埃塞俄比亚的化石表面可能是著名的“露西”的祖先

Ethiopian Fossil Face Could Be Ancestor of Famed ‘Lucy’

A fossil from Ethiopia is letting scientists look deep into the past -- and they see a face looking back.

The fossil is estimated to be 3.8 million years old. It helps complete the face for what scientists believe to be an ancestor of the species represented by Lucy -- the celebrated¹ Ethiopian skeleton found in 1974.

This species is the oldest known member of Australopithecus, a group of creatures that came before our own group of species.

Scientists call it A. anamensis. They have known for a long time that the species existed. Fossil remains² of it that are over 4 million years ago have been found. But remains of the species' face bones that had been found before were limited to pieces of jaws³ and teeth. This made it difficult to fully⁴ understand the species.

The newly reported fossil includes much of the skull⁵ and face. The skull helps scientists learn about a specie's diet, brain size and appearance.

A ‘once-in-a-lifetime discovery

The findings were described recently in the publication Nature. Yohannes Haile-Selassie helped write the report. He is with the Cleveland Museum of Natural History, in the American state of Ohio.

“This is a once-in-a-lifetime discovery,” he told the Reuters news agency. “We are talking about the most complete cranium of an early human ancestor ever found…”

The face appears to be from a male. The middle and lower parts of the face jut⁶ out. In comparison, Lucy, the later skeleton, had a flatter mid-face. The change between the two shows a step toward the flat faces of humans today.

The fossil also shows the beginning of the larger and very strong faces common to Australopithecus. Such facial structures helped the species eat hard food, researchers said.

The fossil was found in 2016, in what once was a sandy area where a river entered a lake. At the time the creature lived, the area was mostly dry.

Earlier research has shown that the A. anamensis possibly walked standing⁷ up on two feet. But there is no evidence that it used pieces of stone to make tools, Stephane Melillo told The Associated Press. Melillo, who also helped write the paper, is with the Max Planck Institute for Evolutionary⁸ Anthropology⁹ in Germany. Earlier findings have shown Lucy’s species used stone tools.

Praise for recreating the face of a species

Experts not connected to the new study praised the work. Eric Delson of Lehman College in New York called the fossil “beautiful.” He said the researchers did a good job of recreating the face in digital form to help scientists understand more about the species.

Having a face for A. anamensis helps scientists “know how they looked and how they differed from the Lucy species,” said Zeray Alemseged. He is with the University of Chicago.

William Kimbel directs the Institute of Human Origins at Arizona State University. He said the discovery helps offer new information on the earliest development of the Australopithecus group.

The study’s writers said the finding also shows that A. anamensis existed for at least 100,000 years after producing Lucy’s species, known as A. afarensis. That differs from the widely accepted idea that there was no period of overlap¹⁰, they wrote.

Scientists care about overlap because its existence could show the process by which one species becomes another.

However, several experts, including Kimbel, are not ready to support that idea. They say it is still not known how Lucy’s species developed from an older one.

I’m Ashley Thompson.

Words in This Story

fossil - n. something (such as a leaf, skeleton, or footprint) that is from a plant or animal which lived in ancient times and that you can see in some rocks?

species - n. a group of animals or plants that are similar and can produce young animals or plants : a group of related animals or plants that is smaller than a genus?

jaws - n.? either one of the two bones of the face where teeth grow

cranium - n.? skull

jut out - phrasal verb. to stick out, up, or forward?

evolution - n. a theory that the differences between modern plants and animals are because of changes that happened by a natural process over a very long time

anthropology - n.? the study of human races, origins, societies, and cultures?

overlap - n.? a part or amount that happens at the same time as something else

1 celebrated   

adj.有名的，声誉卓著的

参考例句：

• He was soon one of the most celebrated young painters in England.不久他就成了英格兰最负盛名的年轻画家之一。
• The celebrated violinist was mobbed by the audience.观众团团围住了这位著名的小提琴演奏家。

2 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

3 jaws   

n.口部；嘴

参考例句：

• The antelope could not escape the crocodile's gaping jaws. 那只羚羊无法从鱷鱼张开的大口中逃脱。
• The scored jaws of a vise help it bite the work. 台钳上有刻痕的虎钳牙帮助它紧咬住工件。

4 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

5 skull   

n.头骨；颅骨

参考例句：

• The skull bones fuse between the ages of fifteen and twenty-five.头骨在15至25岁之间长合。
• He fell out of the window and cracked his skull.他从窗子摔了出去，跌裂了颅骨。

6 jut   

v.突出；n.突出，突出物

参考例句：

• His mouth started to jut out,and his jaw got longer.他的嘴向前突出，下巴也变长了。
• His teeth tend to jut out a little.他的牙齿长得有点儿凸出。

7 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

8 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

9 anthropology   

n.人类学

参考例句：

• I believe he has started reading up anthropology.我相信他已开始深入研究人类学。
• Social anthropology is centrally concerned with the diversity of culture.社会人类学主要关于文化多样性。

10 overlap   

v.重叠，与…交叠；n.重叠

参考例句：

• The overlap between the jacket and the trousers is not good.夹克和裤子重叠的部分不好看。
• Tiles overlap each other.屋瓦相互叠盖。