5.6.2 Postaxial cervical vertebrae
PEFO 34561 doesn’t maintain one post-axial anterior cervical vertebrae, so this malfunction generally is based on PEFO 33861, PEFO 34269, and PEFO 34833 (Profile 8e). The brand new centra is anteroposteriorly short; the latest anteroposterior duration of the fresh centrum are several-thirds its height. The diapophysis is situated on dorsolateral facial skin of your own centrum whereas the fresh parapophysis is located on ventrolateral skin. Between you’ll find sparingly so you can well-put up low-pneumatic fossae. Ventrally, all the centra enjoys well-arranged keels. The newest neural arc and spine try dorsoventrally large as compared to centrum; review off PEFO 33861 and PEFO 34833 implies that the fresh neural spine screens confident allometry relative to this new centrum. The new sensory lower back was posteriorly put and you will quite overhangs the new centrum. It’s laterally compressed and you may anteroposteriorly thin, that have a highly slight extension in the dorsal tip. Brand new zygapophyses was built fifty°–55° out-of horizontal. The fresh new postzygapophysis and has now a proper-put up epipophysis as a consequence of at the very least the latest next cervical vertebra (predicated on PEFO 34833). The presence of post-axial epipophyses is very important because this character enjoys a finite distribution inside archosaurs, and are just present in R. callenderi, saurischian dinosaurs, B. kupferzellensis, V. campi (e.g., PEFO 33978), X. sapingensis (IVPP V6026), Elizabeth. okeeffeae (AMNH FR 30587), and you may Hesperosuchus agilis (AMNH FR 6758; Langer & Benton, 2006 ; Nesbitt, 2011 ).
The new morphology of your center in order to posterior cervical spinal vertebrae is similar to your alot more prior cervical vertebrae than the trunk area vertebrae within the they own light ventral keels and lack distinct vertebral laminae; however, the fresh new centrum is more equant in size (Shape 8f). Furthermore, the fresh diapophysis is present with the sensory arch, this new zygapophyses are proportionally bigger than much more anterior spinal vertebrae, new postzygapophyses use up all your epipophyses, and the transverse expansion of dorsal margin of your own neural back is best set up. Therefore, brand new posterior cervical spinal vertebrae is transformation inside the morphology involving the anterior cervical and also the mid-trunk backbone.
5.six.3 Trunk spinal vertebrae
Proceeded the fresh trend noticed in the cervical series, the initial a couple trunk backbone (dependent on cuddli profili this new associated rib form of) are transitional for the morphology (Shape 8g) between the cervical spinal vertebrae and also the trunk backbone closer to the new sacrum. This new centra is anteroposteriorly longer than dorsoventrally tall, in addition to centrum faces was amphicoelous. The trunk centra lack ventral ridges into midline (= ventral keels). The brand new prezygapophysis are depending 29° off horizontal, whereas the new postzygapophysis is founded only 20° out-of horizontal. The latest neural lower back is far more stretched anteroposteriorly compared to the fresh new cervical vertebrae; so it expansion comes from better-install dorsoventral laminae for the anterior and you may posterior sides of one’s sensory back. The latest dorsal part of the neural lower back are lengthened laterally towards the a comprehensive “back desk” that have a flat dorsal surface, like aetosaurs (elizabeth.grams.,D. spurensis, MNA V9300). Inside the dorsal consider, such back tables try cardio-designed for the top of your own cardiovascular system leading posteriorly. The fresh new diapophysis and parapophysis was linked because of the a proper-created paradiapophyseal lamina; that it lamina is located in other archosaurs (age.grams., Nesbitt, 2005b ), but it is eg higher within these spinal vertebrae out-of R. callenderi. The brand new parapophysis is positioned into the neural arc, but it is perhaps not dorsal for the dorsalmost expansion of one’s centrum. The initial one or two trunk vertebrae have sparingly setup centroprezygapophyseal, centropostzygapophyseal, spinoprezygapophyseal, spinopostzygapophyseal, prezygodiapophyseal, postzygodiapophyseal, and you will intrapostzygapophyseal laminae recognize them about cervical backbone (Wilson, 1999 ).
step one.25pared on the first couple of trunk backbone, the new parapophysis is a lot closer to the fresh new diapophysis; the latest parapophysis is anteromedial into the diapophysis and are generally linked by the a small paradiapophyseal lamina. Brand new centrozygapophyseal and you will spinozygapophyseal laminae commonly as pronounced throughout the even more rear trunk area vertebrae, although intrapostzygapophyseal lamina remains line of, and you can a great intrina is available. The newest neural spines is heart-molded for instance the transitional vertebrae, however they are a bit significantly more anteroposteriorly elongate.