Featured Research

from universities, journals, and other organizations

New Species Of Human Ancestor

Date:
April 23, 1999
Source:
American Association For The Advancement Of Science
Summary:
Two-and-a-half-million-year-old cranial and tooth remains found in Ethiopia belong to a previously unknown hominid that may have been the immediate predecessor of humans, according to a team of Ethiopian, American, and Japanese researchers. Team members also describe other fossils from the same geological layer showing that hominids--though not necessarily the newly identified species--were walking on humanly proportioned legs and using stone tools to strip meat and scrape marrow from the bones of antelopes and horses.

Plus Oldest Evidence Yet Of Tool-Assisted Meat-Eating, Reported In 23 April 1999 Science

Related Articles


Washington, DC -- Two-and-a-half-million-year-old cranial and tooth remains found in Ethiopia belong to a previously unknown hominid that may have been the immediate predecessor of humans, according to a team of Ethiopian, American, and Japanese researchers. Team members also describe other fossils from the same geological layer showing that hominids--though not necessarily the newly identified species--were walking on humanly proportioned legs and using stone tools to strip meat and scrape marrow from the bones of antelopes and horses. This constitutes the earliest example yet of tool-assisted meat-eating. Two reports describe the finds in the 23 April 1999 issue of Science.

Researchers came across the fossils outside the small village of Bouri, a hard two-day drive northeast of Addis Ababa. The site is located in a harsh, desert region of Ethiopia called the Middle Awash, already famous for other major discoveries such as the oldest known hominid, found by the same team of researchers. The new hominid--dubbed Australopithecus garhi, after the local people's word for "surprise"--possesses features that place it at the forefront of one of the hottest debates in paleoanthropology: from what evolutionary branch did the first humans appear?

"No one predicted garhi," said University of California-Berkeley biologist Tim White, who co-led the team with Berhane Asfaw of Ethiopia's Rift Valley Research Service. Instead, researchers have been looking in eastern Africa for A. africanus, a smallish, upright-walking hominid known to have roamed southern Africa two to three million years ago and thought by many to be the best candidate for humanity's immediate forebear. But in Science, the research team presents anatomical analyses and measurements from the A. garhi fossils that they say sharply distinguish the new species from A. africanus and from the other hominid species known to be alive around the same time, including two robust species that eventually died out. If anything, said White, A. garhi's big teeth and projecting face best resemble an older East African species known as A. afarensis, whose most famous representative goes by the name of Lucy.

In addition to the cranial and tooth remains of A. garhi, the research team found in the same geological layer arm and leg bones from several other hominid individuals. Without associated dentition, these individuals can't reliably be assigned to a species. Intriguing, though, is the distinctive way in which their relative limb proportions are intermediate between that of apes and humans. That is, while "Lucy" (3.2 million years ago) had upper arms that were long relative to her legs, and H. erectus (1.7 million years ago) had the shortened forearms and longer femurs of modern humans, the unidentified Bouri hominids were smack in the middle--showing that the femur lengthened at least one million years before the forearm shortened. What this may imply about hominid locomotion and other behaviors, and what pressures this might have put on the subsequent direction of human evolution, remains to be determined.

While walking around on human-like legs, the unidentified Bouri hominids were apparently also using stone tools to fillet meat and pull marrow from the bones of large animals that thrived in the open, grassy plains once surrounding an ancient lake. Researchers found one of the hominid legs buried next to catfish and antelope bones, the latter of which showed definitive cut marks from stone tools. Scattered elsewhere throughout the same geological layer were other antelope and horse bones with similar tell-tale signs of butchery--for example, a lower jaw whose tongue presumably had been cut out and leg bones purposely fractured at both ends, indicative of marrow extraction.

Such unprecedented and unique access to high-fat meat and marrow would have constituted a "dietary revolution," says White, one that "would have opened up a whole new world of food" and possibly fueled humanity's eventual migration out of Africa.

The tools themselves, however, have proved frustratingly elusive. The researchers found only a few isolated tools strewn about the surface of the site and none during excavation. This left them unable to determine the tools' ages or whether the tools belonged with the butchered bones. In their report, the researchers suggest that the area around Bouri 2.5 million years ago lacked the natural features (such as large rushing streams with cobbles or rock-outcroppings) that would have served as source material for stone tools, and that therefore Bouri hominids had been forced to carry in whatever tools they needed to exploit animal life at the lake margins. Still, the site at Bouri begs comparison to another 2.5-million-year-old site at nearby Gona, Ethiopia, where in 1997 nearly 3,000 stone tools were found--the oldest stone tools yet discovered. In contrast to Bouri, the Gona site lacked evidence of what the tools were used for or who might have made them. The researchers argue that the Bouri hominids, including A. garhi, must now be considered strong candidates for the Gona tool-makers.

The newly identified hominid fossils provide much-needed information about what may have been happening in Africa two to three million years ago, a crucial juncture in human evolutionary history. "You go into this period with, in essence, bipedal big-toothed chimps and come out with meat-eating large-brained hominids," said White. "That's a big change in a relatively short time. We'd really like to know more about what happened there."


Story Source:

The above story is based on materials provided by American Association For The Advancement Of Science. Note: Materials may be edited for content and length.


Cite This Page:

American Association For The Advancement Of Science. "New Species Of Human Ancestor." ScienceDaily. ScienceDaily, 23 April 1999. <www.sciencedaily.com/releases/1999/04/990423073714.htm>.
American Association For The Advancement Of Science. (1999, April 23). New Species Of Human Ancestor. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/1999/04/990423073714.htm
American Association For The Advancement Of Science. "New Species Of Human Ancestor." ScienceDaily. www.sciencedaily.com/releases/1999/04/990423073714.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Fossils & Ruins News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

India Clears Cows, Dogs, Dust for Obama Taj Mahal Trip

India Clears Cows, Dogs, Dust for Obama Taj Mahal Trip

AFP (Jan. 23, 2015) Preparations are under way at the Taj Mahal ahead of a visit by Barack and Michelle Obama. Duration: 01:11 Video provided by AFP
Powered by NewsLook.com
Lincoln Collection to Be Auctioned in Dallas

Lincoln Collection to Be Auctioned in Dallas

AP (Jan. 23, 2015) Hundreds of pieces of Lincoln memorabilia collected by a Fort Worth, Texas businessman are set to be auctioned this weekend. (Jan. 23) Video provided by AP
Powered by NewsLook.com
Phones Used 100 Years Ago on Display

Phones Used 100 Years Ago on Display

AP (Jan. 22, 2015) The phones used to make the world&apos;s first coast-to-coast conference call 100 years ago have been put on display at the California Historical Society&apos;s 1915 World&apos;s Fair exhibit space in San Francisco. (Jan. 22) Video provided by AP
Powered by NewsLook.com
King Tutankhamun Burial Mask Sloppily Glued Back Together After Cleaning Mishap

King Tutankhamun Burial Mask Sloppily Glued Back Together After Cleaning Mishap

Buzz60 (Jan. 22, 2015) King Tutankhamun Burial Mask is now being called &apos;irreversibly damaged&apos; after its famous beard broke off in a botched cleaning job and then was hastily glued back together. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins