• Killer cave lured ancient carnivores to their deaths

    Mauricio Anton

    Two sabertooth cats circle a rhinoceros carcass in an underground cave.

    By Tia Ghose, LiveScience

    A cavern in Spain may have lured ancient carnivores to their deaths by offering the promise of food and water, new research suggests.

    The new study, published May 1 in the journal PLOS ONE, may explain how the carcasses of several carnivore species, including saber-toothed cats and "bear dogs," wound up in an underground cavern millions of years ago.

    "Only the carnivores were daring enough to enter," said study co-author M. Soledad Domingo, a paleontologist at the University of Michigan. "But they were unable to make their way out." [See Images of Cave of Death & Ancient Carnivores]

    In 1991, miners drilling about 18.7 miles (30 kilometers) outside Madrid, Spain, uncovered animal bones and called in local paleontologists to excavate. They uncovered a series of underground caverns full of animal fossils — including the remains of red pandas, bear dogs and saber-toothed cats, as well as ancient animals related to modern elephants, giraffes, rhinoceroses and horses. To date, nearly 18,000 fossils have been recovered from the area.

    The so-called Cerro de los Batallones caves formed between 9 million and 10 million years ago in a process known as piping, where sediment falls into cracks or fissures in the surface, carving out hollow spaces in the soft, claylike Earth. Unlike other "pipes" formed in clay that quickly disappear, however, the holes stayed open longer because the area also contained a harder type of rock to buttress the burgeoning caves.

    Exactly what happened to the animals, however, remained a mystery.

    Cave of death
    To solve the mystery, Domingo and her colleagues systematically analyzed all the bones discovered in the bottom level of the site, called Batallones-1. The cave contained an unusually high proportion of carnivores, some of which were completely unknown before the cave's discovery, Domingo told LiveScience.

    The researchers found that nearly 98 percent of the large-mammal fossils were of carnivores, many of them healthy young adults. They also studied the orientation of the skeletons in the cave and the lack of trample marks.

    Based on these findings, the team concluded that the cave probably had a visible opening in the ground, into which the herbivores may have occasionally fallen. (For instance, the cave contains a complete rhinoceros skeleton.) However, most of the herbivores were smart enough to avoid the trap.

    But young-adult carnivores willingly entered the cave, possibly lured by the scent of food or water. The unlucky animals became trapped and died (likely from starvation), and the scent of their rotting carcasses lured other carnivores into the caves, and to their deaths.

    "We think that the carnivores were getting trapped, and then they became additional food for another coming carnivore," Domingo said.

    The researchers still don't know how long the cave was open before flooding brought fresh material to cover it up. And the findings only apply to one cavern at the site — scientists still need to do further studies to determine how herbivores wound up in the upper levels of the cave complex.

    Follow Tia Ghose on Twitter @tiaghose. Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • How researchers use real-life 3-D holodecks to explore virtual frontiers

    Charles Rex Arbogast / AP

    University of Illinois-Chicago computer scientist Jason Leigh stands in the CAVE2 virtual-reality system, where 72 stereoscopic liquid crystal display panels encircle the viewer.

    By Carla K. Johnson, The Associated Press

    CHICAGO — Take a walk through a human brain? Fly over the surface of Mars? Computer scientists at the University of Illinois at Chicago are pushing science fiction closer to reality with a wraparound virtual world where a researcher wearing 3-D glasses can do all that and more.

    In the system, known as CAVE2, an 8-foot-high (2.4-meter-high) screen encircles the viewer 320 degrees. A panorama of images springs from 72 stereoscopic liquid crystal display panels, conveying a dizzying sense of being able to touch what's not really there.

    As far back as 1950, sci-fi author Ray Bradbury imagined a children's nursery that could make bedtime stories disturbingly real. "Star Trek" fans might remember the holodeck as the virtual playground where the fictional Enterprise crew relaxed in fantasy worlds.

    The Illinois computer scientists have more serious matters in mind when they hand visitors 3-D glasses and a controller called a "wand." Scientists in many fields today share a common challenge: How to truly understand overwhelming amounts of data. Jason Leigh, co-inventor of the CAVE2 virtual reality system, believes this technology answers that challenge.

    "In the next five years, we anticipate using the CAVE to look at really large-scale data to help scientists make sense of that information. CAVEs are essentially fantastic lenses for bringing data into focus," Leigh said.

    The CAVE2 virtual world could change the way doctors are trained and improve patient care, Leigh said. Pharmaceutical researchers could use it to model the way new drugs bind to proteins in the human body. Car designers could virtually "drive" their vehicle designs.

    Imagine turning massive amounts of data — the forces behind a hurricane, for example — into a simulation that a weather researcher could enlarge and explore from the inside. Architects could walk through their skyscrapers before they are built. Surgeons could rehearse a procedure using data from an individual patient.

    Charles Rex Arbogast / AP

    Brain surgeon Ali Alaraj talks about the first time he viewed the brain using the CAVE2. "You can walk between the blood vessels," said the University of Illinois College of Medicine neurosurgeon. "You can look at the arteries from below. You can look at the arteries from the side."

    CAVEs aren't cheap
    But the size and expense of room-based virtual reality systems may prove insurmountable barriers to widespread use, said Henry Fuchs, a computer science professor at the University of North Carolina at Chapel Hill, who is familiar with the CAVE technology but wasn't involved in its development.

    While he calls the CAVE2 "a national treasure," Fuchs predicts a smaller technology such as Google's Internet-connected eyeglasses will do more to revolutionize medicine than the CAVE. Still, he says large displays are the best way today for people to interact and collaborate.

    Believers include the people at Marshalltown, Iowa-based Mechdyne Corp., which has licensed the CAVE2 technology for three years and plans to market it to hospitals, the military and in the oil and gas industry, said Kurt Hoffmeister of Mechdyne.

    In Chicago, researchers and graduate students are creating virtual scenarios for testing in the CAVE2. The Mars flyover is created from real NASA data. The brain tour is based on the layout of blood vessels in a real patient.

    Brain surgeon Ali Alaraj remembered the first time he viewed the brain using the CAVE2.

    "You can walk between the blood vessels," said the University of Illinois College of Medicine neurosurgeon. "You can look at the arteries from below. You can look at the arteries from the side.... That was science fiction for me."

    How CAVEs compare
    Would doctors process information faster with fewer errors using CAVE2? That's the question behind a proposed study that would compare CAVE2 to conventional methods of detecting brain aneurysms and determining proper treatment, said Andreas Linninger, UIC professor of bioengineering, chemical engineering and computer science.

    But it's not all serious business at the lab.

    In his spare time during the past two years, research assistant Arthur Nishimoto has been programming the CAVE2 computer with the specifications for the fictional Starship Enterprise. He now can walk around his life-size re-creation of the TV spacecraft.

    The original technology, introduced in the early 1990s, was called CAVE, which stood for Cave Automatic Virtual Environment and also cleverly referred to Plato's cave, the philosopher's analogy about shadows and reality. It was named by former lab co-directors Tom DeFanti and Dan Sandin.

    The second generation of the CAVE, invented by Leigh and his collaborator Andy Johnson, has higher resolution. The project was funded by the National Science Foundation and the Department of Energy.

    "It's fantastic to come to work. Every day is like getting to live a science fiction dream," Leigh said. "To do science in this kind of environment is absolutely amazing."

    More about virtual environments:

    Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.