Another puzzler from the Pterosaur/Dinosaur debate.
Those beasties that were called dinosaurs were divided into two groups: Saurischians and Ornithischians.
I vaguely remember that they were divided based upon their hip structure which was either lizard-hipped (Saurischian) or bird-hipped (Ornithischian).
But “modern birds descended from saurischians”…
Figure that one out!
Welcome to the SDMB, and thank you for posting your comment.
Please include a link to Cecil’s column if it’s on the straight dope web site.
To include a link, it can be as simple as including the web page location in your post (make sure there is a space before and after the text of the URL).
Cecil’s column can be found on-line at this link:
Pterosaurs aren’t considered true dinosaurs. Why not? (30-Jun-1995)
The column (including Slug Signorino’s illustration) can also be found on pages 214-216 of Cecil Adams’ book “Triumph of the Straight Dope”.
By the way, Mustapha, I forgot to respond to your comment <<But “modern birds descended from saurischians”…>>
That does seem surprising at first glance, now that you mention it. I think that Archaeopteryx was most closely related to theropods, which were saurischians, so zoologists think that birds are descended from theropods. I suppose “bird hips” evolved twice, in the same way that flight evolved three times in vertebrates, as mentioned in Cecil’s column.
Yup, that’s pretty much what happened. The illia of Archaeopteryx and other early birds are much more lizard-like than those of their descendants.
Hi guys!
I read some news about Archaeopteryx a few months back, that it had been debunked. The famous fossil that started it all, a small saurian creature with feathers, turns out to have been just one fossil on top of another.
(Yes I do know there are other -opteryx fossils out there)
I read the article in the BBC’s excellent science pages, but sadly I can’t seem to find the article in question.
Does anyone else know of the report in question?
IIRC that was not an Archaeopteryx. It was a fossil from China that had been fabricated to look like a birdlike lizzard just to attract the interest of prospective buyers.
Lars
Aah. Much obliged, I thought I was going mad there.
As Floater said, that was something different. It was a recent fossil that claimed to show a different intermediate form between dinos and birds. Its debunking in no way affected the theories and fossils that already existed before that one was “discovered.”
In the interests of furthering arguments everywhere, I offer this link from the BBC’s science pages.
http://news.bbc.co.uk/hi/english/sci/tech/newsid_802000/802009.stm
The basic gist of the article is that feathers may have evolved much earlier than first thought, and therefore birds may not be directly descended from dinosaurs per se.