Skip to main content

Crocodile evolution through fossils

Polly is in the third year of her PhD in Evolutionary Biology. She studies fossils to understand why crocodiles are how they are today.

Portrait of Polly Russell
Polly Russell

I’m studying the last 70 million years of the fossil record of the crocodile group. I am trying to work out patterns of diversity and skull variations to understand more about their evolution. We’ve been working on a lot of new material so far, and have described a number new species from just after the Cretaceous–Paleogene mass extinction.

My interest in palaeontology developed during my undergraduate degree in Earth Sciences, where I was able to carry out my master’s research in a palaeontology project. After deciding to do a PhD, I applied to a number of PhD projects in palaeontology, but the one Bath offered was the one I liked the most.

Most of my work is based on the computer, especially when writing up my research into papers, like I am at the moment. There is a lot of writing, doing revisions, making figures and rerunning analyses, trying to get the paper published. I’ve been quite lucky and had the opportunity to work directly on new fossil materials for a large proportion of my research.

I just started my third year so it’s now getting intense.

Trip to Morocco

What I enjoy the most are the practical skills that have come with this PhD because they were unexpected, like fossil preparation and photography.

I just came back from a trip to Morocco where I collaborated with another PhD student in Casablanca. My supervisor came across this student who had crocodile material but didn’t actually study them, so he set up the collaboration between me and her. I spent a week sharing what I know about fossil crocodiles. Applying what I’ve learned over the past two years has been really fun and created the opportunity for us to work on a paper together.

The hard part of a PhD is maintaining your motivation throughout the three years. You’ll get peaks and troughs. You will be very focused sometimes, but keeping that going for three years is very hard. I find writing more difficult than doing the research, so writing the thesis might be one of the biggest challenges for me.

Future plans

I’m still deliberating on what I’m going to do in the future. I love working with fossil materials so if I continue with palaeontology, I might try and work in a museum-based job. I also want to travel and work with living animals, so it would be ideal if I got to combine both.

Are you thinking about doing a PhD?

Take your time to find a project you are really passionate about. Also, keep in mind that one of the most important aspects of your PhD is getting along with your supervisor. So don’t rush when considering doing a PhD, wait until you find the right one for you.

‘What I enjoy the most are the practical skills that have come with this PhD, like fossil preparation and photography.’
Polly Russell PhD student

Find out more about the Milner Centre for Evolution

Visit the website