• The fossils were found near the village of Bouri in the Middle Awash study area.

• The Middle Awash lies within the Afar depression, about 140mi (230km) northeast of Ethiopia's capitol Addis Ababa.

• The Middle Awash study area has produced other major discoveries such as the hominid species Ardipithecus ramidus (4 to 6 million years old). In 1999 the same team announced its discovery of Australopithecus garhi, a new hominid species, found in older (2.5 myr) sediments at Bouri.

• The most important of the new Homo erectus fossils is a calvaria (skull lacking the lower face and teeth), was found by Berkeley PhD candidate Henry Gilbert on December 27, 1997, on a normally clear day in 110-degree weather.

• To enable safe transportation from the desert to the National Museum of Ethiopia laboratory where the new find could be carefully and properly extracted, the calvaria was enclosed in a reinforcing plaster "jacket." In the laboratory, working with dental tools, the researchers spent two years removing the skullcap from the matrix of sediment that had tightly held it for a million years. Dr. Berhane Asfaw, of Ethiopia, lead author on the Nature paper, describes the fossil as one of Ethiopia’s most important.

• To date, 7 hominid specimens have been recovered from different Early Pleistocene localities of this age at Bouri.

• The Homo erectus hominid fossils reported by the team include the calvaria, three thighbones (femora), a shin bone (tibia), and other fragments.

• Each of these fossils represents a different individual. Some of them were found miles apart, but all are from the same geological Member, and all belong to the species Homo erectus.

• Without the dentition, the researchers cannot determine whether the adult Daka calvaria represents a male or female. Fossilized leg bones found at nearby Bouri localities indicate statures of approximately 5.5 feet (1.7 meters) for these early hominids.

• Today the Middle Awash is a remote desert inhabited by the Afar people who are pastoralists. Their villages dot the Afar rift valley floor.

• Project geologists and paleontologists have established that the Daka sediments were deposited around the shores of a shallow freshwater lake. Many animal fossils were found in the sediments, ranging from rhinos, horses, and elephants to baboons and hyaenas.

• When Homo erectus walked this landscape, its grasslands were home to thousands of grazing animals. Project member Professor Elisabeth Vrba of Yale University’s Department of Geology and Geophysics studied the abundant antelope fossils in detail.

• Dozens of paleolithic archaeological sites from a stone tool culture known as the Acheulean (characterized by large, bifacially flaked cleavers and handaxes) have been known from the Daka sediments since the 1970s.

• Many of these handaxe sites were excavated by project archaeologists, led by the legendary Berkeley archaeologist J. Desmond Clark, who published a major monograph on them in 2001.

• Dr. Yonas Beyene of the Ethiopian Ministry of Youth, Sports and Culture studied the stone tools most recently recovered from the Daka sediments. He reports evidence for the stone tool butchery of large mammals.

• A key volcanic horizon below the fossils was dated to 1.042 ± 0.009 million years with the argon-argon laser heating method by Dr. Paul Renne at the Berkeley Geochronology Center. This technique is a highly accurate method that determines the time elapsed since the volcanic ash was super-heated in an eruption. Argon gas trapped in the rock after it cooled is measured. This gas is a radioactive decay product of natural potassium and accumulates at a known rate in volcanic rocks and minerals.

• The argon dating results were corroborated by establishing the geomagnetic polarity of the sediments bearing the fossils. These sediments in which the hominids were embedded were reversed in magnetic polarity, and therefore must have been deposited down more than ca. 800,000 years ago (when the earth’s field changed into its ‘normal’ polarity), in the Lower Pleistocene period. Analysis of the evolutionary state of various animal fossils confirmed these results. According to Dr. Renne, the combined dating results make the new Homo erectus fossils among the best dated in the world.

• The new Daka Homo erectus fossils are nearly contemporary with other hominid fossils from Spain, Italy, Java, China, Eritrea, Tanzania, and Kenya.

• The species Homo erectus was discovered in Java in the late 1800s by Eugene Dubois. Later discoveries were made in China, near Beijing.

• By the 1960s Homo erectus was seen by most authorities as the ancestor of our species, Homo sapiens.

• In the 1970s the earliest Homo erectus fossils were found in Africa, dating from approximately 1.8 million years ago. In the 1980s Richard Leakey’s team found the skeleton Turkana Boy, one of the earliest representatives of Homo erectus.

• Scientists have hotly debated the status of Homo erectus as a species for the last twenty years. Some advocated splitting the species into two, with the earlier specimens from Africa being labeled "Homo ergaster", and only the Asian forms being classified as Homo erectus.

• Recent studies have shown that some Javanese fossils and the newly-discovered fossils from Dmanisi, Georgia (former Soviet Union) date to as much as 1.5 million years ago. These fossils and their dates indicate that once Homo erectus originated--probably around two million years ago in a yet-unknown region--the species rapidly spread across much of the Old World, ranging from Africa to Java.

• The new Ethiopian fossils, the most complete evidence of Homo erectus in that country, are very similar to other African, Asian, and European contemporaries.

• The team’s detailed cladistic analysis compared characteristics of the new fossil with other hominids from Africa, Europe and Asia. The analysis showed that it is impossible to cleanly segregate Homo erectus crania from different continents. According to Henry Gilbert of U.C. Berkeley, the analysis showed that as of one million years ago, Homo erectus was probably a single species with gene flow across its known range from Java to Italy to Ethiopia.

• According to Professor Tim White of U.C. Berkeley, a co-author of the study, once Homo erectus had originated, its way of life allowed it to spread widely and invade new habitats. Like other widespread large mammals such as the tiger, Homo erectus was a species that comprised local populations (demes) that differed slightly, but gene flow among them prevented subsequent species-level splitting.

• The report notes that it is possible that the global effects of the major Pleistocene glaciations that began about 950,000 years ago did split the species, with one branch leading to Homo sapiens.

• There are anatomical differences between the Chinese fossils from Zhoukoudian ("Peking Man") and fossils that are more recent than Daka in Africa. The differences suggest that by 500,000 years ago, the ancestral species Homo erectus had split into at least two branches. A European branch would later evolve into the neanderthals.

• The Daka fossils are intermediate in time and anatomy between earlier fossils from Kenya and Tanzania (Turkana, Olduvai) and later fossils in the same Ethiopian study area (Bodo, Middle Awash). These newly discovered fossils complete an evolutionary sequence in Africa between 1.8 and 0.6 million years ago. According to lead author Dr. Berhane Asfaw of Ethiopia, this latest Ethiopian discovery represents one more link in a series of fossils that clearly show human origins and evolution over the last six million years.

• The Middle Awash research team includes over 45 scientists from 13 different countries, specializing in geology, archaeology, and paleontology.

• The Middle Awash research project was initiated in 1981 by the late legendary archaeologist J. Desmond Clark, who published a monograph on the Bouri stone tool assemblages last year. The March 21 Nature paper is dedicated to Clark (see tributes at http://socrates.berkeley.edu/~lhesjdc1/)

• All fossils found in Ethiopia are studied and curated at the National Museum of Ethiopia in Addis Ababa, the capitol.

• Geochemical correlations among dated volcanic ash horizons at Bouri were done at the Los Alamos National Laboratory by Dr. Giday WoldeGabriel, and at Miami University in Ohio by Professor William Hart.

• At the Berkeley Geochronology Center in California, geochronologist Dr. Paul Renne used a laser to fuse single crystals of volcanic rock to provide the Argon-Argon radioisotopic dates for the discoveries, and used paleomagnetic data to confirm these dates.

• Mr. Henry Gilbert intends to complete a monograph on the fossil animals found at the site. Dr. Asfaw will prepare a scientific monograph on the Homo erectus fossils.

• The Middle Awash team has also found, younger hominid fossils at Bouri. The researchers intend to publish on these as soon as their radiometric dating analyses are completed.

• Fieldwork in the Middle Awash continues under the joint direction of Professor Tim White of U.C. Berkeley, Dr. Giday WoldeGabriel of Los Alamos National Laboratory.

• The international research effort in the Middle Awash has been carried out under the Authority for Research and Conservation of Cultural Heritage of the Ethiopian Ministry of Youth, Sports and Culture.

• The research was supported by grants from the U.S. National Science Foundation (Physical Anthropology) and the Institute of Geophysics and Planetary Physics of the University of California at Los Alamos National Laboratory.

• Additional contributions were made by the Graduate School and Hampton Fund for International Initiatives, Miami University.

• Dr. Berhane Asfaw lives in Addis Ababa (7 hours ahead of EST) and will coordinate all Ethiopian-related public information within the Ministry there. Telephone: 251-9-22-31-94; e-mail <ramid@telecom.net.et>

• Mr. Henry Gilbert is in the Department of Integrative Biology at U.C. Berkeley. Telephone: 510-642-7952; E-mail: spider@uclink.berkeley.edu

• Professor Bill Hart chairs the Department of Geology at Miami University, Ohio. Telephone: 513-529-3216; E-mail: hartwk@muohio.edu

• Dr. Giday WoldeGabriel is at Los Alamos National Laboratory. E-mail: wgiday@lanl.gov

• Dr. Paul Renne is at the Berkeley Geochronology Center. E-mail: prenne@bgc.org

• Professor Elisabeth Vrba is in the Department of Geology and Geophysics at Yale University. E-mail: elisabeth.vrba@yale.edu

• Professor Tim White co-directs the Laboratory for Human Evolutionary Studies in the Museum of Vertebrate Zoology, and teaches in the Department of Integrative Biology at U.C. Berkeley. E-mail: timwhite@socrates.berkeley.edu

• Professor C. Owen Lovejoy is at Kent State University. E-mail: OLovejoy@aol.com

• Dr. Gen Suwa of the University of Tokyo; E-mail: suwa@um.u-tokyo.ac.jp

• Professor Clark Howell is at Berkeley. tel. 510-642-1393

• Videotape segments and released photographs are available from

Robert Sanders, Media Relations, Public Affairs, U.C. Berkeley. Telephone (510) 643-6998; E-mail: rls@pa.urel.berkeley.edu

• Additional photographs documenting these discoveries, including more field shots as well as laboratory shots of specimens and scientists, are all available through David L. Brill Photography, 552 Hwy. 279, Fairburn, GA 30213, USA: Phone/Fax: 770-461-5488. E-mail: brill@mindspring.com

-30-