Re: Kickboxing Cassowary

[dinoboygraphics@aol.com]

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