UPI NewsTrack Health and Science News July 22, 2008

Digger's find bites into Japanese record

HAKUSAN , Japan, July 22 (UPI) -- An amateur fossil-hunter's recent dig had some biting results: the discovery of what may be the largest dinosaur tooth found in Japan.

Experts said they think the tooth Satoshi Utsunomiya unearthed in Hakusan belonged to a therapod, a group of meat-eating dinosaurs that includes the Tyrannosaurus rex, The Yomiuri Shimbun reported Tuesday.

The nearly perfectly preserved tooth measures 3.2 inches long and is 1.1 inches at its widest part.

One expert called the Hakusan tooth "the largest specimen found in perfect condition in this country," the newspaper reported.

A former director from the Hakusan Dinosaurs Park Shiramine and the Palaeontological Society of Japan authenticated the tooth.

Japan's National Museum of Nature and Science said the largest tooth found previously in Japan was 2.9 inches long and was found in Mifunemachi in 1979.

Ants go marching using vector navigation

ZURICH, Switzerland, July 22 (UPI) -- Ants traveling in the desert's relentlessly featureless terrain use vector navigation to plot their course, researchers at the University of Zurich found.

The strategy allows desert ants to integrate direction, distance and incline as they travel, the scientists said in an article published in Frontiers in Zoology.

In their study of desert ant locomotion performed on differently slanted surfaces, the researchers said they wanted to examine what mechanisms ants used to estimate step length and inclination.

In a related experiment with ants foraging on slippery surfaces, researchers said they were able to separate the relationship between stepping frequency and step length to examine the ants' ability to gauge distances covered those adverse conditions.

Once they removed the effect of speed, the researchers said they demonstrated slope had only a "marginal influence" on their travels.

The researchers said they think sensing mechanisms on the ant's legs could provide the correlation in monitoring inclination and step length.

Milkweed's defenses evolve to repairs

ITHACA, N.Y., July 22 (UPI) -- The milkweed adheres to the adage "Know your enemy" by using fast repair work when its defenses are damaged by hungry caterpillars, U.S. researchers said.

Cornell University researchers examined the way milkweed evolved to the monarch butterfly caterpillar's changing attempts to disarm the plant, the Ithaca, N.Y., university said in a news release.

They found the plant may be evolving away from its defenses against certain caterpillars toward repairing themselves faster than caterpillars can eat them.

"Some plants seem to have shifted away from resisting (plant-eating animals) and have taken that same energy and used it to repair themselves," said Anurag Agrawal, Cornell associate professor of ecology and evolutionary biology and lead author of a paper in the current issue of the Proceedings of the National Academy of Sciences.

Agrawal and Mark Fishbein, a Portland State University biologist, found evolutionary declines in milkweed's three main resistance traits -- hairs, cardenolides and latex -- and an escalation in the plant's ability to regrow.

One reason, Agrawal said, could be because as its predators have become so specialized, the plant was better off choosing a new defensive tactic "to tolerate the herbivory (plant-eating) damage instead of resisting it."

Center opens in wildlife-rich Bioko Island

MALABO, Equatorial Guinea, July 22 (UPI) -- A new wildlife research station in Equatorial Guinea's Bioko Island should be a boon for conservation and educational opportunities, its U.S. founder says.

Located in a mountainous virgin rain forest, the Bioko Biodiversity Protection Program will provide training and research for scientists, students and others interested in the island's cornucopia of fauna and flora, said Drexel University professor Gail Hearn in a release.

The island's sheltered location provides endangered monkeys and other wildlife a chance to thrive in relative abundance, Hearn said. Eleven species of primates -- including Africa's endangered drill money and Pennant's red colobus monkey -- call Bioko Island home, and four species of endangered sea turtles excavate thousands of nests on the southern beaches.

"We are delighted to see this research station open," Hearn said of the joint educational project between the National University of Equatorial Guinea and Drexel of Philadelphia. "It will serve as the linchpin of conservation efforts throughout the island, attracting scientists and students from around the globe to collaborate with local researchers and enrich our understanding of Bioko Island's unique natural heritage."

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