Marshosaurus?

[Anomotodon]

Recently acquired this very nice tooth from Morrison fm, Moffat County, Colorado. I think it is Marshosaurus, am I right? I am afraid to clean it right now because the tooth is very fragile.

Total length is ~1.6 cm. Ruler is in inches, so 1 line=1/16 inch=~1.5 mm, so distal serration density looks to be around 4/mm; mesial carina seems to end at bottom ~3/4 of the tooth, as I understand, these are Megalosaurid characteristics. Although I couldn't find any info on other medium-small sized theropods, like Tanycolagreus, Coelurus or Ornitholestes.

Thank you for help!

@Troodon

By the way, took those pictures with AmScope USB microscope, very useful tool for detailed teeth

 

[Troodon]

Nice tooth.  Isolated teeth from the Morrison are very difficult to ID just because nothing is published.  Being so small does not help.  I can try to compare it to info from the Lourinhã Fm of Portugal which is similar to the Morisson but need more info.  Can you determine the density of the mesial edge?  I also need the width and depth of the base, any chances since its in matrix.  Prefer all measurements in mm.

 

[Miocene_Mason]

12 minutes ago, Troodon said:

nothing is published.

150 years of research and we still don’t have publications on teeth? Sad state of affairs. Someone needs to get a PhD student on that.

[Troodon]

3 minutes ago, WhodamanHD said:

150 years of research and we still don’t have publications on teeth? Sad state of affairs. Someone needs to get a PhD student on that.

Well nothing may be an overstatement but very very little is around.  Love to see some publications if they are around. The only one I know is one Ceratosaurus 

[Anomotodon]

Was able to successfully prepare it, so here are more measurements: 

distal density ~4.5/mm

mesial density ~4.5/mm (it seems that serrations end completely right near the tip, carinae extends maybe 2/3 further but with no serrations, doesn't seem that they were broken off)

width of the base 11 mm

height ~17 mm

[Troodon]

Great job thanks, let me look at all the info and compare it to some morph types.  No idea if I can get closer to an ID but will try. 

[Max-fossils]

10 hours ago, Troodon said:

Great job thanks, let me look at all the info and compare it to some morph types.  No idea if I can get closer to an ID but will try. 

[Troodon]

Sorry missed it I need to do a CBR ratio need 

CBW : ? CBL is 11mm

 

Its not Marshosaurus since the serration density is the same.  Leaning to an Allosaurid at this point.

[Anomotodon]

Thank you! Hard to tell exactly because it is in matrix, but CBW is about 3 mm, CBW:CBL=0.27.

Actually, mesial density is 4.5 only at the very apical part, check the pictures. It seems that it decreases slightly before going to 0. Do Allosaurids have such a short mesial carina?

[Troodon]

The Allosaurus tooth morphologies from Portugal show the mesial carina extending down some half others 2/3.  I cannot find a good match with that very small thickness compared to length of the base of tooth possibly because it's been compressed in the matrix or because it's such a small tooth.  The shape of the tooth, serration density and mesial carina all speak to Allosaurid.