Both PEFO 34561 and PEFO 34269 uphold partial 2nd sacral vertebrae –

maiotaku-inceleme visitorsBoth PEFO 34561 and PEFO 34269 uphold partial 2nd sacral vertebrae

18 Ağustos 2022by Webmaster0

Both PEFO 34561 and PEFO 34269 uphold partial 2nd sacral vertebrae

5.six.4 Sacral vertebrae

Several isolated sacral centra was amassed (elizabeth.grams., PEFO 33875 and 33819), although sacral rib and you can sensory arc is actually broken out of. What number of sacral vertebrae is decided to get several dependent on: (a) a couple type of sacral rib marks on the ilia of R. callenderi; (b) a couple of ankylosed centra (PEFO 36876) that have obvious articulations for ribs and sensory arches (Data 8i–k); and you may (c) around seem to be simply two morphologies of sacral vertebrae certainly one of the fresh new remote specimens. The 2 ankylosed centra indicates that some specimens of Roentgen. callenderi can get coossify the sacral vertebrae which which profile was changeable when you look at the taxon. As the all of the specimens away from PFV 297 is off comparable proportions, that it coossification in some specimens will not be seemingly size related. Rather, since the inside the ventral look at the horizontal expansions of your own centra as much as this new ankylosed town aren’t perfectly shaped, that it combination you’ll depict an excellent pathology and extra specimens are required to confirm so it.

Brand new sacral centra is actually elongate and you can mediolaterally greater than simply dorsoventrally high, while the centrum face is actually amphicoelous (Figures 8i–k). Next sacral rib articulates with a lot of of your horizontal skin of centrum and the main ventrolateral skin of one’s sensory arc (PEFO 36876). For the dorsal view, this new sacral rib of next sacral vertebra increases considerably to the a keen anteroposteriorly elongate articulation with the ilium (Shape 8l). Inside the lateral look at, so it articulation surface is cigar-shaped; it articulates with most of your own period of the new postacetabular process of one’s ilium. Brand new anterior portion of the articulation try quite convex which have a limited dorsomedial expansion. The rest of the articular epidermis is concave. The new articular body of one’s centrum together with second sacral rib is actually rounded within the horizontal glance at (Profile 8k). A good transverse ridge distinguishes this new articular skin on two fold, a lower life expectancy part that fits for the a slot towards the lateral side of the second sacral centrum, and you can a higher region you to definitely articulates to your neural arch. The fresh new neural arc is not well-preserved in any specimen; brand new prezygapophysis try created sixty° of lateral as well as the postzygapophysis is actually situated simply 10° regarding lateral (regardless of if these include somewhat floor).

The quantity of caudal vertebrae found in R. callenderi try unknown; although not, you’ll find on 34–thirty-six caudal spinal vertebrae about aetosaurian A great. ferratus (J.B. Desojo, individual communications, 2021), and you can an identical amount was contained in this new aetosauriform R. callenderi (Contour 7; Nesbitt, 2011 ; ).

5.6.5 Prior and you will mid-caudal vertebrae

Prior caudal spinal vertebrae (Shape 8m) has actually hourglass-molded centra from inside the ventral look at which can be anteroposteriorly more than mediolaterally wide and you will seriously grooved ventrally (age.g., PEFO 34561). Which groove increases at anterior and you will posterior ends up and that’s noted from the distinctive line of ridges. The newest anterior stop merges that have a couple of posteriorly more inclined faces, hence serve as the fresh articulation surfaces towards chevrons. Such differ from this new link-particularly chevron facets of some rauisuchids (elizabeth.grams., UCMP 124890; A lot of time & Murry, 1995 : fig. 130c). While the anteriormost caudal vertebra isn’t kept, that isn’t clear at which position the chevrons initiate. Brand new articular face try bullet and you can amphicoelous which have evident tires. The newest neural arch are lowest, or just around 1 / 2 of the newest top of the centrum articular deal with. The new prezygapophysis is actually well-arranged building a beneficial posteroventrally, and you will medially dependent apartment articular surface. The distal margins away from each other prezygapophyses merge with her and are also confluent to the prior side of the neural back. The brand new lower back try anteroposteriorly broad having a level posterior edge and you may a keen anteroventrally slanting anterior line. Brand new top is not expanded on the a properly-set up spine table. The fresh postzygapophysis is significantly tall (roughly twice the fresh level) compared to prezygapophysis. The horizontal margin is practically straight, and also the articular skin is actually more inclined ventromedially on the forty five° and face some posteriorly.

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