Hadar, Ethiopia

Hadar
Location in Ethiopia
Location in Ethiopia
Site location in Ethiopia
LocationMille district,
Afar Region,
 Ethiopia
RegionEastern Africa
Coordinates11°10′01″N 40°37′59″E / 11.167°N 40.633°E / 11.167; 40.633
TypeArchaeological
Paleontology
History
PeriodsMiddle - Late Pliocene
Site notes
Excavation dates1970, 1972, 1973, 1974, 2000
ArchaeologistsDonald Johanson
Maurice Taieb
Denis Geraads
Zeresenay Alemseged
ConditionExcavated
OwnershipEthiopian 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

Administrative Zone 1 (Afar Region), Ethiopia

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

Lucy", a 3.2-million-year-old Australopithecus afarensis fossil discovered in Hadar

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.

Although Australopithecus is well-known for its discovery since the 1970s, other specimens from the Hadar Formation contain several fossil remains of artiodactyls, perissodactyls, carnivorans, proboscideans, and other African species that are well preserved. 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).[8][9][10] 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).[11] 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,[12] Leptailurus, Felis, Homotherium, and Panthera), hyaenids (Chasmaporthetes, Ikelohyaena, Crocuta, Hyaena, and cf. Pliocrocuta),[13] herpestids (Herpestes and cf. Helogale), mustelids (Mellivora, Enhydriodon,[14] 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),[15] rhinoceroses (Ceratotherium and Diceros),[16] old world primates (Parapapio, Theropithecus, and Cercopithecoides), proboscideans (the deinothere Deinotherium and elephants Elephas, Loxodonta, and Mammuthus) [17][18][19] old world porcupines (Hystrix and Xenohystrix),[20] murid rodents (Gerbilliscus, Acomys, Golunda, Oenomys, Praomys, Saidomys, Millardia, and Mus),[21] 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).[22][23][24][25][26][27][28][29]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

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)[9] An impala
Beatragus B. sp. Detached braincase with two horn cores[9] A hirola
Budorcas B. churcheri[30] Sida Hakoma Member.[9] Complete skull with horns (AL 136-5 DD2)[9] An extinct takin
Damalops D. sidihakomai[31] Sidi Hakoma Member AL 208–7, a skull with horn cores, right P4–M3, and left M2–3. An extinct genus of Alcelaphinae
Damalborea D. elisabethae Basal and Sidi Hakoma members[9] A skull with horn cores (AL 208-07 SH3)[9] An extinct genus of Alcelaphinae
D. grayi Denen Dora and Kada Hadar members[9] Multiple postcranial fragments, such as horn cores, maxillae, and mandibles[9]
Gazella G. harmonae Kada Hadar Member at Hadar[9] Skull remains, such as isolated teeth, maxillae, frontlets, and occipital bones (AL 444-16)[9] Extinct relatives of modern gazelles
G. cf. janenschi Denen Dora Member Horn cores (AL 302-6 DD)[9]
G. cf. praethomsoni Denen Dora and Kada Hadar members Few Horn core specimens[9]
Hippotragini Praedamalis deturi Kada Hadar, Sida Hakoma, and Denen Dora members at Hadar Multiple specimens based on horn cores and lower teeth[9] Ancestor of modern oryx
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[9]
Madoqua M. sp. Relative of dik-dik
Raphicerus R. sp. Kada Hadar and Sidi Hakoma members Mandibles and horn cores[9] Relative of Neotragini
Parmularius P. pachyceras Sidi Hakoma and Kada Hadar members[9] Braincases and horn cores[9] Large extinct alcelphines related to topis and hartebeests
Pelorovis P. sp.
Tragelaphus T. lockwoodi Basal and Sidi Hakoma members Braincase with complete horn cores (AL 142-3 SH2)[9] 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)[9] Ancestor of Cape buffalo
Giraffidae
Giraffids of the Hadar Formation
Taxa Species Presence Material Notes Images
Giraffa G. jumae Sidi Hakoma and Denen Dora members Partial teeth, vertebrae, ossicones, limb bones, and mandibles[24] Extinct relatives of modern giraffe
G. stillei Sidi Hakoma and Denen Dora members Partial teeth, ossicones, limb bones, and mandibles[24]
Sivatherium S. maurusium Denen Dora, Kada Hadar, and Sidi Hakoma members Partial mandibles and horns[24] Okapi-like giraffid
Hippopotamidae
Hippopotamids of the Hadar Formation
Taxa Species Presence Material Notes Images
Hexaprotodon H. protoamphibius Denen Dora Member Partial skull and teeth Extinct relatives of modern pygmy hippo
H. coryndoni Sidi Hakoma Member[28] Partial skull and teeth
Hippopotamus H. afarensis Basal, Sidi Hakoma, Kada Hadar, and Denen Dora members[28] 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[11] 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[11] Postcranial skull, teeth, and mandibles A Tetraconodontinae pig.
Nyanzachoerus N. kanamensis Basal and Sidi Hakoma members[28] Complete cranium, mandibles, and dentition A Tetraconodontinae pig.
N. pattersoni Basal, Lower and Upper Sidi Hakoma, and Denen Dora members[11] Complete skulls, mandibles, and dentition[11]

Carnivorans

Canidae
Canids of the Hadar Formation
Taxa Species Presence Material Notes Images
Nyctereutes N. lockwoodi Sidi Hakoma and Denen Dora members at Dikika[23] Nearly complete skull (DIK-31-1)[32] A raccoon dog
Felidae
Felids of the Hadar Formation
Taxa Species Presence Material Notes Images
Dinofelis D. aronoki Kada Hadar Member[12] Postcranial member: distal radius (AL-363-20)[12] A machairodontine felid
D. petteri Sidi Hakoma and Denen Dora members[12] Postcranial member: partial humerus (AL 168-30), proximal ulna (AL 262-9), and right astragalus (Al 173-11)[12]
Felis F. sp. Kada Hadar, Sidi Hakoma, and Denen Dora members A small cat relative
Homotherium H. hadarensis Denen Dora Member[23] Complete cranium skull, mandible fragments (DIK-96-1), teeth, and forelimbs[23] A machairodontine felid
Megantereon M. sp. Kada Hadar, Sidi Hakoma, and Denen Dora members A machairodontine felid
Leptailurus L. sp. A serval cat
Panthera P. sp. Sidi Hakoma Member Relatives of lions
Herpestidae
Herpestids of the Hadar Formation
Taxa Species Presence Material Notes Images
Herpestes H. sp. Dikika site Tooth fragments A mongoose
Hyaenidae
Hyaenids of the Hadar Formation
Taxa Species Presence Material Notes Images
Chasmaporthetes C. sp. Sidi Hakoma and Denen Dora members at Hadar[13] A hunting hyena
Crocuta C. dietrichi Sidi Dakoma , Denen Dora, and Basal members at Hadar[13] Fragmented mandibles (DIK-32-1)[23][13] Extinct relatives of modern hyena
C. eturono Kada Hadar Member Partial maxilla (DIK-73-1)[23]
Hyaena H. sp.
Ikelohyaena I. abronia Sidi Hakoma Member at Hadar[13] Early member of the Parahyaena lineage and the earliest close relative of the modern striped hyena
Percrocuta P. sp.
Pliocrocuta P. cf. perierri Sidi Hakoma and Denen Dora members An early hyaena relative, synonym named Pachycrocuta cf. perrieri
Mustelidae
Mustelids of the Hadar Formation
Taxa Species Presence Material Notes Images
Enhydriodon E. dikikae Basal and Sidi Hakoma members at Dikika site[14][23] Partial skull (DIK-56-9) and humerus (DIK-78-1)[14][23] A giant river otter
Lutra L. hearsti Lower part of Sidi Hakoma Member at Dikika Upper teeth fragments (DIK-50–35)[23] Extinct relative of otters
Mellivora M. sp. A honey badger
Poecilogale P. sp. Sidi Hakoma Member
Viverridae
Viverrids of the Hadar Formation
Taxa Species Presence Material Notes Images
Civettictis C. sp. A civet

Perissodactyls

Equidae
Equids of the Hadar Formation
Taxa Species Presence Material Notes Images
Eurygnathohippus E. afarense Kada Hadar Member Partial skull (AL 363-18) and mandibles[15] A hipparionine horse.
E. hasumense Denen Dora Member Partial skull (AL 340-8) and mandibles[15]
Rhinocerotidae
Rhinocerotids of the Hadar Formation
Taxa Species Presence Material Notes Images
Ceratotherium C. mauritanicum Sidi Hakoma Member at Lower Awash of Dikika Complete cranium skull (AL-129-25)[16] Ancestor of modern white rhinoceros
Diceros D. praecox Sidi Hakoma Member at Lower Awash of Dikika Incomplete cranium skull fragments and jawbones[16] Direct ancestor of modern black rhinoceros, formally named Ceratotherium praecox

Primates

Cercopithecidae
Cercopithecids of the Hadar Formation
Taxa Species Presence Material Notes Images
Cercopithecoides C. meaveae Sidi Hakoma Member Partial skeleton (A.L. 2-64 and A.L. 222-14)[25] A colobine monkey
Rhinocolobus R. turkanaensis Sidi Hakoma and Denen Dora members Preserved mandibles and teeth fragments[25] Extinct relative of colobus monkey
Parapapio P. cf. jonesi Sidi Hakoma and Kada Hadar members Complete postcranial skull, partial limbs, teeth fragments, and mandibles[25] A prehistoric baboon
Theropithecus oswaldi[33] T. o. darti Basal, Denen Dora, Kada Hadar, and Sidi Hakoma members Postcranial skulls differentiated between male and female[25] Extinct relatives of gelada baboons
T. o. ecki Denen Dora Member Female cranium skull and mandible
T. o. oswaldi Sidi Hakoma and Kada Hadar members Postcranial skulls differentiated between male and female[25]
Hominidae
Hominids of the Hadar Formation
Taxa Species Presence Material Notes Images
Australopithecus A. afarensis 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 An australopithecine hominid

AL 444-2 skull
AL 444-2 skull

Proboscideans

Deinotheriidae
Deinotheriids of the Hadar Formation
Taxa Species Presence Material Notes Images
Deinotherium D. bozasi Denen Dora, Kada Hadar, and Sidi Hakoma members Complete cranium skull and teeth fragments A large extinct elephant-like proboscidean
Elephantidae
Elephantids of the Hadar Formation
Taxa Species Presence Material Notes Images
Elephas E. ekorensis Sidi Hakoma and Denen Dora members at Hadar and Dikika[18] Mandibles and molar fragments Extinct lineage related to Asian elephant
Loxodonta L. adaurora Denen Dora and Sidi Hakoma members at Hadar[17] Mandibles and molar fragments Extinct subspecies of modern African elephant
L. exoptata Denen Dora Member Undescribed molars[17]
Mammuthus M. sp. Sidi Hakoma and Denen Dora Member. Undescribed molars[17] A mammoth relative
Palaeoloxodon recki P. r. brumpti Sidi Hakoma Member[18] Mandibles and molar fragments Extinct relative of African elephant

Rodents

Rodents of the Hadar Formation
Taxa Species Presence Material Notes Images
Acomys A. cf. lavocati Mandible specimens[21] Relatives of Spiny mice.
A. cf. lemniscomys Right mandible and broken tooth root[21]
Gerbilliscus G. sp. Right maxillary fragment with M2-3 and right mandible fragment with M1-3[21] Relative of gerbil species
Golunda G. gurai Murine rodent closely related to the Indian bush rat
Hystrix H. cf. makapanensis Sidi Hakoma Member[20] An Old World porcupine
Mastomys M. cf. minor Partial skull and mandibles[21] Extinct relative of the multimammate mouse
Millardia M. coppensi Extinct relatives of soft-furred rat
M. taiebi
Mus M. indet. Unknown relative of Murini
Oenomys O. tiercelini Extinct relative of modern rusty-nosed rat
Pelomys P. cf dietrichi Mandibles A groove-toothed swamp rat
Praomys P. sp. Sidi Hakoma Member A.L. 894-35993, a right mandible with M1-3[21] A Muridae species
Saidomys S. afarensis Sidi Hakoma Member Extinct relative of a muroid mouse
Tatera T. sp. Sidi Hakoma and Denen Dora members Extinct relative of the Indian gerbil
Thallomys T. cf. quadrilobatus Complete skull with both mandibles[21] Extinct relative of the rat family endemic to Africa
Thryonomys T. swinderianus A cane rat
Xenohystrix X. cf. crassidens Sidi Hakoma and Denen Dora members An old-world porcupine
Xerus X. sp. Kada Hadar Member An unstriped ground squirrel

Birds

Birds of the Hadar Formation
Taxa Species Presence Material Notes Images
Anhinga A. hadarensis[34] An extinct darter
Balearica B. sp.
Plectropterus P. sp.
Struthio S. sp.

Reptiles

Reptiles of the Hadar Formation
Taxa Species Presence Material Notes Images
Bitis B. sp.
Crocodylus C. sp.
Python P. sp.
Varanus V. sp.

See also

References

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  2. ^ a b DiMaggio, 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.
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