A REVIEW OF THE SOUTH AMERICAN LIZARD GENERA UROSTROPHUS AND ANISOLEPIS (SQUAMATA: IGUANIA: POLYCHRIDAE) RICHARD ETHERIDGE 1 and ERNEST E. WILLIAMS 2 Abstract. Lizards of the genera Urostrophus and Anisolepis represent a small, apparently monophy-letie group of southern South American Iguania, placed in the family Polychridae by Frost and Eth-eridge (1989), and referred to informally as the "para-anoles."Para-anoles are small (70-108 mm maximum snout-vent), with a slender, moderately compressed body, and a long tail (60-77% total length). Females reach a greater maximum adult size than males, and have a slightly shorter tail, but apparently there is no sexual dichromatism. The tail is non-autotomic and has been reported to be prehensile in both species of Urostrophus and in Anisolepis grilli. Two species of Urostrophus are recognized, U. vautieri from the Atlantic Forest of southeastern Bra-zil, and 17. gallardoi, described here as new, from Misiones Province in northeastern Argentina, from the Chacoan Region of northern Argentina, and from southeastern Bolivia. Both species have smooth, flat, juxtaposed dorsal and ventral body scales, and smooth, flat subdigital scales, but the head and body scales of U. gallardoi are smaller and more numerous overall, and it has a larger external ear, a color pattern of greater contrast, and a smaller maximum adult size: female snout-vent length 78 mm rather than 108 mm. Anisolepis differs from Urostrophus in having sharply keeled and strongly imbricate ventral body scales, a longer tail and higher number of caudal vertebrae, caudal transverse processes angled forward rather than laterally, and a higher total number of inscriptional ribs. Anisolepis contains three appar-ently allopatric species: A. grilli, A. undulatus, and A. longicauda, the latter formerly recognized as the only species of the genus Aptycholaemus, here syn-onymized with Anisolepis. The most obvious differ-ences among the species are: the absence of a trans-verse gular fold and presence of a very small external ear in A. longicauda, distinctly heterogeneous sca-lation on the dorsal body and neck in A. undulatus, and the alternatives to these characters in A. grilli — 1 Department of Biology, San Diego State Univer-sity, San Diego, California 98182. -Museum of Comparative Zoology, Harvard Uni-versity, Cambridge, Massachusetts 02138. a large ear, transverse gular fold, and less heteroge-neous scalation. Anisolepis grilli occurs in eastern Brazil in the At-lantic Forest and in the cultural steppe in the state of Sao Paulo, and in Misiones, Argentina. Anisolepis undulatus occurs in extreme southeastern Brazil, Uruguay, and on the south shore of the Rio de La Plata in Argentina; the Uruguayan and Argentinian specimens are larger and have a different pattern than those from Brazil, but the status of the southern pop-ulations is uncertain. Anisolepis longicauda occurs in Paraguay and in Argentina near the western bank of the Rio Paraguay and in Misiones Province, where it may be sympatric with A. grilli. Published and unpublished information on various aspects of para-anole biology are included. Accounts of Urostrophus and A. grilli indicate they live in trees and bushes and are slow in their movements. There are no records of the ecology or behavior of A. lon-gicauda or A. undulatus, but all of their known lo-calities appear to be in a habitat of seasonally flooded grasslands (esteros or barlados), adjacent or close to a large river or lake. One of us (RE) summarizes the long and complex history of hypotheses of para-anole relationships. There is a strong consensus that Polychridae is a monophy-letic family and that Urostrophus and Anisolepis (in-cluding Aptycholaemus) are among its member gen-era, but the historical relationships of these genera to one another and to other members of the family are yet to be resolved. INTRODUCTION Etheridge and de Queiroz (1988), in an analysis of the phylogenetic relationships of "Iguanidae," and Frost and Etheridge (1989) tentatively recognized as mono-phyletic a small group of subtropical South American genera: Urostrophus, Anisole-pis, and Aptycholaemus, and called them the "para-anoles." As the informal name implies, they show a number of resem-blances to the anoles proper, a distinctive Bull. Mus. Comp. Zool., 152(5), 317-361, May, 1991 317
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