Theropod bone

[Dino Dad 81]

Hello,

 

Any thoughts on what animal this bone comes from?

• Judith River Formation, North of Havre, MT close to the Canadian border
• About 1" long

 

 

 

 

 

 

 

Thanks,

[Troodon]

Not a bone we have much info on.  One suggestion you can research is a Dromaeosaurid Digit 1, metacarpal.

 

View of Dromaeosaurus replica. Not sure a hand exists.

 

The real bones on Utahraptor

[Troodon]

Found this image of a Dromaeosaurid from Mongolia.  Paper was paywalled but looks interesting as Digit I-1 metacarpal

 

 

A New Dromaeosaurid (Dinosauria: Coelurosauria) from Khulsan, Central Mongolia James G. Napoli, Alexander A. Ruebenstahl, Bhart-Anjan S. Bhullar, Alan H. Turner, Mark A. Norell

 

[Dino Dad 81]

@Troodon, I was just coming on to propose the exact same bone after seeing the image below from Bambiraptor. Do you think it's more likely to come from Dromaeosaurus or Saurornithelestes?

 

[Troodon]

No idea which one both are dromaeosaurids generally similar in size. 

[Dino Dad 81]

Thanks @Troodon

[Dino Dad 81]

@Troodon, one other comparison occurred to me. I compared the size of this bone with the corresponding bone on my cast velociraptor hand. This bone is almost 30% longer than that of velociraptor.

 

It looks like Velociraptor and Dromaeosaurus are both estimated to be about 2m long and weigh 15kg, whereas Saurornithelestes is estimated to be about 1.8m long and weigh much less at 10kg. Does the fact that this bone is significantly longer than that of Velociraptor suggest that it more likely comes from Dromaeosaurus than from Saurornithelestes?

 

 

 

 

 

 

[Troodon]

You are trying to compare 3 dinosaurs that belong to different subfamilies , a Velociraptorinae, Saurornitholestinae and a Dromaeosaurinae.   It's a stretch to do it that way without knowing how differentthey are.   What's wrong with a positive indet dromaeosaurid assignment versus a guess... You really need to compare the hands of the 2 to make the right call

[Dino Dad 81]

Nothing wrong with indet dromaeosaurid. I just try to make the most out of each specimen I get by learning as much as possible about it. There’s no right or wrong / better or worse—just the pursuit of maximum information. The investigation is the most fun part.

 

Thanks @Troodon

[Troodon]

The skull of this Saurornitholestes skeleton has been published.  Evans/ Currie indicated that the rest will follow and it looks like hands are included.

 

[Dino Dad 81]

Thanks, @Troodon!!

It also looks like this bone was found for Dakotaraptor, but isn't shown in DePalma?!

Err

[Troodon]

Looks a bit different

[Troodon]

FYI

Just read an upcoming SVP meeting abstract on a poster being presented by Jim Kirkland on Utahraptor.   He asks the question does tail morphology differentiate Dromaeosaurines from Velociraptorinae based on several tail sections uncovered on the Utahraptor block.   He describes the difference and cites several examples.   Highlights that we need to be careful comparing bones between different Dromaeosaurid subfamilies which might be a surprise to some.