Hadar or Hadar Formation (also spelled Qad daqar, Qadaqar; Afar "white [qidi] stream [daqar]")Jon Kalb Adventures in the Bone Trade (New York: Copernicus Books, 2001), p. 83 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).
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. 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.
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.
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.
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.
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.) 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).
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. 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. Lucy is the most famous fossil to have been found at Hadar. Lucy is among the oldest hominin fossils ever discovered 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.
Paleofauna
Australopithecus specimens have been well-known for their discoveries since the 1970s. However, other specimens from the Hadar Formation contain several fossil remains of artiodactyls, perissodactyls, carnivorans, proboscideans, and other African species. The bovids found in the formation included the Aepycerotini (Aepyceros), Alcelaphini (Damalborea and Parmularius), Antilopini (Gazella), Bovini (Ugandax and Pelorovis[?]), Caprini (Budorcas), Cephalophini, Hippotragini (Oryx), Neotragini (Raphicerus[?] and Madoqua), Reduncini (Kobus), and Tragelaphini (Tragelaphus). Artiodactyls outside the bovid family were present within the formation as well, namely the giraffids (Giraffa and Sivatherium), Hippopotamidae (Hippopotamus), and suids (Kolpochoerus, Notochoerus, and Nyanzachoerus). While a definitive list of carnivorans found within the Hadar Formation has yet to be compiled, confirmed genera that were found within the Hadar Formation include canids (Canis and Nyctereutes), felids (Dinofelis, Leptailurus, Felis, Homotherium, and Panthera), hyaenids (Chasmaporthetes, Ikelohyaena, Crocuta, Hyaena, and cf. Pliocrocuta), herpestids (Herpestes and cf. Helogale), mustelids (Mellivora, Enhydriodon, and cf. Poecilogale), and the viverrid (cf. Civettictis). Mammals within the formation outside the artiodactyl and carnivoran families include a bat (indeterminate), the leporid (Lepus), the equid (Eurygnathohippus), rhinoceroses (Ceratotherium and Diceros), old world primates (Parapapio, Theropithecus, and Cercopithecoides), proboscideans (the deinothere Deinotherium and elephants Elephas, Loxodonta, and Mammuthus) old world porcupines (Hystrix and Xenohystrix), murid rodents (Gerbilliscus, Acomys, Golunda, Oenomys, Praomys, Saidomys, Millardia, and Mus), the spalacid Tachyoryctes, a squirrel indet., and an aardvark species. Taxons within other classes are present within the Hadar Formation as well, such as birds (Plectropterus, Balearica, Anhinga, and Struthio) and reptiles (Crocodylus, Python, Varanus, and Bitis).
Mammals Artiodactyls Bovidae Bovids of the Hadar Formation Taxa Species Presence Material Notes Images Aepyceros A. datoadeni Kada Hadar Member at Hadar Near-complete skull lacking parts of horn cores (AL 787-1 KH1) An impala Beatragus B. sp. Detached braincase with two horn cores A hirola Budorcas B. churcheri Sida Hakoma Member. Complete skull with horns (AL 136-5 DD2) An extinct takinDamalborea D. elisabethae Basal and Sidi Hakoma members A skull with horn cores (AL 208-07 SH3) An extinct genus of Alcelaphinae D. grayi Denen Dora and Kada Hadar members Multiple postcranial fragments, such as horn cores, maxillae, and mandiblesDamaliscusD. hadari Sidi Hakoma and Kada Hadar Member An early alcelaphine antelope Damalops D. sidihakomai Sidi Hakoma Member AL 208–7, a skull with horn cores, right P4–M3, and left M2–3. An extinct genus of Alcelaphinae GazellaG. harmonae Kada Hadar Member at Hadar Skull remains, such as isolated teeth, maxillae, frontlets, and occipital bones (AL 444-16) Extinct relatives of modern gazellesG. cf. janenschi Denen Dora Member Horn cores (AL 302-6 DD)G. cf. praethomsoni Denen Dora and Kada Hadar members Few Horn core specimens Kobus K. hadarensis Sidi Hakoma, Kada Hadar and Denen Dora member Extinct relatives of antelopes K. oricornus Denen Dora and Kada Hadar members Several specimens of braincase and horn core Madoqua M. sp. Relative of dik-dik Parmularius P. pachyceras Sidi Hakoma and Kada Hadar members Braincases and horn cores Large extinct alcelphines related to topis and hartebeests Pelorovis P. sp.PraedamalisVrba, E.S., & Gatesy, J. (1994). New antelope fossils from Awash, Ethiopia, and phylogenetic analysis of Hippotragini (Bovidae, Mammalia).P. deturi Kada Hadar, Sida Hakoma, and Denen Dora members at Hadar Multiple specimens based on horn cores and lower teeth An early Hippotragini Raphicerus R. sp. Kada Hadar and Sidi Hakoma members Mandibles and horn cores Relative of Neotragini TragelaphusT. lockwoodi Basal and Sidi Hakoma members Braincase with complete horn cores (AL 142-3 SH2) Extinct relatives of spiral-horned antelopes T. rastafari Basal, Sidi Hakoma, Denen Dora, and Kada Hadar members Several horn core specimens Ugandax U. coryndonae Denen Dora and Sidi Hakoma members at Hadar Complete partial skull and horns (AL 194-1 DD1) Ancestor of Cape buffalo
Giraffidae Giraffids of the Hadar Formation Taxa Species Presence Material Notes ImagesGiraffa G. jumae Sidi Hakoma and Denen Dora members Partial teeth, vertebrae, ossicones, limb bones, and mandiblesExtinct relatives of modern giraffe G. stillei Sidi Hakoma and Denen Dora members Partial teeth, ossicones, limb bones, and mandiblesSivatheriumS. maurusiumDenen Dora, Kada Hadar, and Sidi Hakoma membersPartial mandibles and ossicones Okapi-like giraffid
Hippopotamidae Hippopotamids of the Hadar Formation Taxa Species Presence Material Notes ImagesHexaprotodon H. protoamphibius Denen Dora Member Partial skull and teethA Hippopotamid that is smaller than common hippos H. coryndoni Sidi Hakoma Member Partial skull and teeth Hippopotamus H. afarensis Basal, Sidi Hakoma, Kada Hadar, and Denen Dora members Complete postcranial skull and mandibles Extinct subspecies related to common hippopotamus, formally named Trilobophorus afarensis
Suidae Suids of the Hadar Formation Taxa Species Presence Material Notes Images Kolpochoerus K. afarensis Kada Hadar, Sidi Hakoma, and Denen Dora members Postcranial skulls, teeth fragments, and mandibles Extinct relative of the pig family Notochoerus N. eulius Kada Hadar, Lower and Upper Sidi Hakoma, and Denen Dora members Postcranial skull, teeth, and mandibles A Tetraconodontinae pig Nyanzachoerus N. kanamensis Basal and Sidi Hakoma members Complete cranium, mandibles, and dentition A Tetraconodontinae pig N. pattersoni Basal, Lower and Upper Sidi Hakoma, and Denen Dora members Complete skulls, mandibles, and dentition
Carnivorans Canidae Canids of the Hadar Formation Taxa Species Presence Material Notes ImagesCanisC. mesomelas Sidi Hakoma member A black-backed jackal Nyctereutes N. lockwoodi Sidi Hakoma and Denen Dora members at Dikika Nearly complete skull (DIK-31-1) A raccoon dog
Felidae