[单选题]24.Researchers at the University of Oregon have recently unearthed fossils in South Africa that present evidence of life on l2.2 billion years ago — four times older than traditionally thought.
AThe fossilized organisms, dubbed Diskagma buttonii, are no bigger than the size of a standard match head were found threaded together in bunches. Though researchers are still unsure as to their biological function, the organisms most closely resemble a modern fungus (菌类) called Geosiphon. The team believes Diskagma could be the oldest known eukaryote, a cellular organism containing a nucleus.
BThe results of the study, led by geologist Gregory J. Retallack, provide new insight into the development of Earth’s atmosphere. Examining the fossils suggests that the greening of Earth, involving the rise of oxygen emergence of new plant animal forms, occurred much earlier than 500 million years ago, the previous estimate.
CImages of Diskagma were constructed using powerful X-rays from a particle accelerator at Lawrence Berkeley National Laboratory in California. They show hollow, urn-shaped structures with an attached tube. Retallack tells?Popular Science?that the fossils' age was determined using radiometric dating of surrounding rocks.
D“At last we have an idea of what life on llooked like in the Precambrian (前寒武纪) ," Retallack says. "Perhaps with this search image in mind, we can find more different kinds of fossils in ancient soils."
E
F24.1 According to the passage, a cellular organism with a nucleus is called____.
Gfungus
Heukaryote
IDiskagma
JGeosiphon
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