Congratulations to Dr. Serjoscha Evers, a recent DPhil graduate of Oxford Earth Sciences, who was recently awarded the 2019 Alfred Sherwood Romer Prize of the Society of Vertebrate Palaeontology after presenting his PhD research at their 79th Annual Meeting in Brisbane, Australia on 10th October.
The Society of Vertebrate Palaeontology states: “The Alfred Sherwood Romer Prize recognizes an outstanding scientific contribution in Vertebrate Paleontology by a predoctoral student. Selection is based on the scientific value and quality of a submitted abstract summarizing an original research project. The prize is awarded based on the scientific value and quality of the oral presentation of that research during the Romer Prize session at the SVP Annual Meeting.”
Serjoscha, a former student of Prof. Roger Benson, was selected to be among the 16 finalists and was awarded the prize for the best presentation, as judged by an expert jury of senior society members. This talk was titled “New insights into the evolution of secondarily marine lifestyles, marine adaptation, and diversification of turtles.”
Serjoscha is the first person to win this prestigious award who was not based at an US institution for their PhD research. He summarises the findings of his research below:
“During my doctoral studies at the University of Oxford, I investigated the evolutionary relationships of turtles with a specific focus on those turtles that, in the past or today, live at sea. These oceanic or marine turtles evolved from turtles that originally lived on land, and thus had to adapt to a new environment with difficult challenges.
I came up with a new hypothesis regarding the turtle family tree by analysing high-resolution X-ray CT scans of fossil and living turtles, which provided new anatomical data for turtles. This new hypothesis shifts several groups of turtle around with regard to classic ideas of their relationships.
One of the results of my study is that up to six groups of turtles have independently evolved an oceanic lifestyle. Three of these groups lived during the end of the Cretaceous, when an asteroid impact led to a mass extinction that killed off most dinosaurs and also many oceanic reptile groups, such as mosasaurs. Somehow, all three marine turtle groups survived the end-Cretaceous mass extinction, but we do not yet know why that is.
The turtle group that led to modern sea turtles was found to be older than previously thought in my study, because a diverse group of turtles that included several meter-long giant sea turtles that lived during the Cretaceous were found to be close relatives to modern sea turtles. These findings also imply that one key innovation of modern sea turtles, the flipper, evolved relatively rapidly at the beginning of the group’s evolution with relatively little change that evolved afterwards. I also found evidence for marine adaptations in the inner ear of sea turtles: Sea turtles have large spaces surrounding their inner ear organ that were filled with fluid and possibly buffered the ear from pressures during diving.
In summary, the results of my study provide a new hypothesis of turtle relationships and new information regarding the question how reptile groups like turtles evolve during ecological transitions.”
Dr. Evers is now a Postdoctoral Researcher (SNF) in Vertebrate Paleontology, at the University of Fribourg, Switzerland.