The old big bang theory of animal evolution pegged the appearance of birds at the end of the Cretaceous. That is to say, the 'new' animals such as birds and mammals were able to evolve into great diversity only after the dinoaurs had their big death. A new fossil from the Creatceous is contesting that classic theory.
The partial skeleton, found on Vega Island, western Antarctica, in 1992, is clearly a waterfowl and is "most closely related to Anatidae," a bird classification which includes modern ducks, they say.
That requires a rethink of the "big bang" bird theory, for it implies that the forerunners of modern ducks, chickens, ostriches and emus were around during the Cretaceous, authors say in a study published on Thursday in Nature, the weekly British journal.
"At least duck, chicken and ratite bird relatives were co-extant with non-avian dinosaurs," the authors believe. The find has been baptized Vegavis iaii. The first word is an amalgam of Vega and avis, the Latin for bird, while iaii is taken from the initials for the Argentine Antarctica Institute (IAA) whose members collected the specimen.
If Bugs and Duffy ever want to dispute whether Rabbit seaosn or Duck season came first, Daffy would have a better case.
Talk about an early peak for the peeking duck... b'boom.
Global Warming Redux (re-ducks?)
While it seems rather neurotic to worry about th end of the world that won't happen in one's own lifetime, it is clearly un-sentient of a species not to consider the previous deaths of earlier species. Especially a Great Death that befell the mighty dinosaurs. So in the spirit, here's an article claiming that it wasn't an asteroid hit, it was global warming that did it.
But ducks could. Go mighty ducks.There has been recent evidence that a big asteroid or meteor hit the Earth and triggered the catastrophe, but researchers say they now have evidence that something much more long-term -- global warming -- was the culprit.
Kliti Grice of Curtin University of Technology in Perth, Australia, and colleagues studied sediment cores drilled off the coasts of Australia and China and found evidence the ocean was lacking oxygen and full of sulfur-loving bacteria at that time.
This finding would be consistent with an atmosphere low in oxygen and poisoned by hot, sulfurous, volcanic emissions, they wrote in a report published in the journal Science.A second team led by Peter Ward at the University of Washington looked at fossil evidence in South Africa and found little evidence of a catastrophe and instead signs of a gradual die-off. They examined 126 reptile and amphibian skulls from the Karoo Basin in South Africa, where there is an exposed piece of dried sediment from the end of the Permian Era and the beginning of the Triassic, 250 million years ago.
They found two patterns, one showing gradual extinction over about 10 million years leading up to the time of the extinction, and then a spike in extinction rates that lasted another 5 million years, Ward's team reported.
"Animals and plants both on land and in the sea were dying at the same time, and apparently from the same causes -- too much heat and too little oxygen," Ward said in a statement. Ward also believes mass volcanic eruptions may have pumped greenhouse gases into the air, which would have trapped heat in the atmosphere
and raised temperatures."I think temperatures rose to a critical point. It got hotter and hotter until it reached a critical point and everything died," Ward said. "It was a double-whammy of warmer temperatures and low oxygen, and most life couldn't deal with it."
- Art Neuro
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