Morrison Megalosaurid or Allosaurid?

[TeethCollector]

I bought this tooth and the seller named this 'Allosaurus', but the serrations are more dense and the mesial carina stops far before the root. Is this a megalosaurid or allosaurid? Anyone can help?

 

The base width/base length = 4.2mm/12.3mm 

 

Locality: Morrison formation, Wyoming

 

 

 

 

 

 

 

 

 

 

 

 

 

Distal carina

 

Mesial carina

 

[Troodon]

Isolated teeth can be difficult, give it a shot.

 

Need the following information:

 

 

[TeethCollector]

7 minutes ago, Troodon said:

Isolated teeth can be difficult, give it a shot.

 

Need the following information:

 

 

 

 

Mesial carina : 20 / 5mm

Distal carina: 20 / 5mm

 

CBW = 4.2mm

CBL = 12.3mm

CH = 29mm

AL = 31mm

 

mesial serration stops far before root

 

 

[Troodon]

Thank you.  Well I was hoping it was a Marshosaurus but strike that with a DSDI of 1.   Mesial edge serration density needed to be much higher than distal.    I just wanted to quickly get back to you.   I'll keep investigating.

[TeethCollector]

Yes @Troodon that's the one makes the investigation harder. I guess there are 2 megalosaurids from morrison: marshosaurus and torvosaurus , and torvosaurus has 1:1 mesial-distal ratio I guess? 

[Troodon]

15 minutes ago, TeethCollector said:

guess there are 2 megalosaurids from morrison: marshosaurus and torvosaurus

 Marshosauris is a Piatnitzkysauridae which is a Meglosauroidae

 

Key Features: Lateral Tooth, Mesial carina is central positioned, no twist, very blade like, DSDI of 1 and Ratios CHR and CBR fall well into what is described as a meglosauroidae.  

So its not a Marshosaurus but fits into the Morphspace that includes Torvosaurus.   I cannot definitively say its a Torvo but its very possible. 

 

FYI

When measuring the CH of a theropod tooth its from the base of the distal edge to the tip.   I made some adjustments, not a big factor in this identification.

[TeethCollector]

Thank you Troodon.. I really appreciate your help.