动物究竟从什么时候开始具有活动能力?英国和加拿大的研究人员日前报告说,他们从距今有5.65亿年历史的深海化石上找到了动物移动的痕迹,这可能是迄今发现的有关动物移动的最早化石证据之一。
英国牛津大学研究人员和加拿大同行在新一期美国《地质学》(Geology)杂志上报告说,他们在从加拿大纽芬兰附近深海找到的化石上,发现了70余处动物移动的痕迹。研究人员说,虽然还不能确认这是什么动物,但是这种动物已具有通过控制肌肉来行动的能力,它很可能像水生腔肠动物一样,依靠肌肉的收缩来移动,以帮助觅食或躲避危险。
研究人员说,此前也发现过有关动物具有活动能力的化石,但这类化石的形成年代一般都不超过距今5.6亿年,一些研究人员因此认为更古老的动物可能都是静止不动的。而上述新发现不仅使动物开始具有活动能力的时间显著提前,而且说明当时的海洋生态环境比人们目前所了解的更复杂。(生物谷Bioon.com)
生物谷推荐原始出处:
Geology; February 2010; v. 38; no. 2; p. 123-126; DOI: 10.1130/G30368.1
First evidence for locomotion in the Ediacara biota from the 565 Ma Mistaken Point Formation, Newfoundland
Alexander G. Liu1, Duncan Mcllroy2 and Martin D. Brasier1,2
1 Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK
2 Department of Earth Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X5, Canada
Evidence for locomotion in the Precambrian fossil record is scant. Reliable Ediacaran trace fossils are all younger than 560 Ma, and consist of relatively simple horizontal burrows and trails from shallow-water deposits. Here we describe an assemblage of macroscopic locomotory traces from deep-water environments at Mistaken Point, southeastern Newfoundland, Canada, dated to ca. 565 Ma. These trails extend the record of complex trace fossils back into the earliest Avalonian biota. Our new evidence for large motile organisms on the seafloor at this time suggests that at least some of these early Ediacaran organisms, whose biological affinities are widely debated, could have been muscular and of metazoan grade.