Saturday Science: Boom!

A fairly interesting article on a recent find at the K/T boundary -- which is when the dinosaurs were wiped out:

If, on a certain evening about sixty-­six million years ago, you had stood somewhere in North America and looked up at the sky, you would have soon made out what appeared to be a star. If you watched for an hour or two, the star would have seemed to grow in brightness, although it barely moved. That’s because it was not a star but an asteroid, and it was headed directly for Earth at about forty-five thousand miles an hour. Sixty hours later, the asteroid hit. The air in front was compressed and violently heated, and it blasted a hole through the atmosphere, generating a supersonic shock wave. The asteroid struck a shallow sea where the Yucatán peninsula is today. In that moment, the Cretaceous period ended and the Paleogene period began.

The description of the events immediately following the impact is breathtaking. It's a wonder anything survived.

Saturday Science on Friday: Dinosaur Feathers

Just a little bit, 'cause it's exciting. They've found them, still attached to the dinosaur -- well, to part of it.

The tail of a 99-million-year-old dinosaur, including bones, soft tissue, and even feathers, has been found preserved in amber, according to a report published today in the journal Current Biology.

While individual dinosaur-era feathers have been found in amber, and evidence for feathered dinosaurs is captured in fossil impressions, this is the first time that scientists are able to clearly associate well-preserved feathers with a dinosaur, and in turn gain a better understanding of the evolution and structure of dinosaur feathers. . . .

The semitranslucent mid-Cretaceous amber sample, roughly the size and shape of a dried apricot, captures one of the earliest moments of differentiation between the feathers of birds of flight and the feathers of dinosaurs. (Learn more about the evolutionary relationship between dinosaurs and birds.)

Inside the lump of resin is a 1.4-inch appendage covered in delicate feathers, described as chestnut brown with a pale or white underside.

Click through and read the whole thing. Lots more information, and lots of gorgeous -- and very informative -- pictures.

So It Wasn't Hunters With Stone Tools

Picture Credit: Everything Dinosaur

There's a school of thought -- if you want to call it that -- out there that credits human being with all the extinctions throughout prehistory, particularly the North American megafauna at the onset of the latest interglacial period. I've pointed out time and time again that, in most cases, the populations concerned were already under stress from environmental changes (as in the onset of the interglacial). Well, that seems to have been the case with the dinosaurs:

Sixty-five million years ago, a massive asteroid slammed into Earth, causing tsunamis, earthquakes, fires, a global winter and the end of the age of the dinosaurs.

But what if the asteroid had glided safely past our planet? Would dinosaurs still be here today?

New research suggests the answer is probably not. Instead, scientists have found evidence that dinosaurs were in the midst of a long, slow decline that began millions of years before the asteroid struck. . . .

The authors are not sure what caused the speciation rate to slow down, but they have a few ideas. They explain that the Cretaceous period (145.5 million to 65.5 million years ago) was a time of drastic geological changes. The global climate was cooling down, there was prolonged volcanic activity and the continents were breaking apart.

Like I keep saying, environmental changes will do it every time.

Saturday Science: About Those Surviving Dinosaurs

Well, we call them "birds" these days. It seems that, unlike everything else, they kept getting smaller.

Our research shows that the ancestors of birds were the only lineage of dinosaurs to continually shrink in size for an extended period of time (at least 50 million years, and perhaps twice as long). They were also the fastest-evolving lineage of dinosaurs.

Oh, and if you're wondering about feathers, well -- they were pretty common among dinosaurs:

We now know that many bipedal, meat-eating dinosaurs (theropods) – including relatives of T. rex and Velociraptor – were adorned with a variety of feathers. They were preserved in such detail in fine volcanic ash that often even their colours can be reconstructed. Plumage might have even been present in all dinosaurs.

The article is worth reading, although I found it a little dry. But there's a video for those with short attention spans: