科學(xué)家在澳大利亞發(fā)現(xiàn)人類最早祖先的證據(jù)

科學(xué)家在澳大利亞發(fā)現(xiàn)人類最早祖先的證據(jù)

Geologists in Australia have found evidence of mankind’s earliest ancestor – a 555 million-year-old worm-like creature smaller than a grain of rice.

澳大利亞的地質(zhì)學(xué)家發(fā)現(xiàn)了人類最早祖先的證據(jù)——一種5.55億年前的蠕蟲狀生物，比一粒米還小。

Scientists on Monday said the prehistoric tiny worm, found in the Australian outback, represents one of the most significant primordial finds ever.

周一，科學(xué)家們說，在澳大利亞內(nèi)陸發(fā)現(xiàn)的這種史前微小蠕蟲，代表了有史以來最重要的原始發(fā)現(xiàn)之一。

“It’s the oldest fossil we get with this type of complexity,” said Mary Droser, a professor at the University of California Riverside and among the scientists who made the discovery. “We knew that we also had lots of little things and thought these might have been the early bilaterians that we were looking for.”

加州大學(xué)河濱分校教授瑪麗·德羅澤說：“這是我們發(fā)現(xiàn)的最古老的、具有這種復(fù)雜性的化石。”。“我們知道我們也有很多小東西，而且我們認(rèn)為這些可能就是我們正在尋找的早期兩側(cè)對(duì)稱動(dòng)物。”

Bilaterians are animals with bilateral symmetry, organisms that have symmetrical sides, a head, and openings on both ends connected by a gut.

兩側(cè)對(duì)稱動(dòng)物，有對(duì)稱的兩邊，一個(gè)頭，兩端的開口由腸道連接。

Scientists have long agreed that bilaterians created fossilized burrows found in deposits in Nilpena, South Australia, but had been unable to prove it.

長期以來，科學(xué)家們一致認(rèn)為，在南澳大利亞的尼爾佩納(Nilpena)的沉積物中發(fā)現(xiàn)的化石洞穴是由兩側(cè)對(duì)稱動(dòng)物創(chuàng)造的，但一直無法證明這一點(diǎn)。

Droser Lab/UCR/SWNS

But new 3-dimensional laser scanning technology finally enabled researchers to identify the new creature, named Ikaria warjootia, as the culprit behind the burrows.

但新的三維激光掃描技術(shù)，最終使研究人員能夠識(shí)別出這個(gè)名叫伊卡里亞·沃喬蒂亞(Ikaria warjootia)的新生物，就是這些洞穴背后的罪魁禍?zhǔn)住?/p>

The organism is no bigger than seven millimeters long and less than two millimeters wide.

這種生物體長不超過7毫米，寬不到2毫米。

“We thought these animals should have existed during this interval, but always understood they would be difficult to recognize,” said Scott Evans, a doctoral graduate at the California university. “Once we had the 3-D scans, we knew that we had made an important discovery.”

加州大學(xué)博士研究生斯科特·埃文斯說：“我們認(rèn)為這些動(dòng)物應(yīng)該在這段時(shí)間內(nèi)存在，但我們一直都知道它們很難被識(shí)別。”。“直到我們進(jìn)行了三維掃描，我們就知道我們有了一個(gè)重要的發(fā)現(xiàn)。”

The name of the creature was a nod to the original “custodians” of the land where it was found. It’s genus, Ikaria, means “meeting place” in Australian aboriginal language.

這個(gè)生物的名字是為了向最初發(fā)現(xiàn)它的土地的“監(jiān)護(hù)人”致敬。它的屬，伊卡利亞，在澳大利亞土著語言中的意思是“聚會(huì)的地方”。

The name also comes from Warioota Creek in South Australia.

這個(gè)名字也來自南澳大利亞州的Warioota Creek。

Droser Lab/UCR/SWNS

Despite a relatively simple shape, Ikaria was actually complex in comparison to other fossils from the Edicaran Period, which spanned 94 million years from the end of the Cryogenian Period 635 million years ago to the beginning of the Cambrian Period some 541 million years ago.

盡管Ikaria的形狀相對(duì)簡單，但與其他埃迪卡蘭時(shí)期的化石相比，Ikaria實(shí)際上是復(fù)雜的，從6.35億年前的低溫期結(jié)束到大約5.41億年前的寒武紀(jì)時(shí)期，跨越了9400萬年。

The creatures burrowed into oxygenated sand while hunting down organic matter and moved its tiny body by contracting muscles across its body like a worm, Droser said.

Droser說，這些生物在尋找有機(jī)物的同時(shí)鉆入含氧的沙子中，通過像蠕蟲一樣收縮身體上的肌肉來移動(dòng)它的小身體。

Evidence showing the creatures fed on organize matter revealed that Ikaria likely had a mouth, anus and gut, just like humans of today, Droser continued.

Droser繼續(xù)說，有證據(jù)顯示，這些以組織物質(zhì)為食的生物很可能擁有口、肛門和腸道，就像今天的人類一樣。

“This is what evolutionary biologists predicted,” she said. “It’s really exciting that what we have found lines up so neatly with their prediction.”

“這就是進(jìn)化生物學(xué)家的預(yù)測，”她說。“我們所發(fā)現(xiàn)的與他們的預(yù)測非常吻合，這真是令人興奮。”