A new paper in New Mexico Geology has the following rather tendentious title:
Fassett, J.E. 2007. The documentation of in-place dinosaur fossils in the Paleocene Ojo Alamo Sandstone and Animas Formation in the San Juan Basin of New Mexico and Colorado mandates a paradigm shift: dinosaurs can no longer be thought of as absolute index fossils for end-Cretaceous strata in the Western Interior of North America. New Mexico Geology 29(2):56.
Ack! He mentioned the p-word! Now I have to find him and extract his teeth without anesthetic.
So here's the abstract:
Extensive geochronologic studies of the rocks adjacent to the Cretaceous-Tertiary (K-T) interface in the San Juan Basin have now provided compelling data attesting to the Paleocene age of the dinosaur-bearing Ojo Alamo Sandstone in New Mexico and the Animas Formation in Colorado. These data consist of radiometric age determinations for Cretaceous strata underlying the K-T interface and palynologic, paleomagnetic, and geochemical evidence attesting to the Paleocene age of the strata above the K-T interface. The identification of the paleomagnetic normal interval - C29n - in the dinosaur-bearing lower part of the Ojo Alamo Sandstone in the southern San Juan Basin at multiple localities allows for the precise dating of the last occurrence of Paleocene dinosaurs at the top of chron C29n at 64.432 Ma.
The conventional wisdom (entrenched dogma) among most geologists, and especially among vertebrate paleontologists has been, for more than 100 years, that all dinosaurs became extinct at the end of the Cretaceous. Thus, dinosaur bone found in place in a formation provided indisputable evidence that the formation was Cretaceous in age. Now, with the discovery of Paleocene dinosaurs, the paradigm of Cretaceous-only dinosaurs must shift. Let us hope that this paradigm-shift will be a smooth and placid lateral-slip along planar fault blocks rather than a grumbling, rumbling, herky-jerky sliding of jagged-edged, opposing sides past each other. Science must always be conservative and accept such paradigm shifts only on the basis of the most solid evidence, however, when the data do finally speak, the shift must be accepted by all of us who follow the data in the noble pursuit of finding out how the world was made.
On this, T Dykes had this to say on the Dino-L list:
I kind of heard a rumour that a group of maniraptor dinosaurs were sort of already known to have survived the K-T extinction event(s). Allegedly, they subsequently radiated and are presently represented by 9,000 or so species. In the face of that, this paradigm can't have needed much shifting.
I'm also not sure what "absolute index fossils" are or how, absolutely, anybody might try to use them. Perhaps somebody might enlighten me upon this.
<<The conventional wisdom (entrenched dogma) among most geologists, and especially among vertebrate paleontologists has been, for more than 100 years, that all dinosaurs became extinct at the end of the Cretaceous.>>
Holy cow! There was no convincing evidence showing the presence of any living non-birdy dinosaurs beyond about 65 million years ago, and this was well accounted for by the last of them all having dropped dead. That was the entrenched dogma. It happened to be supported by the available evidence, so the entrenched dogmatists accepted it (although, as mentioned, this doesn't entrenchedly dogmatically apply for "all dinosaurs". Many entrenched dogmaticists entrenchedly and dogmatically accepted the aforementioned gang of maniraptor cats failed, in fact, either entrenchedly or dogmatically to drop dead).
As far as I know, not wishing to be seen as a spokesperson of the entrenched dogmatists, the available evidence until now indicated the last non-birdy dinos dropped dead 65 million years ago. Fassett believes he has evidence indicating some actually dropped dead exactly 568,000 years later. Goody. Perhaps he's correct. If so, the entrenched dogmatists would have to radically shift their paradigm from: "The last non-birdy dinos dropped dead about 65 million years ago". This would now have to read: "Just about the last non-birdy dinos dropped dead about 65 million years ago."
Wow, that would be radical, the addition of the words "just about". I'm not sure I could cope with that degree of paradigm shifting.
In fairness to Fassett, this reaction is definitely of the knee-jerk variety to a merely quick perusal of his abstract. I'm sure his paper may be of great interest...
And that, my friends, is how to treat a paradigm shift... give it the bird.
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When I see phrases like "paradigm shift" and "entrenched dogma" I get a little worried. Aren't those the exact words crackpots use?
Crank references to Kuhn aside, this observation of Fassett does qualify. Yes, it is only 0.5 million years beyond the K-T, but what we don't know is what strata and sequences were attributed to being within the Cretaceous solely on the basis of fossils thought to correspond. It would not surprise me that the lineage terminates not at the K-T but into the Eocene. I say this only that the catastrophism associated with the dinosaur's demise would seem to work better with a coup de grace from the Eocene heating. Of course, that presumes they went out with a bang rather than a whimper.
Mike
Wait, so it's the prevailing wisdom that all the dinosaurs dropped dead at exactly the same time, right at the K-T boundary? I always thought it was a gradual process. And this isnt a new thought, cursory searching shows that there was a paper in 1986 (Sloan, et al) suggesting dinos lived at least 40K years after the K-T, and one in 2001 (Fassett, et al) suggesting dinos lived up to 1M after the K-T. So if Fassett presented this already 5 or 6 years ago, (http://www.gsajournals.org/perlserv/?request=get-abstract&doi=10.1130%2…) Why the hullabaloo now?
I can already hear the clink of creationist hammers mining that paper for quotes :-(. I mean, if evolutionists ever change there minds about anything -- even the tiniest detail -- it means the whole thing is supsect, right? So I shudder to think what a "paradigm shift" must imply....
Does the paper say what kind of dinos they found? Were they particularly unrelated to birds?
Damn, if you're gonna write a grandiose abstract like that, why not just go for broke and compare yourself to Galileo and allege you're being persecuted?
This guy's discovery might be really significant. But when people puff up their own work like that, I get suspicious. Just do your job, and let the historians decide whether or not it counts as a "paradigm shift".
off topic, but i saw you were interested in the prehistory of anatolia over at gene expression. this work by kristiansen and larson, The Rise Of Bronze Age Society is the best source i have yet found. it is very interesting covering the middle and late bronze age.
Wilkins Tautology: There Are No Paradigm Shifts.
No episodes in science have brought about the sudden and conceptual revolutions in theory that Kuhn devised. Not even the ones he adduced as evidence.
Wilkins Tautology: There Are No Paradigm Shifts.
No episodes in science have brought about the sudden and conceptual revolutions in theory that Kuhn devised. Not even the ones he adduced as evidence.
John, have you fleshed this comment out anywhere? It would make for an interesting blog post.
Hell, not since undergraduate studies (I did a long essay on Kuhn back when Kuhn was relatively fresh). But I cannot find any such revolutions (I. Bernard Cohen is a source here, if failing memory serves).
I note this is an abstract for a conference talk rather than a formal paper... it doesn't quite excuse the ever-so-slightly self-pitying tone, of course.
I'm also wondering why its necessary, because if he has the data he claims, it's a fairly straightforward interpretation. Sadly all the paridigm huffing and puffing means that the interesting question - the nature and diversity of these post-KT dinosaurs compared to the pre-KT dinosaurs - is left unanswered.
I've always been of the understanding that paleontologists were a little uncomfortable with some Pythonesque 1000lb weight crashing on non-avian dinosaurs at the KT boundary. I don't see how a potential find that actually makes much more sense can be considered a paradigm shift. I realize some people worship Kuhn, or at least run around trying to find some reason to invoke him, but this certainly does not seem to be such an occasion.