Pegomastax, new heterodontosaurid from South Africa in new Sereno monograph (free pdf!)

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com

A new taxon in a new monograph at ZooKeys site. The pdf is free!

Paul Sereno (2012)
Taxonomy, morphology, masticatory function and phylogeny of
heterodontosaurid dinosaurs.
ZooKeys 224: 1-225.
doi: 10.3897/zookeys.224.2840
http://www.pensoft.net/journals/zookeys/article/2840/taxonomy-morphology-masticatory-function-and-phylogeny-of-heterodontosaurid-dinosaurs


Heterodontosaurids comprise an important early radiation of
small-bodied herbivores that persisted for approximately 100 My from
Late Triassic to Early Cretaceous time. Review of available fossils
unequivocally establishes Echinodon as a very small-bodied,
late-surviving northern heterodontosaurid similar to the other
northern genera Fruitadens and Tianyulong. Tianyulong from northern
China has unusual skeletal proportions, including a relatively large
skull, short forelimb, and long manual digit II. The southern African
heterodontosaurid genus Lycorhinus is established as valid, and a new
taxon from the same formation is named Pegomastax africanus gen. n.,
sp. n. Tooth replacement and tooth-to-tooth wear is more common than
previously thought among heterodontosaurids, and in Heterodontosaurus
the angle of tooth-to-tooth shear is shown to increase markedly during
maturation. Long-axis rotation of the lower jaw during occlusion is
identified here as the most likely functional mechanism underlying
marked tooth wear in mature specimens of Heterodontosaurus. Extensive
tooth wear and other evidence suggests that all heterodontosaurids
were predominantly or exclusively herbivores. Basal genera such as
Echinodon, Fruitadens and Tianyulong with primitive, subtriangular
crowns currently are known only from northern landmasses. All other
genera except the enigmatic Pisanosaurus have deeper crown proportions
and currently are known only from southern landmasses.

new release with video:
http://phys.org/news/2012-10-fanged-dwarf-dinosaur-southern-africa.html

(NOTE: One glitch in the name :  mastax "jaw" is feminine in Greek so
the name should be Pegomastax africana to follow the letter of the
rules.)