@article {189,
	title = {The median lingual process of frogs: A bizarre character of Old World ranoids discovered in South American dendrobatids},
	journal = {American Museum Novitates},
	number = {3212},
	year = {1997},
	month = {Nov. 19},
	pages = {1-40},
	abstract = {Unexpected discovery of a median protuberance on the tongue of several Colostethus spp. (Dendrobatidae) provides first knowledge of an unusual anatomical structure in New World frogs. The general term median lingual process is suggested for all similarly positioned structures, previously known only in certain Asian and African frogs of the superfamily Ranoidea. References to the process are mostly buried in taxonomic descriptions under the term "median papilla," although it is many times larger than the tongue{\textquoteright}s fungiform papillae (which carry taste receptors) and the still smaller filiform papillae. Scanning electron microscopy shows a cell-surface ultrastructure of microridges (and microknobs) as is characteristic of certain other epithelia. The function of the median process is unknown but conceivably involved in the sophisticated anuran chemosensory system. From a survey of museum specimens and literature, the median process is shown to occur in one or more species of at least 16 genera of three nominal families and several subfamilies of Old World ranoids. Considerable variation in the median lingual process was found and is preliminarily classified under several morphologies. Type A: Retractile, upright cone-shaped processes occur with alpha-type retraction in Discodeles, Indirana, Mantidactylus, Rhacophorus, and with beta-type retraction in Platymantis and possibly Staurois. Type B: Retractile, upright rugose processes with alpha-type retraction characterize Petropedetes only. Type C: Elongate, longitudinally reclining processes characterize several genera of the Petropedetinae-Arthroleptides with alpha-type retraction, Dimorphognathus, Ericabatrachus, and Phrynodon, retraction unknown, Nothophryne, possibly nonretractile, and Phrynobatrachus, apparently both retractile and nonretractile. Type D: Retractile and nonretractile bumps or other exceptionally short structures occur in various arthroleptines, petropedetines, and ranines-probably a reflection of parallel reduction in both type-A and type-C processes. Overall homology of the several types of lingual process is tenuous and suggested only by the widespread existence of a retractile mechanism in the Old World ranoids and the apparent loss of such a mechanism in some but not all African petropedetines and in South American Colostethus. In dendrobatid Colostethus, the median lingual process is seemingly nonretractile and, except for a reduced (type D) process in one species, conforms generally to the common petropedetine type (type C), resembling most closely the tapered, pointed process of the East African Nothophryne. The median lingual process therefore looks to be homologous at least in the Dendrobatidae and African Petropedetinae. However, scanning electron micrographs show differences in dorsal tongue-surface morphology that have yet to be put in systematic context: Colostethus has a lingual covering of filiform papillae (as in Rana etc.), whereas at least some petropedetines have the mucosal epithelium folded and ridgelike (as in Bufo and Bombina). But Colostethus and petropedetines similarly have a collar of cilia encircling the taste disc (as in Rana etc. but lacking in Bufo and Bombina). Although current molecular evidence (Ruvinsky and Maxson, 1996) places the Dendrobatidae within South American Bufonoidea (= Hyloidea), the lingual process suggests that dendrobatids are New World ranoids, as originally indicated by Cope and Boulenger and more recently by Ford (1993). Still remaining to be investigated is the possibility (Noble, 1922-1931; Lynch, 1971) that dendrobatids may in some way be related to Neotropical Elosiinae (= Hylodinae), whose relationships are not clear. In arguing against Noble{\textquoteright}s hypothesis and promoting a dendrobatid-ranid relationship, Griffiths (1959) misinterpreted dendrobatid thigh musculature and other characters, whereas Noble{\textquoteright}s anatomical observations have been corroborated. Colostethus atopoglossus, new species, is among the dendrobatids having a median lingual process.},
	author = {Grant, Taran and Humphrey, Elaine C. and Myers, Charles W.}
}
@article {179,
	title = {The amphibian tree of life},
	journal = {Bulletin of the American Museum of Natural History},
	volume = {297},
	year = {2006},
	note = {Using Smart Source Parsing292-370},
	pages = {8-291},
	abstract = {<p>The evidentiary basis of the currently accepted classification of living amphibians is discussed and shown not to warrant the degree of authority conferred on it by use and tradition. A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one. This new taxonomy is based on the largest phylogenetic analysis of living Amphibia so far accomplished. We combined the comparative anatomical character evidence of Haas (2003) with DNA sequences from the mitochondrial transcription unit HI (12S and 16S ribosomal RNA and tRNA(Valine) genes, 2,400 bp of mitochondrial sequences) and the nuclear genes histone H3, rhodopsin, tyrosinase, and seven in absentia, and the large ribosomal subunit 28S (approximate to 2,300 bp of nuclear sequences; ca. 1.8 million base pairs; x ($) over bar = 3.7 kb/terminal). The dataset includes 532 terminals sampled from 522 species representative of the global diversity of amphibians as well as seven of the closest living relatives of amphibians for outgroup comparisons.</p>
},
	author = {Frost, Darrel R. and Grant, Taran and Faivovich, Julian and Bain, Raoul H. and Haas, Alexander and Haddad, Celio F. B. and De Sa, Rafael O. and Channing, Alan and Wilkinson, Mark and Donnellan, Stephen C. and Raxworthy, Christopher J. and Campbell, Jonathan A. and Blotto, Boris L. and Moler, Paul and Drewes, R. C. and Nussbaum, Ronald A. and Lynch, John D. and Green, David m and Wheeler, Ward C.}
}
