I I BULLETIN DE L'INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE, BIOLOGIE, 61:121-188, 199 1 BULLETIN VAN HET KONINKL!JK BELGISCH INSTITUUT YOOR NATUURWETENSCHAPPEN, BIOLOGIE, 61:121-1 88, 1991 Generic relationships within Cordyliformes (Reptilia . Squamata) by Mathias LANG Table of Contents comorpha as the sister-taxon of Scincidae is accepted. A phylogenetic hypothesis of generic relationships is proposed based on 74 character complexes. Within Gerrhosauridae, the Madagascan clade Trachelop­ Abstract . 121 tychus-Zonosaurus represents a single speciation event coinciding with Zusammenfassung . 12 1 the separation of Madagascar from Africa. Within African gerrhosau­ Introduction : Historical Review of the taxonomy and proposed rids, the monotypic Angolosaurus is regarded as the earliest diverging affinities of Cordylidae + Gerrhosauridae 122 taxon. Gerrhosaurus is the sister-taxon to a Cordylosaurus-Tetradac­ Monophyly of Cordylidae + Gerrhosauridae 123 tylus clade. Within the purely African Cordylidae, the serpentine Cha­ Goals and problems of this study 124 maesaura is the earliest diverging taxon. Cordylus is the sister-taxon Material and Methods . 124 to a Platysaurus-Pseudocordylus clade. A new classification is propo­ Specimens . 124 sed based on these phylogenetic patterns. This classification parallels Outgroup comparison 124 taxonomic categories within the Scincomorpha. Biogeographical pat­ Systematic Characters 125 terns are evaluated in light of the proposed phylogeny and compared Scale characters 126 with Chamaeleonidae, the only other squamate taxon showing a simi­ Soft Anatomy 132 lar distribution. Cordylidae and Gerrhosauridae differentiated before Cranial Anatomy 135 the Madagascar-Africa separation. The latter coinciding with the diver­ Postcranial Anatomy 141 gence of subfamilies within Gerrhosauridae. Furthermore, diagnostic Life History . 143 features (based on character states and other autapomorphies) are Miscellaneous Characters 143 presented for each monophyletic taxon together with its content and Characters not used in this study . 147 geographical distribution. Discussion of phylogenetic results 150 Key words : Reptilia, Cordyliforrnes, Cordylidae, Gerrhosauridae, Definitions and diagnoses of taxa 151 phylogeny, taxonomy, biogeography. Cordyliforrnes 154 Cordylidae . 154 Chamaesaurinae 155 Cordylinae 156 Cordylini 157 Pseudocordylini 158 Zusammenfassung Gerrhosauridae 162 Gerrhosaurinae . 163 Anhand von Sammlungsmaterial verschiedener Museen wurden 74 Angolosaurini 163 Beschuppungs-, Skelett- und Weichteilmerkmale nebst andere biolo­ Gerrhosaurini 166 gischer Daten Angehorigen aller Gattungen der Cordyliforrnes unter­ Zonosaurinae 170 sucht, urn eine kladistische Merkmalsanalyse durchzufiihren. Dazu Biogeography . 174 wurden zunachst Merkmalszustande definiert und soweit moglich mit Conclusions . 176 dem Au13engruppen-Yerfahren, Polaritaten geklart. Urn die Verwand­ Acknowledgments 176 tschaftsbeziehungen zwischen den Gattungen zu errnitteln wurde ein Literature cited 177 Computer Programm zur Aufstellung eines Kladogramms unter Appendices . 183 Annahme geringstmoglicher Schritte unabhangiger, gleichgestalteter A. List of Specimens examined 183 Merkmalsiibergange benutzt. Danach sind die Cordyliden und Gerrho­ B. Character Data Matrix . 184 sauriden monophyletisch. Die Gerrhosauridae spalteten in einem ers­ C. Apomorphy and change list for preferred phylogenetic ten Schritt in die zwei Subfamilien die Zonosaurinae auf Madagaskar hypothesis . 185 und die Gerrhosaurinae auf dem Afrikanischem Kontinent, auf. Inner­ D. Algorithm for outgroup comparison . 188 halb der afrikanischen Gerrhosaurinae ist die monotypische Gattung Ango/osaurus als am friihesten abgespaltene Einheit anzusehen. Ger­ rhosaurus ist die Schwestergruppe von Cordylosaurus + Tetradacty­ lus. Innerhalb der ausschlielich afrikanischen Cordylidae ist Chamae­ saura die primitivste phylogenetische Einheit. Corclylus ist die Schwestergruppe von Platysaurus + Pseudocordylus. Eine neue Klas­ Abstract sifikation der Cordylifom1es wird vorgeschlagen, die dem Klado­ gramm Rechnung tragt. Following demonstration of Cordyliforrnes (Cordylidae + Gerrhosauri­ SchliiBelworter : Reptilia, Squamata, Cordyli fom1es, Cordylidae, dae) monophyly, the proposed phylogenetic position within the Scin- Gerrhosauridae, Phylogenie, Taxonomie, Biogeographie. I' 122 Mathias LANG Introduction demonstrated beyond reasonable doubt. It is only briefly that McDOWELL and BoGERT (1954) state that gerrhosau­ HISTORICAL REVIEW OF THE TAXONOMY rids and cordylids should be regarded as belonging to AND PROPOSED AFFINITIES the same family : "It may therefore be wise to follow OF CORDYLIDAE + GERRHOSAURIDAE the course taken by CoPE (1871) and include the gerrho­ saurs with the zonures in a single family Cordylidae." The taxonomic history and proposed phylogenetic affini­ This statement was based on the fact that: "(Cordylidae) ties of the herein recognized squamate families Cordyli­ ... resemblance to the gerrhosaurs is particularly close, dae and Gerrhosauridae are rather complex. even to such details as head squamation and the presence CoPE (1871) was the first to indicate affinities between of post-cloacal spines." This is in stark contrast to state­ cordylids and gerrhosaurids and erected the family Cor­ ments by VAN PLETZEN (1946) who suggested that : "A dylidae to incorporate both taxa. BouLENGER (1884) careful comparison of the skulls of Cordylus and Cha­ later defined the family Zonuridae to incorporate the maesaura with that of Gerrhosaurus investigated by now recognized family Cordylidae and the family Ger­ MALAN (1940) affords no evidence of any striking mor­ rhosauridae. BouLENGER 's "Zonuridae" furthermore phological similarities between the families concerned." contained members of the present day Anguidae. His No alternative hypotheses of relationships were propo­ catalogue (1885) is arranged such that taxa follow a sed by VAN PLETZEN (1946). As is also the case with probable line of evolution. The Zonuridae (= Cordyli­ McDOWELL and BoGERT (1954), overall similarities are dae) are located between the Xenosauridae and Angui­ no indication of relationships. dae, whereas his Gerrhosauridae are situated between In contrast to the similarities indicated by McDOWELL the Lacertidae and the Scincidae. and BoGERT (l.c.) shared by these two groups, various On the basis of hemipenial morphology the Zonuridae differences were enumerated such as the morphology of (= Cordylidae) were placed by CoPE (1896) within a the clavicle and the well-developed lateral fold in ger­ phylogenetic context close to the lguanidae, rejecting rhosaurids and the total lack thereof in cordylids. his previous (1871) arrangement and separating them DOWLLNG and DUELLMAN (1978) further complicate the from Gerrhosauridae. GADOW (1901) further supported matter by statements suggesting that "(Cordylidae) CoPE's latter hypothesis and places the Zonuridae (= (sensu Jato) appear to be closely related to the lacertids, Cordylidae) together with the Iguanidae in his suborder from which they may be derived or to which they may Lacertae. have given rise." These statements were not supported CAMP (1923) maintained the Gerrhosauridae as part of by any evidence. Furthermore, the proposed phylogene­ the Scincomorpha, more specifically as related to Lacer­ tic hypotheses of UNDERWOOD (1971), NORTHCUTT tidae (see also skiagram in EsTES et al. 1988). This is (1978) and PRESCH (1988) with respect to the phylogene­ slightly different from BouLENGER 's (1887) notion that tic position of Cordylidae + Gerrhosauridae are rejected the gerrhosaurids occupy an intermediate position be­ (see section on preferred phylogenetic hypothesis tween Lacertidae and Scincidae. CAMP (1923) further­ below). more moved the Zonuridae from their ascalabotan affini­ RtEPPEL's (1980) investigations on the jaw musculature ties as proposed by CoPE (1896) to the superfamily of "lizards" was the first study using cladistic methodo­ Zonuroidea within his section Anguimorpha as closely logy of outgroup comparison to establish the Cordylidae related to Helodermatidae + (Xenosauridae + Anguidae). (sensu Jato) as a monophyletic unit (see section on This although he suggested that some derived characters monophyly). This was however based on but a single such as the split of the geniohyoideus muscle are shared synapomorphy. between Zonuridae (exclusive of Chamaesaura) and EsTES (1983) resurrected the superfamily Cordyloidea lguanidae. STEJNEGER (1936) pointed out that Zonurus which included the fossil taxa Paramacellodidae, and MERREM, 1820 is antedated by Cordylus LAURENTI, 1768 the families Xantusiidae and Cordylidae. and BouLENGER's Zonuridae was therefore emendated EsTES et al. 's (1988) cladistic analysis of squamate fami­ to Cordylidae. lies shows that in CAMP's (1923) arrangement, only two Cordylidae and Gerrhosauridae have thus been main­ families were misplaced at the "section"-level 1• One of tained as separate families since BouLENGER (1886) (see these is Zonuridae (= Cordylinae), which is moved from references above; as also (CoPE (1900), FuRBRINGER Diploglossa within the Anguimorpha to the Scincoidea (1900), MALAN (1940), LOVERIDGE (1942, 1944), FITZ­ within the Scincomorpha. Gerrhosauridae is only shifted SIMONS (1943), etc.) until theformal taxonomic reunifi­ within the Scincomorpha from Lacertoidea to Scincoi­ cation by RoM ER (1956), reflecting CoPE' s (1871) origi­ dea. nal concept. The main thrust of Mc DOW ELL and BoG ERT