Wednesday, December 14, 2011

Fossil eyes

An international team led by scientists from the South Australian Museum and the University of Adelaide discovered exquisite 515-million-year-old fossils with eyes that look like squashed eyes from a recently swatted fly. Just published in Nature are the details of the eyes, which measure 2-3cm and were found in shale on Kangaroo Island, South Australia. They belonged to an ancient shrimp-like "superpredator" that may have been up to 6' long. Each eyeball had 16,000 lenses,demonstrating that primitive animals had excellent vision. A lens produces a pixel of vision, so more lenses mean more pixels and better visual resolution. The creatures had sharp vision and would have been capable of seeing in dim light, in contrast to other marine animals, which would have seen a very blurry world with only about 100 pixels. "Given the tremendous adaptive advantage conferred by sharp vision for avoiding predators and locating food and shelter, there must have been tremendous evolutionary pressure to elaborate and refine visual organs."


Feathers in amber Scientists at the University of Alberta surveyed more than 4,000 amber deposits and found 11 sets of feathers so well-preserved that they were even able to distinguish their colors. They also contained samples of each stage of feather evolution. "All the feathers are preserved down to micron scale, showing indentations and pigmentation. It’s also the first time we've found protofeathers [feathers thought to belong to nonavian dinosaurs] preserved in amber," said team leader Ryan C. McKellar.

Colors of ancient birds Paleontologists at the University of Manchester have used an x-ray technique to unlock the color patterns of the oldest example of a modern bird in the fossil record and the earliest beaked bird. Roy Wogelius explains, "[Eumelanin] controls the dark and light patterns of an animal, so for Confuciusornis sanctus, for example, we can see that its body and the neck were black and its wings were patchy. For years people had been looking at these fossils thinking that the feathers were just impressions. We showed that they have chemistry."

Whale graveyard A group of Chilean and American archaeologists have uncovered the remains of more than 75 fossilized whales dating back 7 million years in the Atacama desert. The finds include a family group (mother, father, and baby), as well as fossilized sharks, dolphins, and seals. “It is one of the richest sites because we have found new species and the discovery has huge significance,” said chief paleontologist Marion Suarez.

Dig shuts down A site in the United States, which has yielded the fossilized remains of 15 mastodons and numerous plants, has closed down after 29 years. "The Hiscock Site, in Northeastern Genesee County, New York is considered one of North America’s most important locations for fossils and archaeological artifacts from the late Ice Age. Discovered in 1959, the site is has been continuously excavated by the Museum since 1983. The owners donated 10 acres to the Buffalo Museum of Science in 1989."

20-million-year-old skull A team of French paleoanthropologists working in northeastern Uganda have excavated fossilized remains that may have belonged to a common ancestor of humans and the other great apes. Leader Martin Pickford says. “Finding the skull of Ugandapithecus is really going to focus the debate on that particular linage, but we must not forget there were quite a few other species running around at the same time. My gut feeling at the moment is that it’s not far from the ancestor of modern African apes and orangutans. I’ve been waiting for about 30 years for this kind of discovery.”

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