The evolution of metamorphosis in temnospondyls
Article first published online: 2 JAN 2007
Volume 35, Issue 4, pages 309–327, December 2002
How to Cite
SCHOCH, R. R. (2002), The evolution of metamorphosis in temnospondyls. Lethaia, 35: 309–327. doi: 10.1111/j.1502-3931.2002.tb00091.x
- Issue published online: 2 JAN 2007
- Article first published online: 2 JAN 2007
- 21st January 2001, revised 16th August 2002.
Temnospondyls, possible relatives of extant amphibians and crudely similar to recent salamanders, are known from larval, neotenic and metamorphosed stages. Here, ontogenetic data of various temnospondyl taxa are analysed in order to recognize metamorphosis. Here, metamorphosis is strictly defined as a shift from an aquatic to a terrestrial existence. Following a check-list of criteria, the most likely metamorphosis-induced changes are proved in three temnospondyl lineages: eryopids, zatrachydids and dissorophoids. In a few other, unrelated taxa, terrestrial adults are known but no larval or metamorphosing forms. The distribution of metamorphosis among the Temnospondyli does not strictly correlate with phylogeny, which highlights the widespread occurrence of neoteny. In each group, characteristic patterns of metamorphosis are described and compared. Among temnospondyls, dissorophoids had the most intensive type of metamorphosis, characterized by a condensed ontogeny and a relatively small body size. The result was a distinct transformed morphotype with far-reaching terrestrial adaptations.