Systematics and phylogeography of the Brazilian Atlantic Forest endemic harvestmen Neosadocus Mello-Leitão, 1926 (Arachnida: Opiliones: Gonyleptidae)

Two new species of Goniosomatinae (Opiliones: Gonyleptidae) narrowly endemic to the Atlantic Forest of Brazil

In the present work, two new species are described for the subfamily Goniosomatinae. Goniosoma bragagnolo sp. nov. is described from the seasonal semideciduous forests of Minas Gerais state and is distinguished from other species in the genus by a unique combination of features: a pair of small tubercles on the ocularium and on area III of the dorsal scutum, a complex dry mark on the dorsal scutum and the presence of a ventral process with a flabellum on the penis. Serracutisoma hara sp. nov. inhabits a cave in dense ombrophilous forests in Santa Catarina state and is considered to be part of a group of species related to Serracutisoma inerme (i.e., the S. inerme group), set apart from other species by the armature of femur III with spines close to each other and the armature of row 2 of femur IV with spines only in the medial-apical portion. For the first time, terminology for the penis macrosetae is discussed for the subfamily. Additionally, the study discusses the phylogenetic implications and biogeographic aspects of the new species. Goniosomatinae species tend to be narrowly endemic in the Atlantic Forest, which is confirmed by these new species ranges, although S. hara is only known by one specimen.

Phylogeographic and genetic insights into Sinonychia martensi: an endemic cave-dwelling harvestman in Beijing

Caves are one of the most exciting environments on earth, often considered an evolutionary laboratory due to the suite of convergent adaptive traits (troglomorphisms) of organisms inhabiting them. Sinonychia martensi Zhang & Derkarabetian, 2021, is the first and only Travunioidea species recorded in China and is endemic to Beijing, being known from multiple caves. However, nothing is known regarding its phylogeographic or evolutionary history. In this study, we assessed the species boundaries of S. martensi from nine caves using morphological and molecular methods to elucidate its phylogenetic position and genealogical relationships. We also investigated the genetic diversity, population genetic structure and demographic history of S. martensi to clarify the population-level relationships and make inferences about historical phylogeography. The results indicate that the species from different caves all belonged to S. martensi but represent different populations. These populations exhibit strong population structure and low genetic diversity. Cave populations may share a common ancestor and multiple independent invasions to different caves. The diversification within S. martensi was likely driven by climate change and subtropical evergreen broadleaf forests associated with the middle Miocene. This study highlights the need for further conservation efforts and exploration in Beijing caves.

Too early for the ferry: The biogeographic history of the Assamiidae of southeast Asia (Chelicerata: Opiliones, Laniatores)

Opiliones (harvestmen) have come to be regarded as an abundant source of model groups for study of historical biogeography, due to their ancient age, poor dispersal capability, and high fidelity to biogeographic terranes. One of the least understood harvestman groups is the Paleotropical Assamiidae, one of the more diverse families of Opiliones. Due to a labyrinthine taxonomy, poorly established generic and subfamilial boundaries, and the lack of taxonomic keys for the group, few efforts have been undertaken to decipher relationships within this arachnid lineage. Neither the monophyly of the family, nor its exact placement in the harvestman phylogeny, have been established. Here, we assessed the internal phylogeny of Assamiidae using a ten-locus Sanger dataset, sampling key lineages putatively ascribed to this family for five of the ten markers. Our analyses recovered Assamiidae as a monophyletic group, in a clade with the primarily Afrotropical Pyramidopidae and the southeast Asian Beloniscidae. Internal relationships of assamiids disfavored the systematic validity of subfamilies, with biogeography reflecting much better phylogenetic structure than the existing higher-level taxonomy. To assess whether the Asian assamiids came to occupy Indo-Pacific terranes via rafting on the Indian subcontinent, we performed divergence dating to infer the age of the family. Our results show that Indo-Pacific clades are ancient, originating well before the Cretaceous and therefore predate a vicariant mechanism commonly encountered for Paleotropical taxa.

A multidisciplinary framework for biodiversity prediction in the Brazilian Atlantic Forest hotspot

Abstract: We briefly describe selected results from our thematic project focused on the biodiversity of the Atlantic Forest (“AF BIOTA”), which was jointly funded by FAPESP’s BIOTA Program, the U.S. National Science Foundation Dimensions of Biodiversity Program, and the National Aeronautics and Space Administration (NASA). As one of the five most important hotspots of biodiversity in the world, the Atlantic Forest (AF) holds less than 16% of its vegetation cover, yet, amongst the hotspots, it still harbors one of the highest numbers of species, including endemics. By gathering specialists across multiple disciplines (biology, geology, engineering), we aimed to understand how this megabiodiversity was built through time, informing biodiversity science and conservation. Among the results, we trained 18 Master’s and 26 Ph.D. students, published more than 400 peer-reviewed papers that improved our knowledge about the forest’s biologic and climatic diversity and dynamics through time, developed new analytical methods, produced outreach videos and articles, and provided data to help define biodiversity conservation policies.