Kem Kem phalanges (theropod or something else?)

[Spinodude]

Just bought these little beauties. Were sold as 'dromaeosauridae sp.' finger bones. Ad also named them deltadromeus. Now, I'm aware of the difficulties with ID'ing Kem Kem theropod but I like buying cheap-ish fossils and then trying to figure out what they really are. Part of the fun I guess.

Total length of both bones is ~63mm. Not sure if the arrangement is correct, bones seem to fit well. They're small, which makes me wonder if they're theropod at all. Did look into deltadromeus, found the gualicho shinyae which might be the best reference point it seems. Bones do look like some of the gualicho material, but more like the feet and not hands. Then again: you'd expect bigger bones for dinosaur, unless these are juvenile I guess. There are some minor repairs on the smaller bone. Nothing too crazy.

So I'm hoping you guys can help out, as always! Am I looking at (juvenile?) theropod bones with a likeliness of being deltadromeus (as advertised) or at something completely else? 

[Troodon]

They are both phalanx of the foot.

The circled one is reptilian, possibly turtle the other is an indeterminate theropod.  Very little is published on hands or feet so we know very little of them or even of the smaller theropods.  Given its size probably a juvie but it's indeterminate.  I dont think it compares well with Gualicho.

 

Nice bones

 

 

[Spinodude]

So this was two species for the price of one then! Nice! 
Just curious, what makes you spot the difference between the theropod and reptile? I see that the reptile phalanx is a bit more flat and wider at the end. But what are other signs to look out for?

[Troodon]

Gosh there are lots of variations in these bones and some between Croc and theropod can be difficult but its through experience and by looking at lots of papers and photo you can try to make call.   Yes those that are wide and flatter are typically not theropod but could be from a herbivore not only reptile if its from other areas than the Kem Kem.  The ligament pits are one features I look at, theropods are usually deep.  My suggestion is to look at photos of theropods and compare them against turtle and croc.

 

[Spinodude]

Ligament pits are the dents on the side of the front, right? Interesting stuff Troodon! Always nice to get some insights from you