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Coding Tenontosaurus species



Dear ListMembers,
last night I've added Tenontosaurus to my Iguanodontia analysis and in view
of this I've also added some characters. One of this is the
premaxilla/lacrimal contact: absent =0 present=1. In Lesothosaurus and
Ornithischia at large the posterolateral process of the premaxilla doesn't
reach the lacrimal, this condition is present also among small Ornithopods
(es. Thescelosaurus, Parksosaurus, Hypsilophodon etc..) and was used to
unite Hypsilophodontids and Tenontosaurus (Wieshampel and Heinrich, 1992).
But in his paper on Tenontosaurus dossi Dr. Winkler stated that the
posterolateral process of premaxilla extend back to contact the lacrimal in
T. dossi as in Camptosaurus and other Iguanodontia, and in his phylogenetic
analysis coding T. dossi and T. tilletti with state '1' for this character.
In all the illustration that I've about T. tilletti skull the posterolateral
process of premaxilla doesn't reach the lacrimal, moreover HP Tracy Ford in
his book "How to draw Dinosaur book.2" drawing the skull of  T. tilletti and
T. dossi has lacking a premaxilla/lacrimal contact instead present in a
specimen from Oklahoma, perhaps OMNH 16562 assigned to Tenontosaurus sp.
Please could someone tell me information to resolve this?

By
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Alessandro Marisa
Via Achille Grandi n°18
38068 Rovereto (TN) ITALY
Email: iguanodontia@yahoo.it
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