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Repost of reply to Tim Williams
Sorry for the repost; due to quirk of yahoo beta mail, even I couldn't figure
out who said what. Hoping this turns out better.
----- Original Message ----
From: Tim Williams <email@example.com>
Sent: Monday, July 3, 2006 4:40:15 PM
Subject: RE: T. rex's vision as SUPPORT for scavenging activitiy...
Don Ohmes wrote:
>>Any candidates for the role of volant scavenger(s) co-existing with T. rex?
>A scavenging lifestyle was suggested for _Quetzalcoatlus_ back in the
>1970's, when this flying beastie was first described. But as I learned from
>Darren Naish's blog...
>... the evidence to support a scavenger lifestyle for _Qutzalcoatlus_ and
>other azhdarchids is very weak.
>I'd bet dollars to donuts that one day a Mesozoic bird (probably an
>enantiornithean) turns up with characters consistent with specialist
When you go dollars to used donut holes, as opposed to just donuts, I'll know
you are confident. Although I agree in the sense we aint seen much of what was
>Considering the sheer bulk of many dinosaur carcasses around in the Jurassic
>and Cretaceous, scavenging seems like too good a niche to pass up. Of
>course, it helps to have a strong digestive system.
Agreed. Pack hunters may have been very efficient, though. And big prey equals
big packs, I'm guessing. (Not to open old wounds, LOL-- How many 100 kg
climbing "terrestrial shark analogues" could a 60 ton carcass feed?)
>>IF there is the presence of a population of volant scavengers, then timely
>>visual cues (eg, circling vultures) to any local large animal death exist,
>>and are detectable from distances up to 40 miles in an open environment.
>AFAIK, nobody has suggested that tyrannosaurs could fly. Apart from George
>Olshevsky, that is. :-)
Huh? Not me, that's for sure. Didn't follow this one, exactly. Bulky carcasses
equals more time to walk to lunch (before it is all gone, or decomposed
>From: don ohmes <firstname.lastname@example.org>
>Reply-To: don ohmes <email@example.com>
>Subject: T. rex's vision as SUPPORT for scavenging activitiy...
>Date: Mon, 03 Jul 2006 13:13:37 -0700 (PDT)
>In my opinion-- obligate scavenger is not the most probable lifestyle for
>T. rex, and there are strong arguments for a top predator lifestyle, as
>well some against the obligate scavenger hypothesis. That said, there is no
>doubt that the ability to scavenge/co-opt fortuitous mortalities in the
>local large animal population is potentially advantageous for top
>The ability to detect fortuitous mortality in a timely fashion is obviously
>critically important to efficient utilization of such resources, and any
>sense used for detection is therefore subject to strong directional
>selection. IF there is the presence of a population of volant scavengers,
>then timely visual cues (eg, circling vultures) to any local large animal
>death exist, and are detectable from distances up to 40 miles in an open
>Given the large size of resource animals extant in the Cretaceous, a
>relatively large time window for utilization would exist. An open
>environment, very large animals, and volant scavengers seems like an ideal
>recipe for evolving keen (ie, long-range) daytime vision in a large
>I don't know if this has been addressed before, in print. If it has, sorry
>about the lack of reference.