Some new Utahraptor fossils described

[Sim]

After four years filled with hints that new Utahraptor fossils show Utahraptor was weirder than previously thought, a paper is out that starts describing the new fossils.

https://www.researchgate.net/publication/308041652_DEPOSITIONAL_CONSTRAINTS_ON_THE_LOWER_CRETACEOUS_STIKES_QUARRY_DINOSAUR_SITE_UPPER_YELLOW_CAT_MEMBER_CEDAR_MOUNTAIN_FORMATION_UTAH

The only new Utahraptor remains described so far are the more front parts of the upper jaw and lower jaw.  It looks like those parts change shape significantly as Utahraptor grows into an adult!

[Flaffy]

Interesting! I wonder if this applies to other large 'raptors' as well. If it does apply, maybe Saurian can consider incorporating it into their dakotaraptor.

[Yutyrannus]

Dakotaraptor is more closely related to Dromaeosaurus than to Utahraptor, so like in Dromaeosaurus the procumbent dentition at the end of the lower jaw were probably less prominent than in Dakotaraptor. The Saurian devs have probably already known about this for a while.

I'm very happy to see that something on these specimens has finally been published !

[Sim]

Yutyrannus, I'm guessing you meant to say Utahraptor instead of Dakotaraptor at the end of the first sentence?

I'm very happy to see that something on these specimens has finally been published !

Same here!  It's good to finally get confirmation Utahraptor really did have that very strange lower jaw with forward pointing teeth, even if only as an adult.  It feels like there's something unusual about the shape of the front of Utahraptor's upper jaw too, but I'm not sure exactly what it is.  It reminds me of that artwork Julius Csotonyi did for these fossils a while back!

[Takama]

So this is all Confirmed ?


I been wanting to commission a model of Utahraptor based on the latest material, but i would like to know if its a little too soon.

[Sim]

@Takama:  The only new anatomy that's confirmed for Utahraptor so far is the front of the upper and lower jaws.  Photos of those parts can be seen in the paper I linked to.  In non-adult Utahraptor those parts seem more like what is seen in some other dromaeosaurids.  In the adult Utahraptor though, the lower jaw looks like it does in that Emily Willoughby picture - it has a strange shape with the front teeth pointing forward.  The front of the upper jaw in Emily Willoughby's Utahraptor picture doesn't look quite right though.  I mentioned earlier that part of Utahraptor seemed unusual too.  Comparing it to Emily's picture, I still find it hard to put into words, but it seems the front of an adult Utahraptor's upper jaw is elongated and a bit pointed?

Julius Csotonyi did this picture based on this Utahraptor fossil discovery, the jaws of the largest Utahraptor in the picture match those of the adult Utahraptor fossil remains and show that kinda pointed upper jaw:



If I wanted to commission a model of Utahraptor, I would wait until the rest of the new fossils are described.

[stargatedalek]

To be fair, with the jaws closed these details would be obscured so if you wanted a figure with the jaws closed I wouldn't bother holding back.

I'm desperate to learn more about this new(?) herbivore and if this was likely to have been natural predation behavior or scavenging/opportunistic.

[Sim]

To be fair, with the jaws closed these details would be obscured so if you wanted a figure with the jaws closed I wouldn't bother holding back.

The shape of the front of Utahraptor's upper jaw is visible even with the mouth closed.  I'm not understanding why obscuring details with the mouth closed matters though since those parts are known now?  The reason why I would personally not commission a model of Utahraptor until the rest of the new fossils are described is in case they show more new anatomy that we don't know of.  That's just how I feel about it though.

[stargatedalek]

I still doubt the teeth are "extreme" enough to be visible with the mouth closed, but I suppose something new could still come up with the general proportions (especially given we have juveniles and adults now).

[Sim]

I still doubt the teeth are "extreme" enough to be visible with the mouth closed, but I suppose something new could still come up with the general proportions (especially given we have juveniles and adults now).

I agree the teeth wouldn't be visible with the mouth closed.  The slightly pointed shape of the front of the upper jaw (snout) in the adult Utahraptor is what I think would be visible.  It's not obvious though, and I could be wrong.  The slightly pointed upper jaw is just something I've been noticing when looking at the adult Utahraptor's premaxilla and I seem to notice it in that picture by Julius Csotonyi I posted too.

I wonder if the premaxilla in the adult is slightly elongated/pointed so those forward pointing teeth in the lower jaw can still fit inside the upper jaw?  I wonder why the head anatomy changes so much as Utahraptor grows into an adult?  The forward pointing teeth are especially curious.