A giant crocodile with a bulging shield of thickened skin on its forehead lived among dinosaurs, a new study reports. The reptile, which researchers are calling Shieldcroc, lived about 95 million years ago, during the Cretaceous period.
A partial specimen suggests its skull was 5 feet long, said Casey M. Holliday, a paleontologist at the University of Missouri who led the study. "An animal with a head that big," he said, "is looking at a body 25 to 35 feet."
Today's crocodiles seldom exceed 20 feet.
Blood-vessel scars on the fossilized skull suggest the presence of a large shield on the crocodile's forehead.
"It was a thickened skull spot, to signal to mates or target adversaries," Holliday said.
The findings, by Holliday and Nick Gardner, an undergraduate at Marshall University in Huntington, W.Va., are reported in the journal PLoS One.
The fossil was originally uncovered in Morocco, and then sold to the Royal Ontario Museum in Toronto, where the skull will be put on display this year.
Up and running: First atomic X-ray laser
Scientists at Stanford Linear Accelerator Center have created the world's first atomic X-ray laser.
The researchers in Menlo Park, Calif., aimed SLAC's Linac Coherent Light Source at a capsule of neon gas, setting off an avalanche of X-ray emissions to create the shortest, purest X-ray laser pulses ever achieved.
"X-rays give us a penetrating view into the world of atoms and molecules," said physicist Nina Rohringer of Germany's Max Planck Society in a news release.
She led the research in collaboration with scientists from SLAC, the Department of Energy's Lawrence Livermore National Laboratory and Colorado State University.
"We envision researchers using this new type of laser for all sorts of interesting things, such as teasing out the details of chemical reactions or watching biological molecules at work," she said.
The news was reported in the Jan. 25 issue of the journal Nature.
San Jose Mercury News
Distracted by very dapper fish
The males of certain species of fish have a yellow band on the tailfin. Females seem uncontrollably drawn to it - and sometimes, a new study suggests, that can be their downfall.
Pregnant females, it seems, can mistake the band for a tasty worm or a damselfly, becoming so distracted by the yellow that their foraging abilities are diminished.
"You can imagine a female trying to feed on damselfly or worm, but a male passes by and she is distracted," said Constantino Macias Garcia, a behavioral ecologist at the National Autonomous University of Mexico, who led the study. "The female doesn't have interest in mating at this point but is attracted and instead loses a feeding opportunity."
He and a colleague, Yolitzi Saldivar Lemus, report their findings in the current issue of Proceedings of the Royal Society B.
The yellow-banded species they studied all belong to a family of North American fish known as Goodeidae.
Even in species where females have evolved to learn that the band is not food, they are still drawn to it, the researchers found.
New York Times
