our research prove that, columella in Malpolon species have only one center of
chondrification which seems to be a universal feature in Ophidia.
They suggested another hypothesis, which is a combination of the previous theories that the FT appeared to be a failure in the
chondrification of the mesenchymal elements derived from the fourth and sixth pharyngeal arches associated with the presence of the vessels and/or nerves proceeding from the superior laryngeal pedicle.
He speculated that the anomaly resulted from failed fusion of either the sclerotomal
chondrification or ossification centers during fetal spinal development.
Recent studies in zebrafish suggest that dorsal and ventral elements in a given arch originate from separate sites of
chondrification within the same condensation of precartilage cells (Schilling and Kimmel, 1997).
The marsupial neonate must at a minimum have a closed secondary palate (providing support to and separation of the oral and respiratory pathways), sufficient ossification and
chondrification (to provide cranial rigidity and support muscle attachment), functional oral musculature (primarily tongue and oral-pharyngeal muscles), and a means to support the lower jaw (because at birth there is no dentary-squamosal contact).
Chondrification may be regarded as a partial or semi-canonical valorization.