The last dorsal neural arches (17-19 dorsal vertebrae) clearly show zygapophyses.
queenslandicus (Kear, 2003), are slender in MP111209-1; the posterior dorsal vertebrae of MP111209-1 exhibit zygapophyses, which according to Kear (2003), do not seem to be present in K.
The platycoelous centra recognized in UPUAM 14072 allow to exclude its assignment to the European pachypleurosaurs, which present amphicoelous centra and pachyostotic zygapophyses (Rieppel, 2000).
Therefore, the transverse processes do not project beyond the zygapophyses. The vertebrae recovered from Fuen caliente de Medinaceli share all these exclusive characters (Fig, 5).
In addition, the narwhal vertebra lacks the prominent zygapophyses
of the Manasquan bone.
With exception of the cervical elements, all seahorse vertebrae lack of articular processes like zygapophyses
. In contrast, the vertebral column of Chamaeleo (Vertebrata, Reptilia) evolved an analogous dorso-ventral tail bending ability with a prehensile function, but through a direct implication of zygapophyses
The vertebrae are longer than wide, constricted in the middle (hourglass-shaped), with caudal ribs strongly compressed from above downward and ventrally deflected, and small zygapophyses
. They also have two ventral ridges, which are obliquely truncated by the chevron facets in the posterior region (Andrews, 1913), or in the anterior and posterior (Herrera et al., 2013b).