28 May 2017
27 May 2017
I truly love finding that I have somehow overlooked a dinosaur that I am and have been aware of for quite some time. This week that dinosaur that I suddenly remembered existed is Citipati osmolskae. Citipati is one of the better known oviraptorids and one of the most iconic members of its family. Possessing a crest on its forehead and a beak characteristic of other oviraptorids. Probably covered completely in feathers, Citipati was a large dinosaur at approximately 3m (10ft) long and were the largest members of their family known between 2001 and 2007. Clark, Norell, and Barsbold named Citipati (Hindi for funeral pyre) after the highly successful paleontologist Halszka Osmólska of Poland. Osmólska was a prolific discoverer and describer of oviraptorids and theropods of Mongolia where Citipati was also discovered.
|Display from "Dinosaurs. Treasures of Gobi Desert" in CosmoCaixa, Barcelona.|
Photo by Eduard Solà
26 May 2017
All of these interpretations are, of course, my personal speculation based on the speculation of artist interpretation of events that may or may not have occurred and may or may not have some kind of scientific evidence underlying them. The most important thing to do with these illustrations is to enjoy them, appreciate them, and create your own ideas about what is happening in them.
24 May 2017
Tuesday there was a paper describing the pelvic armors of different ankylosaurs and Polacanthus was one of the ankylosaurs that was specifically mentioned because it possessed very unique pelvic dermal armors. Most ankylosaurs have somewhat uniform sheets, scutes, or patches of dermal bone that protect their dorsal surfaces. Polacanthus also has dermal armor along its back; however, the dermal armor along the pelvic region is uniquely constructed and protective of the dinosaur's pelvis and hips. Assuming that, as many ankylosaurs are thought to have defended themselves, Polacanthus made itself small when threats loomed, making it difficult to get at its soft underbelly, the expansive pelvic armor was capable of protecting the hips of the animal quite well as it would have served as an armored roof to that area. In many illustrations it appears as though the hips are still exposed (such as that below); however, in the skeletal reconstructions of Polacanthus we can see fairly well that the actual hip socket lies medial and ventral to the armored shelf of bone resting on the pelvis. In some line illustrations this has been exaggerated slightly, such as in the Nopsca drawing which pulls the shelf more laterally than some others, but these small errors in representation do not change the fact that the armored shelf protected the hips of Polacanthus very well and probably kept the dinosaur safe from most direct bites, slashes, and kicks to the hindlimb which, as we saw with Edmontonia, was most likely used to pivot the front shoulder spikes of Polacanthus in threatening displays or actual offensive strikes at rivals and predators.
23 May 2017
Not surprisingly, there are a lot of papers on the armor of Polacanthus and its configuration. Of course, we should start with the original descriptions of Polacanthus fossils but there is only one of those available online. The first few description papers are short and largely unimportant; however, Hulke's 1881 description, featuring a number of quality line drawings of the known fossils to that time, is online and is worth reading. This was followed up approximately 20 years later by a review of English dinosaurs by Franz Nopsca with a dedicated chapter and new descriptions of Polacanthus. This trend of description has continued off and on through a number of different publications, researchers, and specific foci of research in general. The latest descriptive paper of Polacanthus actually describes a number of ankylosaurs and, specifically, focuses on the pelvic armor and its variations across all ankylosaurs.
22 May 2017
21 May 2017
Polacanthus is a bit more popular than a large number of other ankylosaurs and, by being one of those more famous and known dinosaurs, has a lot more pages and videos dedicated to it online than others. These include sites like KidsDinos and Age of Dinosaurs. As we know, most websites contain similarities and work with the same set of information to build their fact files and paragraphs of information. The same can be said for most videos. The prime example of this is the WizScience video series that relates the same information over a series of images of the fossil animal in question. Strangely, there is no cartoon for Polacanthus like the I'm A Dinosaur series; given its popularity this is a little strange.