Kellner revises Pteranodon: new genera

["Thomas R. Holtz, Jr." <tholtz@umd.edu>]

http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0001-37652010000400025&lng=pt&nrm=iso&tlng=en

KELLNER, Alexander W.A.. Comments on the Pteranodontidae (Pterosauria, 
Pterodactyloidea) with the description of two new species.
An. Acad. Bras. Ciênc. [online]. 2010, vol.82, n.4, pp. 1063-1084. ISSN 
0001-3765.  doi: 10.1590/S0001-37652010000400025.

Abstract
Considered one of the best known flying reptiles, Pteranodon has been subject 
to several reviews in the last century. Found
exclusively in the Upper Cretaceous Niobrara Formation and Pierre Shale Group 
11 species have been attributed to this genus
(excluding the ones presently regarded as representing Nyctosaurus). While 
reviewers agree that this number is inflated, there is
disagreement on how many species can be identified. The last review recognized 
only two species (Pteranodon longiceps and Pteranodon
sternbergi) both being sexually dimorphic. Based on several cranial features, 
some specimens previously referred to the genus
Pteranodon are re-evaluated leading to the recognition of the following 
species, two of which new that are described here:
Pteranodon longiceps, Geosternbergia sternbergi, Geosternbergia maiseyi sp. 
nov., and Dawndraco kanzai gen. et sp. nov. They differ
mainly by features such as the direction and extension of the frontal crest, 
the angle and extension of the posterior process of the
premaxillae, the shape and extension of the lower temporal fenestra and the 
length and proportion of the rostrum. The procedures to
recognize a pterosaur species are also discussed here, and must take into 
account primarily morphology, in conjunction with
stratigraphic and geographic data. Although well aware that changes in 
morphology not always reflect taxonomy, the lack of
stratigraphic data and the limited number of specimens that can be confidently 
assigned to one species hampers our understanding on
the morphological variations as a function of ontogeny, individual variation 
and sexual dimorphism. Although the present study has
not eliminated the possibility to recognize such differences, caution is needed 
before models are generalized for pterosaurs.

Pdf at:
http://www.scielo.br/pdf/aabc/v82n4/25.pdf

PS, a request: if this thread morphs into a discussion on etymology, PLEASE 
change the subject line!!

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA