Meeting Abstract

30.11  Friday, Jan. 4  A Combined-Evidence of Anguimorpha (Reptilia, Squamata) CONRAD, JL*; NORELL, MA; AST, JC; AMNH; AMNH; Univ Mich jconrad@amnh.org

Anguimorpha is a clade of limbed and limbless squamates with 181 extant species and a fossil record spanning 100 million years. Morphology-based (MB) and molecule/genetic-based (GB) phylogenetic analyses find contrasting hypotheses for phylogenetic relationships within Anguimorpha. MB and GB analyses consistently differ in their placements of monstersaurs (e.g., Gila monsters), shinisaurs (crocodile lizards), the anguid Anniella (a limbless lizard), carusioids (knobby lizards), and the clades within Varanus (monitor lizards).
In order to understand the relationship between MB and GB analyses and to construct a hypothesis that incorporates available data from multiple sources, we performed a new combined-evidence analysis on Anguimoprha. We constructed a data matrix of 162 fossil and extant anguimorphs, and 2286 parsimony informative characters (334 morphological characters and 2033 molecular characters). We analyzed these data using the computer program TNT using the new technology search with the ratchet. Our results show similarities with both MB and GB analyses, but are identical to neither. Inspection of morphological data identified new diagnostic characters for some clades in the context of this analysis. Placement of carusioids as basal anguimorphs is consistent with MB analyses, but Varanus interrelationships are more like those of GB analyses. A novel placement was found for Anniella. Monstersaur interrelationships remain unresolved and shinisaurs are distinct from carusioids. We will discuss the importance of molecular data (e.g., large number of non-subjective characters) and the strengths of morphological data (e.g., historical data offered by fossil taxa) and their tandem use.