Re: KT boundry event

uraniumcommittee@xxxxxxxxx wrote:

Augray wrote:

On 19 Apr 2006 07:38:01 -0700, uraniumcommittee@xxxxxxxxx wrote in
<1145457481.817814.252520@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> :


Augray wrote:


On what basis do you claim that they've evolved too much to be called
dinosaurs?. I'm hard pressed to think of *any* trait possessed by
living birds that wasn't present in some bird living in the
Cretaceous.

That does not make them dinosaurs. Dinos are extinct.

So, even though you can't point to a trait that's unique to birds,
you're going to make the claim anyway?


FLIGHT! TOOTHLESSNESS!

How are those?

Not so good. Microraptor gui, a dromaeosaurid theropod, could fly. Many
theropods were toothless, and many extinct birds had teeth. Neither of
these is diagnostic.

To call birds 'dinosaurs' makes no more sense than calling them fish.
Birds used to be fish, but are no longer fish.

What do you base this claim on? You keep repeating it, but give no
evidence to back it up.

For one, birds' respiratory system is unique. It is not shared by any
other group.

Absolutely false. Theropod dinosaurs in all likelihood had a
respiratory system very similar to that of living birds. See:

O'Connor, P. M., & L. P. A. M. Claessens. 2005. Basic avian
pulmonary design and flow-through ventilation in non-avian
theropod dinosaurs. Nature 436:253-256.

The book referenced below states that bird respiratory system differes

from all other groups.

http://www.amazon.com/gp/product/0312310080/sr=1-1/qid=1145453804/ref=pd_bbs_1/104-1737020-1779102?%5Fencoding=UTF8&s=books

Since that book, for the most part, contains reprints of Scientific
American articles from the last thirty years, I'd hardly consider it
to be up to date. Is there any particular article that you had in mind
to back your claim?

I can't find it right this instant. Maybe later.


The use of language is somewhat arbitrary. 'Fish' as it is now used, is
applied to a certain class of water-dwelling creatures with gills,
though not to all water-dwelling creatures with gills, nor to all
water-dwelling creatures (though it was in the past applied to
water-dwelling creatures with lungs).

Some salamanders have gills and are water-dwelling, but are not classed
as fish.

Birds as a group are sufficiently different from dinosaurs as a group
to merit separate nomenclature, which is a fait accompli.

You've given a single trait which is incorrect. At what point to you
believe this trait supposedly evolved?

'Modern birds' are not 'dinosaurs'. They belong to the group
dinosauria, but that Latin name is not synonymous with the common name
'dinosaurs'.

That's news to me. What do you base it on? It also seems to be beside
the point. Are you saying that if I were to claim that birds belonged
to the group Dinosauria, would that alleviate your objections?


Yes. The group 'Dinosauria' includes more than the common term
'dinosaurs'.

So we're reduced to arguing the semantics of a vernacular term. Boring.
Yes, the term as commonly used by non-scientists doesn't include birds.
But we try for a bit more technical language here on TO. There are
advantages to cladistic thinking that you should definitely consider.
"Dinosaurs" as a group excluding birds is just an arbitrary collection
of species. If you include birds, though, it's a clade, a real
evolutionary entity. Including birds as dinosaurs can save you from
categorical mistakes like you indulged in at the start of this thread.

Birds are fish too, by the way. We're all fish. Just particularly weird
fish with a variety of bizarre adaptations to a terrestrial lifestyle.
If you think of it that way, evolutionary history becomes much more
compelling, in my opinion.

It is silly and pointless to reduce the number of distinctions.

It's not a case of reducing the number of distinctions, it's pointing
out that "birds are not dinosaurs" is an arbitrary distinction.

It's not any more arbitrary than the modern meaning of 'fish'. In the
past, 'fish'. could mean any water-dwelling creature.

But since the term "fish" is a colloquial term, it's hardly expected
to be precise. On the other hand, you've yet to tell me at what point
birds ceased being dinosaurs, and what you base that claim on.

'Dinosaurs' is likewise a colloquial term that is far from synonymous
with 'Dinosauria'.

'Dinosaurs'
'Birds'
'Fish'
'Snails'
'Slugs'
'Trilobites'
'Crabs'
'Insects'

Some of these groups are extinct, but all are colloquial terms.

Some of them correspond to actual clades, like birds, trilobites, slugs,
and insects. Others can easily be made into clades by including their
excluded subgroups: birds within dinosaurs, tetrapods within fish, slugs
within snails. Crabs are polyphyletic if you count everything with
"crab" in its name; can't do anything for you there.

Colloquial terms are not a good thing to use in discussions of science.
"Dinosaur" excluding birds defines a group with no real existence.

Birds
are NOT dinosaurs; they are birds. Dinos are all extinct.

Birds are *indeed* dinosaurs, just as primates are mammals.

'Dinsosaurs' are all extinct.

That's an arbitrary claim.



'Birds' (i'e., modern birds) are
descended from a larger class of ancient birds, most of which died out
in the Cretaceous. All modern birds, even flightless ones, are desended

from flying Cretaceous birds.

I agree completely.



Birds originated among the earliest
dinosaurs, all of which were bipedal.

That's a very unique assertion. Can you back it up with evidence?


See the SA book. I'm reading it right now.

For those of us who aren't reading it right now, you will have to say
what you mean. Birds, according to most modern accounts, are
maniraptorans, probably most closely related to dromaeosaurs, and these
are many nodes removed from the earliest dinosaurs. The fossil record
being what it is, we don't know just when birds first evolved. But a
good guess would be sometime in the Late Jurassic, around 70 million
years after the first dinosaurs.

.

Relevant Pages

  • Re: KT boundry event
    ... Word usage has everything to do with language. ... that the vernacular term "fish" is not generally used to refer to the ... dinosaurs is getting to be that way, ... record of birds by this definition actually predates, by just a bit, the ...
    (talk.origins)
  • Re: KT boundry event
    ... The word 'fish' does the job it is asked to do. ... Absolutely unacceptable to say "birds are dinosaurs". ... are not 'insects', but no great harm is done in using this term by the ...
    (talk.origins)
  • Re: KT boundry event
    ... I got the notion earlier that you accept the evidence that birds have ... dinosaurs" and "birds ARE dinosaurs". ... Fish have left descendants that inlude whales, ...
    (talk.origins)
  • Re: The Myth of Bird Evolution
    ... > between dinosaurs and birds. ... The fact is, however, that this fossil ... "The evolution of birds", like other claims made by Darwinism, ...
    (talk.origins)
  • Re: Vernacular and Linnaean Naming (Was: KT boundary event)
    ... If you want to say "birds are dinosaurs" it shows you have no ... If you mean can scientists communicate clearly amongst themselves then ... The poor standards of language eductaion have ...
    (talk.origins)
Loading