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Re: Kickboxing Cassowary




So for those of you who are happy to throw out the idea of dromaeosaurs "slashing" at their prey...why can a blunt-tipped claw like a cassowary #2 pedal claw disembowel animals, and are the attacks described as slashing? (e.g. http://www.amazingaustralia.com.au/animals/cassowary-attacks.htm) And given that, what precisely would prevent the much more blade-like dromaeosaur claws from being as (if not substantially more) effective?


Now, granted that on-line discussions may not adhere to the strictest of medical standards, but people are claiming on the list (with apparent seriousness) that keratin cannot maintain a sharp edge, when every beak in existence that can cut through flesh derives that edge from...keratin.

I'm sure that a metal cast of a cassowary claw would fail to "slash" pork rump, but that illustrates one serious flaw in the test design (even ignoring the absence of the keratin sheath): dissembowling is puncturing/ripping a relatively thin wall of muscle and connective tissue to get at the internal viscera. Very much different from attempting to slice through a dense belly of muscle. Dissembowelment can occur from blunt objects with enough force behind them (e.g. cassowary claws) and the sharp tips of tiger claws (which otherwise lack a cutting edge) are quite proficient at it.

I grant you that it would be distasteful (although possibly popular on tv) to try a similar experience on the side of the abdomen
of a recently dead deer, but that would be a far more plausible physical analogy.




Scott Hartman
Science Director
Wyoming Dinosaur Center
110 Carter Ranch Rd.
Thermopolis, WY 82443
(800) 455-3466 ext. 230
Cell: (307) 921-8333

www.skeletaldrawing.com


-----Original Message----- From: David Marjanovic <david.marjanovic@gmx.at> To: DML <dinosaur@usc.edu> Sent: Wed, 1 Oct 2008 4:42 am Subject: Re: Kickboxing Cassowary


Given the number of dinosaurian lineages that appear to have had >
gastralia, disembowlingÂ
may not have been as simple as it is with us mammals and our
powder-puff > bellies.Â
Â
Ornithischians (and sauropods) lacked gastralia. Â