Lambeosaurus in new JVP

[Brad McFeeters <archosauromorph2@hotmail.com>]

Evans, D.C. & R.R. Reisz, 2007.  Anatomy and relationships of Lambeosaurus 
magnicristatus, a crested hadrosaurid dinosaur (Ornithischia) from the 
Dinosaur Park Formation, Alberta.  Journal of Vertebrate Paleontology 27 
(2): 373?393.

Abstract:  The first detailed description of the lambeosaurine Lambeosaurus 
magnicristatus (Ornithischia: Hadrosauridae) confirms that it is a distinct 
taxon characterized by its comparatively enormous cranial crest, formed 
predominantly by the caudodorsal process of the premaxilla, and an acute 
crest-snout angle. The holotype of L. magnicristatus occurs 
stratigraphically higher than all other Dinosaur Park Formation 
lambeosaurines at the Dinosaur Provincial Park locality. The only referred 
specimen was collected over 170 kilometers southeast of the type locality. 
Correlation of its host stratum with the well-known Dinosaur Park section 
reveals that L. magnicristatus has no biostratigraphic overlap with L. 
lambei and suggests that it replaces L. lambei on a regional scale in 
southern Alberta at the end of ?Dinosaur Park time.? Species-level 
phylogenetic analysis of Lambeosaurinae corroborates the monophyly of 
Lambeosaurus. The genus is characterized by five apomorphies, including a 
procumbent crest, complete enclosure of the ophthalmic canal of the 
laterosphenoid, the presence of a flange on the caudodorsal process of the 
premaxilla that overlaps the nasal in the rostral region of the crest, 
caudal extension of the premaxilla such that it forms the caudal margin of 
the crest, and a unique joint between the rostral nasal and the caudodorsal 
process of the premaxilla. Lambeosaurine phylogeny indicates that the 
development of a hypertrophied cranial crest evolved independently at least 
three times within the clade, suggesting that the crest enlargement is a 
recurring evolutionary trend within Lambeosaurinae.

_________________________________________________________________
Upgrade to Windows Live Hotmail for free today! 
www.newhotmail.ca?icid=WLHMENCA151