I wish you’d preserved the original title, though, even though the new one gives a better idea of the subject.
I was doing the merge on my phone while giving a final exam, so those nuances (which thread was merging into the other) go lost. The software always merges the later tread into the earlier, but I think how I set up the merge determines which title is kept.
If it’s any consolation, the other title is on the first post, so it’s not lost to time.
Amber was preserved, as it were.
Small isn’t a problem for fossils. The vast majority of fossils range from small to tiny. Note, for example, the sizes of the known Archaeopteryx specimens.
Hah, ignorance-fought! For some reason, I had a mental image of those critters being more turkey-, than pigeon- sized.
On a similar note, if you have any interest at all in the subject, you really should try to get your hands on a copy of Unearthing the Dragon, a beautifully illustrated book about Chinese feathered dinosaur and bird fossils (and the scientists who study them.)
BTW, I meant to mention that you can download the PDF of the full paper here.
So, is it likely that all dinosaurs were feathered, or is it possible that some had feathers and others had scales?
T-Rex…tastes like Chicken?
Helluva drumstick…
Well, this relates to the idea of phylogenetic bracketing. Basically, this says that any specific identical trait is more likely to have evolved once than it is more than one time. So if you find fossils of two species of dinosaur preserving feathers, you have the choice between assuming that both species evolved the specific and complex trait of feathers independently, or you can assume that the two species shared a common ancestor that also had feathers. This would also mean that any other species descended from the parent species also had feathers, whether the fossils preserve signs of feathers or not.
More than 40 species of dinosaurs so far have been identified with signs of feathers, across both of the big groups of dinosaurs–the “lizard-hipped” and the “bird-hipped.” So this means that the common ancestor of all dinosaurs probably had some sort of primitive feathers, and therefore all dinosaurs had them in their lineage (though some species may have later lost them completely.)
And, there is evidence that at least some pterosaurs had a kind of fuzzy covering. This may have evolved independently, or it may mean that the common ancestor of dinosaurs and pterosaurs shared an extra-primitive proto-feather
No problem, they can fill in the gaps by using the DNA of frogs.
(Actually, that’s a terrible idea…)
Oh come on, if they flew, surely they had feathers. :dubious:
Bats don’t have feathers.
Sniff.
Maybe they are, like, really, really small feathers and no one notices them?
I am reliably informed that eyes have evolved three times. Mammals, birds, and in the Octopus. This is to say that there are three basic structures. Of these, the design of mammalian eyes is not the best - not even close.
I bring this up only to say that to the lay person, it is reasonable to believe that structures like feathers, hair, or claws could arise many times. How true that actually is, I’ll leave to those better informed.
Your scientists were so preoccupied with whether or not they should, they didn’t stop to think if they can.
That’s…not even close to true.
The eyes of all animals that have them seem to have developed from the same source. But the development of the eye has taken different turns in different lineages, including certain structures, such as the lens, developing independently, which is presumably what you’re misremembering.
And even there, the three groups listed are putting the divergences much more recently than they really are. The eyes of vertebrates don’t generally vary in structure that much, suggesting nothing is particularly novel in them. (IIRC, the only structure existing in some, but not in others, is the sclerotic ring, which, based on its ubiquity, would be ancestral to all tetrapods, but lost in some lineages, such as mammals, rather than independently evolving in the lineages that have it.)
I wonder that eyes are usually in twos, but triops have three
As I understand it, there are four lineages of imaging eye: Lensed eyes in the vertebrates, cephalopods, and (of all things) box jellyfish (who wouldn’t seem to have enough of a nervous system to make any use of images, but who knows), plus the compound eyes of arthropods. While these might have had some sort of common ancestry from a primitive light-sensitive organ, that organ would not have been imaging.
That said, there are other vaguely eye-like things in some creatures. Pit vipers have infrared-sensitive pits for detecting prey by body heat, and tuataras have a light-sensitive eye-like organ in the center of their foreheads.
