Phylogenetic relationships of corytophanid lizards (Iguania, Squamata, Reptilia) based on partitioned and total evidence analyses of sperm morphology, gross morphology, and DNA data

Abstract

Phylogenetic relationships of corytophanid lizards (Iguania, Squamata, Reptilia) based on partitioned and total evidence analyses of sperm morphology, gross morphology, and DNA data. -Zoologica Scripta , 34 , 605-625. We conducted partitioned and combined Bayesian and parsimony phylogenetic analyses of corytophanid lizards (Iguania) using mtDNA, gross morphology, and sperm ultrastructure data sets. Bayesian and parsimony hypotheses showed little disagreement. The combined analysis, but not any of the partitioned ones, showed strong support for the monophyly of Corytophanidae and its three genera, Basiliscus , Corytophanes , and Laemanctus . Basiliscus is the sister taxon of a well-supported clade formed by Corytophanes and Laemanctus . The relationships of species within Basiliscus and Corytophanes received weak support, regardless of the method used. We defend those relationships as feasible and open to further testing. Data derived from the ultrastructure of spermatozoa are potentially a good source of characters for systematic inferences of Iguania and its major lineages. A Brooks Parsimony Analysis based on the geographic distributions of corytophanids and the phylogenetic tree obtained from the combined analysis suggested a Central American origin of the group, a recent colonization of northern South America, and the role of epeirogenic uplifts and the formation of lowlands during the late Tertiary in the differentiation of corytophanids.

Ontogenic development of spermatids during spermiogenesis in the high altitude bunchgrass lizard (Sceloporus bicanthalis)

“…However, the nuclear lacuna does not penetrate the entire nucleus and thus may have been missed in previous studies. The midpiece region is relatively short with the fibrous sheath beginning at mitochondria tier two which is consistent among phrynosomatids 7 but differs among other Iguania taxa 5 , 33 , 35 …”

“…The acrosome is laterally compressed which resembles that of other taxa within Iguania 1 , 5 , 33 , 34 . A single perforatorium, a suggested synapomorphy for the squamata 4 , 34 extends into the acrosomal medulla.…”

Sperm ultrastructure of hoplocercid and oplurid lizards (Sauropsida, Squamata, Iguania) and the phylogeny of Iguania

“…Jamieson (1995a,b) considered the broad nuclear fossa of B. karrooicum as being pointed anteriorly, resembling those of sphenomorph skinks. Vieira et al (2005) also found a similar appearance of the nuclear fossa in corytophanid lizards.…”

“…In this way, we predict that discrete data will be much more conservative (less variable) than continuous ones. Another way to validate or reject our hypothesis is through the inclusion of other kinds of data sets, such as behavioural, ecological, molecular, morphological (gross morphology, sensu Vieira et al 2005), etc. Indeed, all groups discussed here are speculative entities that are based on indices (mainly decay index) that are indicators of ambiguity and evidential support, conferring it a heuristic value and pointing to more weak or ambiguously corroborated hypothesis (Grant and Kluge 2003).…”

Ultrastructural examination of spermiogenesis within the testis of the ground skink, Scincella laterale (Squamata, Sauria, Scincidae)

“…Accumulation of data, particularly recognizable variation in the developmental steps of spermiogenesis as outlined here for Scincella laterale may be phylogenetically significant. Mature sperm have been used recently for phylogenetic analysis Teixeira et al, 1999b;Vieira et al, 2004;Vieira et al, 2005) and differences that occur between lizard taxa during spermiogenesis can improve these databases by adding developmental and ontogenetic perspectives that supplement the present nontraditional data used for phylogenetic analysis. These data may ultimately help in our overall understanding of the phylogenetic relationships in Sauria and give us better perspective on the placement of lizard taxa within the order Squamata and the class Reptilia.…”