Phylogenetic and diversity patterns ofBlanusworm lizards (Squamata: Amphisbaenia): insights from mitochondrial and nuclear gene genealogies and species tree

Abstract

Phylogenetic and phylogeographic patterns of amphisbaenians are poorly known. Molecular data from mitochondrial and nuclear loci are particularly needed for amphisbaenian phylogeny and taxonomy because their specializations to subterranean habits make morphology poorly informative and the occurrence of cryptic species probable. The Mediterranean genus Blanus includes five species – three of them have been recently studied mainly at the mitochondrial level. In this study, we collected mitochondrial (16S and nd4) and nuclear (mc1r and pomc) sequences from 49 specimens, including multiple individuals for each of the five species. We used multilocus coalescent‐based species‐tree inference and single‐gene analyses to estimate phylogenetic relationships among Blanus and to assess patterns of intraspecific differentiation within all the five species. Species‐tree and single‐gene phylogenies provided strong support for the Anatolian worm lizard B. strauchi lying outside a clade comprising all other congeners, with a sister relationship between the Iberian clade (B. cinereus and B. mariae) and the North African clade (B. tingitanus and B. mettetali). Mitochondrial and nuclear data supported the genetic distinctiveness of the recently described B. mariae and also indicated that the distribution of this species is wider than previously known and overlaps with B. cinereus in central Portugal. Blanus tingitanus showed two phylogeographic groups, from the northern and the southern portion of the range, respectively, having high mitochondrial and nuclear divergence and a possible contact zone in northwestern Morrocco. Finally, high genetic variation was found within B. mettetali and B. strauchi, suggesting in the latter case, the occurrence of cryptic taxa to be tested by further research.

Hidden in the Arabian Mountains: Multilocus phylogeny reveals cryptic diversity in the endemicOmanosauralizards

“…The divergence time between the two Omanosaura species estimated in this study, approximately 8 Ma, is much more recent than the estimated 35 Ma from a recent squamate timetree by Zheng and Wiens (). Such difference is not limited to this study and seems to present a general discordance between divergence time estimates obtained in the squamate timetree and in studies focused on terminal groups of squamates such as lacertids (Kapli et al., ; Mendes et al., ; Tamar, Carranza et al., ), amphisbaenians (Albert, Zardoya, & Garcia‐Paris, ; Sampaio, Harris, Perera, & Salvi, ), geckos (Carranza & Arnold, ; Gamble et al., ; Šmíd et al., ), skinks (Carranza, Arnold, Geniez, Roca, & Mateo, ; Pereira & Schrago, ), and snakes (Chen, Lemmon, Lemmon, Pyron, & Burbrink, ; Daza, Smith, Páez, & Parkinson, ). This discordance might be attributed to the differences in the calibration methods—fossils of higher taxa in Zheng and Wiens () versus calibration based on rates or recent nodes in other studies.…”

“…Alleles are represented by the letters "a" and "b" after the sample code. Small diamonds represent median vectors, and mutations are represented by white circles on terminal groups of squamates such as lacertids (Kapli et al, 2015;Mendes et al, 2016;Tamar, Carranza et al, 2016), amphisbaenians (Albert, Zardoya, & Garcia-Paris, 2007;Sampaio, Harris, Perera, & Salvi, 2014), geckos (Carranza & Arnold, 2012;Gamble et al, 2011;Sm ıd et al, 2013), skinks (Carranza, Arnold, Geniez, Roca, & Mateo, 2008;Pereira & Schrago, 2017), and snakes (Chen, Lemmon, Lemmon, Pyron, & Burbrink, 2017;Daza, Smith, P aez, & Parkinson, 2009). This discordance might be attributed to the differences in the calibration methods-fossils of higher taxa in Zheng and Wiens (2016) versus calibration based on rates or recent nodes in other studies.…”

Biogeographical crossroad across the Pillars of Hercules: Evolutionary history of Psammodromus lizards in space and time

“…Given the intermittent land connections between Iberia and North Africa during the Miocene and varying extent of sea channels due to marine sea level oscillations during the Pleistocene, biogeographical inference across the Strait of Gibraltar has been documented as if it were a puzzle through time. The legacy of ancient biogeographical events is currently visible in distribution patterns at high taxonomic levels, generally at the genus level (Carranza et al., ; García‐Vázquez et al., ; Sampaio, Harris, Perera, & Salvi, ), whereas more recent processes underlie the phylogeographical patterns of intraspecific groups (Carranza, Harris, et al., ; Jaramillo‐Correa et al., ). While studies at the genus level are scarce, in most studies the genetic lineage distribution on both sides of the Strait is intraspecific, thus providing information for biogeographical events restricted to a relatively recent time‐frame.…”

Diversity and distribution of the Italian Aesculapian snakeZamenis lineatus: A phylogeographic assessment with implications for conservation

“…While in some cases these taxonomic descriptions are due to an ‘over‐splitting’ attitude, which is driven either by a change in species concept (Isaac et al., ) or by a geopolitical bias (Harris & Froufe, ) rather than by the availability of new data, in many others, the newly described species represent well‐distinct lineages of ancient evolutionary divergence which have been overlooked by taxonomist (and conservationist) simply because of their overall morphological resemblance with wide‐ranging species. Examples of such cryptic species among European amphibian and reptiles include the spectacled salamanders ( Salamandrina terdigitata / S. perspicillata ; Mattoccia, Romano, & Sbordoni, ; Nascetti, Zangari, & Canestrelli, ), Iberian worm lizards ( Blanus cinereus / B. mariae ; Albert & Fernández, ; Sampaio, Harris, Perera, & Salvi, ) and Aesculapian rat snakes ( Zamenis longissimus / Z. lineatus ; Lenk & Wüster, ).…”

“…perspicillata; Mattoccia, Romano, & Sbordoni, 2005;Nascetti, Zangari, & Canestrelli, 2005), Iberian worm lizards (Blanus cinereus/B. mariae; Albert & Fern andez, 2009;Sampaio, Harris, Perera, & Salvi, 2015) and Aesculapian rat snakes (Zamenis longissimus/Z. lineatus; Lenk & W€ uster, 1999).…”