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.)
So with all of those posts about ankylosaur taxonomy over the last few weeks, what have we learned about the evolution of this group? Over the course of my PhD research, I was able to identify a bunch of new characters that seemed useful for understanding ankylosaur phylogenetic relationships, including characters related to the cranial ornamentation, pelvis, and osteoderms. Although ornamentation and osteoderms can be tricky, they can still yield useful information if you’re careful about how you construct the characters.
Here’s a sampling of some of the new characters from the supplementary file that goes along with the paper. Long live rainbow ankylosaur skulls. Continue reading
I’m very sad to say that today is my last day in Korea. The last seven weeks have been truly wonderful and I will have many fond memories of my stay in Songsan. I’ve eaten some excellent food and some very strange food, seen wonderful sights, and got to prepare some really great ankylosaur fossils at the lab. Robin and Scott and I have had a great time.
I’m so grateful for all of the people who have helped me out for the last two months – Dr. Lee for hosting me on this research abroad visit, Yun for all of his help at the lab and around town, and Choon-Hyung, Pak-Jin, and Jin-Young for their patience at my lack of Korean and their excellent lunchtime cooking!
Tomorrow Robin returns to Canada and Scott and I head off to Beijing for two weeks of research and the Flugsaurier Symposium. Stay tuned for more updates!
The Hwaseong dinosaur egg site is just a 15 or 20 minute walk from the visitor centre across the salt marsh. The nests are found in these little island outcrops, which look as though waves were crashing on them just yesterday. Continue reading
We’ve had a couple of really nice sunny days in Hwaseong, the first properly sunny days since I arrived in Korea. So, you get some nice outside pictures today!
Construction on a boardwalk out to the egg site is moving along very quickly, and I suspect the boardwalk will be finished later this week or next. The boardwalk will provide a nice dry and non-muddy surface to walk on, and will also protect the surrounding marsh.
Much of the area around Songsan is rural Korea, and almost every usable bit of land has something cultivated on it. The sun has never properly come out yet since I’ve been here, and as such everything always has this interesting misty or hazy look. On Sunday Robin and I went for a walk along one of the hillsides, on a road that kind of wound through a bunch of little farms. Continue reading
Perhaps black fuzzy sneakers were not the wisest choice for this sort of work…
Sometimes, even when you’ve made a good field jacket, bones get a bit beat up on the way from the field to the lab. I find this to be especially true of bones that have not been very mineralized, like many bones from the Gobi. If you’re careful, you can usually get a good amount of the bits back together, but it requires a lot of patience, especially as the pieces get smaller and smaller… Continue reading
The Korea-Mongolia International Dinosaur Project has been collecting fossils from the Gobi Desert for the past several summers, and some of the specimens are housed in the lab in Hwaseong. My visit to Korea is funded through an NSERC Foreign Study Supplement, which is kind of like a study abroad for scientists. The purpose of my visit here is to help prepare a large ankylosaur skeleton, and to get experience working in a different culture and research environment. Continue reading