Ileret (also spelled Illeret) is a village in Marsabit County,

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

. It is located in Northern Kenya, on the eastern shore of

Lake Turkana Lake Turkana () is a saline lake in the Kenyan Rift Valley, in northern Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake. By volume it is the world ...

, north of Sibiloi National Park and near the

Ethiopia Ethiopia, officially the Federal Democratic Republic of Ethiopia, is a landlocked country located in the Horn of Africa region of East Africa. It shares borders with Eritrea to the north, Djibouti to the northeast, Somalia to the east, Ken ...

n border. Numerous hominin fossils have been found near Ileret, including ''

Homo erectus ''Homo erectus'' ( ) is an extinction, extinct species of Homo, archaic human from the Pleistocene, spanning nearly 2 million years. It is the first human species to evolve a humanlike body plan and human gait, gait, to early expansions of h ...

'' footprints dating back to about 1.5 million years ago, making them the second oldest hominin footprints ever found after those at Laetoli, Tanzania.

Hominin fossils found near Ileret

Besides the ''Homo erectus'' footprints, numerous other fossils have been found near the Ileret site. In 2012–2013, a team of researchers from

Stony Brook University Stony Brook University (SBU), officially the State University of New York at Stony Brook, is a public university, public research university in Stony Brook, New York, United States, on Long Island. Along with the University at Buffalo, it is on ...

found new hominin fossils near Ileret, in two sites within the Kolom Odiet area. The fossils were representative of three different individuals, composing of two partial skeletons – KNM-ER ( Kenya National Museum – East Rudolf) 64061 and KNM-ER 64062 – and an almost entirely completed

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

, KNM-ER 64060. KNM-ER 64060 and KNM-ER 64061 date back to 2.02 to 2.03 Ma, and KNM-ER 64062 goes back 1.82 to 1.86 million years ago. The KNM-ER 64060 mandible is only missing the right central incisor. The KNM-ER 64061 partial skeleton includes most of both humeral shafts, a partial right

ulna The ulna or ulnar bone (: ulnae or ulnas) is a long bone in the forearm stretching from the elbow to the wrist. It is on the same side of the forearm as the little finger, running parallel to the Radius (bone), radius, the forearm's other long ...

and right

clavicle The clavicle, collarbone, or keybone is a slender, S-shaped long bone approximately long that serves as a strut between the scapula, shoulder blade and the sternum (breastbone). There are two clavicles, one on each side of the body. The clavic ...

, and a right

shoulder blade The scapula (: scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on either side ...

. Its longer bones appeared to be slender, yet thick in its cross-sections. The KNM-ER 64062 skeleton possesses parts of a distal right humerus and

scaphoid The scaphoid bone is one of the carpal bones of the wrist. It is situated between the hand and forearm on the thumb side of the wrist (also called the lateral or radial side). It forms the radial border of the carpal tunnel. The scaphoid bone ...

, and parts of a right foot with both primitive and derived features. These three individuals most likely represent members of early ''Homo'', the mandible being from ''

Homo habilis ''Homo habilis'' ( 'handy man') is an extinct species of archaic human from the Early Pleistocene of East and South Africa about 2.4 million years ago to 1.65 million years ago ( mya). Upon species description in 1964, ''H. habilis'' was highly ...

'' and the partial skeletons being from ''

''.

''Homo erectus'' footprints at Ileret

Fossilized footprints of ''Homo erectus'' were found in Ileret, Kenya. ''Science'' reported that there were multiple trails of footprints found at the Ileret site: “two trails of two prints each, one of seven prints and a number of isolated prints.” Citation error. See inline comment how to fix. These footprints reveal that these early hominins most likely traveled in groups—evidence which researchers see as a sign of social behavior.Citation error. See inline comment how to fix. Certain social behaviors distinguish humans from other primate species. Researchers attempt to find evidence of similar behaviors in the fossil or footprint records, however, it is difficult because this kind of fossil evidence is lacking. ''Homo erectus'' fossils were discovered in 1.5 million-year-old layers of

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

. These fossils supplied information about soft-tissue and foot structure. Unlike the fossils, the footprints provide researchers with information about early foot anatomy. Moreover, other ''Homo erectus'' fossils have been found in nearby areas and are the approximately the same age as the footprints found at Ileret.

''Homo erectus'' compared to other hominins

Differences have been found between these footprints and common apes. According to

Rutgers University Rutgers University ( ), officially Rutgers, The State University of New Jersey, is a Public university, public land-grant research university consisting of three campuses in New Jersey. Chartered in 1766, Rutgers was originally called Queen's C ...

, “the big toe is parallel to the other toes, unlike that of apes where it is separated in a grasping configuration useful in the trees.” The arch of the footprint is also human-like and the toes are much shorter than those of an ape. Short toes are a sign of “upright bipedal stance.” Additionally, relevant observations point to similarities between ''H. erectus'' and modern humans. The footprints reveal comparable body weights, strides and gaits. These early hominins are the first to have such similar body proportions to modern humans (''Homo sapiens''). Homo footprints

Evidence of bipedalism

Bipedalism Bipedalism is a form of terrestrial locomotion where an animal moves by means of its two rear (or lower) Limb (anatomy), limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from ...

is a characteristic of modern humans. Fossil evidence reveals that

hominins The Hominini (hominins) form a taxonomic tribe of the subfamily Homininae (hominines). They comprise two extant genera: ''Homo'' (humans) and '' Pan'' (chimpanzees and bonobos), and in standard usage exclude the genus ''Gorilla'' (gorillas), ...

walked on two feet as early as 6 to 7 million years ago. It can be difficult to reconstruct

gait Gait is the pattern of Motion (physics), movement of the limb (anatomy), limbs of animals, including Gait (human), humans, during Animal locomotion, locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on s ...

evolution due to the inadequacy and scarcity of the fossil record. Often, fragments of bones are discovered and offer little information about hominins’ walking manners. Additionally, the hominin fossil record does not provide information concerning the social patterns of modern humans and other primates—patterns which drove evolution. The Ileret footprints provide significant evidence that ''Homo erectus'' was a bipedal hominin. The footprints provide evidence for a “modern human-like weight transfer” and support earlier discussions of ''

’'' arched foot.

Researchers

The footprints were discovered in 2007 by John W. Harris, BG Richmond, and David R. Braun.

References

External links

Human Timeline (Interactive)
– Smithsonian,

National Museum of Natural History The National Museum of Natural History (NMNH) is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. With 4.4 ...

(August 2016). {{Archaeological sites in Kenya Populated places in Marsabit County Lake Turkana Archaeological sites in Kenya Pleistocene paleontological sites of Africa Prehistoric Africa Paleoanthropological sites Archaeological sites of Eastern Africa