'' Homo naledi'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of archaic human discovered in 2013 in the

Rising Star Cave The Rising Star cave system (also known as Westminster or Empire cave) is located in the Malmani Subgroup, Malmani dolomites, in Bloubank River valley, about southwest of Swartkrans, part of the Cradle of Humankind World Heritage Site in Sout ...

system,

Gauteng Gauteng ( , ; Sotho-Tswana languages, Sotho-Tswana for 'place of gold'; or ) is one of the nine provinces of South Africa. Situated on the Highveld, Gauteng is the smallest province by land area in South Africa. Although Gauteng accounts f ...

province, South Africa, part of the

Cradle of Humankind The Cradle of Humankind is a paleoanthropological site that is located about northwest of Johannesburg, South Africa, in the Gauteng province. Declared a World Heritage Site by UNESCO in 1999, the site is home to the largest known concentrat ...

, dating back to the

Middle Pleistocene The Chibanian, more widely known as the Middle Pleistocene (its previous informal name), is an Age (geology), age in the international geologic timescale or a Stage (stratigraphy), stage in chronostratigraphy, being a division of the Pleistocen ...

335,000–236,000 years ago. The initial discovery comprises 1,550 specimens of bone, representing 737 different skeletal elements, and at least 15 different individuals. Despite this exceptionally high number of specimens, their classification with other ''

Homo ''Homo'' () is a genus of great ape (family Hominidae) that emerged from the genus ''Australopithecus'' and encompasses only a single extant species, ''Homo sapiens'' (modern humans), along with a number of extinct species (collectively called ...

'' species remains unclear. Along with similarities to contemporary ''Homo'', they share several characteristics with the ancestral ''

Australopithecus ''Australopithecus'' (, ; or (, ) is a genus of early hominins that existed in Africa during the Pliocene and Early Pleistocene. The genera ''Homo'' (which includes modern humans), ''Paranthropus'', and ''Kenyanthropus'' evolved from some ''Aus ...

'' as well as early ''Homo'' ( mosaic evolution), most notably a small cranial capacity of 465–610 cm³ (28.4–37.2 cu in), compared with 1,270–1,330 cm³ (78–81 cu in) in modern humans. They are estimated to have averaged in height and in weight, yielding a small relative brain size,

encephalization quotient Encephalization quotient (EQ), encephalization level (EL), or just encephalization is a relative brain size measure that is defined as the ratio between observed and predicted brain mass for an animal of a given size, based on nonlinear regre ...

, of 4.5. ''H. naledi'' brain anatomy seems to have been similar to contemporary ''Homo'', which could indicate comparable cognitive complexity. The persistence of small-brained humans for so long in the midst of bigger-brained contemporaries revises the previous conception that a larger brain would necessarily lead to an evolutionary advantage, and their mosaic anatomy greatly expands the known range of variation for the genus. ''H. naledi'' anatomy indicates that, although they were capable of long-distance travel with a humanlike stride and gait, they were more

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

than other ''Homo'', better adapted to climbing and suspensory behaviour in trees than endurance running. Tooth anatomy suggests consumption of gritty foods covered in particulates such as dust or dirt. Although they have not been associated with stone tools or any indication of material culture, they appear to have been dexterous enough to produce and handle tools, and therefore may have manufactured Early or Middle Stone Age industries found in excavations near their fossils, since no other human species in the vicinity at that time has been discovered. It has also been controversially postulated that these individuals were buried deliberately by being carried into and placed in the chamber. Some researchers suggest that ''H. naledi'' also may have carved crosshatched rock signs in a passage to what could be a burial chamber, but many paleontologists question this theory.

Discovery

Rising Star Cave system marking the Dinaledi and Lesedi Chambers

On 13 September 2013 while exploring the

system in the

, South Africa, cavers Rick Hunter and Steven Tucker found

hominin 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) ...

fossils at the bottom of the Dinaledi Chamber. On 24 September, they returned to the chamber and took photographs that they showed to South African palaeoanthropologists Pedro Boshoff and Lee Rogers Berger on 1 October. Berger assembled an excavation team that included Hunter and Tucker, the so-called " Underground Astronauts". The chamber had been entered at least once before, by cavers in the early 1990s. They rearranged some bones and may have caused further damage, although much of the floor in the chamber had not been walked on prior to 2013. The site lies about from the main entrance, at the bottom of a vertical drop, and the long main passage is only at its narrowest. In total, more than 1,550 pieces of bone belonging to at least fifteen individuals (9 immature and 6 adults) have been recovered from the

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

-rich sediments. Berger and colleagues published the findings in 2015. The fossils represent 737 anatomical elements – including portions of the skull, jaw, ribs, teeth, limbs, and inner ear bones – from old, adult, young, and infantile individuals. There are also some articulated or near-articulated elements, including the skull with the jaw bone, and nearly complete hands and feet. With the number of individuals of both genders across several age demographics, it then became the richest assemblage of associated fossil hominins discovered in Africa. Aside from the

Sima de los Huesos The Sima de los Huesos hominins are a 430,000 year old population of "pre-Neanderthals" from the archaeological site of Atapuerca, archeological site of Atapuerca, Spain. They are in the "Neanderthal clade", but fall outside of ''Homo neanderthal ...

collection and later

Neanderthal Neanderthals ( ; ''Homo neanderthalensis'' or sometimes ''H. sapiens neanderthalensis'') are an extinction, extinct group of archaic humans who inhabited Europe and Western and Central Asia during the Middle Pleistocene, Middle to Late Plei ...

and modern human samples, the excavation site has the most comprehensive representation of skeletal elements across the lifespan, and from multiple individuals, in the hominin fossil record by that time. The

holotype specimen A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was Species description, formally described. It is either the single such physical example (or illus ...

, DH1, comprises a male partial calvaria (top of the skull), partial

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

, and nearly complete jawbone. The

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype (biology), isotype ...

s, DH2 through DH5, all comprise partial calvaria. Because the remains came from Rising Star Cave, in 2015, Berger and colleagues named the species ''Homo naledi'' with the specific name meaning "star" in the

Sotho language Sotho (), also known as ''Sesotho'' (), Southern Sotho, or ''Sesotho sa Borwa'' is a Southern Bantu languages, Southern Bantu language spoken in Lesotho as its national language and South Africa where it is an official language. Like all Ba ...

. The remains of at least three additional individuals (two adults and a child) were reported in the Lesedi Chamber of the cave by John Hawks and colleagues in 2017.

Classification

In 2017, the Dinaledi remains were dated to 335,000–236,000 years ago in the

, using

electron spin resonance Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials that have unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but the spin ...

(ESR) and uranium–thorium (U-Th) dating on three teeth, and U-Th and paleomagnetic dating of the sediments they were deposited in. Previously, the fossils were thought to have dated to 1–2 million years ago because previously no similarly small-brained hominins had been known from such a recent date in Africa. The smaller-brained ''

Homo floresiensis ''Homo floresiensis'' , also known as "Flores Man" or "Hobbit" (after Hobbit, the fictional species), is an Extinction, extinct species of small archaic humans that inhabited the island of Flores, Indonesia, until the arrival of Homo sapiens, ...

'' of Indonesia lived on an isolated island and, apparently, became extinct shortly after the arrival of modern humans. The ability of such a small-brained hominin to have survived for so long in the midst of bigger-brained ''Homo'' greatly revises previous conceptions of

human evolution ''Homo sapiens'' is a distinct species of the hominid family of primates, which also includes all the great apes. Over their evolutionary history, humans gradually developed traits such as Human skeletal changes due to bipedalism, bipedalism, de ...

and the notion that a larger brain would necessarily lead to an evolutionary advantage. Their mosaic anatomy also greatly expands the range of variation for the genus. ''H. naledi'' is hypothesised to have branched off very early from contemporaneous ''Homo''. It is unclear whether they branched off at approximately the time of '' H. habilis'', ''H. rudolfensis'', and ''A. sediba'', are a

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to '' H. erectus'' and the contemporaneous large-brained ''Homo'', or are a sister taxon to the descendants of ''H. heidelbergensis'' (modern humans and Neanderthals). This would mean that they branched off from contemporary ''Homo'' at latest before 900,000 years ago, and possibly as early as the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58affinities to ''H. erectus''. Comparison of skull features of Homo naledi and other early human species

Comparison of skull features of Homo naledi and other early human species

It is unclear whether these ''H. naledi'' were an isolated population in the Cradle of Humankind, or ranged across Africa. If the latter, then several gracile hominin fossils from African sites that traditionally have been classified as late ''H. erectus'' might represent ''H. naledi'' specimens. Although earlier study placed ''H. naledi'' as the late offshoot from ''H. erectus'' in the phylogenetic tree, the recent study places ''H. naledi'' as the early offshoot from ''H. erectus'' in the phylogenetic tree.

Anatomy

Skull

Two male ''H. naledi'' skulls from the Dinaledi chamber had cranial volumes of approximately , and two female skulls . A male ''H. naledi'' skull from the Lesedi chamber had a cranial volume of . The Dinaledi specimens are more similar to the cranial capacity of australopithecines. For comparison, ''H. erectus'' averaged approximately , and modern humans for males and females respectively. The Lesedi specimen is more within the range of ''H. habilis'' and '' H. e. georgicus''. The

of ''H. naledi'' was estimated at 3.75, which is the same as the pygmy ''H. floresiensis'', but notably smaller than all other ''Homo''. Contemporary ''Homo'' were all above 6, ''H. e. georgicus'' at 3.55, and '' A. africanus'' at 3.81. It is unclear whether ''H. naledi'' inherited small brain size from the last common ''Homo'' ancestor, or whether it was evolved secondarily and more recently. The skull morphology is more similar to ''Homo'', with a slenderer shape, the presence of temporal and

occipital lobe The occipital lobe is one of the four Lobes of the brain, major lobes of the cerebral cortex in the brain of mammals. The name derives from its position at the back of the head, from the Latin , 'behind', and , 'head'. The occipital lobe is the ...

s of the brain, and reduced post-orbital constriction, with the skull not becoming narrower behind the eye-sockets. The

frontal lobe The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a Sulcus (neur ...

morphology is more or less the same in all ''Homo'' brains despite size, and differs from ''Australopithecus'', a characteristic that has been implicated in the production of tools, the development of language, and sociality. Similarly to modern humans (but not to fossil hominins, including South African australopithecines, ''H. erectus'', and Neanderthals) the permanent second molar of ''H. naledi'' erupted comparatively late in life, emerging alongside the premolars instead of before, a characteristic that indicates a slower maturation unusually comparable to modern humans. The tooth formation rate of the front teeth is also most similar to modern humans. The overall size and shape of the molars most closely resemble those of three unidentified ''Homo'' specimens from the local

Swartkrans Swartkrans or Swartkranz is a fossil-bearing cave designated as a National heritage sites (South Africa), South African National Heritage Site, located about from Johannesburg. It is located in the Cradle of Humankind World Heritage Site and is ...

and East African Koobi Fora Caves, and are similar in size (but not shape) to Pleistocene ''H. sapiens''. The necks of the molars are proportionally similar to those of '' A. afarensis'' and ''

Paranthropus ''Paranthropus'' is a genus of extinct hominin which contains two widely accepted species: ''Paranthropus robustus, P. robustus'' and ''P. boisei''. However, the validity of ''Paranthropus'' is contested, and it is sometimes considered to be sy ...

''. Unlike modern humans and contemporary ''Homo'', ''H. naledi'' lacks several accessory dental features, and has a high frequency of individuals who present main cusps, namely the metacone (midline on the tongue-side) and

hypocone A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has ...

(to the right on the lip-side) on the second and third molars, and a Y-shaped hypoconulid (a ridge on the lip-side toward the cheek) on all three molars. The premolars of ''H. naledi'' are characterised by a well-developed P₃ and P₄ metaconid, strongly developed P₃ mesial marginal ridge, a larger P₃ than P₄, and tall crowns, distinguishing them from the premolars of other ''Homo'' species. Nonetheless, ''H. naledi'' also has many dental similarities with contemporary ''Homo''. The

anvil An anvil is a metalworking tool consisting of a large block of metal (usually Forging, forged or Steel casting, cast steel), with a flattened top surface, upon which another object is struck (or "worked"). Anvils are massive because the hi ...

(a middle ear bone) more resembles those of chimps, gorillas, and ''Paranthropus'' than ''Homo''. Like ''H. habilis'' and ''H. erectus'', ''H. naledi'' has a well-developed brow-ridge with a fissure stretching across just above the ridge and, like ''H. erectus'', a pronounced

occipital bun An occipital bun, also called an occipital spur, occipital knob, chignon hook or inion hook, is a prominent bulge or projection of the occipital bone at the back of the human skull, skull. It is important in scientific descriptions of classic Neand ...

. ''H. naledi'' has some facial similarities with '' H. rudolfensis''.

Build

The ''H. naledi'' specimens are estimated to have, on average, stood approximately and weighed . This body mass is intermediate between what is typically seen in ''Australopithecus'' and ''Homo'' species. Like other ''Homo'', female and male ''H. naledi'' were likely about the same size, males on average about 20% larger than females. A juvenile specimen, DH7, is skeletally consistent with a growth rate similar to the faster ape-like trajectories of MH1 (''A. sediba'') and

Turkana boy Turkana Boy, also called Nariokotome Boy, is the name given to fossil KNM-WT 15000, a nearly complete skeleton of a ''Homo erectus'' youth who lived 1.5 to 1.6 million years ago. This specimen is the most complete early hominin skeleton ever fo ...

('' H. ergaster''). Because dental development is so similar to that of modern humans, a slower maturation rate is not completely out of the question. Using the faster growth rate, DH7 would have died at 8–11 years old, but using the slower growth, DH7 would have died at 11–15 years old. Concerning the

spine Spine or spinal may refer to: Science Biology * Spinal column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoology), ...

, only the tenth and eleventh

thoracic vertebra In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebra (anatomy), vertebrae of intermediate size between the ce ...

e (in the chest region) are preserved from presumably a single individual, which are proportionally similar to those of contemporary ''Homo'', although being the smallest recorded of any hominin. The two transverse processes of the vertebra, which jut out diagonally, are most similar to those of Neanderthals. The neural canals within are proportionally large, similar to modern humans, Neanderthals, and ''H. e. georgicus''. The eleventh rib is straight like that of ''A. afarensis'', and the twelfth rib is robust in cross-section like that of Neanderthals. Like Neanderthals, the twelfth rib appears to have supported strong

intercostal muscle The intercostal muscles comprise many different groups of muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle ...

s above, and a strong

quadratus lumborum muscle The quadratus lumborum muscle, informally called the ''QL'', is a paired muscle of the left and right posterior abdominal wall. It is the deepest abdominal muscle, and commonly referred to as a back muscle. Each muscle of the pair is an irregular ...

below. Unlike Neanderthals, there was weak attachment to the diaphragm. Overall, this ''H. naledi'' specimen appears to have been small-bodied compared with other ''Homo'' species, although it is unclear whether this single specimen is representative of the species. The shoulders are more similar to those of australopithecines, with the

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 ...

situated higher on the back and farther from the midline, short

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 ...

s, and little or no humeral torsion. Elevated shoulder and clavicle bones indicate a narrow chest. The

pelvis The pelvis (: pelves or pelvises) is the lower part of an Anatomy, anatomical Trunk (anatomy), trunk, between the human abdomen, abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also c ...

and legs have features reminiscent of ''Australopithecus'', including anterposteriorly compressed (from front to back) femoral necks, mediolaterally compressed (from left to right)

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

e, and a somewhat circular fibular neck; which indicate a wide abdomen. This combination would preclude efficient endurance running in ''H. naledi'', unlike ''H. erectus'' and descendants. Instead, ''H. naledi'' appears to have been more

Limbs

The metacarpal bone of the thumb, which is used in holding and manipulating large objects, was well-developed and had strong crests to support its opponens pollicis muscle used in precision-pinch gripping, and its thenar muscles. This is more similar to other ''Homo'' than ''Australopithecus''. ''H. naledi'' appears to have had strong flexor pollicis longus muscles like modern humans, with humanlike palm and finger pads, which are important for forceful gripping between the thumb and fingers. Unlike ''Homo'', the ''H. naledi'' thumb metacarpal joint is comparably small, relative to the thumb's length, and the thumb phalangeal joint is flattened. The distal thumb phalanx bone is robust, and proportionally more similar to those of ''H. habilis'' and '' P. robustus''. The metacarpals of the other fingers share adaptations with modern humans and Neanderthals to be able to cup and manipulate objects, and the wrist joint is broadly similar to that of modern humans and Neanderthals. Conversely, the proximal phalanges are curved and are almost identical to those of ''A. afarensis'' and ''H. habilis'', which is interpreted as an adaptation for climbing and suspensory behaviour. Such curvature is more pronounced in adults than juveniles, suggesting that adults climbed just as much or more so than juveniles, and this behaviour was common. The fingers are proportionally longer than those of any other fossil hominin, other than the arboreal '' Ardipithecus ramidus'' and a modern human specimen from Qafzeh cave, Israel, which is consistent with climbing behaviour. ''H. naledi'' was a

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

and stood upright. Like other ''Homo'', they had strong insertion for the gluteus muscles, well-defined

linea aspera The linea aspera () is a ridge of roughened surface on the posterior surface of the shaft of the femur. It is the site of attachments of muscles and the intermuscular septum. Its margins diverge above and below. The linea aspera is a prominent ...

(a ridge running down the back of the femur), thick

patella The patella (: patellae or patellas), also known as the kneecap, is a flat, rounded triangular bone which articulates with the femur (thigh bone) and covers and protects the anterior articular surface of the knee joint. The patella is found in m ...

e, long tibiae, and gracile fibulae. These indicate that they were capable of long-distance travel. The ''H. naledi'' foot was similar to that of modern humans and other ''Homo'', with adaptations for

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 ...

and a humanlike gait. The heel bone has a low orientation, comparable to those of non-human great apes, and the

ankle bone The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of foot bones known as the tarsus. The tarsus forms the lower part of the ankle joint. It transmits the entire weight of the body ...

has a low declination, which possibly indicate the foot would have been subtly stiffer during the stance phase of walking before the foot pushed off the ground.

Pathology

The adult right

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 ...

U.W. 101-1142 has a bony lesion, suggestive of a benign tumour. The individual would have experienced some swelling and localised discomfort, but the tumour's position near the medial pterygoid muscle (likely causing discomfort on the jaw hinge) may have impeded function of the muscle, and changed elevation of the right side of the jaw. Dental defects in ''H. naledi'' specimens during 1.6–2.8 and 4.3–7.6 months of development were most likely caused by seasonal stressors. This may have been due to extreme summer and winter temperatures causing food scarcity. Minimum winter temperatures of the area average about , and can drop below freezing. Staying warm for an infant of the small-bodied ''H. naledi'' would have been difficult, and winters likely increased susceptibility to respiratory diseases. Environmental stressors are consistent with present-day

flu season Flu season is an annually recurring time period characterized by the prevalence of an outbreak of influenza (flu). The season occurs during the cold half of the year in each hemisphere. It takes approximately two days to show symptoms. Influen ...

s in South Africa peaking during winter, and paediatric

diarrhoea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

hospitalisation being most frequent at the height of the rainy season in summer. Local hominins were likely preyed upon by large carnivores, such as lions, leopards, and hyaenas. There seems to be a distinct paucity of large carnivore remains from the northern end of the Cradle of Humankind, where Rising Star Cave is located, possibly because carnivores preferred the Blaaubank River to the south that may have offered better hunting grounds with a greater abundance of large prey items. Alternatively, because many more sites are known in the south than the north, carnivore spatial patterns may not be well-represented by the fossil record (

preservation bias Taphonomy is the study of how organisms decay and become fossilized or preserved in the paleontological record. The term ''taphonomy'' (from Greek , 'burial' and , 'law') was introduced to paleontology in 1940 by Soviet scientist Ivan Efremov ...

Culture

Food

Dental chipping and wearing indicates the habitual consumption of small hard objects, such as dirt and dust, and cup-shaped wearing on the back teeth may have stemmed from gritty particles. These could have originated from unwashed roots and tubers. Alternatively, aridity could have stirred up particulates onto food items, coating food in dust. It is possible that they commonly ate larger hard items, such as seeds and nuts, but these were processed into smaller pieces before consumption. ''H. naledi'' occupied a seemingly unique

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of Resource (biology), resources an ...

from previous South African hominins, including ''Australopithecus'' and ''Paranthropus''. The teeth of all three species indicate that they needed to exert high shearing force to chew through perhaps plant or muscle fibres. The teeth of other ''Homo'' cannot produce such high forces perhaps due to the use of some food processing techniques, such as cooking.

Technology

''H. naledi'' could have produced Early Stone Age (

Acheulean Acheulean (; also Acheulian and Mode II), from the French after the type site of Saint-Acheul, is an archaeological industry of stone tool manufacture characterized by the distinctive oval and pear-shaped "hand axes" associated with ''Homo ...

and possibly the earlier

Oldowan The Oldowan (or Mode I) was a widespread stone tool archaeological industry during the early Lower Paleolithic spanning the late Pliocene and the first half of the Early Pleistocene. These early tools were simple, usually made by chipping one ...

) or

Middle Stone Age The Middle Stone Age (or MSA) was a period of African prehistory between the Early Stone Age and the Late Stone Age. It is generally considered to have begun around 280,000 years ago and ended around 50–25,000 years ago. The beginnings of ...

industries because they have the same adaptations to the hand as other human species that are implicated in tool production. ''H. naledi'' is the only identified human species to have existed during the early Middle Stone Age of the

Highveld The Highveld (Afrikaans: ''Hoëveld,'' , ) is the portion of the South African inland plateau which has an altitude above roughly , but below , thus excluding the Lesotho mountain regions to the south-east of the Highveld. It is home to some of t ...

region, South Africa, possibly indicating that this species manufactured and maintained this tradition at least during this time period. In this scenario, such industries and stone cutting techniques would have evolved independently several times among different ''Homo'' species and populations, or were transported over long distances by the inventors or apprentices and taught.

Possible burials

Since the first publication of results from the Dinaledi Chamber, there has been scholarly debate on whether the fossils excavated from the cave provide evidence of ''H. naledi'' engaging in intentional burial activity. If proven true, Dinaledi Chamber would be the oldest known hominin burial, beating out the c. 78,000 year old ''H. sapiens'' burial from Panga ya Saidi cave in Kenya by some 160,000 years. However, a lack of proof regarding the taphonomic,

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

, and mineralogical claims made by the excavators has caused significant academic backlash. In 2015, excavating archaeologists Paul Dirks, Lee Berger, and their colleagues concluded that the bodies had to have been deliberately carried and placed into the chamber by people because they appear to have been intact when they were first deposited in the chamber. They found no evidence of trauma from being dropped into the chamber nor evidence of predation. Furthermore, the chamber is inaccessible to large predators, appears to be an isolated system, and has never been flooded. There is no hidden shaft through which people could have accidentally fallen in, and there is no evidence of some catastrophe that killed all the individuals inside the chamber. The excavating team stated that it is possible that the bodies were dropped down a chute and fell slowly due to the narrowness and irregularity of the path down. Thus, they concluded that, since natural forces were apparently not at play, the bodies must have been deliberately buried. Since the cave is unlit, those burying them would have required artificial light to navigate the cave. The archaeologists have reported finding evidence for fire which may support this claim, yet they have not published it as of July 2024. The excavators claim that the site was used repeatedly for burials since the bodies were not all deposited at the same time. In 2016, paleoanthropologist Aurore Val countered that discounting natural forces for depositing the bodies is unjustified. She identified evidence of damage done by beetles, beetle larvae, and snails, which facilitate decomposition. Since the chamber does not present ideal conditions for snails and does not contain snail shells, she argued that decomposition began before deposition in the chamber, potentially discounting the excavators' claims of intentional burial. Invertebrate damage to the fossils was later confirmed by a 2021 analysis of a fragmentary skull, although this analysis also concludes that it is likely that "some" hominin agency was involved in the deposition of the bone fragments. In 2017, Dirks, Berger, and colleagues reaffirmed that there is no evidence of water flow into the cave and that it is more likely that the bodies were deliberately deposited into the chamber. They theorized that as it is possible that the ''H. naledi'' bones were deposited by contemporary ''Homo'', such as the ancestors of modern humans, rather than other ''H. naledi'', but that the cultural behavior of burial practices is not impossible for ''H. naledi''. They proposed that placement in the chamber may have been done to remove decaying bodies from a settlement, prevent scavengers, or as a consequence of social bonding and grief. During ongoing excavations in 2018, researchers began to hypothesize that ''Homo naledi'' engaged in burial practices. In 2018, anthropologist Charles Egeland and colleagues echoed Val's arguments and stated that there is insufficient evidence to conclude that such an early hominid species had developed a concept of

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as often associated with burials. They said that the preservation of the Dinaledi individuals is similar to those of baboon carcasses that accumulate in larger caves, either by natural death of cave-dwelling baboons or by a leopard dragging carcasses into caves. After papers with new findings were rejected by an unspecified journal, Berger and colleagues published three unreviewed preprints in 2023, alongside a Netflix documentary titled ''Unknown: Cave of Bones''. Critics argued that Berger et al. exploited ''

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s new preprint publication model to garner attention. Even though the three 2023 articles have not undergone peer review, reviewer statements were published alongside them, all of which were highly critical. One of the preprints suggested ''H. naledi'' buried their dead near carvings on the cave walls. The carvings include geometrical shapes and a symbol composed of two cross-hatching equal signs. Other paleoanthropologists such as Michael Petraglia criticized the causative link between the ''H. naledi'' fossils and the incisions, pointing out that, without dating,

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. In 2025, the paleoanthropologists Kimberly K. Foecke, Alain Queffelec and Robyn Pickering found the data analysis of the preprint "Evidence for deliberate burial of the dead by ''Homo naledi''" to be "heavily influenced by a presupposed narrative" and published a paper to criticize the preprint's faulty statistical methods. A primary concern is that Berger's original geochemical soil analyses purported to show a difference between the soil directly surrounding the fossils and further away, evidence the ground had been dug up to bury the bodies. Foecke, Queffelec & Pickering (2025) reanalyzed the soil and were unable to replicate Berger's findings, thus undermining a key piece of evidence in the burial hypothesis.

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Reconstructions of ''H. naledi''
by palaeoartist John Gurche * * * * * * {{Authority control Early species of Homo Pleistocene primates Prehistoric mammals of Africa Fossils of South Africa Fossil taxa described in 2015 Mammals described in 2015 Taxa named by Lee Rogers Berger 2013 archaeological discoveries Cradle of Humankind fauna