Hadar or Hadar Formation (also spelled Qad daqar, Qadaqar; Afar "white [qidi] stream [daqar]") 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.

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. 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

thumb|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. 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 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

{| class="wikitable" align="center"

|-

! colspan="6" align="center" | 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)

| Sida Hakoma Member.

| Sidi Hakoma Member

| AL 208–7, a skull with horn cores, right P4–M3, and left M2–3.

| An extinct genus of Alcelaphinae

|

|-

| rowspan = "3"| Gazella

|G. harmonae

| Kada Hadar Member at Hadar

|P. deturi

| Kada Hadar, Sida Hakoma, and Denen Dora members at Hadar

| Multiple specimens based on horn cores and lower teeth

| A raccoon dog

|

|}

; Felidae

{| class="wikitable" align="center"

|-

! colspan="6" align="center" | Felids of the Hadar Formation

|-

! Taxa !! Species !! Presence !! Material !! Notes !! Images

|-

| rowspan = "2"| Dinofelis

| D. aronoki

| Kada Hadar Member

|T. oswaldi darti

| Basal, Denen Dora, Kada Hadar, and Sidi Hakoma members

| Postcranial skulls differentiated between male and female

|

| A tarsometatarsus

| An extinct darter

|

|-

|Balearica

|B. sp.

|

|

|

|

|-

|Plectropterus

|P. sp.

|

|

|

|

|-

|Struthio

|S. sp.

|

|

|

|

|-

|}

Reptiles

{| class="wikitable" align="center"

|-

! colspan="6" align="center" | Reptiles of the Hadar Formation

|-

! Taxa !! Species !! Presence !! Material !! Notes !! Images

|-

|Bitis

|B. sp.

|

|

| A venomous snake

| rowspan =100|

|-

|rowspan = 2|Crocodylus

| C. lucivenator

| Sidi Hakoma Member

| A complete cranium skull with the matching lower jaw (A.L. 138-16)

| The first named crocodile species discovered from this site

|-

|C. sp.

|

| Specimens consist of dentition

| A crocodile

|-

|Pelusios

|P. awashi

| Denen Dora Member

| A partial cranium (A.L. 207 − 15)

| An African mud turtle, the first named turtle species discovered from this site

|-

|Python

| P. sp.

|

|

| A python

|-

|Varanus

|V. sp.

|

|

| A monitor lizard

|-

|}

See also

  • Ledi-Geraru

==References==<!-- Geobios15:505. -->

  • Photo gallery from a University of Washington archaeological field season