Re: Claw function in Deinonychus

[Tim Williams <twilliams_alpha@hotmail.com>]

Michael Habib wrote:

> I am pretty certain (those by no means absolutely so) that the 
> disemboweling blows delivered by ratites are really abdomenal ruptures 
> caused by the extreme force of the blow, rather than a slicing attack.  If 
> anyone can confirm/deny this based on some published observations, that 
> would be great.  I don't have any on hand right this moment.

When it comes to cassowaries it's 'all of the above'.  Slicing attacks are 
documented, as well as punctures, broken bones and abdominal ruptures...

"The foot of a cassowary has three toes (Fig. 2): the outer and middle with 
pointed nails, and the innermost with a spike-like claw up to 12 cm long and 
3 cm wide at the base.  The foot can be used as a formidable weapon by 
extension of the lef in a quick kick forward or to the side, capable of 
causing serious injuries such as lacerations, puncture wounds and ruptures 
of internal organs. (Kofron, 1999; p.376)?

Reference

Kofron, C.P. (1999).  Attacks to humans and domestic animals by the southern 
cassowary (_Casuarius casuarius johnsonii_) in Queensland, Australia. J. 
Zool. (Lond). 249(4): 375-381.

Human fatalities as a result of cassowary attacks are exceedingly rare - at 
least in Australia (where the cassowary has a very limited distribution).  
Ostriches are also reported to physically attack and kill humans.  The 
really big ratites are all extinct (moas, elephant birds), and the only 
danger a kiwi would pose to a human would be if you happen to trip over one 
in the dark.  Emus can deliver a nasty peck (I speak from experience).

> 1) Do not forget about the function of the forelimbs in predation.  They 
> manual claws are nearly as large and dangerous in many dromeosaurids as the 
> enlarged pedal claw.

However, the manus of dromaeosaurs was capable of only limited mobility - as 
Gishlick's work demonstrated.  The fingers are long and relatively 
inflexible.  But I fully agree with the idea that the manual claws were 
deadly devices for predation, and that the forelimbs played an active role 
in holding and dispatching prey.

Cheers

Tim