Thread: Maybe Dinosaurus didn't die from meteor.

I was talking to a friend,and he told me about this article:

Maybe an Asteroid Didn't Kill the Dinosaurs - TIME

I was curious,how come dinosaurs fossils are below the iridium layer caused by the metorite?
Does this mean dinosaurs didn't extinct from meteorite strike?

my feeling is that the general thinking is that the dinosaurs were already under stress from the massive magma outpourings of the Deccan traps, something to which the impactor which caused the iridium layer may well have added enough grief to tip them over the edge - whether that would have meant instantaneous extinction or a somewhat protracted one is debatable

I'd imagine the megafauna dinosaurs so to speak (such as brachiosaurs, allosaurs, and T-Rexs) most likely would have died out. However, smaller species could have survived, as their energy requirements were not as large.

I read light-sensitive species survived,and extinctions don’t correlate with crater dates.
I also read the iridium enrichment, supposedly a key proof of meteor impact, is not nearly as clearly defined as claimed.

Within experimental error, the Deccan eruptions and the asteroid strike are very close in time. There is a school of thought that suggests the strike caused the eruptions. Allowing for continental drift, the strike spot, and the Deccan traps were opposite sides of the globe. The speculation is that seismic waves carrying immense energy travelled around the world, and reinforced when they reached the point where the eruptions took place. Like a lens focussing sun rays to light a fire, the seismic energy was focussed on one point, to trigger eruptions.

I do not know if this is true. If so, the extinctions, even if caused by the eruptions, were still ultimately a result of the asteroid impact.

The consensus view remains that, at the very least, the impact played a part in the end Cretaceous extinction event. But this remains a disputed area. At present we appear to lack the data to give a definitive answer.

For me the smoking gun is the upsurge in ferns. Something led to a catastrophic failure of the ecology and the demise of much of the planets plant life. I find the 'nuclear winter' from a bolide strike more likely than one from rampant vulcanism.

I will note that 300,00 years is for a ll intents and purposes a geologic blink of an eye. There are very very few dinosaurian fossils found below the iridium layer, and many of those have been called into question re: initial or secondary deposition.

Originally Posted by John Galt

The consensus view remains that, at the very least, the impact played a part in the end Cretaceous extinction event. But this remains a disputed area. At present we appear to lack the data to give a definitive answer.

For me the smoking gun is the upsurge in ferns. Something led to a catastrophic failure of the ecology and the demise of much of the planets plant life. I find the 'nuclear winter' from a bolide strike more likely than one from rampant vulcanism.

I am inclined to think that both were working to alter the climate.

Originally Posted by Paleoichneum

I will note that 300,00 years is for a ll intents and purposes a geologic blink of an eye. There are very very few dinosaurian fossils found below the iridium layer, and many of those have been called into question re: initial or secondary deposition.

You mean above the iridium layer?

I meant in sediments younger then the iridium layer. Apologies for any confusion.