My interview with Imperial College on the rise and fall of ancient dinosaur-eating crocodiles

While back in London recently for my PhD viva, the opportunity came up to speak with the Communications Office at Imperial College about some of my research. Naturally I pounced at the chance to discuss my research and broadcast it to a wider audience. The short audio for the interview is now online here, and we discuss everything from the impact of changing climates on biodiversity to giant, dinosaur-devouring crocodiles! Enjoy 🙂

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Dr Jon Tennant studied these creatures as part of his PhD in theDepartment of Earth Science and Engineering. He was exploring the biodiversity and the extinction of some tetrapods, which is a classification for all creatures with four limbs.

Dr Tennant, who is also a science communicator and children’s author, looked at some of the most fearsome tetrapods of them all – crocodilians. These creatures, which alligators and crocodiles are modern ancestors of, lived on Earth over one hundred million years ago in the deserts, coasts, oceans and even the artic regions of our planet. Some, like the Sarchosuchus, were the size of double-decker buses, and going by the fossil evidence, fed on dinosaurs, who were rival ‘apex’ predators.

Dr Tennant discovered in his research that changes in sea level, brought on by fluctuations in the climate and continent movements, changed the world of tetrapods like the Sarchosuchus forever. Now, he is embarking on a six-month exploration of the planet, including some of the regions where modern crocodilians live. Colin Smith caught up with Dr Tennant to talk about his favourite ancient crocodilians and how changes in early Earth impacted on their biodiversity. 

Full podcast here and you can download the mp3 file here.

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Ecological reshuffle following a crocodyliform extinction

Chaaaaange places! Sometimes, when extinction hits it’s not quite the dramatic ‘great dying’ we might think of where animals choke their final breaths out in the desolate, lifeless wastelands. Sometimes, it’s more like the Mad Hatter’s tea party from Alice in Wonderland: chaotic, messy, no major character dies, but you can be sure that something pretty weird and dramatic has just happened.

Well, I think this is what happened around 145 million years ago at the Jurassic/Cretaceous boundary. In a recent paper, we analysed the diversity and extinction patterns of crocodyliforms – the group that includes modern crocodiles and their super cool ancestors – and found that they got hit pretty hard by an extinction event around this time.

Why I think the Jurassic/Cretaceous boundary is super important

Mass extinctions are insanely catastrophic, but important, events that punctuate the history of life on Earth. The Jurassic/Cretaceous boundary, around 145 million years ago, was originally thought of to represent a mass extinction, but has subsequently been ‘down-graded’ to a minor extinction event based on new discoveries.

However, compared to other important stratigraphic boundaries, like the end-Triassic or the end-Cretaceous, both time periods representing mass extinction events, the Jurassic/Cretaceous (J/K) boundary actually remains really poorly understood. This is both in terms of what was going on with different animal groups at the time, and what environmental changes were occurring alongside this.

Well, I have a new research paper out now that synthesises more than 600 research articles, bringing them together to try and build a single picture of what was going on around this time! It’s free to read here, and is essentially the literature review from my thesis, or as I like to think of it, the justification for my existence as a researcher!

Your bite or mine?

This was originally posted at: http://blogs.egu.eu/palaeoblog/?p=1250

It rises from the dark waters like some behemoth from the deep, and lets out a blood-curdling roar. It’s feeding time. One of the most iconic scenes from Jurassic Park III is where the long-snouted, sail-backed giant theropod dinosaur Spinosaurus emerges from underwater to try, yet again, to eat our beleaguered rabble of misfortunates. It’s always been the way these dinosaurs have been portrayed, including one of Spinosaurus’ close cousins Baryonyx from the UK. With their long snouts, bulbous tips, and pointy teeth, it’s often been thought that spinosaurid dinosaurs were quite a lot like modern crocodiles. But how much of this is true?

It’s been a while..!

This was originally posted at: http://blogs.egu.eu/palaeoblog/?p=939

In a post two months ago, I promised that I’d keep you updated with how my research is progressing. Needless to say, I’ve done a pretty poor job of that, unless you follow me on Twitter! I must apologise – the workload while traveling was severely under-estimated, and I’ve barely had time to catch a nip. I’m writing to you now from Lyon, where I finally had a day off in about a month to explore the Basilica and Roman amphitheater ruins here, and am now nestled in a snug pub hammering away at a manuscript!