Subject:
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Re: Evidence of Warm Blooded Dinosaurs
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Newsgroups:
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lugnet.off-topic.fun
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Date:
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Tue, 25 Apr 2000 10:30:14 GMT
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Viewed:
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305 times
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Jeff Stembel wrote:
> In lugnet.off-topic.fun, Bruce Schlickbernd writes:
> > In lugnet.off-topic.fun, Lindsay Frederick Braun writes:
> > > Jeff Stembel wrote:
> > >
> > > > Anyone interested in Dinosaurs should check this out:
> > > > <http://www.washingtonpost.com/wp-dyn/articles/A53547-2000Apr20.html>
> > > > Pretty cool, huh? :)
> > >
> > > I saw that! It sort of confirms what palaeontologists have thought since
> > > about 1980. The fact that it's a plant-eater is more interesting,
> > > though--the suggestion existed that "only predators needed that level of
> > > energy." Hm.
> >
> >
> > A similiar article appeared in the L.A. Times. One would suspect that
> > warm-bloodedness goes back at least till the dinosaur-mammal split given the
> > plant-eater angle.
>
> This prompted me to pull out one of my dinosaur books, and examine the dinosaur
> family tree. :) Anyway, if this chart is correct (it's ten years old, but I
> doubt its changed much), then I'd guess Dinosaurs and mammals both evolved
> warm-bloodedness separetly.
Darn sacci-frasso-rassin' kids, stealin' my thunder...;) But yeah, that's the
story. Why do crocodiles not have a high, warm-blooded metabolism? They don't
need it, and have never needed it. They're archosaurs like monotremes are
mammals--they have *some* of the features, but not all. Dr Gregory Paul has
written (and illustrated--he's quite talented) an excellent book called "Predatory
Dinosaurs of the World", in which he argues quite reasonably two things:
1. Dromaeosaurs and Cretaceous coelurosaurs (an outdated term, as it conflates
several distinct lineages) in fact are *back-evolved* from the first birds, based
upon structural information, metabolic clues, and evidence of later (post K-T) bird
back-evolution into large ground predators; and
2. Amateur and professional fossil-hunters both are guilty of mucking up the
Archosaurian family tree by vainly trying to name "their own" dinosaur, and thus
giving specimens we can today quite readily tell are male, female, or juvenile,
three different genera names. Paul clears a lot of this up, and apparently he made
some people not-too-happy by suggesting that "their" dinosaur be collapsed into
another category.
There's a corollary to this, and that's that birds should not be in a separate
taxonomic class (Aves). Rather, they should be a subclass under Archosauria (which
should be a class, not a subclass of Reptilia as it's accepted
now--Archosauromorpha). To call birds non-archosaurs is like calling bats
non-mammals, just because they can fly.
I'm not sure you can call late therapsids truly "reptiles," though. They were
furry, after all. If you're talking finbacks (pelycosaurs/edaphosaurs), well, yes.
> I'd like to hear other's opinions on this, especially if you have evidence to
> contradict or confirm my idea (since I just made it up :) ). I'll also try to
> find some of my more recent books on the subject. :)
I'm in basic agreement--although the relation of dinosaurian groups is kind of
weird right now, because I've been seeing a lot of material lately that suggests
the "traditional view" separating dinosaurs by hip type is just plain silly, and
that separating them by size is also just plain silly. At least we know where our
'gators stand; their ancestor arose in the mid-Triassic, about the same time as the
earliest known "dinosaur" (is that still considered to be Euparkeria, or do they
have a new "earliest and greatest" candidate?).
best
Lindsay
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Message has 2 Replies:
 | | Re: Evidence of Warm Blooded Dinosaurs
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| (...) the (...) dinosaur (...) I (...) don't (...) "Predatory (...) conflates (...) based (...) bird (...) thus (...) juvenile, (...) made (...) into (...) (which (...) yes. (...) to (...) to (...) suggests (...) and (...) our (...) as the (...) (...) (25 years ago, 25-Apr-00, to lugnet.off-topic.fun)
| | | Re: Evidence of Warm Blooded Dinosaurs
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| (...) I've never heard of it, so I'll have to check this book out. :) (...) I find this hard to swallow. What happened to their skulls and the wishbone? It is true that some birds later evolved into Dinosaur-like creatures(1), but I wouldn't use (...) (25 years ago, 25-Apr-00, to lugnet.off-topic.fun)
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Message is in Reply To:
| | Re: Evidence of Warm Blooded Dinosaurs
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| (...) This prompted me to pull out one of my dinosaur books, and examine the dinosaur family tree. :) Anyway, if this chart is correct (it's ten years old, but I doubt its changed much), then I'd guess Dinosaurs and mammals both evolved (...) (25 years ago, 25-Apr-00, to lugnet.off-topic.fun)
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