Friday Headlines: 3-22-13

Friday Headlines, March 22, 2013

THE LATEST IN THE GEOSCIENCES

 

5-MILLION-YEAR-OLD SABER-TOOTHED CAT FOSSIL DISCOVERED

Saber-toothed cats are cool. You’ve probably heard of the ‘saber-toothed tiger,’ also known as Smilodon fatalis, commonly found at the La Brea Tar Pits in Los Angeles.

A reconstruction of Smilodon fatalis

But did you know that there have been many, many other species and types of saber-toothed cat? In fact, while Smilodon is a true cat (in the Family Felidae), carnivores that look like cats and possessed the long saber-like canines have been found in many other families of the larger Order Carnivora. There’s even a saber-toothed marsupial ‘cat’ called Thylacosmilus.

Skull of Thylacosmilus

A new species (and genus) of saber-toothed cat, Rhizosmilodon fiteae, was found in Polk County of Florida. This one is a true cat and is closely related to the much larger Smilodon. This goes to show that there are still fantastic new fossil discoveries to be made!

Lower jaw of Rhizosmilodon fiteae. Photo by Jeff Gage, Florida Museum of Natural History

Here’s the direct link to the PLOSone paper describing this new fossil. It’s open access, so anyone can read it!

 

SCIENTISTS DISCOVER LAYER OF LIQUIFIED MOLTEN ROCK IN EARTH’S MANTLE

The Earth’s mantle is the part of the planet between the crust (the outer surface where we life, which is only a few 10’s of kilometers thick) and the planet’s core.

The general structure of the Earth.

It is thought that motion in the mantle is what helps propel the continental plates to move around on the Earth’s surface. It is also known, through study of earthquake waves passing through the planet, that the mantle is solid. (Read more about the structure of the Earth here.)

Scientists at Scripps Institution of Oceanography used an electromagnetic receiver to generate images of the mantle below the crust along the Middle America Trench off the shore of Nicaragua.

Map of the survey region where the research was conducted. Credit: Scripps Institution of Oceanography

What they found was a region of low resistivity in the mantle, which is indicative of molten rock.

Orange-colored area enclosed by dashed line denotes recently discovered magma layer. Credit: Scripps Institution of Oceanography

This discovery has broad implications for our understanding of how plate tectonics works. If there are actually molten layers in the mantle, these may provide a mechanism for the tectonic plates to slide across the mantle. Stay tuned!

 

FAIR WARNING – FROM A TRAVELING SCIENCE BLOGGER

 

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