Plant predation by insects is a major driver of high plant diversity in modern tropical forests. Previous reports of leaf damage in middle–late Paleocene Neotropical rainforests of Cerrejón, Colombia, show that leaf herbivory was abundant but of low diversity, mainly inflicted by generalized feeders. Here, we present and describe plant-insect associations in leaf fossils from the middle–late Paleocene Bogotá Formation, central Colombia, to test whether the high abundance and low richness of insect damage typified early evolving Neotropical rainforests. The Bogotá flora records the highest richness and frequency of insect-damage associations among comparable Paleocene floras in North America, Patagonia, and Europe, as well as the highest number of leaf mines and galling associations. These results indicate that by the middle–late Paleocene, plant-insect herbivore interactions were much more intense and host-specialized in Neotropical rainforests of the Bogotá region than elsewhere. The rich and frequent galling associations, a distinctive feature of the Bogotá flora, are consistent with the preferential use of canopy leaves by galling insects seen in modern Neotropical rainforests. Our results also indicate differences in plant-insect associations among Paleocene Neotropical rainforests, perhaps reflecting a geographically heterogeneous ecological recovery from the end-Cretaceous ecological crisis. Plant insect-associations in the Bogotá flora also suggest a deep historical context for negative density-dependence as a potential driver (and maintainer) of the high plant diversity observed in modern Neotropical rainforests.

Community assembly processes (environmental filtering and limiting similarity) determine the values of quantitative functional traits within communities. The environment influences the number of viable functional strategies species might take. A strong effect of environmental filtering often results in communities having species with similar trait values and narrow functional niches. On the other hand, resource competition (i.e., limiting similarity) leads to communities with broader functional spaces and smaller niche overlap among competing species. The degree to which community assembly processes influence wood trait variation has important implications for paleoclimate estimation using fossil woods since the central tenet of the approach is environmental-driven trait convergence, which assumes a central role of environmental filtering. To infer the strength of these two community assembly forces, we used a functional diversity approach to determine how three wood anatomical traits vary in 14 extant communities (272 species) growing under different climates. We found smaller functional spaces in communities growing in dry/cool places, suggesting that trait convergence could be the result of more robust habitat filtering in these communities. A weaker environmental filtering in warm/wet environments, likely results in an amplification of other drivers that promote a higher number of hydraulic strategies through niche partition in highly structured communities. More complex ecological structures in mild, tropical places likely lead to a higher spread of wood trait values. This asymmetry in the strength of environmental filtering along climate gradients suggests that this differential strength of the trait-climate convergence should be incorporated in paleoclimate prediction models.

The endemic Patagonian genus Titomaya gen. nov. is erected to include the Danian Meretrix chalcedonica (Lefipan and Salamanca formations) and Titomaya longobucca sp. nov. (Salamanca Formation) from the Chubut Province (Argentina). Although Meretrix and Titomaya share the same characteristic sculpture of their nymphs, Titomaya is differentiated by having medium to small, subtriangular, higher than long shells, a narrower and shorter hinge plate, smaller cardinal and anterior teeth, and by the development of a deeper pallial sinus. This new genus rules out the presence of Meretrix in Patagonia, as was long believed, and increases the list of endemic taxa that characterize the Danian assemblages of Patagonia.

We present the first fossil record of the sawshark genus Pliotrema from the south-eastern Pacific Ocean. The examined material was obtained from a little-known fossil locality named “Arenas de Caldera” in the Atacama Region of Chile. The fossiliferous deposits belong to the Bahía Inglesa Formation, which is most likely middle Miocene–early Pliocene in age. There are no extant species of this sawfish in the eastern Pacific, probably due to the onset of cooling conditions during the Neogene. The type of environment for the elasmobranchs reported in this study is interpreted as demersal, based on the bathymetric affinities of extant species. Our results show that future studies are needed to better understand the evolutionary history and past distributions of this sawshark genus and their implications on current biogeographic patterns.

Erythrosuchid archosauriforms are quadrupedal carnivorous reptiles with a proportionally huge skull. They represent one of the first evolutionary radiations of medium to large predatory diapsids after the Permo–Triassic mass extinction. Erythrosuchids are known from Lower–Middle Triassic rocks of South Africa, Russia, and China, and there have been preliminary reports from the Middle Triassic Yerrapalli Formation of south-central India. Here we describe, compare and figure for the first time these Indian erythrosuchid remains. We erect the new genus and species Bharitalasuchus tapani based on a holotype and paratype that preserve tooth-bearing cranial fragments, at least 17 presacral vertebrae, some ribs and probable intercentra, and partial shoulder and pelvic girdles and hindlimb and allow recognizing a series of autapomorphies and unique combination of character states among erythrosuchids. Our phylogenetic analysis recovered Bharitalasuchus tapani most closely related to Shansisuchus shansisuchus and Chalishevia cothurnata from the late Anisian of China and Ladinian of Russia, respectively. The phylogenetic affinities of this new taxon and a revision of the tetrapod assemblage of the Yerrapalli Formation shed light on the age of this unit. The presence of the Wadiasaurus-Rechnisaurus-Bharitalasuchus association in the Yerrapalli Formation closely resembles the Sinokannemeyeria-Shansisuchus dicynodont-erythrosuchid association of late Anisian to early Ladinian Chinese units. This evidence supports a post-early–middle Anisian age, even possibly early Ladinian, for the Yerrapalli Formation. The presence of possibly one of the last erythrosuchids in India would indicate that the clade still retained both a northern and southern Pangean distribution before its extinction.