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Some Large Dinosaurs Survived the K-T Extinction
mmmscience sends along coverage from the Examiner on evidence that some dinosaurs survived the extinction event(s) at the end of the Cretaceous period. Here is the original journal article. "A US paleontologist is challenging one of the field's greatest theories: the mass extinction of dinosaurs at the end of the Cretaceous period. Jim Fassett, a paleontologist who holds an emeritus position at the US Geological Survey, recently published a paper in Palaeontologia Electronica with evidence that points to a pocket of dinosaurs that somehow survived in remote parts New Mexico and Colorado for up to half a million years past the end of the Cretaceous period. If this theory holds up, these dinosaurs would be the only ones that made it to the Paleocene Age."
Jesus sure did.
Mit der Dummheit kämpfen Götter selbst vergebens
That's what gets taught in schools unfortunately.. especially the 'decided to evolve' bit, like a dinosaur woke up one day and thought it would grow some feathers for a change. Many people retain this view through adulthood.
Ever heard the whole silly 'a cow fell into the sea and became a whale' idea? Straight out of school textbooks.. I can remember being taught it myself.
The problem education makes is it dumbs things down for children then ignores the issue when they grow up - then some nutjob comes along, points out how silly the version they understand is therefore 'evolution' must be wrong, and we get the whole debate starting again. Maybe teaching 8 year olds about random genetic mutation might be a bit much, but by the time they are 15 they should be able to handle it.
It continues to dismay me how many really don't get it. The impact, or impact+major vulcanism (BTW, what order were those in, and could the impact have pinged the earth hard enough to initiate a major volcanic event at whatever the interval?), didn't kill the dinosaurs by direct effect. They didn't all die in a week or a month, or, even a few decades, centuries, or millennia, most likely.
What happened was a significant enough change in climate in nearly all habitats, over a short enough period of time, that the vast majority of major fauna, particularly dinosaurs, and a lot of the flora simply could not adapt to the new conditions, nor migrate to a location that suited them (nor build bubble cities in which to weather the change). If the birth/death ratio slips below 1 long enough the species is extinct. If it is only slightly less than 1 because the available nutrition is not quite good enough, or there's enough hard dust around to reduce lung efficiency, or the temperatures don't allow eggs to brood quite as well, or some such, then it can take a VERY long time to kill off populations in the tens of millions. Small regions of "better", if not quite "good enough", might easily sustain a very slowly declining ecosystem for hundreds of millennia.
Bottom line, though, is that there are a LOT of dinosaur fossils below the iridium-enriched layer and VERY few, and those not for very long, above it.
The K-T boundary is not a simple line defining before and after. It is a phenomenon that took place over time - the estimated occurrence of the event was 65.5 (+||- 0.3)Ma. That is a 600,000 year margin, and when you consider that the earliest human species (read as - only just not monkeys) were at the most 2 million years old, it is not unreasonable to theorise that the causative event did not represent a definite cut off point for any species. Things can change a lot in 600K years. And it is also a dangerous habit to take estimated figures and then apply them to suit your own hypothesis too rigorously. Chinese whispers and all that. As somebody else posted further up, it would be more of a surprise to NOT find specimens outside of the accepted period.
So does that mean skimpily clad cavewomen really *did* ride around on dinosaurs? mmmm...
Not really. It says they made it to the "Paleocene", i.e. the epoch adjacent to the Cretaceous. To have meet any cavemen they'd have had to survive through the Eocene, Oligocene, Miocene all the way to the Pleistocene era. That would still be around 60 million years.
I also highly doubt cavemen (or cavewomen for that matter) had the skill or technology to time travel back to the Paleocene. Afaik only genetically enhanced laboratory mice can do that.
And when you gaze long enough into the code, the code will also gaze into you.
That's not the whole argument.
The show I saw pointed out that there were fewer and fewer fossils being found the closer they get to K-T event. The claim was that there are twice as many known fossils 5-6 million years before than there are 2-3 million years before. I don't know if your suggested statistical side effect explains that.
And they pointed out that lots of frog species seemed to survive pretty easily even though they are very sensitive to acid rain, forest fires and other such things that would have happened if the K-T impact was the primary explanation of extinction.
Sorry, but it really seems like you're talking out of your arse. You do not prove things in any science, you come up with falsifiable theories, and test them out. The more falsifiable the better. It is also clear that you are not at all familiar with the research in the area. The bolide impact theory has a lot of interface with the data, and is immensely falsifiable. It has enormous explanatory power, and is not at this moment falsified by any data.
Could it be wrong? Sure it could! But coming up with little pet theories about what "killed the dinosaurs" is not going to cut it, and neither are tired and refuted arguments like the one above.
These arguments are trashed out in the literature, you just have to look at it.
It's a bit telling that the study is published in an obscure web-only paleontology journal called "Palaeontologica Electronica". I'm not saying that good work can't be published in obscure journals, but I would argue that if you had really strong evidence for post-Cretaceous dinosaurs, you wouldn't publish it in a journal that nobody's ever heard of. You'd be publishing in Nature, Science, or PNAS. That suggests that he published here because he didn't have a lot of options, because the scientific community was pretty unreceptive to evidence presented in this study. Obviously, the conventional wisdom isn't everything. Geologists hated the idea of continental drift, and the asteroid impact hypothesis got a very cold reception before the Chicxulub crater was found. But it's worth asking whether the evidence here is any good or not.
First off, it's not as if they've suddenly discovered dinosaurs where nobody expected them. Paleontologists have known for decades that these rock beds contain dinosaurs (as well as typical Cretaceous mammals). It's just that everyone else has always interpreted these rocks as being of Cretaceous age, rather than post-Cretaceous. What he's doing is arguing that the rocks are older than we thought.
Second, what's his evidence for saying these are post-Cretaceous rocks? The best evidence would be a marker bed- if you could show that a skeleton lay above the iridium layer formed by the fallout of the asteroid, then it would be pretty much unrefutable. However, the iridium layer has *not* been recognized in this area. The second best evidence would be a layer of volcanic ash which can be dated using radioactive dating. There are no ashes under the bones which are younger than 65.5 million years old (the date of the impact). In fact all the ashes under the bones are around 75-73 million years old. So his evidence is the pollen grains. He says they look like post-Cretaceous pollen, not Cretaceous pollen. That doesn't seem terribly convincing in my mind. Given that the mammals seen in the same rocks are pretty clearly Cretaceous type mammals, the fossil evidence is contradictory here. His other evidence is something called magnetostratigraphy- the Earth's magnetic poles reverse every few hundred thousand or million years, with series of normal and reversed polarities. If you can match up a series of polarity changes, you can *sometimes* figure out how old the rocks are. But it's not a very precise method, and it's a bit tricky to figure out where a particular sequence going "normal-reversed-normal-reversed" fits into the geological record. It's a bit like trying to figure out the time and date by whether your neighbor has his house lights on or off, or whether the trash has been picked up recently or not.
In short, it would take a lot more than this one paper to overturn the consensus that has resulted from one hundred years of scientific research. I mean, if someone published an experiment tomorrow saying that Einstein was wrong, what would your reaction be? To reject Einstein? Or to think that the experimenter might have screwed up? Currently, the bulk of the evidence says that the extinction took place 65.5 million years ago, and that (with the exception of birds) the dinosaurs didn't make it.
Oh. You want cites? Ah.
Look! A bunny! Look at the bunny! (runs away)
Oh come one, that's not even trying...
http://en.wikipedia.org/wiki/Tyrannosaurus#Skin_and_feathers