What kind of Niger tooth ?

[Brevicollis]

Hello, I was scrolling throug some already sold pieces on some lesser known online auction sites, and came across this tooth.

Sadly, there were no pictures of the sides included.

 

It was sold as an undescribed Spinosaurid tooth, and certainly has the shape of one, but Spinosaurid teeth dont have a carina like that ! Maybe some kind of Ceratosaurid tooth ? Is the species that this tooth belongs to really undescribed ? I have no idea, but maybe you !

[North]

Would need to see side pictures since it looks bit compressed on other side in the pictures. Also mesial carinae is not visible.

In other hand, there seems to be some sort of fluting on other side.

 

There might be lot of undescribed species in Niger and without trustfull exact location it would be Theropod indet.

[Kikokuryu]

This is a tough call.

 

It does have Ceratosauridae-esque affinities which could indicate a Middle Jurassic aged Irhazer Group. However, the preservation does look awfully closer to the Elrhaz Formation. The shape does have some Spinosauridae affinities as well, but the denticles seem way too coarse for a spinosaurid. But I guess it could always be a pathological Suchomimus or an undescribed basal spinosaurid.

 

That said, ceratosaurids are technically not restricted to the Jurassic as Genyodectes is found into the Aptian in Argentina. Unknown if any survived in North Africa during this time, but this is something I overlooked when assuming every ceratosaurid tooth must be Middle Jurassic by default.

 

If it's missing a mesial carinae all together (absent completely, not unserrated), that is consistent with Middle Jurassic morphs found in the El Mers (Morocco) and Isalo III (Madagascar). I don't think that condition is seen in the later Ceratosaurus sp.

[Brevicollis]

50 minutes ago, Kikokuryu said:

basal

What does the term "basal" mean ?

[Kikokuryu]

15 minutes ago, Brevicollis said:

What does the term "basal" mean ?

 

"Basal" is essentially a more formal way of saying "primitive", but less proper than more accurately saying, "early diverging".

 

The two major group of spinosaurids, Spinosaurinae and Baryonychinae have teeth that do not possess large denticles like those of typical theropods. But spinosaurids are megalosauroids, so presumably at some point in time, they had "normal" serrations. But early spinosaurids are a complete mystery as they seemingly appear out of nowhere.

 

On a side note, "derived" is generally used as the opposite of "basal" to indicate something has more "advanced" characteristics of the clade.

Edited June 8 by Kikokuryu