Identification of Some Hadrosaur Teeth from North America

[Troodon]

Although identification of Hadrosaurid teeth in North America is very difficult or impossible some older publications by John Horner give us some information to help us with a few.  The information goes back a bit so there might be some new understanding but will share what is published.   If anyone has publications that can add to the dentary information of teeth from North America please feel free to post it.

 

Horner notes that on dentary teeth all Saurolophinae teeth have diamond-shaped crown whereas Lambeosaurinae teeth are more elongate see figure 13.4.  So one may not be able to assign it to a specific genus but a Subfamily may be possible.  Maxillary teeth can be different but not discussed..

Saurolophinae include: Edmontosaurus, Kritosaurus, Gryposaurus, Brachylophosaurus, Maiasaura, Brachylophoslaurus

Lambeosaurinae include: Lambeosaurus, Parasaurolophus, Corythosaurus, Hypacrosaurus

 

 

I would suggest that only complete teeth with fairly good preservation be used in any attempt to identify these teeth. 

 

Hell Creek & Lance Formation

 

A publication on Edmontosaurus diversity in North America by N. Campione and D. Evans 2011 concluded that all there is only one species of hadrosaur in these faunas so all teeth found can be assigned to Edmontosaurus annectens.   

 

Judith River Formation

 

Horner identifies dentary teeth with small denticles as Gryptosaurus  (However not sure its been described from JRF so I would question this assignment)

 

 

 

 

Two Medicine Formation

 

Horner identifies dentary teeth with big denticles as Gryptosaurus latidens

 

 

Horner identifies dentary teeth with very small denticles as Prosaurolophus maximus

 

 

Hypacrosaurus stebingeri - 

 

 

 

 

The figure below shows variations with several species of dentary teeth

 

 

 

Book:  John Horner: Evidence of diphyletic origination of the Hadrosaruian in Dinosaur Systematics Approaches & Perspective Currie & Carpenter Chapter 13

Book: Dinosaurs under the Big Sky by Jack Horner 2001

[jpc]

as troodon mentions, this is only for unworn teeth.  99 % of all the hadrosaur teeth I find are worn.  It is a thrill to find a complete one.