The new ventral articular body bears a couple convex surfaces separated of the a great concave epidermis

12th Srpen 2022

The new ventral articular body bears a couple convex surfaces separated of the a great concave epidermis

5.2.13 Squamosal

The fresh morphology and sideways against orientation of your squamosal may be very like aetosaurs such S. robertsoni, An effective. ferratus, P. andressorum, and you may D. spurensis (Figure 4u, v; Walker, 1961 : fig. 2; Brief, 2002 : fig. 2; Schoch, 2007 : fig. 8; Schoch & Desojo, 2016 : fig. 4). The fresh oddly-formed squamosal (described as “sword-like” to possess A great. ferratus from the Schoch, 2007 ) variations new posterodorsal margin of one's supratemporal fenestra. T. ruthae likewise has an excellent laterally established squamosal; not, Roentgen. callenderi and you will aetosaurs lack the noticable ventral projection included in you to definitely taxon (Ezcurra et al., 2017 ).

The brand new squamosal bears three procedure, a keen anterior process, a posterodorsal procedure, and you will an effective posteroventral techniques. The mediolaterally thin anterior techniques is the biggest of your around three and you may articulates ventrally with the quadratojugal, variations a little portion of the posterodorsal margin of your own lateral temporal fenestra, and articulates dorsally with the posteroventral side of this new postorbital. A lateral ridge on the dorsal portion of the squamosal bounds this new supratemporal fenestra sideways and you can goes on anteriorly onto the dorsolateral margin of one's postorbital. A tiny anteriorly leading apex of the anterior means of the newest squamosal underlies a good posterodorsal projecting prong of the dorsal procedure for the fresh new jugal. This get in touch with excludes the fresh new postorbital of contribution regarding the margin regarding the newest infratemporal fenestra as previously mentioned in the past, just as the symptom in P. kirkpatricki (Weinbaum, 2011 ), and other in the condition in aetosaurs (elizabeth.g., P. andressorum, Schoch & Desojo, 2016 ). A small slot with the anteroventral surface of the anterior procedure suits a thinner dorsal procedure of the fresh new quadratojugal.

The brand new posterior portion of the squamosal stretches posterior to your direct of the quadrate and splits towards the a good posteroventral and you will a keen anterodorsal techniques. Your face of your own quadrate matches toward a distinct ventrally facing fossa you to offers onto the anterior a portion of the posteroventral process (Profile 4v); therefore, the brand new posteroventral techniques therefore the lateral edge of the new articulation body covers your face of your own quadrate from lateral look at. Additionally, into posteroventral osal, there was a condo, posteriorly up against bookshelf that accepts this new slim anterodorsal margin of one's quadrate. This new rear skin of one's posteroventral processes has actually a tiny aspect you to definitely articulates to the paroccipital means of brand new opisthotic (Profile 4v). Unlike most archosauriforms, this aspect is actually thickened mediolaterally and you will circular towards a knob similar on the condition in T. dabanensis (IVPP V3237) and you will aetosaurs (Nesbitt, 2011 ). The new posterodorsal techniques carries a slit to your their posterior edge that fits brand new posterolateral procedure for the brand new parietal.

Among the skeleton of your palate, the brand new vomers commonly accepted regarding any identified specimen. Although not, new ectopterygoid, pterygoid, and you may palatine is actually maintained from inside the PEFO 34561 and an extra ectopterygoid known (PEFO 33857); the brand new palate is complete but obscured within the PEFO 34089 (Contour three-dimensional).

5.dos.fourteen Pterygoid

Even if not one are completely kept (Contour 5a), the newest pterygoid includes the brand new anterior techniques, horizontal process, and you will posterior procedure. The new prior processes try triangular in the mix-part that have a high dorsal ridge you to spells out new function at brand new midline. The newest ventral skin with the processes try concave. It tapers anteriorly however the connection with the palatine try unfamiliar. The brand new lateral process consists of an effective posteriorly indicated wing one to slopes posteroventrally. The fresh new lateral portion of the ventral skin and has a big part along the entire duration of the fresh new horizontal procedure that articulates with the fresh new dorsal body of your ectopterygoid (Figure 5a). This new pterygoid person is a thin, vertically centered knife. The new ventral facial skin holds a curved anteroposteriorly based ridge one to goes on onto the prior processes. Pterygoid teeth try absent. Brand new rear techniques (= quadrate processes) is actually broken in the specimens (e.g., PEFO 34561) rear with the articulation point with the semi-rounded fossa for the basipterygoid means of the newest parabasisphenoid. The anteroposterior length of the brand new pterygoid is like you to definitely during the archosauriforms including Erythrosuchus africanus (Gower, 2003 ) and you may P. kirkpatricki (TTU P-9000), rather than the anteroposteriorly abbreviated pterygoids off aetosaurs (e.grams., L. meadei, TMM 31185-98; Neoaetosauroides engaeus, PVL 5698).