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Clade
Subclade

Taxon
Taxon
Thecodontia
Nominal Author
Owen 1859
2nd Nominal Author
Taxon Status INACTIVE
Comments
Potential Synonomy
Thecodonta (Haeckel 1866, spelling variant)

Active Phylogenetic Definition
Active Definition
Shorthand
Definitional Author
Definition Status Unknown
Definition Type Unknown
Node-Stem Triplet Unknown
Other Triplet Taxa
Specifiers
Specifier(s) A
Specifier(s) B
Specifier(s) C
Qualifiers
+Taxon
-Taxon
Datum
Taxonomic Content
Publication Year Unknown
Unknown
Unknown

Inactive Taxon Status
Rejection Criteria junior synonym
no definition
Critique

No definition has been proposed for this traditional paraphyletic assemblage of basal archosaurs and closest relatives. Before the widespread use of cladistics, this taxon was used to encompass archosaurs assumed to be ancestral to dinosaurs, crocodiles, and pterosaurs. Thecodontia is included in this compilation because many authors (e.g. Romer 1956) listed it within Archosauria, even though it members included a few taxa now excluded from Archosauria. It could also be considered a potential junior synonym for Archosauria.

All recent cladistic studies (e.g. Gauthier 1986) have confirmed Thecodontia as a paraphyletic taxon, the members of which are not united by any shared characteristics. Thus, this taxon name is best preserved for its historical meaning and has been abandoned, despite Gardiner’s (1982) attempt to use it within a cladistic framework.

 

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