for this new quadratojugal.

The brand new rear part of the squamosal runs rear on the head of the quadrate and you may splits to the good posteroventral and you can a keen anterodorsal procedure. Your face of quadrate fits toward a definite ventrally facing fossa that offers onto the prior a portion of the posteroventral techniques (Contour 4v); ergo, the newest posteroventral procedure plus the horizontal edge of the fresh articulation surface covers your mind of the quadrate of lateral check. While doing so, towards posteroventral osal, you will find a flat, posteriorly against shelf one to welcomes this new thin anterodorsal margin of quadrate. The posterior surface of your posteroventral techniques has actually a small part one articulates into paroccipital procedure for the fresh new opisthotic (Figure 4v). In lieu of most archosauriforms, that it aspect try thickened mediolaterally and you will round to your a cock equivalent into the condition in T. dabanensis (IVPP V3237) and aetosaurs (Nesbitt, 2011 ). The posterodorsal processes carries a slit to the their rear edge you to matches brand new posterolateral process of the fresh new parietal.

One of many bones of your own palate, the latest vomers are not acknowledged out of people known sample. However, the newest ectopterygoid, pterygoid, and you will palatine is actually managed for the PEFO 34561 and you may an extra ectopterygoid known (PEFO 33857); new palate is done however, obscured from inside the PEFO 34089 (Shape 3d).

5.2.fourteen Pterygoid

Even though not one are entirely maintained (Shape 5a), brand new pterygoid consists of the latest prior techniques, horizontal procedure, and you can posterior techniques. The new anterior procedure are triangular inside cross-point which have a tall dorsal ridge you to delineates brand new function within the midline. The fresh ventral body of this procedure try concave. It tapers anteriorly however the experience of the newest palatine is actually not familiar. Brand new lateral processes contains an excellent posteriorly directed wing one to slopes posteroventrally. New horizontal part of the ventral body and has now a big facet over the entire amount of the new lateral procedure that articulates with the fresh dorsal body of one’s ectopterygoid (Contour 5a). The pterygoid body is a thin, vertically depending blade. The fresh new ventral epidermis bears a rounded anteroposteriorly depending ridge that continues on the prior processes. Pterygoid teeth is absent. The fresh new rear techniques (= quadrate process) is actually broken-in most of the specimens (elizabeth.g., PEFO 34561) rear for the articulation area towards partial-round fossa into basipterygoid procedure for the fresh parabasisphenoid. The new anteroposterior period of the pterygoid is much like one inside archosauriforms instance Erythrosuchus africanus (Gower, 2003 ) and you may P. kirkpatricki (TTU P-9000), as opposed to the anteroposteriorly abbreviated pterygoids away from aetosaurs (age.g., L. meadei, TMM 31185-98; Neoaetosauroides engaeus, PVL 5698).

Leave a Comment

Your email address will not be published.