Possibly a spinosaurid ulna bone?

[talon22]

I have been looking at this ulna bone from the kem kem, and wondering if a large isolated bone like this can be identified. It is about 26.5cm (10.4 inches) and looks like a chunk of one end in missing (which might make it harder to id).

 

 

 

It seems to resemble this megaraptor ulna....

 

[gigantoraptor]

Looks like an Ulna of a spinosaurid. There are two described in the Kem Kem beds and I don't know how to tell them apart.  So It could be Spinosaurus aegyptiacus or Sigilmassasaurus brevicollis. Here is a picture with ulnae from different species of Theropod dinosaurs. The first one is from the Spinosaurid Suchomimus tenerensis from Niger.

A: Suchomimus tenerensis

B: Allosaurus fragilis

C: Megaraptor namunhuaiquii

D: cf. Megaraptor sp.

E: Megaraptor namunhuaiquii

 

[LordTrilobite]

Neither Spinosaurus or Sigilmassasaurus has a described ulna. So there's no way to tell them apart. But this does indeed show some resemblance to the Suchomimus example. Could indeed be Spinosaurid.

[Troodon]

I do not believe it an ulna looks more like a hip bone and connot even say Dinosaurian, dont know.

 

If you look at ulna here and in the photo provided by gigantoraptor the distal end "e" is roundish, bulbous, not triangular in shape like in the bone in question.   The end is blunt to line up with the metacarpals in the hand.

[LordTrilobite]

I think Troodon has a point. I did not consider hip.

[talon22]

I didn't consider other possibilities like a hip bone, it just seemed to match the shape of a dinosaur ulna bone so i was confident with that id, but i see Troodon's point quite well and i agree, i also suppose the possibility of the bone being from a crocodylomorph can't be ruled out either.