How the ankylosaur got its tail club

Ankylosaur tail clubs are odd structures, odder than they are usually given credit for. They represent substantial modifications to two different skeletal systems – the endoskeleton, in the form of the caudal vertebrae, and the dermal skeleton, in the form of the caudal osteoderms. The centra of the caudal vertebrae lengthen but stay robust, and the neural arches undergo huge changes, such that the prezygapophyses, postzygapophyses, and neural spine become a robust, V-shaped structure on the top of the centrum, and which creates a tightly interlocking vertebral series with almost no flexibility. We call this the handle of the tail club. The osteoderms at the tip of the tail smush together and two of them become huge: although the tail club knob is small in some species, there are colossal knobs exceeding 60 cm in width. The ankylosaur tail club represents one of the most extreme modifications to the tail in terrestrial tetrapods.

Look at that thing. That is a weird thing.

(This is UALVP 47273, a really nice club that I studied for my MSc work on tail club biomechanics.)

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Flying away again…

I arrived in Ulaanbaatar last Saturday and am heading out to the Gobi Desert tomorrow morning. I’ve got a few blog posts that will appear while I’m away, but emails and facebook will be on hiatus until I return in late September.

However, I will leave you with a few palaeo notes and photos before I disappear for four weeks. During the Flugsaurier Symposium Scott and I had the opportunity to go on a field trip to Liaoning province to visit Jehol group outcrops and museums. Yesterday I posted a few photos of the Chaoyang Geopark. Today I’ve got some pictures of the Sihetun Fossil Museum and Darwinopterus field locality.
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Chaoyang Geopark


During the Flugsaurier Symposium I went on a field trip to Liaoning Province, which was a great opportunity to see different parts of China and visit Jehol group outcrops and museums. We first visited the Chaoyang Fossil Bird Geopark, which included a museum, in situ exhibits, parks, and lots of interesting statues. This is Nurhachius, an istiodactylid pterosaur from the Jiufotang Formation. The model has too many teeth, but he’s still pretty fun.


One of the best parts of the visit was this great in situ display exposing Jehol Group rocks. It had fairly good descriptions of the geology, and even marked on faults and other interesting features. Fossils discovered during the excavation were left in place, and included Cathayornis, Shenzhouraptor, and lots of fish.


Inside the museum proper were literally hundreds of Liaoning fossils of every sort – insects, plants, fish, turtles, champsosaurs, theropods, birds, pterosaurs – the list goes on and on. Here’s just a single display case showing off various fossil birds – I think they are all Confuciusornis, but may be mistaken.


It was easy to be overwhelmed by the sheer volume of fossil material in the geopark. After we finished in the museum we entered the fossil forest full of enormous petrified stumps. Incredible!

The museum and geopark had a few glitches – some specimens were mislabelled or in the wrong hallway, and there may have been a few ‘plussed’ specimens on display – but it was a really cool place that certainly has a lot of potential if a few of these errors are fixed up. Continue reading

A long list of dragons.

Lots of Chinese dinosaurs often incorporate the word ‘long’ into the genus or species name – Banji long (an oviraptorid), Beishanlong (an ornithomimosaur), Dilong (a tyrannosaur), Guanlong (another tyrannosaur), Mei long (a troodontid), Qiaowanlong (a brachiosaurid), Shaochilong (a carcharodontosaurid), Tianyulong (a heterodontosaurid), Yinlong (a ceratopsian), and Xiongguanlong (yet another tyrannosaur). I’m sure I am missing some, but you get the idea. China loves their dragons. Growing up I was a huge, huge fan of dragons of all sorts (perhaps resulting from my love of dinosaurs), and so it was really excellent to see so many varieties of Chinese dragons during my stay in Beijing. Here’s a few of my favourites and where I found them.

Turtle dragon at Bei Hai Park.
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