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!

Last dinosaur of its kind found in the land that time forgot

This was originally posted at: http://blogs.egu.eu/palaeoblog/?p=1241

In terms of iconic dinosaurs, the gargantuan sauropods are certainly up there. Along with the mostly meat eating-theropods, and herbivorous and often armoured ornithischians, they form one of the three major groups, or clades, of dinosaurs, and were the biggest animals to ever walk this Earth.

The end of the Jurassic period, some 145 million years ago, was a pretty important time for sauropods. Their diversity was already in decline through some of the latter part of the Jurassic, but it seems that they were hit pretty badly at the Jurassic/Cretaceous (J/K) boundary, in an extinction event that may have been quite severe among land and marine-dwelling animals.

The greatest mass extinction in the history of life

This was originally posted at: http://blogs.egu.eu/palaeoblog/?p=1204

In palaeontology, there are so many things more important than dinosaurs. For example, the study of large-scale patterns in the history of life on Earth, commonly known as macroevolution, is all about uncovering patterns of speciation and extinction. We are currently about to enter the sixth mass extinction within the last 542 million years of life on Earth, so figuring out exactly what happened during periods of elevated extinction and ecosystem catastrophe is pretty damn important if we want to offset as much damage as possible.

Recently, a suite of new papers have been published giving detailed insight into the environmental and biological patterns and processes throughout the Permian-Triassic mass extinction, an event 252 million years ago that saw the demise of greater than 90% of life on this planet (numbers vary depending on which measure you use). What I’d like to offer here are bitesize summaries of each, and show that there is much more important research out there in palaeontology than just ‘woo new dinosaur’.

Where did all the mammoths go?

This was originally posted at: http://blogs.egu.eu/palaeoblog/?p=1037

Let’s go meta. Recently, ecologist extraordinaire Dr. Jacquelyn Gill (or is it Professor cos of that weird American system?) wrote a wonderful review article on the extinctions that affected many large mammal species during the last 50-10,000 years. This period is known as the Quaternary, and was a time when ice ages were running rife between warmer periods, and herds of enigmatic mammals roamed the steppes. It’s also a time when many wonderful animals, such as mammoths, disappeared from our planet forever, apart from rare fuzzy sightings from drunk Russians that later turn out to be a bear, or nothing. The result is that although we have a spectacular range of mammals decorating our landscapes today, this is but a shadow of mammals’ true splendour back just a few thousand years.

Legit scientific claims (source)