Abstract
The spiny lizard genus Sceloporus was described by Wiegmann in 1828, with S. torquatus posteriorly designated as the type species. The taxonomic history of S. torquatus is complicated, as it has been confused with other taxa by numerous authors. Many modern systematics works have been published on Sceloporus, but none have included all five recognized S. torquatus subspecies: S. t. torquatus, S. t. melanogaster, S. t. binocularis, S. t. mikeprestoni, and S. t. madrensis. Additionally, there is previous evidence for at least one unnamed taxon. The present study is the first taxonomic revision of the enigmatic S. torquatus based on molecular phylogenies using combined molecular data from 12S, ND4 and RAG1 genes, and Maximum Likelihood and Bayesian inference phylogenetic methods. This work includes the most extensive sampling across the entire distribution, as well as divergence time estimates and environmental niche modelling, which combined offer a spatio-temporal framework for understanding the evolution of the species. Additionally, a series of morphological characters are analyzed to identify significant differences between lineages consistently recovered in the molecular phylogenies. Using this integrative approach, evidence is presented for eight lineages within the S. torquatus complex, five of which correspond to previously recognized subspecies and three represent unnamed taxa masked by morphological conservatism. Finally, to maintain taxonomic stability a lectotype and paralectoype are designated for S. torquatus, and certain taxonomic changes are suggested in order to reflect the phylogenetic relationships within the S. torquatus complex.
Highlights
If we were to choose a representative genus of North American reptiles, Sceloporus Wiegmann, 1828 would certainly be a good candidate, as it is one of the most diverse and conspicuous
We discovered that more than one species is represented in the type series of S. torquatus (Fig. 2)
The results we present here, show that the specimens ZMB 628 and ZMB 630 belong to distinct taxonomic species other than S. torquatus, causing instability in the application of the species name, and warranting a lectotype to be designated from the syntypes (ICZN Arts. 70.3, 74.1)
Summary
If we were to choose a representative genus of North American reptiles, Sceloporus Wiegmann, 1828 would certainly be a good candidate, as it is one of the most diverse and conspicuous. Sceloporus is a genus of Phrynosomatid lizards distributed from southern Canada to western Panama with over 100 species (Sites et al 1992; Köhler and Heimes 2002; Bell et al 2003; Wiens et al 2010; Uetz et al 2020), the greatest diversity is found in Mexico (Flores-Villela and García-Vázquez 2014), where new species are still being described (Castañeda-Gaytán and Díaz-Cárdenas in Díaz-Cárdenas et al 2017). Sceloporus torquatus is the type species of the genus (Smith 1938) and is currently recognized as a polytypic species comprising five subspecies that display minimal morphological differentiation, essentially distinguishable by color pattern, number of ventral scales, body size and arm length (Olson 1990): S. t. Madrensis has a disjunct distribution, whos’s northern and southern populations are divided by ~175 km and isolated on a mountainous range of eastern Mexico (Olson 1991) Among the five recognized subspecies, only S. t. madrensis has a disjunct distribution, whos’s northern and southern populations are divided by ~175 km and isolated on a mountainous range of eastern Mexico (Olson 1991)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
