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Nothronychus graffami

Congratulations to Lindsay and her team:


Zanno, L.E., D.D. Gillette, L.B. Albright, and A.L. Titus. 2009. A new North
American therizinosaurid and the role of herbivory in 'predatory' dinosaur
evolution. Proc. R. Soc. B published online before print July 15, 2009,


Historically, ecomorphological inferences regarding theropod (i.e.
'predatory') dinosaurs were guided by an assumption that they were
singularly hypercarnivorous. A recent plethora of maniraptoran discoveries
has produced evidence challenging this notion. Here, we report on a new
species of maniraptoran theropod, Nothronychus graffami sp. nov. Relative
completeness of this specimen permits a phylogenetic reassessment of
Therizinosauria-the theropod clade exhibiting the most substantial
anatomical evidence of herbivory. In the most comprehensive phylogenetic
study of the clade conducted to date, we recover Therizinosauria as the
basalmost maniraptoran lineage. Using concentrated changes tests, we present
evidence for correlated character evolution among herbivorous and
hypercarnivorous taxa and propose ecomorphological indicators for future
interpretations of diet among maniraptoran clades. Maximum parsimony
optimizations of character evolution within our study indicate an ancestral
origin for dietary plasticity and facultative herbivory (omnivory) within
the clade. These findings suggest that hypercarnivory in paravian dinosaurs
is a secondarily derived dietary specialization and provide a potential
mechanism for the invasion of novel morpho- and ecospace early in
coelurosaurian evolution-the loss of obligate carnivory and origin of
dietary opportunism.


Here is the basic phylogeny (formatted via Mike Keesey's Text Tree Maker

   |  `--Tyrannosauroidea

Note that the root of Maniraptoriformes (Ornithomimosauria crownward) would
seem to be non-hypercarnivorous.

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
Fax: 301-314-9661               

Faculty Director, Earth, Life & Time Program, College Park Scholars
Faculty Director, Science & Global Change Program, College Park Scholars
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