Some Kem Kem oddballs

[gigantoraptor]

Hello all

 

Yesterday, I could add a few more items to my ever expanding Kem Kem collection. I am very excited with these pieces, but some of them I have a lot of questions by. 

 

1) This weird lungfish toothplate. Currently there are 3 species of lungfish known from the Kem Kem beds. 

The first and most common species is Neoceratodus africanus, of which the toothplates are described as 'Toothplates with deeply incised ridges'.

The second species is Ceratodus humei, described as 'small toothplates with low ornamentation and only four low ridges'

Third species is Arganodus tiguidensis, described as 'small toothplates with a characteristic radiating pattern of ridges'

I have the first two species, and have only rarely seen Arganodus popping up in the Kem Kem beds.

 

But now I got this tooth:

 

This tooth doesn't match any of the descriptions of the three regular species of lungfish. The only match I could find was Lupaceratodus useviaensis, a extinct lungfish species from the Cretaceous Galula formation in Tanzania. My tooth is a lot bigger however, standing at 4.5 cm and having 8 ridges instead of the 6 of the Tanzanian specimen.

 

So what could this one be? I'm thinking it's most likely a new species or a species new to the location. I would be happy to hear the opinions of the people on here.

 

2: Double barbed Onchopristis barbs

 

A while ago I made a topic regarding one of these barbs. The general consensus then was that it was a rare pathology, but now I have multiple specimens with double barbs all found at the same location. They are all in better quality then my first specimen and with the exception of some small repairs, no work has been done on them. Would you all still think this is a pathology? How large is the chance that multiple of these would be found in the same spot? All of these are in the normal size range of Onchopristis barbs.

 

Link to previous topic:

 

 

 

3) This is probably a piece of chunkosaurus. Not sure if it's still in any way recognizable. It was sold as Coelacanth skull bone, but I'm more interested in the weird patterns on the bone. I've been searching a long time for traces of invertebrates from the Kem Kem beds (they don't really fossilize unfortunatly) and I think this time I might have found some. Could these tracks (marked in red) be tunnels of some kind of burrowing creature? If anyone recognizes the weird texture on this piece of bone that would be really helpfull.

 

 

 

 

Thanks in advance

 

Edit: Sources of quotes and image:

‘Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco’. Geraadpleegd 6 juni 2022. https://zookeys.pensoft.net/article/47517/.

Gottfried, Michael, Nancy Stevens, Eric Roberts, Patrick O’Connor, en Remigius Chami. ‘A new Cretaceous lungfish (Dipnoi: Ceratodontidae) from the Rukwa Rift Basin, Tanzania’. African Natural History 5 (1 december 2009): 31–36.

 

Edited June 6, 2022 by gigantoraptor

[Fossildude19]

Regarding the lungfish tooth - you might try to get a hold of this paper:

 

"Developmental Anomalies in the Tooth Plates and Jaw Bones of Lungfish" - A. Kemp

 

 

 

 

 

[gigantoraptor]

31 minutes ago, Fossildude19 said:

Regarding the lungfish tooth - you might try to get a hold of this paper:

 

"Developmental Anomalies in the Tooth Plates and Jaw Bones of Lungfish" - A. Kemp

 

It was a very interesting read, and now I really want a pathological example of a lungfish tooth from the Kem Kem beds as well.

 

Unfortunatly I don't think this tooth is pathological. The paper talks about doubled or split ridges, doubled cusp rows, missing ridges... none of those I think appear on this particular tooth.

[Tidgy's Dad]

Interesting items.

I have seen quite a lot of the double barbed Onchopristis. 

Don't think they're pathological, though it's possible to have a common pathology. 

Maybe a different species or different age, sex, or position in the mouth? 

[gigantoraptor]

23 hours ago, Tidgy's Dad said:

I have seen quite a lot of the double barbed Onchopristis. 

 

Interesting, I don't think I've seen more than 6 outside of my own collection and papers.

 

23 hours ago, Tidgy's Dad said:

Don't think they're pathological, though it's possible to have a common pathology. 

One possible idea I read about was that these barbs belonged to two different populations of Onchopristis (from different oceans) that just happened to overlap in the Kem Kem beds. 

[siteseer]

I guess it's possible about two O. numidus populations intermixing but the species is known only from north Africa so that's not much of a geographic range.  Maybe there was some barrier separating populations but a temporary rise in sea level or a storm briefly allowed them to get together somehow. 

 

You mentioned in the other thread that your first specimen had a twisted second barb so that one was likely a pathological one.  Thinking about it all again, it's also possible that it's just a rare genetic expression of a trait an ancestor, an atavism.  I used to see boxes of those spines at Tucson and that had to be a tiny fraction of what was for sale in Europe, and of course, Morocco.  More have been noticed in the past couple of years because more people have their eyes open for them now.  Some of the broken teeth or those coated in gunk/matrix might have had a second barb but nobody noticed.

[abyssunder]

It looks like specimen 3 has bioerosional marks. Can you prep it a little?

[Troodon]

If this adds to the conversation: ref: Onchopristis double barb

From the abstract

A single crown of sawfish rostral ‘tooth’ with at least two barbs along its posterior margin is comparable with Onchopristis dunklei from the Woodbine Formation of Texas and Atlanticopristis equatorialis from the Alcântara Formation of Brazil. However, it is regarded here as an aberrant Onchopristis numidus, the typical form from North Africa. An aberrant morph of O. numidus is considered pathological. The taxonomic utility of barb number in pristid rostral ‘teeth’ is discussed. The genus and species Australopristis wiffeni gen. et sp. nov is erected to accommodate some multi-cusped rostral teeth from the Late Cretaceous of
New Zealand.

 

martill2012.pdf

[gigantoraptor]

On 6/7/2022 at 9:40 PM, siteseer said:

I guess it's possible about two O. numidus populations intermixing but the species is known only from north Africa so that's not much of a geographic range.  Maybe there was some barrier separating populations but a temporary rise in sea level or a storm briefly allowed them to get together somehow. 

 

You mentioned in the other thread that your first specimen had a twisted second barb so that one was likely a pathological one.  Thinking about it all again, it's also possible that it's just a rare genetic expression of a trait an ancestor, an atavism.  I used to see boxes of those spines at Tucson and that had to be a tiny fraction of what was for sale in Europe, and of course, Morocco.  More have been noticed in the past couple of years because more people have their eyes open for them now.  Some of the broken teeth or those coated in gunk/matrix might have had a second barb but nobody noticed.

The weird thing about that would be that these were all found at the same site, with, from what I've seen, none of the regular barbs.

 

 

On 6/7/2022 at 10:14 PM, abyssunder said:

It looks like specimen 3 has bioerosional marks. Can you prep it a little?

Unfortunatly not, I has been consolidated and the sand won't come loose. I might get it prepped a bit further if I ever have other pieces that need some prep.