Acta Zoologica Cracoviensia, 31() 1988
On the presence of zygosphene-zygantrum vertebral articulations in salamandrids
Abstract:
The presence of zygosphene-zygantrum intervertebral articulations is documented for the first time in the order Caudata. In the newt Salamandrina terdigitata (Salamandridae) such articulation can be observed in both the trunk and caudal regions. Examination of the angular relations between the zygapophyseal and zygosphene articular surfaces allows quantification of the intracolumnar variation and makes possible its comparison with other amphibians and reptiles. The results indicate that the morphological degree of development of such articulation in Salamandrina approaches that of lacertilians. From an evolutionary point of view, this structure seems to have independently evolved in quite different lineages. Its functionality is here interpreted as related to an extreme concave bending of the columnar axis.
