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ambar, Middle Miocene, Peru
Evolutionary Ecology
My lab seeks to understand how the interaction of biological, climatic, and geological processes have determined and shaped the ecological evolution of mammals and other vertebrates in the Amazon. Although, the Amazon rainforest includes the world's highest mammalian species richness, little is known about niche structure and ecological roles of Amazonian mammalian communities over time. Generalizations on closed canopy rainforest mammalian communities have been largely based on African ecosystems. By working in western Amazonia, a geographic setting severely understudied, my research has recognized differences in the ecologic structure of mammals from analogous closed-canopy rainforests.
Credit: P.-O. Antoine
Thalassocnus natans from Pisco Fm in Peru
Sloths as a study system
Sloths are an interesting case study as they represent a combination of low extant diversity, extremely high levels of extinction, and debated phylogenetic interrelationships between fossil and extant taxa. Sloths possess unique morphological and physiological traits that depart from the typical mammalian bauplan. Their "weirdness" makes them the perfect system to test many truisms established on more "conventional" mammals. We are interested in different biological aspects of sloth evolution and our work ranges from phylogenetic analyses to understand their evolutionary history and biogeographic patterns, to controlled feeding experiments to assess physiological and ecological aspects of their biologies.
Credit: Falco Rivera
Mylodon darwinii, osteoderm, and coprolite at AMNH
Comparative physiology and paleophysiology
Understanding the physiological processes underlying the isotopic variability observed in modern organisms is the first necessary step to attempt a thorough and cautious interpretation of the geochemical signals preserved in the fossil record. We address this topic by conducting controlled feeding experiments with zoological animals and analyses with museum specimens with detailed accession information.
Credit: J. Tejada
Mylodon reconstruction. Jorge Blanco
Feeding and trophic ecology
Understanding extinct and extant animal feeding ecology is crucial to assess palaeoclimate, vegetation structure, habitat use, niche partitioning, and predator–prey interactions in fossil ecosystems. Stable isotope geochemistry is a powerful tool to reconstruct ancient ecologies and ecosystems, as it is independent of morphology and reflects dietary ecology. Information from stable isotope methods, however, is limited by poorly experimentally constrained assumptions on diet-tissue fractionations across organisms. By experimentally analyzing Neotropical mammals never before assessed, my lab seeks to identify and understand patterns of isotope fractionation across different taxonomic groups.
Credit: Illustration: Jorge Blanco
Peruvian Amazonia
Tropical Paleontology
Our different projects have led to the recovery of many new fossil faunas from poorly known regions in South America (from the Andean highlands to tropical lowlands), with numerous publications and research projects mostly centered on the evolution of pan- and proto-Amazon ecosystems and the Andean plateau from both biological and geological perspectives (see list of publications).
Credit: J. Tejada
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