Carcharodontosaurus or Deltadromeus tooth?

[Patrik Djurfeldt]

Hi,

I am new to this forum. I have had an interest in dinosaurs since I was a little kid, but this has "matured" in recent years. Recently, I got a tooth as a present. It was bought as a Carcharodontosaurus tooth, about 19 mm long (0.75"), at a large exhibition/museum in Kalmar, Sweden. But since the creator of the exhibition managed to lable a (flattened) Mosasaur scull as a Carch as well, I am not too confident in the identification. The tooth is small, but pretty. Did it belong to a juvenile Carcharodontosaurus, a Deltadromeus, or something else? I would be grateful for any help on this. At the moment I do not know where it was found originally.

[Troodon]

Do you have any information on where it's from, you indicate no info.   On the surface it appears to be from the Kem Kem beds of Morocco, especially if it was sold as Carcharodontosaurus.  If it's from those deposits it's from a indeterminate Abelisaurid.   Most teeth from that region are difficult to ID to anything other than a family level.  No skull was ever found with Deltadromeus so we really do not know what the teeth look like.

[Runner64]

I believe Rugops sp. was described from the KK beds but unsure if there may be an additional Abelisaurid or not.

[Dino Dad 81]

Gorgeous tooth! I too had my childhood fascination "mature" in recent years and, even though it's become a bigger hobby for me than it currently is for you, I still really appreciate the nice-looking Kem Kem abelisaur teeth I've got--and occasionally keep adding to them.

[Patrik Djurfeldt]

But Carcharodontosaurus is not an Abelisaur? If so, why can't it be from a juvenile Carch.? There must have been many more juveniles than adults... Is there a feature that doesn't fit?

[Troodon]

3 hours ago, Runner64 said:

I believe Rugops sp. was described from the KK beds but unsure if there may be an additional Abelisaurid or not.

 Well, some paleontologists have said that the indet Abelisaurid in the KK is Rugops and that is based on the maxilla, UCPC PV10, however Ibraham et al (2020) believe the diagnostic features that describes Rugops primus are not in this specimen so they cannot refer this KK maxilla to Rugops sp.   

 

1 hour ago, Patrik Djurfeldt said:

But Carcharodontosaurus is not an Abelisaur? If so, why can't it be from a juvenile Carch.? There must have been many more juveniles than adults... Is there a feature that doesn't fit?

Correct Carcharodontosaurus is not an Abelisaur.   Abelisaurids have a very different tooth morphology than Carcharodontosaurids.  They have a very different overall shape and base profile and your specimen compares well with what has been published.   At some point, your tooth will probably be assigned to the Abelisaurid Rugops sp..  Juvenile Carchs that I've seen are stubby and wide, not narrow and long.

[Patrik Djurfeldt]

2 hours ago, Troodon said:

 Abelisaurids [...] have a very different overall shape and base profile and your specimen compares well with what has been published.   At some point, your tooth will probably be assigned to the Abelisaurid Rugops sp..  Juvenile Carchs that I've seen are stubby and wide, not narrow and long.

Thanks for your info and conclusion. Very helpful.