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Identification of Torvosaurus Teeth


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Torvosaurus tanneri is one of the apex theropods found in the Morrison Formation and has the largest dentition.

Teeth of this and other theropods are commonly sold through online Dealers, Auction Houses and at Fossil shows. Just because a site/dealer sells Jurassic material does not guarantee accuracy.  Variation of the teeth in the jaw also adds to the complexity.  Isolated teeth from the Morrison Formation are very difficult to diagnose and all require an understanding of additional characteristics than normal, in hopes of properly identifying them.  I have not been able to find any publication that describes the teeth of this species so it's beyond me how Sellers identify them other that they are big and look like Rex :(.   The best I can do is to look at reference publications which include similar teeth from Portugal which describes Torvosaurus cf. gurneyi.  Should be pretty close to Torvosaurus tanneri of the Morrison.   A recent paper by C. Hendrickx has published a study of a couple of these teeth from the Morrison formation which I've added in this edit.

 

The following information is needed to help identify these teeth: 

 

1)Photo of tooth both sides and one of the mesial edge

2)Serration density of both edges, 5 mm wide at midline

3)Dimensions: CBL, CBW, CH

4)Locality: State and County

1974486799_TheropodtoothID.thumb.jpg.4d0963e7b26888dc1b7ccbf1208bcdc5.jpg

Information from the Hendrickx study 2 teeth

DSDI: 1

Distal Density 7.5 and 8 / 5 mm

Mesial Density 7.5 and 8 / 5 mm

CHR:  2.4 Avg

CBR:   0.44 Avg

 

 

 

Mesial teeth  

CHR : appox 2.75   Crown height ratio CH÷CBL

CBR : appox .65   Crown base ratio CBW÷CBL

Mesial Density:  7 to 8 per 5 mm, Distal Density: 7 to 8 per 5 mm all at midline.  DSDI = 1 ( DSDI : Denticle size density index =  Mesial Density ÷ Distal Density)

Mesial and distal denticles decrease in size towards the base of the crown and similarly towards the crown apex.

Mesial serrations occupy 55 to 65% of the crown height

Distal serrations extend to below the cervex

Cross-section base :  sub-circular

 

Lateral teeth 

CHR : 1.4 (short crowns), 2.8 (elongated crowns)  Crown height ratio CH÷CBL

CBR :  .35 to .65   Crown base ratio CBW÷CBL

Mesial Density:  6 to 9.5 per 5 mm, Distal Density: 6 to 9.5 per 5 mm all at midline.  DSDI = 1 ( DSDI : Denticle size density index =  Mesial Density ÷ Distal Density)

Mesial serrations occupy 40 to 80% of the crown height

Distal serrations extend to below the cervex

Wide transverse undulations covering most of the tooth are common  

 

Screenshot_20180830-101639.thumb.jpg.50202ddc3f81f131ace67d6869c117e8.jpg Isolated tooth of Torvosaurus cf. gurneyi  in lingual (C1), labial (C2), mesial (C3), and distal (C4) views, with details of mesial (C5) and distal (C6) denticles, and enamel texture (C7) in lateral views.

 

Reconstruction  Skull of Torvosaurus from Utah Museum of Natural History.

So you can see variation of the teeth in the jaw

DSC_0158.thumb.jpg.8136c298aa6d3f1cbab759624ad3482e.jpg

 

Reference:

Hendrickx, C., Mateus, O., and Araújo, R. 2015. The dentition of megalosaurid theropods. Acta Palaeontologica Polonica 60 (3): 627–642.

Screenshot_20180829-100407.jpg

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The Amateur Paleontologist

Thanks for this :) Will be very useful for the lucky few owners of Jurassic megalosaurid teeth ;) 

-Christian

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Jour.Iberian Geol.43/1-2017

New data on the anatomy of Torvosaurus and other remains of megalosauroid (Dinosauria, Theropoda) from the Upper Jurassic of Portugal

Authors

Authors and affiliations

E. Malafaia

P. Mocho

F. Escaso

F. Ortega

indeterminate isolated dentition figured

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Funnily enough,the isolated dentition figured is from Malafaia (2017)et al,and (re)using this imagery might constitute a significant breach of copyright

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3 hours ago, doushantuo said:

Funnily enough,the isolated dentition figured is from Malafaia (2017)et al,and (re)using this imagery might constitute a significant breach of copyright

The images are from an open paper of Hendrickx 2015

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You are absolutely right,and I was dead wrong.Apologies to all concerned,and in particular to you

Malafaia et al do have a figure which contain teeth figured from C1 to C7,but they are different.

 

 

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45 minutes ago, doushantuo said:

You are absolutely right,and I was dead wrong.Apologies to all concerned,and in particular to you

Malafaia et al do have a figure which contain teeth figured from C1 to C7,but they are different.

 

 

No apology needed happy you are keeping us on our best behavior

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