Feathers On Reptiles Predating Dinosaurs

Weedhopper writes: "This is a news item in reference to an article in the latest issue of Science about a reptile with feathers that predates archeopteryx by 75 million years - predating most dinosaurs in fact. Though I am suspicious of any claim that a particular biological structure is too complex to have evolved twice, the case may be that birds may not have descended from dinosaurs as is commonly believed."

Comments

Re:Haiku

[funkman]

Sorry I was wrong

My numbers were very off

Burn me at the stake

Re:feathers on reptiles predating dinosaurs

[Black Parrot]

> Its really open to interpretation on whether or not it had feathers at all.

Some scientists are scoffing at the idea. See e.g. the report at ABC News -

"Those are not feathers," said Chris Brochu, a paleontologist at the Field Museum of Natural History in Chicago. "None of the evidence they cite are preserved well enough to be convincing."
Hans-Dieter Sues, a paleontologist at the Royal Ontario Museum in Toronto, Canada, says he studied the Longisquama fossil in his laboratory for months two years ago and he is sure the mysterious appendages are scales, not feathers.
"The structures are solid and they have overlap with adjoining scales. They're definitely not feathers," he says. "These scientists are trying to show that birds may not have evolved from dinosaurs - that's clearly their agenda."

Of course, both sides of an argument can have an agenda. I think it will take several months for a basic consensus to shake out, and of course the basic dinosaur -&gt bird question was already controversial before this, and will likely remain so.

One claim by one of the dinosaur != bird crowd really annoys me, though -

Jones says the sequence of bird-like dinosaurs appearing after the earliest known bird has never made sense to him. "It's like saying your grandmother was born after you died," he says.

No, it's more like apes appearing after the earliest known hominid.

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Re:feathers on reptiles predating dinosaurs

[Black Parrot]

> No, it's more like apes appearing after the earliest known hominid.

I should have said, "more like specific species of ape appearing after the earliest known hominid." I.e., not a big problem.

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Re:not too meaningful

[Mark Gordon]

I've never seen cephalopod eyes on a gastropod. ;-)

If anything, cephalopod eyes are of a superior design. The nerves leading away from the photoreceptors in cephalopod eyes stick out the back. In vertebrates, the nerves stick out the front, blocking some of the light, and they have go out the back of the retina, resulting in a blind spot.

This difference helps underscore the fact that cephalopod eyes and vertebrate eyes evolved separately (much like bird wings, bat wings, pterosaur wings, and insect wings). Parallel evolution is seldom parallel in the finer details.

Re:feathers on reptiles predating dinosaurs

[YU Nicks NE Way]

For what it's worth, I'm actually somewhat ambivalent on the birds as tiny therapods thesis. At this point, I think that it's quite plausible that the birds arose from saurians; no obviously non-saurean precursors to the birds have been found, and a number of homologous structure in the therapoda and the avians have been discovered.

That doesn't mean that birds are baby dinosaurs, though. It's certainly reasonable to assume that the therapods and the birds share close a common ancestor, but it seems hardly likely that the birds actually are derived from any of the dinosaurs that we know and love. (I've always liked Steve Gould's comment on why dinosaurs are so popular: "They're big, they're mean...and they're dead.")