Phylogeography of an Italian endemic salamander (genus Salamandrina): glacial refugia,postglacial expansions,and secondary contact

The Italian endemic genus Salamandrina has been historically regarded as monotypic but, recently, studies based on both mitochondrial and nuclear markers have indicated the existence of two distinct species of spectacled salamanders: Salamandrina perspicillata, in central and northern Italy, and Salamandrina terdigitata, in southern Italy. We analyzed nucleotide variation at mitochondrial and nuclear genes [cytochrome b, 12S and 16S rRNA, recombination activating gene (RAG 1)] in 223 individuals from 56 locations, aiming to investigate their genetic structure and recent evolutionary histories. Phylogenetic and phylogeographical analyses revealed the existence of three and two genetically distinct groups of populations in northern and southern salamander, respectively. Historical demographic analyses led to the inference of range expansion for both species in the late Pleistocene. During the last glacial stage, each salamander survived in a single refugium, namely the southern in Calabria and the northern in central Italy. At the end of this period, both lineages expanded northward and established secondary contact. Spatial distribution of RAG 1 haplotype variation revealed two differentiated population groups corresponding to the major mitochondrial (mt)DNA clades. Nuclear pattern of introgressive hybridization was more extensive than the highly limited introgression of mtDNA markers. From a conservation standpoint, southern Latium and Calabria proved to be the major genetic diversity reservoirs, thus deserving particular conservation efforts. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 903–922.     

The marine diapsid reptile Endennasaurus from the Upper Triassic of Italy

Abstract:  The marine reptile Endennasaurus from the Upper Triassic Zorzino Limestone of northern Italy is redescribed and reassessed. New details of the skull and postcranial skeleton are revealed, confirming the attribution of this genus to the diapsid reptile clade Thalattosauriformes. Phylogenetic analysis suggests that Endennasaurus was related to the European genus Askeptosaurus and the Chinese Anshunsaurus . Despite a rather conservative postcranial morphology, Endennasaurus clearly occupied a highly specialized dietary niche as it combined a slender tapering premaxillary rostrum with a complete absence of either marginal or palatal teeth.     

Analysis of the mitochondrial genome of Schistocerca gregaria gregaria (Orthoptera: Acrididae)

In the present study, we present the full sequence of the mitochondrial genome of the African desert locust Schistocerca gregaria gregaria. The size of 15625 bp reported matches very well with mitochondrial genomes of other Orthopteriodea. The mitochondrial genome comprises 13 protein‐coding genes, two ribosomal RNAs and 22 t‐RNAs with two t‐RNA (trnD and trnK) rearrangements that are typical for the taxon Caelifera. We compared the sequence with 12 mitochondrial genes of Schistocerca gregaria flaviventris and Schistocerca americana and used some of these data to construct phylogenetic trees, which confirm the close relationship between the two subspecies S. g. flaviventris and S. g. gregaria. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 296–305.