Theropod Premax Tooth

[Dino Dad 81]

Hi all,

 

Curious to know what family you think this tooth likely came from. Could it be Allosaurid?

• From Isalo IIIb in the Mahajanga basin of Madagascar
• CH: About 27.5mm (estimating for tip)
• CBL (carina-to-carina): 14mm
• CBW (mesial side to distal side): 8.5mm
• Mesial Serration Density: 1.9mmm
• Distal Serration Density: 2.1/mm

 

Thank you!!

 

 

 

 

 

 

 

 

 

 

 

 

[Kikokuryu]

Are you 100% certain this is Isalo and not a Majungasaurus from Maevarano fm. There's been a lot of material from both deposits recently, so stuff could get mixed up.

[Troodon]

Agreed, you have the same issue with material from Madagascar that exist with Niger....PROVENANCE.

 

The Mahajanga Basin contains all the Mid Jurassic and Cretaceous deposits.

 

This tooth looks more like a premaxillary of Majungatholus who morphology is very similar to Allosaurus

[Dino Dad 81]

Yes, I was shocked to see how similar they look.

[Dino Dad 81]

I checked and the seller is confident in these being Jurassic. They were posted at two separate times, both times along side a teeth from Razanandrongobe , Bothriospondylus , and/or Archaeodontosaurus. There were a couple of Majungatholus teeth posted as well, but described as being from the Maevarano formation.

[Dino Dad 81]

@Kikokuryu  @Troodon

what do you think?

[Kikokuryu]

6 hours ago, Dino Dad 81 said:

@Kikokuryu  @Troodon

what do you think?

They both still look Majungasaurus to me, but if you're confident in the Jurassic age, then, I guess theropoda indet. or maybe abelisauridae indet. I mean, abelisaurids are I guess super old given that they already appear in the Lower Jurassic with Eoabelisaurus and implies they split off from noasaurids and ceratosaurids even earlier. But it just seems a bit, iffy when you have 2 teeth that look like Majungasaurus. I think there was a paper somewhere that described Majungasaurus-like teeth from the Isalo, but it has finer serration density? Maybe @Troodon remembers, or if I'm imagining it existed, but I recall someone saying something of that nature.

 

Some from my collection for comparison.

 

There is one morphology from the Isalo 3 I have that is peculiar; unfortunately, the tip is gone. Although, the cross-section feels more crocodylomorph than theropod, but I could be wrong. But the serration density seems too fine to be Razanandrongobe. There's a lot of weird things that would have been around the Middle Jurassic.

 

Mesial - 16/5mm

Distal - 16/5mm

CBW: 7.3mm

CBL: 11mm

 

Comparison between Majunga and the Isalo 3.

[Troodon]

7 hours ago, Kikokuryu said:

Maybe @Troodon remembers, or if I'm imagining it existed, but I recall someone saying something of that nature.

Yes there is a paper that describes a few Isalo teeth into morph types.  This one fits Morph 1 which they say might have affinities to an Abelisauridae.  Unfortunately with this tooth we have NO provenance to support the deposit and even if we did how accurate its it.  Remember these deposits are very close to one another.  I agree the tooth preservation looks more like one from the Maevarano Fm than Isalo III.

[doushantuo]

I think this might be the paper Troodon referred to

 

Fanti/Therrien(2007),less than 1 MB

Theropod_tooth_tffassemblages_from_the.pdf

Edited April 16, 2023 by doushantuo

[Kikokuryu]

33 minutes ago, doushantuo said:

I think this might be the paper Troodon referred to

 

Fanti/Therrien(2007),less than 1 MB

Theropod_tooth_tffassemblages_from_the.pdf 828.04 kB · 1 download

I looked around, and I found it; it's this paper. Although, as it's already been said, the tooth in question still look Majungasaurus rather than an Isalo 3.

 

https://www.researchgate.net/publication/257651210_First_description_of_theropod_remains_from_the_Middle_Jurassic_Bathonian_of_Madagascar

Edited April 16, 2023 by Kikokuryu