Meet the Staff: Dr Alfio Alessandro Chiarenza, Royal Society Newton International Fellow

I’m Dr. Alessandro Chiarenza, a palaeontologist interested in the evolutionary history of dinosaurs and other Mesozoic reptiles, such as crocodylomorphs (crocodilians and their extinct relatives). I’m currently a Royal Society Newton International Fellow at University College London. My research focuses on palaeobiology, macroevolution, macroecology, and extinction, employing phylogenetic comparative methods, biogeographic models, statistical analyses, and Earth System Modelling tools.
I’m particularly interested in how changes in climate and geography shape biodiversity patterns, the drivers of evolutionary adaptations and extinction, and how to untangle biases in the fossil record to reveal genuine biodiversity signals from deep time.
I grew up in Catania, Southern Italy, where my fascination with palaeontology began early. Watching dinosaur documentaries as a child sparked my imagination, and I vividly remember my hopeful yet fruitless hunts for fossils in the volcanic landscapes around Mount Etna. My parents often recount how I debated the causes of dinosaur extinction with my kindergarten teachers, long before I fully understood what those words meant!
I earned a Bachelor’s degree in Natural Science from the University of Catania, spending summers excavating Late Cretaceous dinosaurs in Catalonia (Spain) and Montana (USA). I then moved to the University of Bologna to complete a Master’s in Evolutionary Biology before pursuing a PhD in Earth Science at Imperial College London. My doctoral research focused on how Late Cretaceous dinosaurs were influenced by changes in climate and geography, as well as the drivers behind their extinction at the Cretaceous-Paleogene boundary, 66 million years ago.
Following my PhD, I’ve had the privilege of working in various research roles, from the Perot Museum of Nature and Science in Texas to an ERC-funded postdoc in Spain. My projects have ranged from studying Arctic dinosaurs to investigating crocodilian diversity and the ecological dynamics of extinction events. Currently, my research at UCL explores the evolution of Mesozoic terrestrial animals during periods of extreme climate change.

Caption: Fieldwork in the Gobi Desert of Mongolia, August 2024, excavating dinosaurs with a team led by Dr. Lindsay Zanno of the North Carolina Museum of Natural Sciences. These dinosaurs lived through one of the most dramatic global warming events in Earth's history, some 93 million years ago. 

Fieldwork has always been one of my favorite aspects of this career. I’ve participated in excavations across Europe, the U.S., and Asia, including spending seven weeks last summer (2024) in the Gobi Desert with some of my favorite colleagues from the North Carolina Museum of Natural Sciences (where I hold an adjunct position) and North Carolina State University in Raleigh. To date, I’ve accumulated over 260 days of fieldwork, and skipping showers clearly doesn’t seem to bother me or my close field collaborators!
My current research focuses on investigating the intrinsic and extrinsic factors that influence the tempo and mode of evolution. What forces shape biodiversity patterns across space and time? How have millions of years of shifting climates and changing geography constrained the evolutionary history of long-lived archosaur lineages like dinosaurs and crocodilians?
Dinosaurs and crocodilians are ideal study systems, not just because of my lifelong fascination, but because their evolutionary history spans an impressive 250 million years, half the time it took for all multicellular life to evolve. During this quarter-billion-year interval, these lineages experienced monumental changes, such as the breakup of Pangea into the continental landmasses we recognize today, as well as major climatic events, including cooling trends and ice-cap-melting periods of global warming. My research also examines how the climatic upheaval of the end-Cretaceous mass extinction—which wiped out all dinosaurs with the exception of birds—shaped the evolutionary trajectories of life on Earth. What adaptations, such as temperature regulation strategies, enabled these lineages to survive and thrive through such turbulent times?

Caption: Dinosaurs dominated ecosystems in what is now the Gobi Desert, but 70 million years ago, it was a greener and more diverse environment. By combining data from fossils, rocks and their chemistry, and advanced modeling tools, we can investigate the evolutionary history of these species and their interactions, providing a vivid picture of those ancient environments and their significance for understanding the history of life on Earth (artwork from Chiarenza 2024).

Over the next three years at University College London, I will combine field-collected fossils with macroevolutionary and ecological modeling. This work will integrate evolutionary trees with data on extinct species and their ancient environments. My ultimate goal is to lay the groundwork for answering fundamental questions about the history of life on our planet, with a focus on climate-driven evolutionary dynamics.

Links:

• Dr Ale Chiarenza's academic profile
• Dr Ale Chiarenza's personal website
• Dinosaurs were thriving before asteroid strike that wiped them out.
• Asteroid impact, not volcanoes, made the Earth uninhabitable for dinosaurs.
• Sauropod dinosaurs were restricted to warmer regions of Earth.
• First ‘warm-blooded’ dinosaurs may have emerged 180 million years ago