Phylogenetic evidence suggests that platyrrhine (or New World) monkeys and caviomorph rodents of the Western Hemisphere derive from source groups from the Eocene of Afro-Arabia, a landmass that was ~1500 to 2000 kilometers east of South America during the late Paleogene. Here, we report evidence for a third mammalian lineage of African origin in the Paleogene of South America—a newly discovered genus and species of parapithecid anthropoid primate from Santa Rosa in Amazonian Perú. Bayesian...

Natural history collections are important data repositories, but different chemical treatments of specimens can influence morphological measurements and DNA extraction, complicating taxonomic and conservation decisions dependent upon these data. One such example is the Bay Springs Salamander (Plethodon ainsworthi), the only United States amphibian categorized as Extinct by the IUCN. Recent research has proposed that P. ainsworthi is an invalid taxon, arguing that the 55-year-old type specimens’ morphological distinctiveness from syntopic P. mississippi is a...

We describe three-dimensionally preserved feathers in mid-Cretaceous Burmese amber that share macro-morphological similarities (e.g., proportionally wide rachis with a “medial stripe”) with lithic, two-dimensionally preserved rachis-dominated feathers. These feathers in amber reveal a unique ventrally concave and dorsoventrally thin rachis, and a dorsal groove (sometimes pigmented) that we identify as the “medial stripe” visible in many rachis-dominated rectrices of Mesozoic birds. The distally pennaceous portion of these feathers shows differentiated proximal and distal barbules, the...

Understanding how habitat structure and resource availability affect local species distributions is a key goal of community ecology. Where habitats occur as a mosaic, variation in connectivity among patches influences both local species richness and composition, and connectivity is a key conservation concern in fragmented landscapes. Similarly, availability of limiting resources frequently determines species co-existence or exclusion. For primarily cursorial arthropods like ants, gaps between neighboring trees are a significant barrier to movement through the...