Posted on 07/16/2011 4:39:22 PM PDT by nickcarraway
A fossil discovered in Montana has given new momentum to the hypothesis that dinosaurs were thriving right up until a devastating meteor hit Earth 65 million years ago, causing their extinction.
Scientists from Yale University have found what is believed to be the youngest dinosaur fossil ever found, thought to be from just before the mass extinction took place.
The discovery, described in a study published in the online edition of the journal Biology Letters, contradicts the theory that the dinosaurs slowly went extinct before the cosmic impact.
The fossil -- a 45-centimetre horn believed to be from a triceratops -- was found in Montana's Hell Creek formation. It was located just below the K-T boundary, the band of the Earth's crust that represents the time period in which the meteor struck.
One of the main problems with the meteor theory has been the lack of any non-avian dinosaur fossils buried within 10 feet of the boundary -- known as the 'three metre gap.'
The absence of fossils, some paleontologists say, indicates dinosaurs were already extinct when the cosmic impact occurred.
Yale paleontologist Tyler Lyson, lead author of the study, says the new discovery proves otherwise.
"To all of our surprise the boundary was no more than 13 centimetres above this horn, and the significance is this indicates that at least some dinosaurs were doing quite well in this locale at the time of the meteor impact," he told CTV.ca.
There is evidence that avian dinosaurs thrived up to and into the K-T boundary. In fact, they are believed to have survived the meteor and evolved into modern-day birds.
(Excerpt) Read more at ottawa.ctv.ca ...
Now that Bobby “Big” Byrd and Uncle Teddy are gone, who is the last surviving dinosaur?
In evidence, number does not equal quality. Quality is what counts.
One single hair could get you the death penalty in a crime, if that hair was properly verified.
Unless, of course, you're Casey Anthony.
I agree.
A meteor/comet that large would punch a large hole in the ozone, and allow the atmosphere to escape into space. This would dilute the content, besides the other chemicals and gases that the meteor/comet and the explosion would ADD to it.
Death would probably come slow, with the creatures becoming erratic (losing their minds) from the lack of proper breathing atmosphere. Of course, this would all be dependent on their distance from the impact site.
Thanks. I understand that. But they can't really tell for sure, can they?
Paleontology has always been a competitive science with competing schools of thought trying to push their theory to acceptance.
My personal belief is somewhere between the two competing theories. I don’t think they were completely gone but were nearing extinction all by themselves. The fact that mammals were already on the rise seems to suggest that they were filling vacated ecological niches.
I also have problems with the animals that survived. Not all were aquatic dwellers or burrowers. Even some aquatic dwellers like alligators are shallow water dwellers and would have to survive years of super heating or super cooling depending on the global effects. Lots of insects that aren’t burrowers or swimmers survived.
I think it was a real bad time but not as bad is the impact extinctionists need it to be to exterminate a world full of dinosaurs.
Its all theoretical till somebody invents a time machine and proves it.
Your analysis of fluid dynamics is too simple. I believe that the Flintstones Show proves that Man and Dinosaurs co-existed.
In after the Helen Thomas pic!
As for the hyperbolic headline, it was written by some hack in a cubbyhole, not a scientist. I can find nothing in the article itself that says what the headline claims.
And what kind of headline says the youngest living dinosaur has been dead 65 million years? Is it young? living? or very old and very dead?
I want my Gansus not the Geico lizard in a feather boa looking like a cross between Jesse Ventura and Swamp Thing.
With the Dino-Asteroid theory unfortunately politics and the media got involved. It kind of caught fire with the anti-nuke movement in the 1980s (Nuclear winter killed the Dinos so just image what it can do to you kids so join us in stopping Reagan) and it’s used a lot to try and re-ignite the myth of the noble savage (If a meteor killed the dinos then maybe one or more killed all those animals instead of the peace loving ancient humans).
It also has a coolness factor, the dinos just capture our imagination and being wiped out by a meteor just has that great Hollywood type ending.
Those things keep the impact hypothesis going, despite the mounting evidence against it.
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It could even be a few million years. According to the history channel, there is a desert in Chile where the topsoil hasn't changed much for several million years.
The preponderance of evidence is, continues to be, and always has been, that the dinosaur die-off was basically immediate and due to the impact of at least one large object. This doesn’t preclude the possibility that the impactor arrived in more than one consecutive chunk, or that it came apart a very short time before impact. There has never been any evidence at all for gradual extinction (which is an oxymoron), and there’s no evidence that some kind of (undocumented, despite claims to the contrary) volcanism played any role at all. The same tired old arguments that were refuted twenty years ago keep getting trotted out by the same tired old unreconstructed Darwinian gradualists in the UK and by their eastern seaboard lackeys.
Impact forensic evidence announced
Jeff Poling
http://www.dinosauria.com/jdp/impact/forensic.html
[snip] When the object from space slammed into the earth, it punched a hole in the ground that, within minutes, rebounded to hurl superheated rock and steam back into the atmosphere. Some of the material was blown into space, while the rest fell to earth creating a parabolic swath of destruction that incinerated North America... Using seismic instruments to measure ballistics more than a kilometer below the Yucatan, the scientists found evidence that the initial crater gouged by the object was around 100 km in diameter. From this, the scientists concluded the object was 10 to 14 km across. They estimate that if the object was an asteroid, it was moving at 20 km/s. If it was a comet, it slammed into the earth going 65 km/s. [/snip]
[snip] 11/19/98 — A meteorite from the Cretaceous/Tertiary boundary (FRANK T. KYTE, Nature 396: 6708): Cretaceous/Tertiary boundary sediments are now widely recognized to contain the record of a large asteroid or comet impact event, probably at the site of the Chicxulub crater on the Yucatan peninsula. After nearly two decades of intensive research, however, much remains unknown about the specific nature of the projectile and of the impact event itself. Here we describe a 2.5-mm fossil meteorite found in sediments retrieved from the Cretaceous/Tertiary boundary in the North Pacific Ocean that we infer may be a piece of the projectile responsible for the Chicxulub crater. Geochemical and petrographic analyses of this meteorite indicate that it probably came from a typical metal- and sulphide-rich carbonaceous chondrite rather than the porous aggregate type of interplanetary dust considered typical of cometary materials. The fact that meteorite survival should be enhanced by impacts at low (asteroidal) velocities also implies that this meteorite had an asteroidal rather than a cometary origin. [/snip]
Researchers Study Ancient Rocks To Test Theory on End of Dinosaurs>
by Halimah Abdullah
July 9, 1997
http://query.nytimes.com/search/article-page.html?res=9C01E6D91239F930A15751C0A9679C8B63&fta=y
[snip] “If there was a major fire after the meteorite hit the earth,” Dr. Wolbach said, “we would see soot in samples from Denmark and around the world. We looked at sedimentary rocks 65 million years old from other geographically distant sites and found soot in them, too. The fire was a global phenomenon.” [/snip]
‘Quick’ demise for the dinosaurs
by BBC News Online’s Jonathan Amos
Thursday, 8 March, 2001, 19:01 GMT
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1209000/1209870.stm
[snip] The evidence comes from a study of rocks in Italy and Tunisia. The work lends support to the idea that a single, giant impact of an asteroid or comet was responsible for the mass extinction of life that occurred 65 million years ago... Sujoy Mukhopadhyay and colleagues studied sedimentary rocks that mark the so-called K-T boundary... 70% of all life, including the dinosaurs, suddenly disappears from the fossil record... They analysed the amount of helium-3 in the rocks of the K-T boundary... The research suggests the K-T boundary was deposited in about 10,000 years. He said the short period lent support to the theory that the dinosaurs were wiped out in a sudden, catastrophic event such as the impact of an extraterrestrial body. The constant rate of accumulation of helium-3 also indicates that the impactor was not part of a comet shower or bombardment... “The Deccan Traps erupted over much longer timescales — over 500,000 years or more. If the recovery of life starts after only 10,000 years, it is hard for us to see how the traps are influencing the mass extinction.” [/snip]
Dino asteroid led to ‘global devastation’
The impact would have shaken the affected planet
By Helen Briggs
BBC News Online
Thursday, 22 November, 2001, 19:32 GMT
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1670000/1670035.stm
[snip] The asteroid thought to have wiped out the dinosaurs destroyed plant life thousands of kilometres from where it struck, say scientists. Fossils uncovered in New Zealand point to major disturbances in climate that led to the death of most trees and flowering plants. Clues from the plant fossil record suggest that even the Southern Hemisphere experienced an artificial winter, acid rain, and raging forest fires. This is the first clear fossil evidence for destruction of plant life so far from the Mexico coast, where the space object is believed to have landed. Dr Timothy Flannery, an expert at the South Australian Museum in Adelaide, told BBC News Online: “The asteroid devastated pretty much everything. This was a case of global devastation rather than North American catastrophe.” [/snip]
Pfft, everyone knows that Denver was the last dinosaur.
Yeah, it sort of just hits you.:)
Huh?
Wrong thread, sorry.
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