There are kids shows that treat Stygimoloch from both sides of the argument of its phylogenetic/familial relationship. Rather than discuss which show is more correct than the others, that is simply too bad for today. Here are the clips from Dino Dan (no longer regularly on Nickelodeon) and Dinosaur Train (still on PBS). I have included an episode of Dinosaur Train dedicated to Stygimoloch at the end also:
Stygimoloch, regardless of its family tree, had a head made for hitting things. The horns around the circumference of the dermatocranium were probably less well adapted for smashing into other skulls than the flattened dome-y parts. The skull, unlike in this illustration, was much flatter than it appears in both of these animals. The shape shown here would have been detrimental for hitting head to head and even head to body. The body of the animal on the ground, assuming it was hit in the chest, for instance, would be in a fairly bad predicament if a solid cone shaped skull impacted it. Additionally, the cone shaped skull of the still standing dinosaur, despite its ability to deflect and transmit stresses, would probably still be damaged from smashing into the chest of another dinosaur. Regardless, the head ornamentation and shape of the dome are the most distinctive features of this illustration. The body plan of Stygimoloch would have been reminiscent, in overall shape, to those of other pachycephalosaurs. Those, in turn, were somewhat similar to other large bipedal herbivores such as hadrosaurs.
This week is going to be odd and a little difficult
. The reason posts the last two days have been a little bit late, backdated, or seem rushed is because the last two days have seen myself, and possibly many other biologists, paleontologists, and geologists triple checking posters and presentations in preparation for the Society of Vertebrate Paleontology meeting that begins next Wednesday in Dallas. This week's animal is going to be a contentious animal, partly because it is always fun to look at animals that have been lumped and split by various studies, and partly because there are enough materials that it will be easy to write about the dinosaur and also update, as I can, on some of the more general happenings of the conference.
Somehow, in all the years we have been going over dinosaurs, we have not discussed a still debated (though not as hotly as before I am sure) intermediate form of Pachycephalosaurus. The proposed life cycle of Pachycephalosaurus includes a juvenile form (Dracorex), a subadult form (Stygimoloch), and the adult Pachycephalosaurus. This week we are interested in the subadult form and, for our purposes, we will consider the animal outside of the debate (or as a split genus if one cannot separate the animals and the debate); this is not an endorsement of either side of the debate and we really just want to look at this animal. Stygimoloch continues our October of evil sounding fossil names and, additionally, adds an even more evil appearance to the taxa being discussed. Juvenile, female, or separate species, this is an interesting dinosaur and should be a delight to discuss as this week goes on.
We know that the Walking With Dinosaurs movie came out a few years ago and we know that it spawned toys, as movies (especially action movies) tend to do. Therefore, it is quite easy to find the toys all over the internet, with the Gorgosaurus line being fairly popular. They were the "villains" of the story after all. As far as toys go, they are acceptable versions of dinosaurs; however, they have a lot of small joints and overlaps of elements which make it look a little strange.
I cannot say why they renamed the animal.
Between the movie, the extensive historical record, and cartoons like I'm a Dinosaur and Dinosaur Train (a Gorgosaurus family owns a forest in the PBS show), Gorgosaurus is an extremely well known dinosaur. Regardless of the modern push of Gorgosaurus into the limelight, the museums and multiple specimens and casts that are visible to the public have kept Gorgosaurus in the public eye for over a century now.
Typically I try not to host links to other hosted sites, but now and again there are very good reasons for doing just that. Over twenty Gorgosaurus specimens are known to science currently and one of the more recent arrivals to the pack was being prepared in and around the year 2011. The undertaking was documented well and, rather than steal pictures and reexamine the process, any interested party could read about the work on a different blog.
In terms of anatomy that we find very interesting, most of the Gorgosaurus body is very similar to other mid-family tree tyrannosaurids. The head, however, is similar to other theropods, including tyrannosaurids, in the ways in which it is different. The confusion of that statement is all housed in the supraorbital area of the dermatocranium. Directly above the eyes there are two small horns, typically illustrated much larger than the dermal bones would indicate, that are rostrolaterally oriented and could only be ornamental in nature. This ornamentation would typically be interpreted as evidence of sexual ornamentation or sexual dimorphism. However, the recent trend in regards to sexual dimorphism in tyrannosaurs has been to look for (mostly hope for) medullary tissue in the bones; ornamentations have been considered, since, as species indicators and communicative structures that could be used to signal to rivals as well as the other sex when needed. Many of these symbolic communication studies are difficult to validate because of the lack of naturally acting tyrannosaurs roaming the countryside. The horns, despite their interpreted size, add a bit more devilishness whatever their purpose.
Gorgosaurus has a number of papers per find. I would not go so far as to say tenfold (that would be over 200 papers), though there could certainly be that many papers concerning the genus; the internet surely does not hold all of the literature and knowledge of the ages despite the fact that it does indeed hold many and more individual treasure troves of such. In many recent papers Gorgosaurus is considered in conjunction with, or contrast with, many of the dinosaurs that are being discovered in China and Mongolia (the linked paper is from 1955, but is indicative of many of these types of papers) and in many family-wide comparisons. There are papers that discuss Gorgosaurus behaviors in relation to other tyrannosaurid behaviors, especially the gregarious behaviors associated with hypothesized pack hunters. In the modern era of science, Gorgosaurus is still making a name for itself, especially in the 3D world with digital finite element analyses (FEA). Strain and stresses are buzz words in science and Gorgosaurus s one of those few dinosaur that has had its bones stressed and tested in the digital world of FEA. The results are fantastic and the images that come from these sorts of studies are beautiful.