Category Archives: Nature

Ancient Giant Turtle Fossil Revealed

Picture a turtle the size of a Smart car, with a shell large enough to double as a kiddie pool. Paleontologists from North Carolina State University have found just such a specimen – the fossilized remains of a 60-million-year-old South American giant that lived in what is now Colombia.

The turtle in question is Carbonemys cofrinii, which means “coal turtle,” and is part of a group of side-necked turtles known as pelomedusoides. The fossil was named Carbonemys because it was discovered in 2005 in a coal mine that was part of northern Colombia’s Cerrejon formation. The specimen’s skull measures 24 centimeters, roughly the size of a regulation NFL football. The shell which was recovered nearby – and is believed to belong to the same species – measures 172 centimeters, or about 5 feet 7 inches, long. That’s the same height as Edwin Cadena, the NC State doctoral student who discovered the fossil. (more…)

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Counting Horseshoe Crabs

Marine science majors conduct field research with horseshoe crab census

Wearing sneakers and rain boots, University of Delaware freshmen got their feet wet as marine biologists recently while counting horseshoe crabs along the Delaware Bay. The students participated in a monitoring effort to gain firsthand experience in field research with their fellow marine science majors.

“Where else can you go on a Saturday night to count horseshoe crabs?” freshman Will Goldman said. (more…)

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First Satellite Tag Study for Manta Rays Reveals Habits And Hidden Journeys of Ocean Giants

Using the latest satellite tracking technology, conservationists from the Wildlife Conservation Society, the University of Exeter and the Government of Mexico have completed a ground-breaking study on a mysterious ocean giant: the manta ray.

The research team has produced the first published study on the use of satellite telemetry to track the open-ocean journeys of the world’s largest ray, which can grow up to 25 feet in width.

Researchers say the manta ray—listed as ‘Vulnerable’ by the International Union for the Conservation of Nature (IUCN)—has become increasingly threatened by fishing and accidental capture and now needs more protection. (more…)

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Five-Limbed Brittle Stars Move Bilaterally, Like People

Brittle stars and people have something in common: They move in fundamentally similar ways. Though not bilaterally symmetrical like humans and many other animals, brittle stars have come up with a mechanism to choose any of its five limbs to direct its movement on the seabed. It’s as if each arm can be the creature’s front, capable of locomotion and charting direction. Results appear in the Journal of Experimental Biology.

PROVIDENCE, R.I. [Brown University] — It appears that the brittle star, the humble, five-limbed dragnet of the seabed, moves very similarly to us.

In a series of first-time experiments, Brown University evolutionary biologist Henry Astley discovered that brittle stars, despite having no brain, move in a very coordinated fashion, choosing a central arm to chart direction and then designating other limbs to propel it along. Yet when the brittle star wants to change direction, it designates a new front, meaning that it chooses a new center arm and two other limbs to move. Brittle stars have come up with a mechanism to choose any of its five limbs to be central control, each capable of determining direction or pitching in to help it move. (more…)

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Construction of New Rock Spawning Reefs Will Help Great Lakes Native Fish

ANN ARBOR, Mich.—The first of nine rock reefs is under construction in the St. Clair River delta northeast of Detroit. The goal of the project, which is led by Michigan Sea Grant, is to boost populations of lake sturgeon and other rare native fish by providing river-bottom rock structures where they can spawn.

The rock reefs are designed to assist several native species that are considered threatened or endangered in Michigan, including lake sturgeon, mooneye, the northern madtom catfish and the river redhorse sucker. Walleye, a popular sport fish, and commercially important lake whitefish should also benefit. (more…)

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Ecosystem Effects of Biodiversity Loss Could Rival Impacts of Climate Change, Pollution

ANN ARBOR, Mich.— Loss of biodiversity appears to impact ecosystems as much as climate change, pollution and other major forms of environmental stress, according to a new study from an international research team.

The study is the first comprehensive effort to directly compare the impacts of biological diversity loss to the anticipated effects of a host of other human-caused environmental changes.

The results highlight the need for stronger local, national and international efforts to protect biodiversity and the benefits it provides, according to the researchers, who are based at nine institutions in the United States, Canada and Sweden. (more…)

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Biologists Turn Back the Clock to Understand Evolution of Sex Differences

Battles of sexes shown to spur adaptive sex differences

Sex differences account for some of the most of the spectacular traits in nature: the wild colours of male guppies, the plumage of peacocks, tusks on walruses and antlers on moose. Sexual conflict – the battle between males and females over mating – is thought to be a particularly potent force in driving the evolution of traits that differ in males and females.

However, the genetic processes responsible for producing such traits are not well understood, nor how they evolved from their simpler less elaborate ancestral forms. We tend to assume that each tiny step in evolution is an advantage. But are they really? (more…)

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Handful of Heavyweight Trees Per Acre Are Forest Champs

Big trees three or more feet in diameter accounted for nearly half the biomass measured at a Yosemite National Park site, yet represented only 1 percent of the trees growing there.

This means just a few towering white fir, sugar pine and incense cedars per acre at the Yosemite site are disproportionately responsible for photosynthesis, converting carbon dioxide into plant tissue and sequestering that carbon in the forest, sometimes for centuries, according to James Lutz, a University of Washington research scientist in environmental and forest sciences. He’s lead author of a paper on the largest quantitative study yet of the importance of big trees in temperate forests being published online May 2 on PLoS ONE. (more…)

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