Read the Article
Total Page：16
File Type：pdf, Size：1020Kb
The American Geological Institute 4220 King Street, Alexandria, VA 22302-1502, U.S.A. 703-379-2480; Fax: 703-379-7563; [email protected] www.earthmagazine.org Ancient elephants “rose from the dead” David B. Williams EARTH Vol. 55 (No. 4), p. 16 REPRODUCTION: More than one photocopy of an item from EARTH may be made provided that fees are paid directly to the Copyright Clearance Center, 222 Rosewood Dr., Danvers, MA 01923, USA. Phone: (978)750-8400. Fax: (978)646-8600. Any other form of reproduction requires special permission from and is subject to fees by EARTH. Information about obtaining reprints of this article or about obtaining permission to reproduce this article in whole or in part can be found by e-mailing [email protected]. EARTH is published monthly for a base subscription rate of $34.50 a year (single copies $4.99) by the American Geological Institute. © 2010 American Geological Institute. Standard mail, nonprofit postage paid at Denver, Colo., and at other mailing offices. Claims for missing issues will be honored only up to six months. Issues undelivered through failure to notify EARTH of address change will not be replaced. www.earthmagazine.org ANCIENT ELEPHANTS news notes • “ROSE FROM THE DEAD” rchaeologists have long starting about 100,000 years before known that the earliest humans first set foot in the New World. North Americans hunted The evidence comes from fossils and mastodons and mammoths. artifacts found in northwestern Mexico ANow, researchers have enticing evidence at the first known site in North America that the hunters also pursued the hirsute with remains from both gomphotheres beasts’ close cousins, gomphotheres — and Clovis people. The discovery is help- news notes • which previously seemed to disappear ing archaeologists rewrite the history of from the North American fossil record both the hunter and the hunted. Three key elephants of the Late Pleistocene. Left to right: mastodon, mammoth and gomphothere. news notes • news notes • Local ranchers had known about the big bones in the region since the 1990s, but it was not until 2007 that Guadalupe Sanchez of the National Institute of Anthropology and History in Mexico City and Vance Holliday of the University news notes of Arizona in Tucson began the first excavations. They • reported on their work at the Geological Society of America’s annual meeting in Portland, Ore., last October. Dubbed El Fin del Mundo, or the End of the Earth, due to its remote location north of Hermosillo, Mexico, and three hours down a dirt road, the site sits in a basin surrounded by volcanic peaks. The 50-square-meter dig area contains two bone beds with artifacts. Radiocarbon dating constrained the ages of the bone beds to between 13,500 and 11,200 years ago. news notes • Holliday and Sanchez are trying to pinpoint a more specific date, Holliday says. In two field seasons, Holliday and Sanchez’s team has found the ribs, parts of pelvises, limb bones and vertebrae from at least two juvenile gomphotheres. “We didn’t know what we had at first. They were too small to be a mammoth,” Holliday says. Initially, one team member thought they were the right size to be a bison. But in late 2008, the team found an upside-down mandible stuck in the ground, which from the side resembled news notes • a mastodon. Then last year, after cleaning the jaw, researchers noted that a tooth clearly revealed that they had a gomphothere. Remains of a juvenile gomphothere found at El Fin del Mundo. Mexican artist by and photo Gaines; Edmund de la Rosa;Gaines sculptures Edmund top: Sergio to Bottom 16 EARTH April 2010 www.earthmagazine.org news notes • news notes SKYLIGHT ON THE MOON • news notes • news notes The Japanese moon orbiter SELENE captured images of a possible lunar lava tube skylight 65 meters across in the moon’s Marius Hills region. arth’s moon still bears the Lava tubes — channels that still-fluid remnants of ancient volcanic lava travels through beneath the hard- Excavations under way. Lake deposits activity, including the vast, ening, cooling outer crust of a lava flow • are peeled away from the gompho there dark plains of basaltic lava — are common on Earth, and several news notes remains. Ecalled mare. Scientists studying high- have been identified on Mars as well. resolution images of the moon taken But intact lava tubes on the moon — at Identified as Cuvieronius, it was the last by the Japanese moon orbiter SELENE least those peeking out to the surface, surviving North American genus of these have identified another possible rem- called “skylights” — appear to be rare. elephant relatives. nant of the moon’s bygone volcanism: This skylight, the scientists wrote, likely Cuvieronius sported two spiraled tusks a large vertical hole that may be an formed when part of the lava tube’s roof — other gomphotheres had four — and ancient lava tube. The hole, estimated collapsed. stood about 3 meters tall. Their remains to be 65 meters in diameter and more Lunar lava tubes are not only geologi- • have been found throughout South and than 80 meters deep, was spotted by cally interesting, the scientists noted, but news notes Central America, persisting until the end the orbiter on the near side of the may also be likely sites for a future lunar of the Pleistocene about 10,000 years ago. moon in a once-volcanic region known base, because the deep holes offer some In North America, Cuvieronius fossils as the Marius Hills, reported planetary protection from meteorite impacts, tem- have been found in California, Florida, scientist Junichi Haruyama of JAXA, perature extremes, high-energy ultravio- New Mexico and Texas. Until this dis- the Japan Aerospace Exploration let radiation and other hazards on the covery, the youngest fossils found were Agency, and colleagues in Geophysical moon’s surface. about 120,000 years old. Research Letters. Carolyn Gramling It’s appears as if Cuvieronius “rose • from the dead … begging the question of where it had been hiding all this Holliday also notes the importance of news notes time,” says David Lambert, a gom- the team’s artifact discoveries, including A Clovis point projectile found near the phothere specialist at the Louisiana flint flakes and Clovis points made from eroded margins of the gomphothere School of Math, Science and the Arts a quartz crystal and chert. The material bone bed. in Natchitoches. “Successfully hiding is the first documented evidence in place an elephant for any length of time is a for Clovis people outside of the United real feat.” States, he says. None of the points were Lambert and other proboscidean found with the gomphotheres, but a experts had previously proposed that chert tool was found directly below a • news notes one reason more recent gomphothere mold of the bones, indirectly tying peo- remains have not previously been found ple to the gomphotheres. “We’ll never is that Cuvieronius lived along the coasts know if they killed the gomphothere of North America. If that were the case, or scavenged it,” Holliday says. “But I then their remains would now be cov- am not surprised at the locality [of the ered by the post-glacial rise in sea level, fossils] considering that the highest con- Lambert says. The new find casts some centration of Clovis mammoth kill sites doubt on the coastal preference hypoth- is just across the border in Arizona.” • Bottom: Vance Holliday; top right set: ©2009 by the American Geophysical Union Holliday; the American Geophysical right set: ©2009 by top Vance Bottom: esis, he says. David B. Williams news notes www.earthmagazine.org EARTH April 2010 17.