5.six.4 Sacral spinal vertebrae
Multiple separated sacral centra was accumulated (age.grams., PEFO 33875 and you can 33819), however the sacral rib and you can sensory arch try damaged out-of. How many sacral spinal vertebrae is determined becoming a few depending on: (a) a couple of collection of sacral rib markings for the ilia regarding Roentgen. callenderi; (b) one or two ankylosed centra (PEFO 36876) having obvious articulations to have ribs and you can neural arches (Numbers 8i–k); and you may amolatina nedir (c) here be seemingly merely two morphologies of sacral vertebrae certainly one of the fresh new isolated specimens. The two ankylosed centra demonstrates some specimens regarding Roentgen. callenderi can get coossify its sacral vertebrae which it character are variable in taxon. While the the specimens out of PFV 297 was away from comparable proportions, this coossification in a few specimens doesn’t seem to be size related. Alternatively, because the into the ventral view the lateral expansions of one’s centra doing new ankylosed urban area commonly perfectly shaped, which combo you will depict an effective pathology and extra specimens are essential to confirm that it.
This new sacral centra try elongate and you will mediolaterally wide than just dorsoventrally high, as well as the centrum faces is actually amphicoelous (Rates 8i–k). Another sacral rib articulates with a lot of of horizontal body of one’s centrum and you will area of the ventrolateral surface of neural arc (PEFO 36876). In the dorsal glance at, the latest sacral rib of your own next sacral vertebra grows significantly toward an enthusiastic anteroposteriorly elongate articulation towards the ilium (Shape 8l). Inside lateral take a look at, which articulation skin is cigar-shaped; this articulates with many of your own amount of the fresh new postacetabular procedure of ilium. This new anterior portion of the articulation try a little convex which have a good slight dorsomedial expansion. The rest of the articular surface try concave. The fresh new articular body of one’s centrum and also the 2nd sacral rib are round for the horizontal examine (Figure 8k). A great transverse ridge distinguishes the newest articular surface towards two fold, a diminished region that fits with the a position towards the horizontal side of the next sacral centrum, and you will an upper area one articulates into neural arch. The brand new sensory arc is not better-maintained in virtually any specimen; new prezygapophysis was based sixty° out-of horizontal and also the postzygapophysis was built just 10° out of horizontal (regardless of if these are typically somewhat soil).
The full number of caudal vertebrae found in Roentgen. callenderi is actually not familiar; although not, there are during the 34–thirty-six caudal backbone about aetosaurian A beneficial. ferratus (J.B. Desojo, individual communication, 2021), and you can an equivalent amount was contained in the new aetosauriform R. callenderi (Profile seven; Nesbitt, 2011 ; ).
5.6.5 Anterior and mid-caudal vertebrae
Anterior caudal backbone (Shape 8m) provides hourglass-molded centra for the ventral check which can be anteroposteriorly longer than mediolaterally greater and you can profoundly grooved ventrally (age.g., PEFO 34561). So it groove grows at anterior and you will posterior comes to an end which is noted by line of ridges. The new prior prevent merges with a couple of posteriorly inclined faces, and that act as the brand new articulation surfaces toward chevrons. These types of change from brand new link-instance chevron components of certain rauisuchids (age.grams., UCMP 124890; Much time & Murry, 1995 : fig. 130c). As anteriormost caudal vertebra is not maintained, this is simply not clear where place the chevrons begin. The newest articular faces is actually bullet and you will amphicoelous that have clear rims. The fresh new sensory arc is actually reasonable, or about 1 / 2 of the fresh level of the centrum articular deal with. New prezygapophysis was well-created building a great posteroventrally, and medially mainly based apartment articular body. The new distal margins of both prezygapophyses mix with her and are usually confluent with the anterior side of the fresh sensory lower back. New back try anteroposteriorly greater with a level posterior border and you may an enthusiastic anteroventrally slanting prior edge. New apex is not lengthened on a highly-install lower back table. The fresh new postzygapophysis is much tall (around double the fresh new peak) as compared to prezygapophysis. Its lateral margin is virtually upright, as well as the articular facial skin is more likely ventromedially regarding the forty-five° and you will face quite posteriorly.