OF CARNEGIE MUSEUM OF NATURAL HISTORY PHYLOGEMETIC SYSTEMATICS OF CROTAPm-mS (mIGUANW CROTAPHYTIDAE) JIMMY A. McOUIRE BULLETIN of CARNEGIE MUSEUM OF NATURAL HISTORY PHYLOGENETIC SYSTEMATICS OF CROTAPHYTID LIZARDS (REPTILIA: IGUANIA: CROTAPHYTIDAE) JIMMY A. McGUIRE 1 Department of Biology, San Diego State University, San Diego, Cal$ornia 92182-0057 Current address: Department of Zoology and Texas Memorial Museum, The University of Texas at Austin, Austin, Texas 78712-1064. NUMBER 32 PITTSBURGH, 1996 'h BULLETIN OF CARNEGIE MUSEUM OF NATURAL HISTORY Number 32, pages 1-1 43, 52 figures Isstted 25 June 1996 James E. King. Director Editorial StaE John L. Caner, Editor; Bradley C. Livezey. Editor; David R. Watters, Editor Mary Ann Schmidt, ELS. Assistant Editor Cover illustration: An adult male Crotaphytus dickersonae photographed approximately 2 km north of Bahia Kino Nuevo, Sonora, Mexico (see Fig. 3 18). BULLETINS OF CARNEGIE MUSEUM OF NATURAL HISTORY are published at irregular intervals by Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, Pennsylvania 152 13-4080, by the authority of the Board of Trustees of Carnegie Institute. O 1996 by Carnegie Institute. all rights reserved. THE CARNEGIE MUSEUM OF NATURAL HlSrORY Abstract .................................................................................. Introduction .............................................................................. Historical Review ......................................................................... Materials and Methods ..................................................................... Frequency Coding ....................................................................... Allozyme Data Set ....................................................................... Ingroup Monophyly ...................................................................... Choice of Terminal Taxa ................................................................. Outgroup Taxa .......................................................................... Morphology and Character Descriptions ........................... .. ....................... Skull Roof .............................................................................. Palate .................................................................................. Braincase ............................................................................... Mandible ............................................................................... Miscellaneous Features of the Head Skeleton ................................ .. ............ Axial Skeleton .................... .. ................................................... Pectoral Girdle ...................... .. .......... .. .................................... Pelvic Girdle ............................................................................ Limbs ..................................... ............................................ Squamation ............................................................................. Pockets and Folds ....................................................................... Additional Morphological Characters ............................... ...................... Coloration .............................................................................. Behavioral Characters .................................................................... Character List ............................................................................. Results ................................................................................... Discussion ................................................................................ Comparison with Previous Hypotheses ................................ .. ................. Character Evolution ..................................................................... Taxonomic Accounts ...................................................................... Crotaphytidae ........................................................................... Crotaphytus ........................................................................... C. antiquus ......................................................................... C. bicinctores ........................................................................ C. collaris ........................................................................... C. dickersonae ...................................................................... C. grismeri .......................................................................... C. insularis ......................................................................... C. nebrius .......................................................................... C. oligocenicust ..................................................................... C. reticulatus ........................................................................ C. vestigium ......................................................................... Gambelia ............................................................................. G.copei ............................................................................ G. coronat .......................................................................... G. silus ............................................................................. G. wislizenii ......................................................................... Key to the Species of Crotaphytus and Gambelia .............................................. Acknowledgments ......................................................................... Literature Cited ........................................................................... ... 111 Appendices ......................... ..................................................... 120 1 . Specimens Examined ..................................................................120 2 . Data Matrix .......................... ............................................. 126 3 . Outgroup Data Matrix ......................... .. .. ... ...........................128 4 .Step Matrices for Manhattan Distance Frequency Approach .......................... .... 132 5 . Character Transformations for Each Stem of the Single Most Parsimonious Tree ............. 134 6 . List of Character State Changes by Character ............................................. 139 7 . Scleral Ossicle Data ...................................................................143 ABSTRACT A revision of the alpha taxonomy of Crotaphytidae revealed uous synapomorphies). The hypothesis of relationshipsestimated that there are at least 12 and probably 13 species. A data set here was used to address life history and morphological evolution including 88 characters drawn from osteology, squamation, soA within the group including the relationship between head mor- tissues, color pattern, life history, and behavior was collected. In phology and diet, the evolution of display-oriented morphology addition, an allozyme data set composed of ten phylopnetically in males, the evolution of bipedal locomotion, and a functional informative characters was obtained from the literature. Analysis consideration of gravid coloration. A taxonomic account is pro- of these data resulted in the following hypothesis of relationships: vided for Crotaphytidae, Crotaphytus, Gambelia, and each spe- ((Gambelia silus (G. coronat (G. copei + G. wislizenii))) + (Cro- cies. Each species account includes a synonymy, an etymology, taphyrus reticulatus (C. collaris (C. antiquus (C. nebrius (C. dick- a diagnosis for the species, a detailed description of scalation and ersonae (C. grismeri (C. bicinctores (C. insularis + C. vesrig- coloration, a section describing maximum adult size as well as ium))))))))). Although little character evidence in suppon of size dimorphism, a description of the species geographic distri- crotaphytid monophyly has been presented in the literature (Eth- bution with a dot distribution map, an account of the known eridge and de Queiroz, 1988; Frost and Etheridge, 1989), cro- fossil record, a summary of available natural history information, taphytid monophyly was found to be strongly supported with and a listing of references that provide illustrations of the species. five fixed, unambiguous synapomorphies. Strong support was Separate dichotomous keys are provided for males, females, and also discovered for monophyly of Crotaphytus (12 fixed, un- juveniles of Crotaphytus and Gambelia. ambiguous synapomorphies) and Gambelia (six fixed, unambig- 2 BULLETIN CARNEGIE MUSEUM OF NATURAL HISTORY NO. 32 INTRODUCTION Lizards of the family Crotaphytidae (collared and 1975), phylogenetic relationships within Crotaphy- leopard lizards) are among the most familiar squa- tidae remain largely unresolved. Although the mates of western North America. This familiarity monophyly of the group has never been questioned, probably stems from their relatively large size (com- few derived characters have yet been offered to sup- pared to other North American lizards), often vi- port this contention (Etheridge and de Queiroz, 1988; brant coloration, predatory lifestyle, and pugnacious Frost and Etheridge, 1989). The same can be said habits. Crotaphytidae, one of nine iguanian families for the monophyly of the genera. The phylogenetic proposed by Frost and Etheridge (1 989), is currently relationships of the group have been addressed using comprised of two genera, Crotaphytus (seven or eight cladistic methodology only once (Montanucci et al., species) and Gambelia