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."

Other findings.

[Mr2cents]

Just a day ago, I read another article claiming that the impact predates the extinction event by 300000 years [spacedaily.com]. The last thing hasn't been said about the dinosaurs, that's for sure. I really like the way David Polly puts it in the article (the one linked to by /.): "Finding conclusive evidence, however, is a difficult matter when the crime scene is 65 million years old".

Re:But of course

[Anonymous Coward]

Some LARGE dinosaurs survived.
Where are the 50 ton birds?

Surprising?

[TFer_Atvar]

After reading the abstract, it sounds very interesting. I do have one big question: Do the remains show any difference from similar specimens prior to the K-T boundary? When you have small, isolated populations, you tend to get rapid evolution to suit the species to that specific area. If this small group of animals survived in an isolated fashion, I'd expect some sort of physiological drift from the mainline in order to compensate for their unique area.

If they don't show much difference, I have to wonder what, if anything, this says about the K-T event itself; whether it created a long-term climatological change in addition to a catastrophic change evidenced by the K-T geologic boundary. I'm also intrigued by the fact that these specimens were found in Colorado/New Mexico, which is pretty darn close to the best impact site candidate. I'd expect any animals that survived to be much further away.

Re:Other findings.

[Burnhard]

I wrote a paper on this many years ago, concluding that the KT event caused extinctions in species already in decline. For example, the Ammonoidea were becoming less numerous for ten million years before the impact. But previous posters are quite correct, the Dinosaurs are survived by Birds!

cautionary notes from a paleo geek

[Dr_Snugglebunny]

2 points to be aware of: 1. The journal this is published in is not held in high esteem by most paleontologists. This may be telling; I imagine the paper was rejected by several other journals before ending up here. Peer review seems a little light at PE. That doesn't mean it's wrong, but calls for caution. 2. Everything hangs on the authors' interpretation of the age of the sediments; the bones don't seem reworked (i.e. moved around from older sediments), which is one source of error, but he could be wrong with the radiometric age estimation, which even in the best cases has a moderate margin of error. BUT it remains an interesting question of any dinosaurs survived long past the extinction; most of our picture of the K-T event comes from central/western North America, so who knows what happened elsewhere.

Re:Other findings.

[nyctopterus]

The problem with the "already in decline" arguments is that there are statistical effects [wikipedia.org] that make sudden extinctions look gradual. This has pretty much been demonstrated to be the case for Late Cretaceous dinosaurs (I don't know about ammonites).

People want to cling to the K/T extinction being a mystery for some reason. It just isn't anymore. If you want a good mystery, the Permian-Triassic extinction event [wikipedia.org] is bigger, and still (relatively) unexplained.

Re:Other findings.

[jellomizer]

Unfortunatly a lot of people don't like that idea. Not because of the science but because it puts us an other chip down. So most people are willing to accept evolution, but they take comfort their ancestors who resembled mice were in some way so much more superior then those giant monsters, and could survive a mass extinction while those huge monsters couldn't. We are just getting to the point where we can grasp that some dinosaurs evolved into birds, however we kinda are wishing they were more birdlike before the mass extinction.

Re:Fossil records cannot be show extinction dates

[nyctopterus]

That would be true if the sample is small (which to a certain extent it is). We will never "prove" (proof is for mathematicians) that a bunch of things went extinct on a certain date, but we can built a compelling statistical likelihood.

Re:Cavemen?

[jbengt]

Cats have very inefficient digestive systems, and, ignoring the possibility of parasites, the sad fact is that there's probably more nutrition, protein especially, in cat feces than in many commercial dog foods.
Still disgusting, though.

Re:Cavemen?

[Patch86]

For the cat faeces to be more nutritious than dog food, cat food would have to be significantly more nutritious again.

Have you any idea exactly how much ash there is in cat food...?