|
A Modern Taxonomy of Chordates
Over the past two decades, evidence has accumulated that recognition of the Class Reptilia is not consistent with evolutionary history. However, due to historical inertia, the herpetological community has been reluctant to incorporate nomenclatural changes consistent with contemporary phylogenetic discoveries. In order to clarify this situation, CNAH has adopted the following classification based on the phylogenetic hypothesis presented below.
Class Reptilia has been traditionally composed of Order Chelonia (the turtles), Order Crocodylia (the crocodilians), Order Squamata (the lizards, snakes, and amphisbaenids), and Order Rhynchocephalia (the Tuataras). The discovery that birds (Class Aves) are the closest modern relative to the crocodilians, or the sister clade to crocodilians and turtles, renders the Class Reptilia as an unnatural grouping. In order to reconcile the taxonomy with evolutionary history, the following classification is adopted by The Center for North American Herpetology until further data suggest otherwise. Due to the arbitrary nature in which higher taxa may be delineated, CNAH has tried to reach a classification in which the maximum explanatory power is retained.
| Phylogenetic
hypothesis of the extant Classes
of the Phylum Chordata (Chordates) as recognized by
The Center
for North American Herpetology.
The North American taxa from
the groups depicted in red are
covered under the auspices of
CNAH and are included in the
standard common and current
scientific names list. The former Class Pisces (Fishes)
was long ago divided and the arrangement
of them shown here is taken directly from the two
refernces below that are followed by a blue asterisk. |
|
| Adapted from:
Ahlberg, P. E. and A. R. Milner.
1994. The
Origin and Early Diversification
of Tetrapods. Nature
368: 507-514. Hedges, S. B. and L. Poling. 1999. A Molecular Phylogeny of Reptiles. Science 283: 998-1001. Iwabe, Naoyuki, Yuichiro Hara, Yoshinori Kumazawa, Kaori Shibamoto, Yumi Saito, Takashi Miyata, and Kazutaka Katoh. 2005. Sister Group Relationship of Turtles to the Bird-Crocodilian Clade Revealed by Nuclear DNA-Coded Proteins. Molecular Biology and Evolution. 22(4): pp. 810-813. Jiang, Zhi J., Todd A. Castoe, Christopher C. Austin, Frank T. Burbrink, Matthew D. Herron, Jimmy A. McGuire, Christopher L. Parkinson & David D. Pollock. 2007. Comparative mitochondrial genomics of snakes: Extraordinary substitution rate dynamics and functionality of the duplicate control region. BMC Evolutionary Biology 7(123): 14 pages.
Kirsch, J. W. A. and Mayer, G. C. 1998. The
platypus is not a rodent: DNA hybridization,
amniote phylogeny and the palimpsest theory.
Philosophical Transactions of the Royal Society
of London Series B 353, 1221. Nelson, Joseph S. 2006. Fishes of the World. Fourth Edition. John Wiley and Sons, New York. xvii + 601 pp. * Nelson, J. S., E. J. Crossman, H. Espinosa-Pérez, L. T. Findley, C. R. Gilbert, R. N. Lea, and J. D. Williams. 2004. Common and Scientific Names of Fishes from the United States, Canada, and Mexico. 6th Edition. American Fisheries Society, Special Publication 29: ix + 386 pp. *
Rest, Joshua S., Jennifer C. Ast, Christopher C. Austin, Peter J. Waddell, Elizabeth A. Tibbetts, Jennifer M. Hay, and David P. Mindell. 2003. Molecular systematics of primary reptilian lineages and the tuatara mitochondrial genome. Molecular Phylogenetics and Evolution 29: 289-297.
Zardoya,
R. and A. Meyer. 1998. Complete
mitochondrial genome suggests diapsid affinities
of turtles. Proceedings of the National
Academy of Science 95(24): 14226-31. |
 |
|
| © 1994-2008, CNAH - Director - Joseph T. Collins | Programmer/Webmaster - Travis W. Taggart |
| Accessed at: 8/27/2008 8:23:48 PM CST. | |