Donald Johanson Maurice Taieb Denis Geraads Zeresenay Alemseged
Condition
Excavated
Ownership
Ethiopian Government
Hadar or Hadar Formation (also spelled Qad daqar, Qadaqar; Afar "white [qidi] stream [daqar]")[1] is a paleontological fossil site located in Mille district, Administrative Zone 1 of the Afar Region, Ethiopia, 15 km upstream (west) of the A1 road's bridge across the Awash River (Adayitu kebele).[2]
It is situated on the southern edge of the Afar Triangle (part of East Africa's Great Rift Valley), along the left banks of the Awash River, between two minor tributaries, the eponymous Kada Hadar and the Kada Gona.[2] In 1972, Taieb organized a small exploratory reconnaissance of the Afar region to investigate more paleontological finds there. After six weeks of exploration, the party focused on the Hadar site.[3]
The site has yielded some of the most well-known hominin fossils, including "Lucy". These hominin fossils range in age from approximately 3.42 to 2.90 million years ago. These finds give us a greater understanding of hominin evolution during this period.
It is postulated that the specimens in the region were deposited by way of a large river system with associated crevasse channels/splays, deltas, and distributary channels, as well as periodic transgressions of paleolake Hadar located east of the research area (Aronson and Taieb, 1981, Tiercelin, 1986, Campisano and Feibel, in press) possibly related to geological activity or climatic cycles in at least the Kada Hadar Member (Yemane et al., 1996, Yemane, 1997, Campisano and Feibel, in press)."
According to Jon Kalb, early maps show caravan routes passing within 10 to 15 km of Hadar but not through it. The British explorer L.M. Nesbitt passed 15 km west of Hadar in 1928.[1]
Geology
The region's rocks consist mainly of mudstones, siltstones, fine-grained sandstones and volcanic tuffs. The region of Hadar has been divided into four geologic members — Basal (~3.8–3.42 Ma), Sidi Hakoma (~3.42–3.26 Ma), Denen Dora (~3.26–3.2 Ma), and Kada Hadar (<~3.2 Ma)—with three tuffs (Sidi Hakoma Tuff [SHT], Triple Tuff [TT] and Kada Hadar Tuff [KHT]) separating the four members.
The Sidi Hakoma member tends towards high rainfall and low seasonality. The overlying Denan Dora Member was a grassland habitat. Finally, the Kada Hadar Member was an even more open and arid habitat, as seen in the high abundance of antilopines, which frequent these types of terrains.[3]
Paleontology
The first paleo-geological explorations of the Hadar area were conducted by Maurice Taieb. He found Hadar in December 1970 by following the Ledi River, which originates in the highlands north of Bati to empty into the Awash River. Taieb recovered several fossils in the area and led a party back to Hadar in May 1972. In October 1973, 16 individuals with the International Afar Research Expedition (IARE) arrived at Hadar and camped there for two months during which the first hominin fossil was found. (Taieb claims in his 1985 book Sur la Terre des premiers Hommes to have discovered the Hadar fields in 1968, but Kalb argues that claim to be incorrect.)[4] The IARE party examined a series of sedimentary layers called the Hadar Formation, which was dated to the late Pliocene to early Pleistocene epochs (3.5 to 2.3 million years ago).[5]
Discovery of Lucy
The anthropologist Donald Johanson, a member of the 1973 expedition to Hadar, returned the next year and discovered the fossil hominin "Lucy" in the late fall of 1974.[6] He spotted a right proximal ulna in a gully, followed by an occipital bone, a femur, some ribs, a pelvis, and a lower jaw. Within two weeks, nearly 40% of the hominoid skeleton had been identified and cataloged.[7] Lucy is the most famous fossil to have been found at Hadar. Lucy is among the oldest hominin fossils ever discovered[6] and was later given the taxonomic classification Australopithecus afarensis. (The name 'Lucy' was inspired by the song "Lucy in the Sky with Diamonds" by The Beatles, which happened to be playing on the radio at base camp.)
Specimens and inferences
In 1975, Donald Johanson made another discovery at a nearby site in Hadar: 216 specimens from approximately 17 individuals, most likely related and varying in age, called AL 333 (colloquially referred to as the "First Family").
About thirty years later in nearby Dikika, another Australopithecus afarensis fossil skeleton was found in a separate outcrop of the Hadar Formation across the Awash River from Hadar. The skeleton is of a three-year-old girl later named "Selam," which means peace in Amharic Ethiopian languages.
In 1973 and 1974 when the first anatomical discoveries were made, their size and shape pointed towards a variety of taxa, but further research has confirmed that only one hominin taxon is present here. The first find there was a fossil knee joint estimated to date from 3.4 million years ago. Since then, the Hadar research area has yielded 370 specimens of A. afarensis, one specimen of Homo, and 7571 additional vertebrate specimens.
The specimens recovered display a variety of different primitive cranial post features, which indicate A. afarensis is distinct from other species of Australopithecus: small cranial capacity, palate similar to African apes (parallel tooth rows, shallow, long from front to back, narrow from side to side), primitive occipital, basal cranium anatomy, high frequency of unicuspid third premolars, prognathic face, and primitive mandibular anatomy. Postcranially, the pelvis, knee, ankle, and foot indicate habitual, terrestrial bipedalism, but ape-like curved finger and foot bones are retained ancestral ape-like features.[3]
Paleofauna
According to the geological members of Hadar, the Awash River (top) and Omo Valley (bottom) biomes might resemble the Hadar paleoenvironment.
Basal, Denen Dora, Kada Hadar, and Sidi Hakoma members
Partial skeletons featuring small cranial capacity, primitive occipitals, basal cranium anatomy, high frequency of unicuspid third premolars, prognathic faces, and primitive mandibular anatomy
^ abJon KalbAdventures in the Bone Trade (New York: Copernicus Books, 2001), p. 83
^ abDiMaggio, Erin N.; Arrowsmith, J Ramón; Campisano, Christopher J.; Johnson, Roy; Deino, Alan L.; Warren, Mark; Fisseha, Shimeles; Cohen, Andrew S. (December 2015). "Tephrostratigraphy and depositional environment of young (<2.94 Ma) Hadar Formation deposits at Ledi-Geraru, Afar, Ethiopia". Journal of African Earth Sciences. 112: 234–250. Bibcode:2015JAfES.112..234D. doi:10.1016/j.jafrearsci.2015.09.018.
^ abcJohanson, Donald (March 2017). "The paleoanthropology of Hadar, Ethiopia". Comptes Rendus Palevol. 16 (2): 140–154. Bibcode:2017CRPal..16..140J. doi:10.1016/j.crpv.2016.10.005.
^Halstead, Lambert Beverly (1984). A la recherche du passé: la vie sur terre des origines aux premiers hommes. Hachette. ISBN 978-2-01-009602-0. OCLC 25125386.[page needed]
^Feibel, Craig S. (November 2004). Sedimentary Patterns in the Pliocene Hadar Formation, Afar Rift, Ethiopia. 2004 Denver Annual Meeting of The Geological Society of America.
^ abHogenboom, Melissa. "The 'Lucy' fossil rewrote the story of humanity". Retrieved 25 October 2018.
^"Lucy's Story | Institute of Human Origins". iho.asu.edu. Retrieved 25 October 2018.
^Reed, Kaye E.; Bibi, Faysal (March 2011). "Fossil Tragelaphini (Artiodactyla: Bovidae) from the Late Pliocene Hadar Formation, Afar Regional State, Ethiopia". Journal of Mammalian Evolution. 18 (1): 57–69. doi:10.1007/s10914-010-9146-6.
^ abcdefghijklmnopqrstGeraads, Denis; Bobe, René; Reed, Kaye (2012). "Pliocene Bovidae (mammalia) from the Hadar Formation of Hadar and Ledi-Geraru, Lower Awash, Ethiopia". Journal of Vertebrate Paleontology. 32 (1): 180–197. Bibcode:2012JVPal..32..180G. doi:10.1080/02724634.2012.632046. JSTOR 41407716.
^Reed, Kaye E. (June 2008). "Paleoecological patterns at the Hadar hominin site, Afar Regional State, Ethiopia". Journal of Human Evolution. 54 (6): 743–768. doi:10.1016/J.JHEVOL.2007.08.013. PMID 18191177.
^ abcdeCooke, H B S (1978). "Pliocene-Pleistocene Suidae from Hadar, Ethiopia". Kirtlandia. 29: 1–63.
^ abcdeWerdelin, Lars; Lewis, Margaret E. (June 2001). "A revision of the genus Dinofelis (Mammalia, Felidae)". Zoological Journal of the Linnean Society. 132 (2): 147–258. doi:10.1111/j.1096-3642.2001.tb02465.x.
^ abcdeWerdelin, Lars; Lewis, Margaret E. (2008). "New Species of Crocuta from the Early Pliocene of Kenya, with an Overview of Early Pliocene Hyenas of Eastern Africa". Journal of Vertebrate Paleontology. 28 (4): 1162–1170. Bibcode:2008JVPal..28.1162W. doi:10.1671/0272-4634-28.4.1162. JSTOR 20491047.
^ abcGeraads, Denis; Alemseged, Zeresenay; Bobe, René; Reed, Denné (17 March 2011). "Enhydriodon dikikae , sp. nov. (Carnivora: Mammalia), a gigantic otter from the Pliocene of Dikika, Lower Awash, Ethiopia". Journal of Vertebrate Paleontology. 31 (2): 447–453. Bibcode:2011JVPal..31..447G. doi:10.1080/02724634.2011.550356.
^ abcGilbert, W. Henry; Bernor, Raymond L. (2009). "Equidae". Homo erectus: Pleistocene Evidence from the Middle Awash, Ethiopia. pp. 133–166. doi:10.1525/california/9780520251205.003.0006. ISBN 978-0-520-25120-5.
^ abcGeraads, Denis (2005). "Pliocene Rhinocerotidae (Mammalia) from Hadar and Dikika (Lower Awash, Ethiopia), and a Revision of the Origin of Modern African Rhinos" (PDF). Journal of Vertebrate Paleontology. 25 (2): 451–461. doi:10.1671/0272-4634(2005)025[0451:PRMFHA]2.0.CO;2. JSTOR 4524458.
^ abcdKalb, Jon E.; Mebrate, Assefa; Tischler, Doris (1993). "Fossil Elephantoids: From the Hominid-Bearing Awash Group, Middle Awash Valley, Afar Depression, Ethiopia". Transactions of the American Philosophical Society. 83 (1): i–114. doi:10.2307/1006558. JSTOR 1006558.
^ abcSanders, William J.; Haile-Selassie, Yohannes (June 2012). "A New Assemblage of Mid-Pliocene Proboscideans from the Woranso-Mille Area, Afar Region, Ethiopia: Taxonomic, Evolutionary, and Paleoecological Considerations". Journal of Mammalian Evolution. 19 (2): 105–128. doi:10.1007/s10914-011-9181-y.
^Rowan, John; Lazagabaster, Ignacio A.; Campisano, Christopher J.; Bibi, Faysal; Bobe, René; Boisserie, Jean-Renaud; Frost, Stephen R.; Getachew, Tomas; Gilbert, Christopher C.; Lewis, Margaret E.; Melaku, Sahleselasie; Scott, Eric; Souron, Antoine; Werdelin, Lars; Kimbel, William H.; Reed, Kaye E. (6 April 2022). "Early Pleistocene large mammals from Maka'amitalu, Hadar, lower Awash Valley, Ethiopia". PeerJ. 10: e13210. doi:10.7717/peerj.13210. PMC 8994497. PMID 35411256.
^ abAzzarà, Beatrice; Cherin, Marco; Adams, Justin; Boschian, Giovanni; Crotti, Marco; Denys, Christiane; Fressoia, Lorenzo; Kimambo, Jackson S.; Kwekason, Amandus; Iurino, Dawid A.; Manzi, Giorgio; Masao, Fidelis T.; Melaku, Sahleselasie; Menconero, Sofia; Mori, Emiliano; Zipfel, Bernhard (June 2022). "The Thorny Issue of African Porcupines: a New Mandible of Hystrix makapanensis from Olduvai Gorge (Tanzania) and Rediagnosis of the Species". Journal of Mammalian Evolution. 29 (2): 447–474. doi:10.1007/s10914-021-09588-z. PMC 8776392. PMID 35079214.
^ abcdefgReed, Denné N. (2011). "New Murid (mammalia, Rodentia) Fossils from a Late Pliocene (2.4 Ma) Locality, Hadar A.l. 894, Afar Region, Ethiopia". Journal of Vertebrate Paleontology. 31 (6): 1326–1337. Bibcode:2011JVPal..31.1326R. doi:10.1080/02724634.2011.620676. JSTOR 41407688.
^Campisano, Christopher J.; Rowan, John; Reed, Kaye E. (2022). "The Hadar Formation, Afar Regional State, Ethiopia: Geology, Fauna, and Paleoenvironmental Reconstructions". African Paleoecology and Human Evolution. pp. 214–228. doi:10.1017/9781139696470.018. ISBN 978-1-139-69647-0.
^ abcdefghiGeraads, Denis; Alemseged, Zeresenay; Bobe, René; Reed, Denné (July 2015). "Pliocene Carnivora (Mammalia) from the Hadar Formation at Dikika, Lower Awash Valley, Ethiopia". Journal of African Earth Sciences. 107: 28–35. Bibcode:2015JAfES.107...28G. doi:10.1016/j.jafrearsci.2015.03.020.
^ abcdGeraads, Denis; Reed, Kaye; Bobe, Rene (March 2013). "Pliocene Giraffidae (Mammalia) from the Hadar Formation of Hadar and Ledi-Geraru, Lower Awash, Ethiopia". Journal of Vertebrate Paleontology. 33 (2): 470–481. Bibcode:2013JVPal..33..470G. doi:10.1080/02724634.2013.723657.
^ abcdefFrost, Stephen R.; Delson, Eric (November 2002). "Fossil Cercopithecidae from the Hadar Formation and surrounding areas of the Afar Depression, Ethiopia". Journal of Human Evolution. 43 (5): 687–748. doi:10.1006/jhev.2002.0603. PMID 12457855.
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^Kalb, Jon E.; Jolly, Clifford J.; Tebedge, Sleshi; Mebrate, Assefa; Smart, Charles; Oswald, Elizabeth B.; Whitehead, Paul F.; Woods, Craig B.; Adefris, Tsrha; Rawn-Schatzinger, Viola (1982). "Vertebrate Faunas from the Awash Group, Middle Awash Valley, Afar, Ethiopia". Journal of Vertebrate Paleontology. 2 (2): 237–258. Bibcode:1982JVPal...2..237K. doi:10.1080/02724634.1982.10011932. JSTOR 4522897.
^ abcdReed, Kaye E. (June 2008). "Paleoecological patterns at the Hadar hominin site, Afar Regional State, Ethiopia". Journal of Human Evolution. 54 (6): 743–768. doi:10.1016/J.JHEVOL.2007.08.013. PMID 18191177.
^Howell, F. C.; Petter, G. (1979). "Diversification et affinites des Carnivores pliocenes du groupe de l'Omo et de la formation d'Hadar (Ethiopie)". Bulletin de la Société Géologique de France. S7-XXI (3): 289–293. doi:10.2113/gssgfbull.s7-xxi.3.289.
^Gentry, A.W. (1996). "A fossil Budorcas (Mammalia, Bovidae) from Africa". Palaeoecology and Palaeoenvironments of Late Cenozoic Mammals. pp. 571–587. doi:10.3138/9781487574154-028. ISBN 978-1-4875-7415-4.
^Vrba, E. S. (1997). "New fossils of Alcelaphini and Caprinae (Bovidae: Mammalia) from Awash, Ethiopia, and phylogenetic analysis of Alcelaphini". Palaeontologia Africana. 34. hdl:10539/16416.
^Geraads, Denis; Alemseged, Zeresenay; Bobe, René; Reed, Denné (2010). "Nyctereutes Lockwoodi , N. Sp., a New Canid (carnivora: Mammalia) from the Middle Pliocene of Dikika, Lower Awash, Ethiopia". Journal of Vertebrate Paleontology. 30 (3): 981–987. Bibcode:2010JVPal..30..981G. doi:10.1080/02724631003758326. JSTOR 40666211.
^Getahun, Dagmawit Abebe; Delson, Eric; Seyoum, Chalachew Mesfin (July 2023). "A review of Theropithecus oswaldi with the proposal of a new subspecies" (PDF). Journal of Human Evolution. 180: 103373. doi:10.1016/j.jhevol.2023.103373. PMID 37269782.
^Brodkorb, Pierce; Mourer-Chauviré, Cécile (January 1982). "Fossil Anhingas (Aves: Anhingidae) from Early Man Sites of Hadar and Omo (Ethiopia) and Olduvai Gorge (Tanzania)". Geobios. 15 (4): 505–515. Bibcode:1982Geobi..15..505B. doi:10.1016/S0016-6995(82)80071-5.
External links
Photo gallery from a University of Washington archaeological field season