Yutyrannus: Allosaur or Tyrannosaur?
Carnosaur
MemberCompsognathusApril 22, 20146604 Views10 RepliesRead something on Scott Hartmans Deviant art stating Yutyrannus was a species of allosaur. And, upon doing some research, have come to that conclusion as well.
Here's why i think it's an Allosaur...
The arms are long, and three fingered. A trait of early, small tyrannosaurs. Sure. However, they are not present in the Large bodied Tyrannosaurs.
Daspletosaurus, an animal of equal size (9 meters, 4 tons) and living at the approximate same time, almost shares no resemblance.
Note the two fingered, small arms
Gorgosaurus, another similarly sized animal, again shows no resemblance.
"But wait!" you must be saying to yourselves, ' it also has a covering of feathers, Do you think it isn't a Tyrannosaur because of this?"
Well, no. Small Tyrannosaurs had them as well. Such a large animal that coincidently has them as well doesn't entirely convince of Yutyrannus being one as well.
Now, let's look at the skull..
The skull reminded me of another large bodied predator..
That, is the skull of Allosaurus Fragilis.
The skulls look remarkably similar, even sharing the structure at the top of the head.
Now, let's compare Yutyrannus to the skull of Daspletosaurus
More compact, with larger spaces for powerful jaw muscles. We do not see this in Yutyrannus.
The Skull of Yutyrannus is more elongated, with smaller serrated teeth. The Characteristic'D' shape of Tyrannosaurid is not terribly noticeable in the teeth of Yutyrannus. Once again, resembling more of those of Allosaurus
Onto something a bit easier to follow...
Yutyrannosaurus shares the body plan of Allosauridae. having a relatively long neck, and an elongated tail.
Similarly sized Tyrannosaurs have a thick powerful neck, and an equally thick, powerful tail.
In conclusion...
i believe Yutyrannus is a species of Allosaur, sharing some traits with The tyrannosauridae through convergent evolution. Perhaps we are seeing an adaptation for a new prey source.
This also is the first evidence for feathers on Allosaurs, if my theory is correct. Exciting indeed.
Nature doesn't deceive us; it is we who deceive ourselves.
I still think it was a tyrannosaur. One reason is that the front teeth of all tyrannosaurs have one thing in common, a D shaped cross section. This is true only in tyrannosaurs. Also, Sinotyrannus and Dryptosaurus are two other similarly sized species of confirmed tyrannosaurs with long arms and 3 fingers. Sinotyrannus also has a covering of feathers and a similar body plan to Yutyrannus. It's also been proposed that Gorgosaurus and Albertosaurus may have had feathers. Nanuqsaurus probably had them too. Large bodied tyrannosaurs with feathers is nothing new, primitive or not. Primitive tyrannosaurs, which is what Yutyrannus is classified as, almost all have feathers, long arms with 3 fingers, and crest like structures. Guanlong is a good example of this. Albertosaurus and Gorgosaurus also have crests. So, to me, Yutyrannus remains a primitive tyrannosaur.
(No offense was inteded with this pic, I just couldn't resist)
Dryptosaurus is framentaryily known, i mean look at this ( brown coloration is reconstructed based on the body plan of Appalachiosaurus)
to my knowledge, Dryptosaurus doesn't share the D crossection. 'm quite sure classification is being disputed at this very moment as well..
Yes, all primitive tyrrannosaurs do in fact have feathers, but they do not reach the size of Yutyrannus. Sinotyrannus belongs to the Proceratosauridae, an offshoot of the Tyrannosaur family.
Tyrannosauroidea ProceratosauridaeSinotyrannus kazuoensis
Appalachiosaurus montgomeriensis
Allosaurs are distant relatives to the Tyrannosaurs.
I was very tempted to use that pic as well, shoulda ;P
Nature doesn't deceive us; it is we who deceive ourselves.
