Comments on: New Wrinkle to the Story of the Last Dinosaurs

By: Annibale bocca

Annibale bocca — Sun, 13 May 2012 15:45:10 +0000

Number and localisation of specimen considered are statistically insufficent for a conclusive theory. In a distressing environment small animals can survive more easily than big ones. (almost) total extinction takes time and is gradual even if the primary case is unique. Primary effects will sometimes become cause of secondary effects, and so on.

By: Dan in MO

Dan in MO — Thu, 10 May 2012 14:51:05 +0000

Thanks for the story from a geologist and dinophile. Hooray! Logic is not dead.

By: Aaron in NM

Aaron in NM — Mon, 07 May 2012 21:52:12 +0000

It’s interesting that hadrosaurs & ceratopsians were declining while tyrannosaurs held steady. I remember learning that the primary prey of tyrannosaurs were probably hadrosaurs and ceratopsians. This was admittedly a long time ago (when I was a kid back in the 80s-90s), and science may have changed. But, is it possible that even though species diversity was decreasing, the absolute numbers of individual dinosaurs didn’t decline? For a modern example, European settlers in America encountered only one large grazing herbivore species (bison), but their numbers were in the millions.

By: Catherine Moore

Catherine Moore — Sun, 06 May 2012 20:30:44 +0000

The asteroid impact had nothing to do with fire and burning and everything to do with a vast amount of dust kicked up into the atmosphere. The debris took years, or even decades, to drop out of the atmosphere and resulted in far less sunlight reaching the surface. No sunlight -> no plants. No plants -> no food. Less sunlight will also make the temperature drop dramatically; those organisms who are cold-intolerant will suffer more than those who are more flexible. The big animals will drop out first. The smaller ones will be able to get by on what they can scrounge from scavenging and the smaller degree of plants that manage to pull through the darkness. There will also be a seedbank in the dirt that will survive a few years and sprout when conditions improve. The trick is getting through the dark days.

By: Neal W. Welsh

Neal W. Welsh — Sun, 06 May 2012 17:16:29 +0000

Here we go with another infusion of opinion from the ignorati and irrationalista in which a reach for biblical answers to scientific questions occurs. No wonder we rank something like 14th in the world arena of the educated. The last dinosaur died out at least 64 millions of years before the first humanoid ever made an appearance. The Bible is not a scientific treatise but is a compendium of religious folklore infused with mysticism. This is hardly a tool for rational scientific investigation. That’s it. No more explanation is required.

By: Richard

Richard — Sun, 06 May 2012 17:07:02 +0000

All I can say is who cares except those making their living by writing about it !!!

By: Vrahno

Vrahno — Sat, 05 May 2012 22:42:29 +0000

Why does this study seem to attract K/Pg extinction theorists? I came across another article on another site discussing the same study, and it had some weirdo making a speech in the comment section about how the mammals ate the dinosaurs, thereby driving them to extinction…

By: acson005

acson005 — Thu, 03 May 2012 10:01:05 +0000

It has been for quite sometimes accepted that the Dinosaurs were killed off by a massive impact in the gulf of Mexico but in the absence of Charcoal near and far from ground zero at the time of impact definitely ruled out any burning that we have been shown over and over in animations of the hellfire that killed the Dinos. We have not even found any charred Dinosaur bones of any kind. The scientific community will have to grow away from their obsession with the impact theory if they want to find the scientific truth. How about an alien virus…? It will only take few years if not months to kill them off if aliens of the human kind decided to colonize earth.

By: Barbara Land

Barbara Land — Thu, 03 May 2012 05:20:27 +0000

At the risk of being politically incorrect, or unscientific; They all died out during the flood of Noah’s time. That’s why some had food in their mouths. And why all kinds of animals who normally wouldn’t be found together were often found together; in caves & trenches, etc.

By: Chad in AK

Chad in AK — Thu, 03 May 2012 00:43:05 +0000

Everything becomes simple and clear when you understand that all planetary bodies and moons are growing and increasing in mass. The Earth has a (possibily periodic) growth that increases gravity. There were no big oceans early in dinosaur history. The Earth was much smaller with much less gravity, and that is what enabled the big dinosaurs to be fast, and that is also what killed them off first as gravity increased. The evidence for planetary body and moon growth can be easily seen in all the crusts on the surface. I can’t believe scientists ignore this. It is so obvious.

By: CC

CC — Wed, 02 May 2012 17:05:47 +0000

Talking about global changes and the effects on species, there is another paper coming out which also takes an interesting approach:

http://archaeologynewsnetwork.blogspot.com/2012/04/palms-reveal-significance-of-climate.html

By: Chris Noto

Chris Noto — Wed, 02 May 2012 16:53:18 +0000

I find it particularly interesting that smaller taxa, both carnivore and herbivore, maintained greater disparity/diversity (what the relationship between disparity and diversity is is still debatable). This fits well with ecological theory when studying environments under stress: megafauna are almost always affected first and more strongly. What about sauropods? It could be that their more generalized feeding habits insulated them from some of the ecological/climate changes occurring at the very end of the Cretaceous, whereas the ceratopsians and hadrosaurs were more specialized and suffered as a result. In any case, I’m very pleased to see a more nuanced approach to questions of mass extinctions and large-scale, global changes. This approach will no doubt be useful in studying other periods of massive faunal turnover.

By: Laura Peterson

Laura Peterson — Wed, 02 May 2012 15:36:25 +0000

At any given time there will be species on the rise and species in decline. And even extremely successful species like modern Homo sapiens have gone through MINISCULE bottlenecks. Finding one or even a few examples of species in decline only informs on one species, it’s not proof of a large-scale pattern.

By: Kevin

Kevin — Wed, 02 May 2012 03:43:43 +0000

Love that Troodon reconstruction.

By: BJ Nicholls

BJ Nicholls — Tue, 01 May 2012 21:21:01 +0000

For this paper, one can’t even see the paywall price without registering first.

I’m no statistician, but I often wonder if the relatively tiny sample universe for dinosaur fossils is large enough to make a survey like this meaningful — except as a snapshot of what’s in collections at this moment.