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.

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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!

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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?

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Another clue to the origins of dinosaurs

This was originally posted at: http://blogs.egu.eu/palaeoblog/?p=1222

Often the early evolution and radiation of the first dinosaurs is an overlooked part of their tale, in favour of the more dramatic but arguably no less important tales of their later radiations and extinctions. It is actually a fairly poorly understood part of their evolution too, with the timing, and actual mechanism that drove them to become the most successful land group ever still a bit of a mystery.

We are, however,  learning more and more about this important phase of their history, in a time known as the Late Triassic some 231-201 million years ago. A new fossil site from this time in Poland – probably not one of the places you’d associate with important fossils – is helping to fill in the blanks. Usually, dinosaur-bearing sites from around this time are known from the southwestern United States and southern South America, so a European locality can potentially tell us quite a bit!

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Macroecology – scaling the time barrier

This was originally posted at: http://blogs.egu.eu/palaeoblog/?p=1178

If there was ever an overdue discussion in palaeontology, it was how we reconcile the differences in time scales when looking at different periods in our history. This is becoming increasingly more important as scientific research is being asked to have demonstrably greater ‘impact’ in terms of some social, economic, or environmental relevance, and for palaeobiologists and palaeoecologists, this means having some sort of notable effect on our changing world.

The day kicked off with Andy Purvis summarising what we actually mean by macroecology – I mean, it’s an impressive sounding term, but what is it scientifically? It’s actually varied quite a bit in time, with new tools and datasets meaning that our analyses have diversified and become more intricate, with the ability to answer and ask new questions about how species and populations diversify and change through time, especially with respect to the environment.

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