황소보다 큰, 4백만년 전 ‘마이티 마우스’ 화석 발견
앙상한삶의혼 2008.01.18 09:33:40
황소보다 큰, 4백만년 전 ‘마이티 마우스’ 화석 발견
팝뉴스|기사입력 2008-01-16 11:36
약 4백만 년 전 남아메리카 지역에 황소보다 더 크고 자동차 크기와 비슷한 쥐가 살았다.
우루과이에서 발견된 53센티미터 크기의 두개골 화석을 근거로 추정하면 화제의 쥐(Josephoartigasia monesi)는 무게가 1톤가량이었을 것으로 보인다.
길이는 3미터, 어깨까지의 높이는 1.5미터로 지구에 살았던 쥐 중에서 가장 큰 종류라는 게 과학자들의 평가.
화석 연구를 진행한 몬테비디오 인류학 및 자연사 박물관의 과학자들은 거대한 몸집의 쥐에 ‘마이티 마우스’라는 별명을 붙였다.
초식 동물이며 하마처럼 물속에서 주로 생활을 했을 것으로 보인다. 체중 때문에 몸이 받았을 스트레스를 줄이기 위한 방책이었다.
김화영 기자 (저작권자 팝뉴스)
출처 : http://news.naver.com/main/read.nhn?mode=LSD&mid=sec&sid1=104&oid=105&aid=0000007971
2008.01.18 09:39:21 (58.227.74.9) 앙상한삶의혼
기사 원문 : http://www.nytimes.com/2008/01/17/science/17rat_web.html
January 17, 2008
Long Ago, a Rodent as Big as a Bull Lurked in South America
By THE ASSOCIATED PRESS
LONDON — Imagine a rodent that weighed a ton and was as big as a bull.
Uruguayan scientists say they have uncovered fossil evidence of the biggest species of rodent ever found, one that scurried across wooded areas of South America about four million years ago, when the continent was not connected to North America.
A herbivore, the beast may have been a contemporary, and possibly prey, of saber-toothed cats — a prehistoric version of Tom and Jerry.
Its huge skull, more than 20 inches long, suggested a beast more than eight feet long and weighing between 1,700 and 3,000 pounds.
Although British newspapers variously described it as a mouse or a rat, researchers say the animal, named Josephoartigasia monesi, actually was more closely related to a guinea pig or porcupine. “These are totally different from the rats and mice we’re accustomed to,” said Bruce Patterson, the curator of mammals at the Field Museum in Chicago, adding that it was the biggest rodent that he had ever heard of.
An artist’s rendering showed a creature that looked like a cross between a hippopotamus and a guinea pig.
The fossil was found in 1987 about 65 miles west of the capital, Montevideo, near the vast River Plate estuary — a muddy waterway separating Uruguay from Argentina that empties into the South Atlantic. That area is the site of ancient riverbanks and other deposits where fossils have been found, Mr. Patterson said.
An Argentine fossil collector identified as Sergio Viera donated the skull to Uruguay’s National History and Anthropology Museum nearly two decades ago, said the museum’s director, Arturo Toscano.
It spent years hidden away in a box at the museum and was rediscovered by a curator, Andrés Rinderknecht, who enlisted the help of a fellow researcher, Ernesto Blanco, to study it.
Mr. Blanco said he was shocked when he first came face to face with the fossil, saying it looked even bigger than a cow skull. “It’s a beautiful piece of nature,” he said in an interview. “You feel the power of a very big animal behind this.”
The research by Mr. Rinderknecht and Mr. Blanco was published Wednesday in this week’s issue of a biological research journal, Proceedings of the Royal Society B.
Mr. Blanco said the skull’s shape and the huge incisors left no doubt that they were dealing with a rodent, but he cautioned that the estimate of the animal’s bulk was imprecise.
The extinct rodent clearly outclassed its nearest rival, the Phoberomys, found in Venezuela and estimated to weigh between 880 and 1,500 pounds.
Mr. Blanco said the rodent was far bigger than any South American rodent alive today, surpassing the present-day capybara, which can weigh up to 110 pounds.
He said the animal’s teeth pointed to a diet of aquatic plants.
“From what we can tell, we know it was a herbivore that lived on the shores of rivers or alongside streams in woodland areas,” Mr. Rinderknecht said. “Possibly it had a behavior similar to other water-faring rodents that exist today, such as beavers, which split their time between land and water.”
