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Varanus komodoensis feeding
D'Amore DC, Moreno K, McHenry CR, Wroe S (2011) The Effects of Biting and
Pulling on the Forces Generated during Feeding in the
Komodo Dragon (Varanus komodoensis). PLoS ONE 6(10): e26226.
In addition to biting, it has been speculated that the forces resulting from
pulling on food items may also contribute to feeding
success in carnivorous vertebrates. We present an in vivo analysis of both bite
and pulling forces in Varanus komodoensis, the
Komodo dragon, to determine how they contribute to feeding behavior.
Observations of cranial modeling and behavior suggest that V.
komodoensis feeds using bite force supplemented by pulling in the
caudal/ventrocaudal direction. We tested these observations using
force gauges/transducers to measure biting and pulling forces. Maximum bite
force correlates with both body mass and total body
length, likely due to increased muscle mass. Individuals showed consistent
behaviors when biting, including the typical
medial-caudal head rotation. Pull force correlates best with total body length,
longer limbs and larger postcranial motions. None of
these forces correlated well with head dimensions. When pulling, V. komodoensis
use neck and limb movements that are associated with
increased caudal and ventral oriented force. Measured bite force in Varanus
komodoensis is similar to several previous estimations
based on 3D models, but is low for its body mass relative to other vertebrates.
Pull force, especially in the ventrocaudal
direction, would allow individuals to hunt and deflesh with high success
without the need of strong jaw adductors. In future
studies, pull forces need to be considered for a complete understanding of
vertebrate carnivore feeding dynamics.
>From the Conclusions:
lthough the V. komodoensis behavior model is unique amongst extant taxa, it can
shed light upon the feeding behaviors of extinct
ziphodont tetrapods, especially theropods , . Supposedly some theropods
also had relatively low bite forces given their size
and cranial morphology . As in V. komodoensis, such low bite forces may have
been supplemented by a strong pull and would not
hinder the animal's ability to modify flesh. Both tooth mark data and cranial
morphometrics suggest that theropods used caudally
oriented force during feeding -. Modeled neck musculature implies that
some theropods (i.e. Ceratosaurus and Allosaurus)
also displayed significant ventroflexion, suggesting the "pulling" or "raking"
of ziphodont teeth through the use of these
postcranial muscles .
Thomas R. Holtz, Jr.
Email: firstname.lastname@example.org Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
Faculty Director, Science & Global Change Program, College Park Scholars
Mailing Address: Thomas R. Holtz, Jr.
Department of Geology
Building 237, Room 1117
University of Maryland
College Park, MD 20742 USA