Theropoda is a term entrenched in the literature for carnivorous dinosaurs, but it's had competition over the years. Today we'll reflect on these alternative names for the group.
Cope (1866) named Goniopoda for Dryptosaurus (his Laelaps) and Streptospondylus (his Megalosaurus) based on his misinterpretation of their astragalus as the fibula, as a fibula which wraps distally around the tibia would be unique. The taxon was almost exclusively used by Cope through the 1880's, who eventually gave it a scope and diagnosis similar to Marsh's Theropoda (e.g. Cope, 1883). After Cope's death, Theropoda became the term exclusively used for carnivorous dinosaurs.
Harpagosauria was seen as a paraphyletic order of dinosaurs by Haeckel (1866), containing Megalosaurus, Plateosaurus and Pelorosaurus (but not Iguanodon). Haeckel refers to these as the carnivorous dinosaurs, which led Cope to synonymize the taxon with his Goniopoda (starting in 1870, and consistantly misspelled Harpagmosauria). However, Haeckel's original usage suggests it is instead the equivalent to Saurischia. Baur (1887) uses Harpagosauria as a dinosaurian group containing only Goniopoda, with Sauropoda separate. Haeckel (1895) later used Harpagosauria as a junior synonym for his new dinosaurian taxon Dysdracones including both Arctopoda (containing basal sauropodomorphs) and Theropoda, with sauropods now placed in his Eudracones that contained all herbivorous dinosaurs. Harpagosauria was said by Haeckel to contain the carnivorous dinosaurs with sharp teeth and claws. It has not been used since.
Proposed as part of a cladistic reclassification of ornithischians, Carnosauriformes was named by Cooper (1985) as a cohort of dinosaurs "retaining the primitive condition of recurved thecodontian dentition with finely serrated cutting edges." No justification for using this name over Theropoda was given, and it is today rightfully considered a junior synonym.
References- Cope, 1866. [On the anomalous relations existing between the tibia and fibula in certain of the Dinosauria]. Proceedings of the Academy of Natural Sciences of Philadelphia. 18, 316-317.
Haeckel, 1866. Generelle Morphologie der Organismen. Allgemeine Grundzuge der organischen Formen Wissenschaft, mechanisch begrundet durch die von Charles Darwin reformiete Deszendenz-Theorie. II. Allgemeine Entwicklungsgeschichte der Organismen. Kritische Grundzuge der mechanischen Wissenschaft von dan entstehenden Formen der Organismen, begrundet durch die Deszendenz-Theorie. Georg Reimer, Berlin. 462 pp.
Cope, 1870. Synopsis of the extinct Batrachia and Reptilia of North America. Transactions of the American Philosophical Society. 14, 1-252.
Cope, 1883. On the characters of the skull in the Hadrosauridae. Proceedings of the Philadelphia Academy of Natural Sciences. 35, 97-107.
Baur, 1887. On the phylogenetic arrangement of the Sauropsida. Journal of Morphology. 1, 93-104.
Haeckel, 1895. Systematische Phylogenie: Entwurf eines Natürlichen Systems der Organismen auf Grund ihrer Stammesgeschichte. Dritter Theil: Systematische Phylogenie der Wirbelthiere (Vertebrata). Georg Reimer, Berlin. 660 pp.
Cooper, 1985. A revision of the ornithischian dinosaur Kangnasaurus coetzeei Haughton, with a classification of the Ornithischia. Annals of the South African Museum. 95(8), 281-317.
Cool, I hadn't heard of most of these. You mention Carnosauriformes is considered a junior synonym, which led me to wonder, once PhyloCode is published, as the first and only code governing higher-level taxa, will all these be considered nomina nuda or what? Simply unconverted clade names in the cases where they were never given a definition?
ReplyDeleteWait for the Phylocode... ;-)
ReplyDeleteUnless these names are defined as clades under PhyloCode governance, they will have no standing under the code. And why would anyone define them? They will not return from their graves to haunt us, unless someone decides they're useful as slightly less inclusive near-synonyms of Theropoda. (I can't imagine why anyone would, but you never know -- theropod workers just love defining clades!)
ReplyDelete