View Details:  Prev Record    Next Record
Clade
Subclade

Taxon
Taxon
Crurotarsi
Nominal Author
Sereno and Arcucci 1990
2nd Nominal Author
Taxon Status ACTIVE
Comments

The original intention in defining Crurotarsi was to coin a “stem-based taxon” in place of Pseudosuchia (Sereno 1991:42). The active definition is a second-order revision, because the original definition (Sereno and Arcucci 1990:41) and that in Sereno (1991:27) were node-based in error. As defined here, Crocodylotarsi and Pseudosuchia are potentially synonomous with Crurotarsi. Given the “Pan-” prefix suggested recently as a convention (Joyce et al. 2004), there may eventually be an additional junior synonym (“Pancrocodylia”).

Preference is given to Crurotarsi over Pseudosuchia (or Crocodylotarsi) despite the earlier date of definition of the latter, because of the long historical association of Pseudosuchia (“false crocodiles”) with polyphyletic taxonomic content that excluded crocodylomorphs as well as phytosaurs. In Krebs’ (1976) review, Pseudosuchia includes archosaur outgroups (Euparkeria) and taxa closer to birds (Scleromochlus) but excludes crocodylomorphs and phytosaurs. Abandoning Pseudosuchia for a more recently coined and defined taxon Crurotarsi is done reluctantly. Factors that enter such a decision include the mportance of past use regarding Pseudosuchia as well as the etymology of both taxa. Although taxa such as Dinosauria have successfully accommodated a living crown clade (Aves) that was once excluded, the name of the taxon at hand was not “Pseudoaves” and was not erected specifically for non-birds.

Crocodylotarsi, coined two years prior to Crurotarsi but first defined two years later, would have been another possibility. However, it has been defined as a less inclusive, node-based clade linked to the “crocodile normal” tarsus. Basal relationships within Crurotarsi are not well established, and so a taxon so defined may well prove redundant. Recently Parrish (1997) has abandoned Crocodylotarsi and Crurotarsi, whereas other authors have adopted Crurotarsi (Juu, 1994, Brochu 2001).

Potential Synonomy
Pseudosuchia, Crocodylotarsi

Active Phylogenetic Definition
Active Definition
The most inclusive clade containing Crocodylus niloticus (Laurenti 1768) but not Passer domesticus (Linnaeus 1758).
Shorthand
> Crocodylus niloticus but not Passer domesticus.
Definitional Author
Sereno 2005
Definition Status checked
Definition Type STEM
Node-Stem Triplet STEM
Other Triplet Taxa
Archosauria, Avemetatarsalia
Specifiers
Specifier(s) A
Crocodylus niloticus
Specifier(s) B
Specifier(s) C
Passer domesticus
Qualifiers
+Taxon
-Taxon
Datum
Taxonomic Content
Publication Year Unknown
Unknown
Unknown
2005

Inactive Taxon Status
Rejection Criteria
Critique
 

Definitional History #1
Earliest Record
Ornithosuchidae, Parasuchia, Aetosauria, Rauisuchia, Crocodylomorpha, and all extinct descendants that are most closely related to these taxa.
Latest Record
Sereno and Arcucci 1990:41
Range (My)
Range (My)
Ornithosuchidae, Parasuchia, Aetosauria, Rauisuchia, Crocodylomorpha
Range (My)

Definitional History #2
Earliest Record
Parasuchia, Ornithosuchidae, Prestosuchus, Suchia, and all descendants of their common ancestor.
Latest Record
Sereno 1991:27
Range (My)
Range (My)
Parasuchia, Ornithosuchidae, Prestosuchus, Suchia
Range (My)

Definitional History #3
Earliest Record
The last common ancestor of Ornithosuchidae (e.g., Riojasuchus; Fig. 4A) and Crocodylotarsi and all its descendants.
Latest Record
Parrish 1993:291
Range (My)
Range (My)
Ornithosuchidae, Crocodylotarsi
Range (My)

Definitional History #4
Earliest Record
Phytosaurs and crocodiles and all descendants of their most recent common ancestor.
Latest Record
Parrish 1997:
Range (My)
Range (My)
phytosaurs, crocodiles
Range (My)

Definitional History #5
Earliest Record
Phytosauridae, Ornithosuchidae, Prestosuchus, Suchia, and all descendants of their common ancestor.
Latest Record
Benton 2004:14
Range (My)
Range (My)
Phytosauridae, Ornithosuchidae, Prestosuchus, Suchia
Range (My)

Definitional History #6
Earliest Record
Latest Record
Range (My)
Range (My)
Range (My)

Definitional History #7
Earliest Record
Latest Record
Range (My)
Range (My)
Range (My)

Definitional History #8
Earliest Record
Latest Record
Range (My)
Range (My)
Range (My)

Definitional History #9
Earliest Record
Latest Record
Range (My)
Range (My)
Range (My)

Definitional History #10
Earliest Record
Latest Record
Range (My)
Range (My)
Range (My)