Saturday, April 24, 2021

[Herpetology • 2021] Sceloporus dixoni & S. hesperus • Cryptic Diversity Across the Trans-Mexican Volcanic Belt of Mexico in the Montane Bunchgrass Lizard Sceloporus subniger (Squamata: Phrynosomatidae)


Sceloporus dixoni 
Sceloporus hesperus 
Bryson & Grummer

in Bryson, Grummer, ... et Klicka, 2021. 

Abstract
Sceloporus subniger Poglaygen & Smith is a montane bunchgrass lizard distributed across pine-oak forests of central Mexico. Prompted by the discovery of a new population of this lizard in far western Mexico, and by recent studies suggesting S. subniger may be a composite of several distinct species, we examined in more detail the genetic structure of S. subniger. We generated a mitochondrial DNA (mtDNA) dataset from 81 specimens and an ultraconserved elements (UCE) dataset representing thousands of genomic regions from 12 specimens to specifically evaluate the genetic distinctiveness of populations from western Michoacán and adjacent Jalisco along with the newly discovered population in the Sierra de Mascota in western Jalisco. We also recorded morphological data from 47 museum specimens to compare to our genetic data. Results from our analyses of the genetic data, augmented by specimen measurements and scale counts, support the notion that S. subniger is indeed a composite of distinct species. Montane bunchgrass lizards from western Michoacán and adjacent Jalisco, and from the Sierra de Mascota in western Jalisco, each represent distinct new species, which we describe and name here.

Keywords: mitochondrial DNA, new species, phylogenomics, Sceloporus scalaris group, ultraconserved elements




Dorsal and ventral aspects of male Sceloporus dixoni sp. nov. from the type locality.  
Male Sceloporus hesperus sp. nov. from the type locality.
Specimen photographed and released.

Sceloporus dixoni sp. nov. Bryson & Grummer

Etymology. The specific epithet is a patronym honoring the late James R. Dixon for his decades of research on Mexican herpetofauna, including several insightful studies of the S. scalaris group. “Doc” Dixon took an early interest in the academic growth of the first author and made a profound and lasting impact. For this and for his encouragement and support, he will be truly missed.



Sceloporus hesperus sp. nov. Bryson & Grummer

Etymology. The specific epithet is derived from the Greek word hesperos, meaning “western”, and is used in reference to the type locality located at the far western end of the Trans-Mexican Volcanic Belt.

    


Robert W. Bryson Jr. Jared A. Grummer, Elizabeth M. Connors, Joseph Tirpak, John E. McCormack and John Klicka. 2021. Cryptic Diversity Across the Trans-Mexican Volcanic Belt of Mexico in the Montane Bunchgrass Lizard Sceloporus subniger (Squamata: Phrynosomatidae).  Zootaxa. 4963(2); 335–353. DOI: 10.11646/zootaxa.4963.2.5