A Modern Day Dinosaur Extinction

During the Cretaceous, dome-headed pachycephalosaurs roamed through what is now the Hell Creek Formation, covering parts of Montana, Wyoming, and North and South Dakota. But UCMP Curator Mark Goodwin and Museum of the Rockies Curator Jack Horner argue that there were fewer pachycephalosaur species than we thought. Mark and Jack suggest that two species, Dracorex hogwartsia and Stygimoloch spinifer, are actually juveniles and teenagers of the species Pachycephalosaurus wyomingensis. Learn about this modern day dinosaur extinction — read Mark and Jack's paper, published in the open access journal PLoS ONE, and watch this video!

Read the open-access, full-text article here:
http://dx.plos.org/10.1371/journal.pone.0007626

Category:

Science & Technology

Tags:

• dinosaur
• dinosaurs
• pachycephalosaur
• pachycephalosaurs
• Dracorex
• Stygimoloch
• Pachycephalosaurus
• Mark Goodwin
• Museum of the Rockies
• Jack Horner
• Hell Creek
• Hell Creek Formation
• paleontology
• fossil
• fossils
• evolution
• CT scans

[facelessone86]

@tyrantslayer24 The dog and cat comment is so off base its hilarious. Just because they don't look the same is not an issue. It's the point. They can also cut into the bones and tell that the horns shrink and the dome grows.

[Marveh]

Dracorex hogwartsia? haha draco, hogwarts? hmmmm

[Ninjarni]

HOGWARTS!!!!!!1

[tyrantslayer24]

I don't agree with anything said in the video. I can see how someone might think Stygimoloch and Pachycephalosaurus could be the same animal, but I don't think Dracorex should be part of this theory. It looks too different from the other two that you might as well say a dog and cat are the same thing.

[Tarbtano]

and yet they completely forget the skull bones in the jugal, orbital, and post orbital regions are fused, a clear as day indication Stigimoloch and Dracorex are already nearly fully grown.

Horn shape can change, but horn size doesn't. Stigi has up to 4 inch long horns on the back of it's head, Pachy only has 1 inch tall bumps. This narrator is terribly misinformed.

PS: Juvenile Pachy found, looks nothing like Stigi or Draco

[Allosaurus333]

Ive dis papa!!!

Love papas about synonymizations! Really!

Also

Triceratops=Torosaurus

[MandaloretheYoung]

This is a very interesting theory. They make a good case for it, but I feel we need more fossils to be certain.

[GWolfV2]

About the horns. I've asked this, and while it is logical to get the idea that the horns would change shape, Stygimoloch's would have had to completely regress, and according to my source, there's no evidence of that in any modern animals. I'll check out the paper for myself

[Salmo77]

Great Vid!

[puncheex]

squamosal. It means "flat" in Latin, referring to the fact that the cells are flat, plate shaped. Skin cells are squamous cells. The reference to bone refers to the fact that the bone is set down in many flat layers.