Clade | |
Subclade |
Taxon | |
Taxon |
Arctometatarsalia
|
Nominal Author | Holtz 1994 |
2nd Nominal Author | |
Taxon Status | INACTIVE |
Comments | |
Potential Synonomy | Ornithomimiformes, Ornithomimosauria |
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 |
other |
Critique | This taxon is considered inactive, because there is little support for the taxon under its original apomorphy-based definition. Arctometatarsalia was coined as the flagship taxon to reorganize theropod phylogeny (Holtz 1994). Holtz coined and defined Arctometatarsalia as the first theropod with the arctometatarsalian condition and all of its descendants, an incomplete definition (as there is no specific internal specifier mentioned). He intended the clade to include Ornithomimosauria, Tyrannosauridae, Troodontidae, Elmisauridae and Avimimus but to exclude Dromaeosauridae and birds. Later Holtz (1996) replaced this form-qualified definition with a simple stem-based definition: the clade composed of Ornithomimus and all theropods sharing a more recent common ancestor with Ornithomimus than with birds. Subsequently Holtz (2000) replaced the vulgar term “birds” with Neornithes. The new taxonimic content of the taxon, however, no longer resembles the original, which was the signpost for a radically different phylogenetic hypothesis within Coelurosauria (see Ornithomimosauria). Because other taxa are available that do not have this history, Arctometatarrsalia is here regarded as inactive. |
Definitional History #1 | |
Earliest Record | The first theropod to develop the arctometatarsalian pes and all of its descendants. |
Latest Record | Holtz 1994:1108 |
Range (My) | |
Range (My) |
(none) |
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Definitional History #2 | |
Earliest Record | Ornithomimus and all theropods sharing a more recent common ancestor with Ornithomimus than with birds. |
Latest Record | Holtz 1996:536 |
Range (My) | |
Range (My) |
Ornithomimus, birds |
Range (My) |
Definitional History #3 | |
Earliest Record | Ornithomimus and all taxa sharing a more recent common ancestor with Ornithomimus than with Neornithes. |
Latest Record | Holtz 2000:28 |
Range (My) | |
Range (My) |
Ornithomimus, Neornithes |
Range (My) |
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Definitional History #6 | |
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Definitional History #7 | |
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Definitional History #8 | |
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Definitional History #9 | |
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Definitional History #10 | |
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