Kem-Kem Beds Fossils Up For Id

[sander]

Hi All,

These fossils are my Kem-Kem Beds collection, but I wonder what you guys think of the ID I gave them, I'm not really sure if the names are right and maybe some should be renamed?

Photo 1-5:

could be the front halve of the left ilium or the rear halve of the right ilium of (i think) a Theropod. looking at the size I think it is not Spinosaurus or Carcharodontosaurus, altough maybe it was from a younger individual.

let me know what you think that this might be,

Gr,

Sander

[sander]

From left to Right:

1: partial fish tooth? don't know which gen. or sp.

2: Coloborhynchus moroccensis?

3: Sarcosuchus imperator?

4: Dermal scute of Rebbachisaurus garasbae?

5: Rebbachisaurus garasbae?

6: Rebbachisaurus garasbae? (look more like a Nigersaurus tooth in my opinion, but those have not yet been found in morocco I think?)

7: Spinosaurus aegyptiacus? (Might be Suchomimus becasue of the shape?)

8: Carcharodontosaurus saharicus?

9: Deltadromeus agilis? (or Rugops like abelisaurus? o something else?)

Thanks in advance,

Sander

[Diceros]

Sander - Thanks so much for the ID of the flat disc in #4 (a sauropod dermal scute) - I would never have thought of that! I bought one at Tucson in 2013, and it's been driving me crazy ever since. I really love the Kem Kem fauna, it's rich in both diversity and habitat (terrestrial, fluviatile, and the primary shallow-water marine fauna).

[sander]

Hi Diceros,

I don't know if they really are dermal scutes of Rebbachisaurus, but they are being sold under that name everywhere.

Maybe check out what the rest of the forum has to say about it before making a new label for it.

Gr,

Sander

[Troodon]

3 - unknown croc tooth, Sarcosuchus imperator has yet to be described from the Kem Kem

4 - These are sold as sauropod dermal scutes but if I had to guess are not. The ones I've seen in papers are a bit more irregular and not as circular in shape.

5 & 6- These are sold as Rebbachisaurus and most likely are but unless found in the skull there is no way to prove its not from another undescribed Diplodocoidea in the Kem Kem. The difference in the two teeth is most likely positional in the jaw and not Nigersaurus which has not been described from the Kem Kem.

7 - Spinosaurus

8 - Carcharodontosaurus

9 - Abelisaurid like tooth. Deltadromeus agilis has been described but without a skull so there is no knowledge of what the teeth looks like. Rugops and Abelisaurus sp. has not been described from the Kem Kem.

[Diceros]

Isn't Deltadromeus agilis Sereno et al., 1996 from Kem Kem the same thing as Bahariasaurus ingens Stromer, 1934, from the contemporaneous Bahariya Oasis in Egypt?

Just to get the full names on the record:

Spinosaurus aegypticus Stromer, 1915

Carcharodontosaurus saharicus (Deperet & Savornin, 1927)

Rebbachisaurus garasbae Lavocat, 1954

Don't make me do all the snarge crocs.

[Troodon]

Isn't Deltadromeus agilis Sereno et al., 1996 from Kem Kem the same thing as Bahariasaurus ingens Stromer, 1934, from the contemporaneous Bahariya Oasis in Egypt?Just to get the full names on the record:Spinosaurus aegypticus Stromer, 1915Carcharodontosaurus saharicus (Deperet & Savornin, 1927)Rebbachisaurus garasbae Lavocat, 1954Don't make me do all the snarge crocs.

D. agilis that was described from the Kem Kem did not contain a skull so its impossible to identify a tooth to that species. There is a debate on where to classify Bahariasaurus from Egypt but I'm not the one say its the same species from the Kem Kem find until knowledgeable paleontologist make that call. Were teeth found with the Egyptian find?

There is lots of uncertainty with the theropods of north Africa especially those of the Kem Kem. For example, I saw a 2010 paper on a Carch. skull element with a different morphology that was very distinct from Carcharodontosaurus saharicus. They called it a new Carcharodontosaurid from the Kem Kem. Another paper examined a group of Spinosaurus teeth and noted three different ornamentation morphologies. One had strong vertical ridges on both sides, a second group had strong ridges on one side and weak ones on the other and a third set were smooth. So the conclusions raised the question are there more than one species of Spinosaurus in the Kem Kem or are we just looking at jaw to jaw variation.

Bottom line we know very little from this region and should not be quick to label everything in concrete.

[sander]

Thanks for the ID, have you got any ideas on the ilium?

Gr,

Sander

[Troodon]

I cannot help you on the ilium. Very little comparative material has been identified to draw conclusions as to species. Try contacting Nizar Ibrahim (nibrahim@uchicago.edu) who recenty co-authored the paper on Spinosaurus. He might give you a response.