University of São Paulo
December 06, 2022
The origin of tympanic ear in reptiles from a Paleo-Evo-Devo perspective
The tympanic middle ear is a key evolutionary trait in the tetrapods’ successful invasion of terrestrial environments. Despite the morphological similarities in different lineages, current literature indicates that this sensory structure evolved independently in major tetrapod groups. Based on an integrative approach combining data from the fossil record and the embryonic development we investigate the origin and homology of the tympanic ear in reptiles.
January 17, 2023
Usambara Mountains Archaeology and Palaeoecology Project (UMAPP)
The Usambaras, in northeastern Tanzania, are a biodiversity hotspot that host remarkably rich and diversified plants and animals that may have lived in this area for millions of years. However, we know very little about the climatic, ecological, and human history of this region as very few long-term studies have been conducted here. Additionally, and despite the biological wealth the mountains host, they are under threat from both anthropogenic climate change and the conversion of natural vegetation to agricultural plantations.
In July-August 2022, we conducted a pilot field season to survey archaeological sites and document local plant ecology and biodiversity. We visited and surveyed 22 rockshelters and 6 open-air sites across the East and West Usambara Mountains and uncovered over 400 lithic and pottery artifacts. This talk explores the survey results and future plans for archaeological and palaeoecological projects in the Usambara Mountains.
Swedish University of Agricultural Sciences, Sweden
January 24, 2023
Neglecting vegetation fires as a geochemical process could undermine the
reliability of paleoecological interpretations
Long-term paleoecological and paleofire records have been widely used to
elucidate the impact of vegetation fires on ecosystem dynamics, such as the distribution of
biomes, vegetation structure, carbon fluxes, nutrient cycles, and hydrological conditions.
However, in fire-prone biomes, the interpretation of paleoecological proxies is subjected to
uncertainties as the plant biomarkers/molecules are thermally modified, and the extent and
nature of alterations are yet to be well-constrained. To shed light on the current knowledge
gaps, we performed a series of controlled experiments in which leaf samples from C 3 (tree and
shrub) and C 4 (grass) plants and a topsoil sample were burned/heated under ambient oxygen at
temperatures between 200 °C and 500 °C. In this talk, I will discuss the effect of experimental
burns on commonly used paleoecological proxies such as total organic carbon content, bulk
carbon isotopic compositions, and concentration and isotopic composition of lipid biomarkers
(namely, n-alkanes and n-alkanoic acids). I will also discuss the inferences drawn from the
burning experiment and possible implications for paleoecological studies.