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Re: cobra analogy

> Animals that spit or otherwise deliver venom
> might employ some visual device which causes intended victims to look at the
> animal.  This allows the venom to be delivered into a sensitive area - the
> eyes, disabling the prey or rendering it much less able to fight back or even
> flee.  The Indian cobra is one such example, able to spit venom 2 meters or
> more, with a display device ("hood" with special markings on it).

The special markings on the cobra hoods that I've seen (and presumably also on
the Spitting Cobra) are on the _BACK_ of the head. The markings are evolved to
resemble eyes, and the spread hood makes the animal's head look larger and more
imposing. The cobra actually turns its back to the threat, and thus it would be
impossible for the cobra to spit venom at any animal looking at the markings.

> In Greg Paul's "Predatory Dinosaurs of the World", he relates that some have
> proposed that dilophosaurus had a snout that was too weak to attack prey, and
> that it must have used its feet to kill or mostly scavenged for food.

It's snout may have been too weak to attack large prey, but perhaps
dilophosaurus specialized in smaller prey. Like a lion, it may have pinned an
animal to the ground with its weight, and killed by biting the vulnerable neck.
I think its unnecessary for a 20-foot long animal to require venom to kill.
Evolution seldom produces unnecessary features.

Scott Horton
Geophysicist/Computer Programmer