Friday 22 May 2026 1:00pm to 2:00pm
Sainsbury Laboratory Auditorium
47 Bateman Street, Cambridge CB2 1LRJoin us in person for this talk from Andres Alfonso-Rojas on his research studying how snakes in the tropical Americas evolved and became so diverse, with a focus on colubroid snakes, and combining fossil evidence, DNA data, and information about snake ecology and life histories.
About
Complex biogeographical patterns revealed by new species of fossil snakes from the Oligo-Miocene of South America
Speaker: Andrés Alfonso-Rojas (Department of Zoology, University of Cambridge
Venue: Sainsbury Laboratory auditorium, 47 Bateman Street, Cambridge CB2 1LR | Find us
Please note: This talk will take place in person only.
About the talk
The Miocene of South America represents a pivotal interval in the establishment of modern snake faunas. By this time, modern lineages of snakes like boas and pipe snakes were already present in the continent, represented by multiple fossils recovered mainly in Argentina, Brazil, Colombia and Venezuela. During the first two decades of the 21st century, numerous Oligocene and Miocene localities in Bolivia, Peru, Colombia, Venezuela, and Panama have yielded an expanding record of fossil snakes.
Here I present newly discovered colubroid fossils, including at least two new species, as well as a new lineage of a widespread alethinophidian snake. These colubroid fossils provide unambiguous support for molecular biogeographical hypotheses proposing the arrival of colubroids to South America from North America prior to the Miocene, with a potential dispersal route via Central America. Additionally, a new species of large-bodied snake recovered from multiple depositional environments across northern South America suggests the existence of an ecologically diverse lineage capable of dispersing from Andean settings to the Greater Antilles.
About the speaker
Andrés Alfonso-Rojas is a Colombian biologist and paleontologist currently completing his PhD in the Department of Zoology at the University of Cambridge. He earned a bachelor’s degree in civil engineering in 2017 and a bachelor’s degree in biology in 2018 from Universidad de los Andes, Colombia. After working for a year as an engineer, he began a master’s in Natural Sciences at Universidad del Rosario, Colombia, where he also worked as a research assistant. He moved to Cambridge in 2022 to pursue his PhD, funded by the Gates Cambridge Scholarship. His research focuses on understanding the origin of modern snake communities in South America using fossils, phylogenies, and ecological data.
Read this feature article on Andrés Alfonso-Rojas's research, which has reconstructed ancient anacondas from 12.4-million-year-old fossils discovered in Venezuela, to find these tropical snakes were a whopping 5.2 metres long.
Branching Out public talk series
We are 100% dedicated to plants at the Sainsbury Laboratory, but we also enjoy the chance to “branch out” and explore the exciting research taking place across other scientific disciplines.
Branching Out is a free lunchtime talk series held once a month during term time. Rather than traditional scientific seminars aimed at specialists, these talks are designed to be engaging, accessible and thought-provoking for the wider Cambridge community.
The series was originally conceived by Emilio Aldorino and is now organised by a committee of researchers at the Sainsbury Laboratory.
Everyone is welcome to attend.
If you are interested in attending a future talk, giving a talk, or contacting the organisers, please get in touch.