寒武紀就有大龍蝦了嗎

A huge arthropod that lived 480 million years ago used spines on its head to filter seawater and to trap tiny particles of food. The lobsterlike animAl, six feet long, is one of the earliest giant filter-feeder ever discovered, scientists reported in the journal Nature.

4.8億年前，地球上曾生活着一種大型節肢動物，用頭上的骨骼過濾海水，獲取食物微粒。科學家們在《自然》(Nature)雜誌上報告說，這種龍蝦狀的動物長六英尺，是迄今發現的最早的大型濾食性動物之一。

“It implies there was a rich source of plankton at the time, upon which these things may have fed,” said Derek Briggs, a paleontologist at Yale University and one of the study’s authors.

“這表明，當時浮游生物資源豐富，這類動物以它們爲食，”該項研究的作者之一、耶魯大學古生物學家德里克·布里格斯(Derek Briggs)說。

Dr. Briggs and his colleagues discovered the fossil remains of the new species, named Aegirocassis benMoulae, in Morocco. It belongs to an extinct family of marine animals called anomalocaridids, which first appeared during the Cambrian Period 520 million years ago.

布里格斯和同事們在摩洛哥發現了這種名爲“Aegirocassis benmoulae”的新物種的化石。它屬於已滅絕的奇蝦屬(anomalocaridid)海洋動物，最早是在5.2億年前的寒武紀出現的。

Aegirocassis had double flaps along the side of its body, rather than the single flaps seen in previous anomalocaridid fossils. The bottom flaps may have helped Aegirocassis swim, while the top set of flaps may have been used for stabilization, Dr. Briggs said.

Aegirocassis benmoulae身體兩側有雙鰭，而之前的奇蝦屬化石都只有單鰭。布里格斯博士說，下側的鰭可能是用來幫助遊動，上面的可能是用來保持身體平衡。

The fossil remains are three-dimensional and exceptionally well preserved. Almost all previous anomalocaridid fossils were flat.

這些化石是三維的，保存得格外完好。之前的所有奇蝦屬化石几乎都是扁平的。

“We think it is because these things were buried quite rapidly by a storm or other event on the seafloor,” Dr. Briggs said.

“我們認爲，原因是這些動物因爲風暴或海底的其他動盪而被快速掩埋了，”布里格斯說。