Nice theory, but I have questions.

[Gawdzilla Sama]

...So stegosaurs are not dinosaurs either then. Right?

No, they came from previous types of animals, the most recent of which were dinosaurs.

So to conclude - nothing is a dinosaur then?

Nothing is currently a dinosaur. Evolution has moved on.

We've evolved, so are we no longer mammals?

Some info for the layperson (short, not very detailed):

http://www.miketaylor.org.uk/dino/FAQ/s ... /index.htm

It's a matter of where you say one starts and the other leaves off. We evolved, so we're no longer fish.

[klr]

...So stegosaurs are not dinosaurs either then. Right?

No, they came from previous types of animals, the most recent of which were dinosaurs.

So to conclude - nothing is a dinosaur then?

Nothing is currently a dinosaur. Evolution has moved on.

We've evolved, so are we no longer mammals?

Some info for the layperson (short, not very detailed):

http://www.miketaylor.org.uk/dino/FAQ/s ... /index.htm

Linky no worky ...

[Gawdzilla Sama]

...So stegosaurs are not dinosaurs either then. Right?

No, they came from previous types of animals, the most recent of which were dinosaurs.

So to conclude - nothing is a dinosaur then?

Nothing is currently a dinosaur. Evolution has moved on.

We've evolved, so are we no longer mammals?

Some info for the layperson (short, not very detailed):

http://www.miketaylor.org.uk/dino/FAQ/s ... /index.htm

Linky no worky ...

Its' evolved into something else.

[Clinton Huxley]

It's a matter of where you say one starts and the other leaves off. We evolved, so we're no longer fish.

Pedantically, we are heavily modified fish. But then I suppose you could say we are very, very modified RNA.

[Gawdzilla Sama]

It's a matter of where you say one starts and the other leaves off. We evolved, so we're no longer fish.

Pedantically, we are heavily modified fish. But then I suppose you could say we are very, very modified RNA.

Exactly. "We are all made of stars." Where does it end?

[GeneticJen]

Oops, add an "L" to the very end.

Gawd, are you suggesting that the differences between avian and non-avian dinosaurs are like the differences between fish and mammals?

[Gawdzilla Sama]

Oops, add an "L" to the very end.

Gawd, are you suggesting that the differences between avian and non-avian dinosaurs are like the differences between fish and mammals?

If we carry the logic of saying birds are dinosaurs out to the end, I'm saying that we're all remnants of the Big Bang. Makes things a bit fuzzy, that.

[GeneticJen]

We describe these taxa as having specific anatomical features etc. We can define "Dinosaur" and this includes the pigeon for the same reason that it includes a member of the Stegosauria. Fish cannot be defined as dinosaurs. If a bird isn't a dinosaur, then a theropod isn't a dinosaur. Or a sauropod isn't a dinosaur.

[Gawdzilla Sama]

We describe these taxa as having specific anatomical features etc. We can define "Dinosaur" and this includes the pigeon for the same reason that it includes a member of the Stegosauria. Fish cannot be defined as dinosaurs. If a bird isn't a dinosaur, then a theropod isn't a dinosaur. Or a sauropod isn't a dinosaur.

Then we should be calling them therapods, not dinosaurs.

[Horwood Beer-Master]

...So stegosaurs are not dinosaurs either then. Right?

No, they came from previous types of animals, the most recent of which were dinosaurs.

So to conclude - nothing is a dinosaur then?

Nothing is currently a dinosaur. Evolution has moved on.

But using your rationale, what grounds do we have to call anything alive or dead a dinosaur?

In other words, if you can take select groups of dinosaurs (be it the birds, or the stegosaurs or whatever) and label them as "not dinosaurs, merely descended from dinosaurs", then you can do the same with the whole sodding lot.
You end up with just one hypothetical species somewhere back in the Triassic called "the dinosaur", and all the rest just "descended from it".

Where do you draw the line? You could just as well say that nothing alive today is an 'animal', rather there was a species somewhere back in the Neoproterozoic called "the animal", and today we merely have things which are "descended from the animal".

[GeneticJen]

To be fair, you are right, we go back to star dust. And that is fuzzy. And since fuzzy is often useless, we've come up with a man-made system of taxonomy rather than just describing all of life as one thing. You aren't wrong pointing out how continuous evolutionary history is. But we have coined the term "mammal" and given it a definition. Us humans evolve from other mammals, but we still fit into the definition. On top of that, using the definition and excluding us (despite us fitting nicely into the definiton) would result in a paraphyletic group, which isn't accurate and isn't very useful.

One group of dinosaurs didn't die out. They fit the definition we give dinosaurs. Their inclusion stops the unscientific use of a paraphyletic group.

You said we should call birds theropods and not dinosaurs. But theropods are dinosaurs. That's like saying we are primates, not mammals.

[Horwood Beer-Master]

...It's a matter of where you say one starts and the other leaves off. We evolved, so we're no longer fish.

Yes we are.

[Horwood Beer-Master]

It's a matter of where you say one starts and the other leaves off. We evolved, so we're no longer fish.

Pedantically, we are heavily modified fish. But then I suppose you could say we are very, very modified RNA.

Yup

[Horwood Beer-Master]

It's a matter of where you say one starts and the other leaves off. We evolved, so we're no longer fish.

Pedantically, we are heavily modified fish. But then I suppose you could say we are very, very modified RNA.

Exactly. "We are all made of stars." Where does it end?

It doesn't.

[Horwood Beer-Master]

Oops, add an "L" to the very end.

Gawd, are you suggesting that the differences between avian and non-avian dinosaurs are like the differences between fish and mammals?

If we carry the logic of saying birds are dinosaurs out to the end, I'm saying that we're all remnants of the Big Bang. Makes things a bit fuzzy, that.

More importantly, it makes things a bit accurate.