[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Spinosaurs as what?

Demetrios Vital wrote:

How plausible is this behavior considering the environs of
Spinosaurus?  Are there other species of fish that congregate in
shade, or other predators that use their shadow to hunt?

Well, I'm not all that knowledgeable about the paleoenvironment in that region of Africa (Baharija Fm.), except that it was an estuary. *Spinosaurus* has as far as we know piscivorous adaptations; I'm just proposing a modus operandi for the creature's feeding habits based on extant creatures that approximate its niche (if there are any). In fact, *Spinosaurus* might as well had brightly colored feet as some herons do to scare off fish as it waded ;-)
Being a big animal and presumably catching big fish in murky waters, I think this way of fishing provided two benefits: fish are naturally attracted to shades as they tend to denote thick vegetation and rocky areas where land-bound and aerial predators are less likely to attack them (at least that's what I hear on wildlife shows); the animal could use its shade as a way to diminish the glare the water's surface produces thus being able to see the fish more clearly.

Really interesting speculation. Is this even remotely provable?

If we had an generous amount of fossil evidence we could look at asymmetries in oxygen isotope ratios on the ribs or each side of the neurapophyses as these would be exposed to diferent temperatures and perhaps even histological evidence that shows how these temperature differences affected the bone. But this would only be valid if the animal used consistently the same side of the sail to produce shade. To prove that the animal waded regularly one could compare the oxygen isotope ratios on the feet and leg to the ones on for example the pubic bones, with obviously a calibration chart with results from extant waders, extinct waders and non-waders of each type.
I am perhaps going out on a limb here but it would be interesting if this could be done even on an academic standpoint.

Renato Santos

Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/