h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Well done GB! another inspirational piece of research

Great to know it's appreciated, thanks

Seconded. Excellent piece of work.

I enjoyed it too Galaxy Babe! I have a few comments though ... not enough time right now, I'll get to it sometime tomorrow, I hope.

Willem

thanks both

OK Galaxy Babe, some comments! I know this entry is already 'finished' ... and also, most folks reading it, would not be very concerned with the full technical details ... but since this is a topic I know a lot about I still would like to make the following additional comments for the sake of interest, for anyone reading here.

1. More about the idea that birds and dinosaurs have a common ancestor ... you say 'some researchers believe' that, but I'd like to add and make clear that those 'researchers' are pretty kooky, not in the mainstream of science, and their position (called BAND - Birds Are Not Dinosaurs) is less and less supported by the evidence, the more fossils of feathered and bird-like dinosaurs that are discovered. The idea of a 'common ancestor' of birds and dinosaurs implies that way back - well before Archaeopteryx, indeed, 225 million years or more ago - there existed a thing which had one set of descendants that were dinosaurs, and another set of descendants that were birds, the two being entirely separate groups.

Most paleontological evidence, though, seems to imply that birds are descendents of a particular group of dinosaurs ... strictly speaking, birds ARE dinosaurs. When the first known bird, Archaeopteryx (but see later comments), existed, there also existed many other dinosaurs ... it was just one dinosaur species among many, and it happened to have feathers, and it probably was on the line leading to modern birds. So, the more accurate thing to say is, that *some* dinosaurs were the ancestors of modern birds.

The rest of your entry is written from the mainstream perspective, namely, that birds are dinosaurs ... specifically speaking of birds as 'avian dinosaurs' and hence against the BAND-position.

(I can tell you a lot more about the 'Birds Are Not Dinosaurs' fellas and why they are wrong if you're interested!)

Thus, Confuciusornis and its relatives were proper birds and only a dinosaur in the sense that all birds are dinosaurs. At least ... the way we define 'bird'. It is possible to classify things - and some scientists do indeed so - as to make Confuciusornis 'not a bird' because of not falling 'within' the branch of the family tree containing all living birds ... but then Archaeopteryx wasn't a bird either, nor were a great many prehistoric feathered, flying creatures that anyone who saw them would instantly call 'birds'.

This can get quite confusing ... some scientists use the term 'Avialae' to define a bigger group than birds 'proper', in which to include Archaeopteryx, Confuciusornis and other related feathered and even flying dinosaurs, while not including them in the group 'Aves' or 'Birds' proper. This seems silly to me ... I would vote for Archaeopteryx being considered a bird, and everything closer than it, than to its other dinosaur relatives, thus being called birds as well.

OK just this for now ... more later, perhaps!

I believe Robert Bakker proposed a major revision of the taxonomic tree thing back in the 70s, whereby birds would lose their current position as a separate group (Aves) and instead become a third order within the Dinosauria group (so Saurischia, Ornithschia and Aves) - wasn't given serious discussion as I recall.

Saw a TV show about tyrannosaurs which proposed they might be feathered, based not on any direct evidence but the fact that every other dinosaur in that group whose skin has been preserved had them. Still not sure how compelling that is...