Ontogeny and phylogeny in temnospondyls: a new method of analysis

Authors
Citation
Js. Steyer, Ontogeny and phylogeny in temnospondyls: a new method of analysis, ZOOL J LINN, 130(3), 2000, pp. 449-467
Citations number
78
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences
Journal title
ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
ISSN journal
0024-4082 → ACNP
Volume
130
Issue
3
Year of publication
2000
Pages
449 - 467
Database
ISI
SICI code
0024-4082(200011)130:3<449:OAPITA>2.0.ZU;2-L
Abstract
A new method has been devised to compare the ontogeny and phylogeny of some of the better documented tetrapods from the Stephanian to the Trias. This approach is based on global parsimony analysis of several temnospondyl amph ibians, in which some ontogenetic sequences have been highlighted. Forty-on e homologous morphoanatomical character states have been separated into lar val, juvenile and adult stages of each of six tetrapod species. The taxonom ic congruence (TC) approach involves comparing trees based on lan;al, juven ile and adult character states. These so-called 'ontotrees' are not congrue nt, either in their topologies or in the distribution of the character stal es. The total evidence (TE) approach involves a combined analysis of all th e character states observed in the various growth stages of the taxa, and i s secondarily used in order to test this taxonomic incongruence. In this ca se, the TE result corroborates the TC analysis: the TE tree is robust and r eveals a few homoplasies which cause the taxonomic incongruence. This is in terpreted as either the result of heterochronic events in temnospondyl evol ution, or as the product of inaccurate identification of larval and metamor phic fossil forms. (C) 2000 The Linnean Society or London.