From what I can find, The earliest ungulates go back 90 million years
Some birds do burrow, or take over existing burrows.
Yeah a few, But the vast majority do not and the vast majority of birds seemed to come through with no problem.
Plus even if Alligators and Frogs were underwater during the impact wouldn't they die when they came up to breath?
Many species of frog burrow into the mud and estivate during the summer or drought.
And many do not,
I can see some frogs and possibly some birds making it but all of them? No way!!
No particular reason 'gator eggs wouldn't survive, as you contend some dino eggs did. (KEWL!)
Because whether a gator is a male or female depends on the temperature the eggs are exposed to, So even if they survived the heat blast the global winter afterwards if it didn't kill them outright it would guarantee all gators would be born the same sex, So they would have gone extinct eventually anyhow.
And I don't contend that, the Geologist (of course) who found the fossils is guessing/wishing it. Geologist tend to make up all kinds of crazy things when they find something that conflicts with the Dino-Asteroid hypothesis (see the "Iridium is missing from the Chicxulub crater itself!!!!" link I posted before, The findings in that report clearly show that whatever happened at Chicxulub has nothing to do with the K-T yet the scientists refuses to even consider the possibility, They even go as far to say so in the paper, and instead they come up with all kinds of crazy explanations)
But it does bring up a good point in regards to this article, If gator eggs could survive the heat blast why couldn't buried Dino eggs around the world (not just in New Mexico) survive?
Just a guess - Bottom layer large/or low ejection angle (initial impact) spherules that settled out early. Mid layer turbite marls for the seiches of water sloshing in the Gulf of Mexico basin. Top layer lighter/high ejection angle (carbonate decomposition driven) ejecta.
No, The two spherule layers can not be from the same Asteroid.
Another picture of the duel sphere layer from the Geological society
|Figure 3. El Penon, Mexico. Impact spherule layer at base of siliciclastic deposit is separated by a 15-20 cm thick sandy limestone. J-shaped burrows infilled with spherules are present in the sandy limestone and sandstone unit above. This indicates that both the spherule and sandstone units were deposited over an extended time period that excludes tsunami deposition.|
I see most of the data supporting an impact and impact triggered vulcanism as consistent with the pattern of victims and survivors. I don't see anything that doesn't fit the hypothesis.
I see vulcanism being the reason or having a part in the demise of the Dinosaurs and other creatures but not an Asteroid.
Another thing to note is there is increasing evidence that the Chicxulub crater predates the end-Cretaceous mass extinction by about 300,000 years. (More info here and here).
We are clearly operating off subtly different data sets, and have reached differing conclusions. It will be fascinating to see where and how we converge on a consistent understanding.
We will, Once the Asteroid killed the Dinosaurs hypothesis is finally extinct.
Once again, excellent post. This is why I love FR!
You might then enjoy this article http://forteantimesmag.co.uk/articles/111_asteroid.shtml (Yeah, Yeah , I know what site it comes from but it's the best take on this "Controversy" I've seen)