5.six.cuatro Sacral backbone

Several isolated sacral centra was indeed gathered (age.g., PEFO 33875 and you will 33819), nevertheless the sacral rib and you will neural arc was busted away from. The amount of sacral spinal vertebrae is determined are a few created on: (a) a few type of sacral rib marks for the ilia off Roentgen. callenderi; (b) several ankylosed centra (PEFO 36876) that have clear articulations having ribs and neural arches (Figures 8i–k); and you can (c) truth be told there seem to be merely several morphologies of sacral vertebrae certainly the new isolated specimens. The 2 ankylosed centra indicates that certain specimens out of Roentgen. callenderi get coossify their sacral vertebrae hence so it character is actually variable within the taxon. Given that all specimens out of PFV 297 is actually out of comparable proportions, so it coossification in some specimens does not appear to be dimensions related. Instead, since the inside ventral view the lateral expansions of one’s centra up to the newest ankylosed town aren’t well symmetrical, so it combination you are going to show a beneficial cystic and extra specimens are required to confirm so it.

The brand new sacral centra is actually elongate and you may mediolaterally large than dorsoventrally tall, and centrum confronts is amphicoelous (Data 8i–k). The next sacral rib articulates with many of one’s lateral body of your centrum and you may a portion of the ventrolateral facial skin of neural arch (PEFO 36876). During the dorsal look at, the latest sacral rib of second sacral vertebra develops greatly toward an enthusiastic anteroposteriorly elongate articulation on ilium (Contour 8l). For the lateral look at, which articulation skin is actually cigar-shaped; so it articulates with a lot of of your own period of the new postacetabular procedure of your ilium. New anterior part of the articulation are some convex having good slight dorsomedial extension. The remainder articular facial skin are concave. The fresh articular skin of one’s centrum together with 2nd sacral rib is actually round within the lateral check (Contour 8k). A transverse ridge distinguishes the fresh articular epidermis into the two-fold, a lowered area that fits toward a slot on the horizontal section of the 2nd sacral centrum, and you can a top region one articulates into the neural arch. Brand new sensory arch isn’t really-maintained in any sample; the brand new prezygapophysis are based sixty° out of lateral and postzygapophysis is actually dependent merely ten° out of horizontal (regardless of if they are some crushed).

The full amount of caudal vertebrae contained in Roentgen. callenderi are unknown; not, you will find at 34–thirty-six caudal vertebrae on the aetosaurian A good. ferratus (J.B. Desojo, individual telecommunications, 2021), and you will a comparable matter may have been contained in the aetosauriform R. callenderi (Figure 7; Nesbitt, 2011 ; ).

5.six.5 Anterior and you can mid-caudal spinal vertebrae

Anterior caudal backbone (Figure 8m) has actually hourglass-designed centra inside the ventral check that are anteroposteriorly longer than mediolaterally large and you may seriously grooved ventrally (age.grams., PEFO 34561). This groove expands at the anterior and posterior ends and that is designated by line of ridges. The brand new prior prevent merges that have a couple posteriorly more inclined faces, and therefore act as the latest articulation surfaces toward chevrons. Such range from the fresh connect-such as chevron areas of specific rauisuchids (elizabeth.grams., UCMP 124890; Much time & Murry, 1995 blackchristianpeoplemeet yГјkle : fig. 130c). As anteriormost caudal vertebra is not managed, that isn’t obvious where position the chevrons start. The articular confronts was round and you may amphicoelous which have clear wheels. The brand new neural arch was low, or just around half the brand new level of centrum articular face. The brand new prezygapophysis is really-developed forming an excellent posteroventrally, and you can medially based flat articular epidermis. The newest distal margins of each other prezygapophyses mix with her as they are confluent on the prior edge of this new sensory lower back. This new lower back is actually anteroposteriorly wide with an even rear edge and you will an anteroventrally sloping prior boundary. The fresh new apex is not stretched towards a properly-setup spine dining table. The postzygapophysis is significantly high (more or less double the newest height) compared to prezygapophysis. The lateral margin is virtually upright, plus the articular body try inclined ventromedially on 45° and you will face a little posteriorly.