The members of Sauropterygia presents double-headed cervical ribs contacting with the parapophyses in the cervical centra, and with the diapophyses
in the cervical neural arches.
Calyptocephalellidae diagnosable on the basis of the following combination of characters (autapomorphies marked by asterisk): 1) relatively well-developed pterygoid process of the maxilla, 2) unsculptured alveolar region of the labial face of the maxilla dorsoventrally narrow *, 3) premaxilla with anterior portion of palatine shelf well defined in lingual view, 4) atlantal cotyles bean-shaped *, 5) unfused atlas and second presacral vertebra, 6) strong anteroposterior extension of sacral vertebral diapophyses *.
The diapophyses are well-fused to the neural arch and are oriented anteriorly, a morphology recalling that of Calyptocephalella and Gigantobatrachus (CASAMIQUELA, 1958).
The parapophyses are slightly anterior of the diapophyses (*; Fig.
Characters of the diapophyses and parapophyses (presented above) and the overall size of the vertebrae omit the fossils from the Rhyacotritonidae, Ambystomatidae, Dicamptodontidae, and Salamandridae.
The first four cervical vertebrae have the parapophyses in an anterior position and towards the base of the centrum, while in the fifth cervical vertebra, both the diapophyses
and parapophyses have moved up the centrum (Wilkinson et al.
At least three cervical vertebrae (probably the 5th, 7th and 8th based on the shape and position of the diapophyses
and parapophyses) and six dorsal vertebrae (the first five from the thoracic region and one from the lumbar region) have been preserved partially complete (Fig.