December 2022 – February 2023

Mario Bronzati

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.

Robert Patalano

Image is of Robert standing in front of the Oldupai Gorge, Tanzania in 2017. Bryant is wearing a blue shirt. The image was taken while conducting fieldwork for Robert’s PhD. 

Bryant University

January 17, 2023

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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.

Vijayananda Sarangi

The image is a headshot of Vijayananda Sarangi (Vijay). He is a brown-skinned man with dark hair and glasses, holding a test wheel of Mars 2020 Perseverance Rover

Swedish University of Agricultural Sciences, Sweden

January 24, 2023

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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.

Margot Cramwinckel

This photo is a headshot of Margot Cramwinckel looking happy with fields and mountains in the background. The picture was taken on the way back from a hiking holiday in Italy, hence the happy facial expression. They are a light-skinned person with brown eyes and short-ish brown hair, wearing a black-and-white flannel and several necklaces and earrings.

Utrecht University, Netherlands

January 31, 2023

Investigating early Eocene hydroclimate using fossils and models: wet-gets-wetter, dry-gets-drier?

Earth’s hydrological cycle is expected to intensify in response to global warming, with a
‘wet-gets-wetter, dry-gets-drier’ response anticipated. In this, the arid subtropics (~15-30°
N/S) are predicted to become drier. Yet proxy evidence from past warm climates suggests
these regions may instead have been characterised by wetter conditions. In this talk, I will
investigate this further using the early Eocene hothouse as case study, extracting
information on past rainfall patterns from both model simulations and proxy
reconstructions.

Anthony Shillito

University of Saskatchewan, Canada

February 07, 2023

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Life Finds a Way: Understanding the Theatre of Terrestrialization

The colonization of subaerial and non-marine landscapes (“terrestrialization”) by animals and plants was a defining and irreversible innovation during the co-evolution of Earth and its biosphere. Our understanding of when, where, and even how the first animals gained a foothold on land, 420 million years ago, is increasingly refined, but many of the big questions surrounding the issue of terrestrialization remain unanswered. In this presentation I will discuss how the trace fossil record sheds light on different aspects of the initial colonization of land, from how pioneering organisms made subaerial excursions as early as the Cambrian, to the types of behaviours that dominated the first terrestrial ecosystems.

Miranta Kouvari

Miranta Kouvari in her workspace which includes screens showing her scientific illustrations, a graphics tablet, and a coffee mug (cause coffee is life).

University College London, United Kingdom

February 14, 2023

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South American climate & the Andes influence eutherian mammal diversity through time & latitude

South America has a unique geobiological history that is at heightened risk from the current climate emergency. Applying subsampling and Bayesian approaches to a comprehensive dataset of South American terrestrial eutherian mammal fossil occurrences, I find increases in diversity throughout the Paleogene, resulting from several intervals of high speciation rate. The remainder of the Cenozoic is characterized by greater variability, including a diversity peak in the late Miocene and pulses of heightened extinction rate in the Plio-Pleistocene. These results suggest that the present-day latitudinal biodiversity gradient first appeared in South America in the Plio-Pleistocene, at a similar time as proposed for North American mammals. This appears to have been driven by a decline in mean annual temperatures at higher latitudes in South America, in tandem with an increase in precipitation at lower latitudes that might have been accentuated by Andean uplift.

Abdur Rahman

12 noon UTC!

Image is of Abdur wearing a white lab coat and trying to explain what they do in their lab to a 6th grade student on National Science Day (NSD). He is a brown man with black hair and is pointing to an equipment.

Physical Research Laboratory, India

February 21, 2023

History of the forest fire in the western Himalaya and its linkage to
climate and human

Understanding of the past climate-human-vegetation-fire interactions is critical for
understanding modern fire dynamics associated with climate change and anthropogenic
perturbation. Because fire has played an important role in human evolution and
diversification across continents, studying past fire events provides insight into civilizational
imprints in the past, which can be implicated in present and future forest fires for mitigation
and policy making. In this talk, I will discuss about forest fire history of fire prone
mountainous region, i.e., western Himalaya using the sedimentary black carbon as a fire
proxy.

Joshua Zimmt

Image is a headshot of Joshua Zimmt. He is a white Caucasian man with brown hair.
Here, he is wearing a gray beanie and blue jacket and is standing with mountains in the
background.

University of California
Berkeley, United States

February 28, 2023

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Exploring the stratigraphic expression of extinction events: A case study
of the Late Ordovician mass extinction

The structure of the stratigraphic record controls the expression of extinction events in
the fossil record, causing last occurrences of taxa to predictably cluster below facies
shifts and major stratigraphic surfaces. These stratigraphically-generated clusters of last
occurrences can easily be mistaken for pulses of extinction, leading to
misinterpretations of the pattern and drivers of an extinction event. In this talk, I will
showcase the first published method for identifying and removing these
stratigraphically-generated clusters of last occurrences from basinwide analyses of the
fossil record to determine the underlying pattern of an extinction event. Critically, this
method provides a road map for future field-based studies of mass extinction events. I
will then highlight recent advances in applying this approach to the fossil record on
Anticosti Island (Québec, Canada), combining stratigraphic, paleobiological, and
geochemical data to develop an integrative perspective of Earth System change and the
Late Ordovician mass extinction.

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