The first notosuchian crocodyliform from the Araçatuba Formation (Bauru Group, Paraná Basin), and diversification of sphagesaurians.

The mesoeucrocodylian record from the Bauru Group (Paraná Basin, Brazil) comes from three formations: Adamantina (Late Turonian-Early Maastrichtian), Presidente Prudente (Early Campanian-Early Maastrichtian) and Marília (Maastrichtian). These records are restricted to the Early Coniacian-Early Maastrichtian. Here, we report a new crocodyliform record from the Bauru Group, which was the first of the Araçatuba Formation, from a new locality of Coronel Goulart district, in Álvares Machado municipality. Coronelsuchus civali gen. nov. et sp. nov. comprises two related specimens - FFP PG 13 and FFP PG 14 recovered close to each other and on the same muddy sandstone level. We perform a phylogenetic analysis with 392 characters (five new added) and 88 taxa. Our analyses supported the new clades: Sphagesauria, Sphagesaurinae and Caipirasuchinae. Our phylogenetic results suggest C. civali as a basal Sphagesauria. Regarding the Crocodyliform Assemblage Zones (CAZ), the new species is correlated to the CAZ 1, together with small sphagesaurians, Caryonosuchus and itasuchids. The C. civali reveals an older appearing (pre-Turonian) and diversification of Sphagesauria. The specimens also expand the stratigraphic range for Notosuchia in the Bauru Group.

The roles of hybridization and habitat fragmentation in the evolution of Brazil's enigmatic longwing butterflies, Heliconius nattereri and H. hermathena.

BACKGROUND: Heliconius butterflies are widely distributed across the Neotropics and have evolved a stunning array of wing color patterns that mediate Müllerian mimicry and mating behavior. Their rapid radiation has been strongly influenced by hybridization, which has created new species and allowed sharing of color patterning alleles between mimetic species pairs. While these processes have frequently been observed in widespread species with contiguous distributions, many Heliconius species inhabit patchy or rare habitats that may strongly influence the origin and spread of species and color patterns. Here, we assess the effects of historical population fragmentation and unique biology on the origins, genetic health, and color pattern evolution of two rare and sparsely distributed Brazilian butterflies, Heliconius hermathena and Heliconius nattereri. RESULTS: We assembled genomes and re-sequenced whole genomes of eight H. nattereri and 71 H. hermathena individuals. These species harbor little genetic diversity, skewed site frequency spectra, and high deleterious mutation loads consistent with recent population bottlenecks. Heliconius hermathena consists of discrete, strongly isolated populations that likely arose from a single population that dispersed after the last glacial maximum. Despite having a unique color pattern combination that suggested a hybrid origin, we found no genome-wide evidence that H. hermathena is a hybrid species. However, H. hermathena mimicry evolved via introgression, from co-mimetic Heliconius erato, of a small genomic region upstream of the color patterning gene cortex. CONCLUSIONS: Heliconius hermathena and H. nattereri population fragmentation, potentially driven by historical climate change and recent deforestation, has significantly reduced the genetic health of these rare species. Our results contribute to a growing body of evidence that introgression of color patterning alleles between co-mimetic species appears to be a general feature of Heliconius evolution.

Atolchelys lepida, a new side-necked turtle from the Early Cretaceous of Brazil and the age of crown Pleurodira.

We report a new pleurodiran turtle from the Barremian Morro do Chaves Formation, Sergipe-Alagoas Basin, Brazil. We tested the phylogenetic position of Atolchelys lepida gen. et sp. nov. by including it in a comprehensive cladistic analysis of pleurodires. The new species is a basal member of Bothremydidae and simultaneously the oldest unambiguous crown Pleurodira. The biogeographic and chronostratigraphic significance of the finding has implications for the calibration of molecular clocks studies by pushing back the minimum age of crown Pleurodira by more than 12 Ma (ca 125 Ma). The reanalysis of Pelomedusoides relationships provides evidence that the early evolution and relationships among the main lineages of side-necked turtles can be explained, at least partially, by a sequence of vicariance events.