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Re: Long-necked stegosaur coming out in Proceedings B
Don Ohmes wrote:
> I share and likely over-match your lack of anatomical
> knowledge, but would be surprised if they could not pivot
> effectively. I somehow doubt that "evasive action" was one
> of their talents, though.
It's not really a 'talent'. Putting as much distance between yourself and a
potential predator is just common sense.
> That said, an incremental difference in individual neck
> length will logically have a negligible effect on predator
> detection, which begs the question; what model of evolution
> can be used to create a long neck using enhanced
> predator-detection as a primary driver?
Homeotic transformations, such as those mediated by mutations in Hox genes,
would allow whole segments (in this case, individual vertebrae) to be added
wholesale to the cervical column. A substantial increase in the total length
of the neck would therefore occur quite rapidly. So I don't necessarily agree
that changes in neck length would "have a negligible effect on predator
detection". (You could also use your line of reasoning to argue that the same
changes would have a negligible effect on foraging ability, because the
proximate advantage in browse height would be fairly minimal per each
incremental increase in neck length.)
Jason (firstname.lastname@example.org) wrote:
> While possible, I'd have to wonder why the rear end of the
> tail would be facing the predator, rather than the side.
> Most animals that use their tails in defense (crocodiles,
> monitor lizards, iguanas, etc) tend to present one side, or
> another to an attacker. This has the benefit of presenting a
> much larger target to the predator (which in this case,
> would be intimidating rather than inviting), and allowing
> for "better aim" of the tail.
Actually, that's kinda what I had in mind: a stegosaur angled such that the
tail is positioned to deliver maximum force against the attacker. By
"tail-first" I didn't literally mean that the stegosaur was positioned directly
in front of the predator, like a two-way conga line. :-)
Abyssal (email@example.com) wrote
> Am I the only one who immediately thought of Bakker's
> "tripodal mid-height feeders" hypothesis from the Heresies
> when Miragaia was announced? It looks like he may have just
> been at least partially vindicated here. Did anyone ever
> investigate the Stegosaurs ability to rear up since Bakker
> proposed that? I remember there being some skepticism
> directed at the idea but never learned what really became of
Mateus &c do not seem to be much in favor of this idea - and they discuss why
in the Supplementary Information (where _The Dinosaur Heresies_ is explicitly
Hope that helps!