DOI: 10.1126/science.1184944, 195 (2010);328 Science

et al.Lee R. Bergerfrom South Africa

-Like AustralopithHomo: A New Species of Australopithecus sediba

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Australopithecus sediba: A NewSpecies of Homo-Like Australopithfrom South AfricaLee R. Berger,1,2* Darryl J. de Ruiter,3,1 Steven E. Churchill,4,1 Peter Schmid,5,1Kristian J. Carlson,1,6 Paul H. G. M. Dirks,2,7 Job M. Kibii1

Despite a rich African Plio-Pleistocene hominin fossil record, the ancestry of Homo and its relationto earlier australopithecines remain unresolved. Here we report on two partial skeletons with anage of 1.95 to 1.78 million years. The fossils were encased in cave deposits at the Malapa site inSouth Africa. The skeletons were found close together and are directly associated with craniodentalremains. Together they represent a new species of Australopithecus that is probably descendedfrom Australopithecus africanus. Combined craniodental and postcranial evidence demonstratesthat this new species shares more derived features with early Homo than any other australopithspecies and thus might help reveal the ancestor of that genus.

The origin of the genus Homo is widelydebated, with several candidate ancestorsbeing proposed in the genus Australopith-

ecus (1–3) or perhaps Kenyanthropus (4). Theearliest occurrence of fossils attributed to Homo(H. aff.H. habilis) at 2.33 million years ago (Ma)in Ethiopia (5) makes it temporally antecedent toall other known species of the genus Homo.Within early Homo, the hypodigms and phylo-genetic relationships between H. habilis andanother early species, H. rudolfensis, remainunresolved (6–8), and the placement of thesespecies within Homo has been challenged (9).H. habilis is generally thought to be the ancestorof H. erectus (10–13), although this might bequestioned on the basis of the considerabletemporal overlap that existed between them(14). The identity of the direct ancestor of thegenusHomo, and thus its link to earlier Australo-pithecus, remains controversial. Herewe describetwo recently discovered, directly associated, par-tially articulated Australopithecus skeletons fromthe Malapa site in South Africa, which allow usto investigate several competing hypotheses re-garding the ancestry of Homo. These skeletonscannot be accommodated within any existingfossil taxon; thus, we establish a new species,Australopithecus sediba, on the basis of a com-

bination of primitive and derived characters of thecranium and postcranium.

The following is a description of Au. sediba:Order Primates Linnaeus 1758; suborder Anthro-poidea Mivart 1864; superfamily HominoideaGray 1825; family Hominidae Gray 1825; genusAustralopithecus DART 1925; species Australo-pithecus sediba sp. nov.

Etymology. The word sediba means “foun-tain” or “wellspring” in the seSotho language.

Holotype and paratype. Malapa Hominin1 (MH1) is a juvenile individual represented bya partial cranium, fragmented mandible, and par-tial postcranial skeleton that we designate asthe species holotype [Figs. 1 and 2, supportingonline material (SOM) text S1, figs. S1 and S2,and table S1]. The first hominin specimen re-covered from Malapa was the right clavicle ofMH1 (UW88-1), discovered by Matthew Bergeron 15 August 2008. MH2 is an adult individualrepresented by isolated maxillary teeth, a partialmandible, and partial postcranial skeleton that wedesignate as the species paratype. AlthoughMH1is a juvenile, the second molars are alreadyerupted and in occlusion. Using either a humanor an ape model, this indicates that MH1 hadprobably attained at least 95% of adult brain size(15). Although additional growth would haveoccurred in the skull and skeleton of thisindividual, we judge that it would not haveappreciably altered the morphology on whichthis diagnosis is based.

Locality. The two Au. sediba type skeletonswere recovered from the Malapa site (meaning“homestead” in seSotho), situated roughly 15 kmNNE of the well-known sites of Sterkfontein,Swartkrans, and Kromdraai in Gauteng Province,South Africa. Detailed information regardinggeology and dating of the site is in (16).

RESEARCHARTICLES

1Institute for Human Evolution, University of the Witwatersrand,Private Bag 3, Wits 2050, South Africa. 2School of Geosciences,University of theWitwatersrand, Private Bag 3, Wits 2050, SouthAfrica. 3Department of Anthropology, Texas A&M University,College Station, TX 77843, USA. 4Department of EvolutionaryAnthropology, Box 90383, DukeUniversity, Durham, NC 27708,USA. 5Anthropological Institute and Museum, University ofZürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.6Department of Anthropology, Indiana University, Bloomington,IN 47405, USA. 7School of Earth and Environmental Sciences,James Cook University, Townsville, Queensland 4811, Australia.

*To whom correspondence should be addressed. E-mail:profleeberger@yahoo.com

Fig. 1. Craniodental elements of Au. sediba. UW88-50 (MH1) juvenile cranium in (A) superior, (B)frontal, and (C) left lateral views. (D) UW88-8 (MH1) juvenile mandible in right lateral view, (E)UW88-54 (MH2) adult mandible in right lateral view, (F) UW88-8 mandible in occlusal view, (G)UW 88-54 mandible in occlusal view, and (H) UW 88-50 right maxilla in occlusal view (scale barsare in centimeters).

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Diagnosis. Au. sediba can be distinguishedfrom other species of Australopithecus by acombination of characters presented in Table 1;comparative cranial measures are presented inTable 2. A number of derived characters separateAu. sediba from the older chronospecies Au.anamensis and Au. afarensis. Au. sediba exhibitsneither the extreme megadontia, extensive cra-nial cresting, nor facial prognathism of Au. garhi.The suite of derived features characterizingAu. aethiopicus, Au. boisei, and Au. robustus,in particular the pronounced cranial muscle mark-ings, derived facial morphology, mandibularcorpus robusticity, and postcanine megadontia,are absent in Au. sediba. The closest morpholog-ical comparison for Au. sediba is Au. africanus,as these taxa share numerous similarities in thecranial vault, facial skeleton, mandible, andteeth (Table 1). Nevertheless, Au. sediba can bereadily differentiated from Au. africanus onboth craniodental and postcranial evidence.Among the more notable differences, we ob-serve that although the cranium is small, thevault is relatively transversely expanded withvertically oriented parietal walls and widelyspaced temporal lines; the face lacks the pro-

nounced, flaring zygomatics of Au. africanus;the arrangement of the supraorbital torus, naso-alveolar region, infraorbital region, and zy-gomatics result in a derived facial mask; themandibular symphysis is vertically oriented witha slight bony chin and a weak post-incisive pla-num; and the teeth are differentiated by theweakly defined buccal grooves of the maxillarypremolars, the weakly developed median lingualridge of the mandibular canine, and the smallabsolute size of the postcanine dentition. Theseexact differences also align Au. sediba with thegenusHomo (see SOM text S2 for hypodigms usedin this study). However, we consider Au. sedibato be more appropriately positioned withinAustralopithecus, based on the following cranio-dental features: small cranial capacity, pronouncedglabelar region, patent premaxillary suture,moderate canine jugum with canine fossa, smallanterior nasal spine, steeply inclined zygomati-coalveolar crest, high masseter origin, moderatedevelopment of the mesial marginal ridge of themaxillary central incisor, and relatively closelyspaced premolar and molar cusps.

Postcranially, Au. sediba is similar to otheraustralopiths in its small body size, its relatively

long upper limbs with large joint surfaces, andthe retention of apparently primitive charac-teristics in the upper and lower limbs (table S2).Au. sediba differs from other australopiths, butshares with Homo a number of derived featuresof the os coxa, including increased buttressing ofthe ilium and expansion of its posterior portion,relative reduction in the distance between thesacroiliac and hip joints, and reduction of dis-tance from the acetabulum to the ischial tuberos-ity. These synapomorphies with Homo anticipatethe reorganization of the pelvis and lower limb inH. erectus and possibly the emergence of moreenergetically efficient walking and running inthat taxon (17). As with the associated cranialremains, the postcranium of Au. sediba is definednot by the presence of autapomorphic featuresbut by a unique combination of primitive andderived traits.

Cranium. The cranium is fragmented andslightly distorted. The minimum cranial capacityof MH1 is estimated at 420 cm3 (SOM text S4).The vault is ovoid, with transversely expanded,vertically oriented parietal walls. The widelyspaced temporal lines do not approach themidline. Postorbital constriction is slight. Theweakly arched supraorbital torus is moderatelydeveloped and laterally extended, with sharplyangled lateral corners and a weakly definedsupratoral sulcus. A robust glabelar region isevident, with only a faint depression of thesupraorbital torus at the midline. The frontalprocess of the zygomatic faces primarily laterallyand is expanded medially but not laterally. Thezygomatic prominence does not show antero-lateral expansion. The zygomatics are weaklyflared laterally, resulting in an uninterruptedfrontal profile of the facial mask that is squaredsuperiorly and tapered inferiorly. The zygomat-icoalveolar crests are long, straight, and steep-ly inclined, resulting in a high masseter origin.The root of the zygomatic begins at the anteriormargin of M1. The nasal bones are widenedsuperiorly, become narrowest about one-thirdof the way down, and flare to their widest extentat their inferior margin. The nasal bones areelevated as a prominent ridge at the internasalsuture, with an increasingly anterior projectioninferiorly. The bone surface of the maxilla re-treats gently away from the nasal aperture lat-erally, resulting in an everted margin of thesuperolateral portion of the aperture relative tothe infraorbital region. The inferolateral portionof the nasal aperture becomes bluntly rounded.The infraorbital region is slightly convex (18)and is oriented at an approximately right angleto the alveolar plane. There is a trace of a pre-maxillary suture near the superolateral marginof the nasal aperture. Prominent canine jugadelineate moderately developed canine fossae.Anterior pillars are absent. The inferior marginof the nasal aperture is marked by a steppednasal sill and a small but distinct anterior nasalspine. The subnasal region is straight in the cor-onal plane and only weakly projecting relative

Fig. 2. Associated skeletal elements of MH1 (left) and MH2 (right), in approximate anatomical position,superimposed over an illustration of an idealized Au. africanus skeleton (with some adjustment fordifferences in body proportions). The proximal right tibia of MH1 has been reconstructed from a naturalcast of the proximal metaphysis.

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page

Table1.

Listof

charactersused

todiagnose

Au.sediba.

Thesecharactersarecommonlyused

inhominin

phylogeneticstudies(11,

38–4

0)or

have

been

recorded

asdiagnosticforvarious

hominin

taxa

inthepast

(3,10

,36

).Recogn

izingthepotentialpitfalls

ofperforminga

cladistic

analysison

possibly

interdependent

characters

ofun

certainvalence,

weproduced

acladogram

from

thedata

inthistableas

atestof

theph

ylogeneticpositio

nof

Au.sediba(fig.

S3).Our

mostparsimonious

cladogram

places

Au.sediba

atthestem

oftheHom

oclade.

Num

bers

inparenthesesin

the

first

column

referto

measurespresented

inTable

2;descriptions

ofthesecharacterstates

areprovided

inSO

Mtext

S3.Ab

breviatio

nsareas

follo

ws:

A-M,anteromedial;costasupr.,costasupraorbita

lis;interm

ed.,interm

ediate;lat.,

lateral;med.,medial;mesognath.,mesognathic;mod.,moderately;

MMR,

mesialmarginal

ridge;

orthogn.,orthognathic;procum

b.,procum

bent;proj.,projectin

g;TM

J,temperoman-

dibularjoint.

Chara

cters

Au.

afaren

sisAu

.ga

rhiAu

.afr

icanu

sAu

.sed

ibaH.

habil

isH.

rudolf

ensis

H.ere

ctus

Au.

aethi

opicu

sAu

.bo

isei

Au.

robustus

Vau

ltCranialcapacity

(1)

Small

Small

Small

Small

Interm

ed.

Large

Large

Small

Small

Small

A-M

incursionof

temporallin

eson

frontal

bone

(9)

Strong

Moderate

Moderate

Weak

Weak

Weak

Weak

Strong

Strong

Strong

Positio

nof

temporallin

eson

parie

talbones

Crest

Crest

Varia

ble

Wide

Varia

ble

Wide

Wide

Crest

Crest

Crest

Compoundtemporal

nuchal

crest(m

ales)

Extensive

?Ab

sent

Absent

Varia

ble

Absent

Absent

Extensive

Varia

ble

Absent

Postorbitalconstrictio

n(5)

Marked

Moderate

Moderate

Slight

Moderate

Moderate

Slight

Marked

Marked

Marked

Pneumatizationof

temporalsquama

Extensive

?Extensive

Reduced

Reduced

Reduced

Reduced

Extensive

Varia

ble

Reduced

Facial

hafting

Low

Low

Low

Low

Low

Low

Low

High

High

High

Frontaltrigon

Present

Present

Absent

Absent

Absent

Absent

Absent

Present

Present

Present

Supraglenoid

gutter

width

Narrow

?Narrow

Narrow

Narrow

Narrow

Narrow

Wide

Wide

Wide

Horizontaldistance

betweenTM

Jand

M2/M3(6)

Long

?Long

Short

Short

Long

Short

Long

Long

Long

Parie

taltransverse

expansion/tuber

Absent

Absent

Absent

Present

Present

Present

Present

Absent

Absent

Absent

Facial

skeleton

Supraorbitalexpression

Costasupr.

Costasupr.

Interm

ed.

Torus

Torus

Interm

ed.

Torus

Costasupr.

Costasupr.

Costasupr.

Supraorbitalcontour

Less

arched

Less

arched

Varia

ble

Arched

Arched

Arched

Arched

Less

arched

Varia

ble

Arched

Glabellarregion

form

sas

prom

inentblock

No

No

Varia

ble

Yes

No

Varia

ble

No

No

Yes

Yes

Lat.halfof

infraorbital

marginblunt

andprotruding

No

?No

No

No

No

No

Yes

No

Yes

Zygomaticarch

relativeto

inferio

rorbitalmargin

Above

?Level

Level

Level

?Level

Above

Above

Above

Convexity/concavity

ofinfraorbitalregion

??

Convex

Convex

Concave

Concave

Convex

Concave

Concave

Concave

Nasal

bone

projectio

nabovefrontomaxillary

suture

Expanded

?Varia

ble

No

No

No

No

Tapered

Expanded

Expanded

Inferio

rwidth

ofprojectin

gnasalbone

(25)

Wide

?Varia

ble

Wide

Varia

ble

Narrow

Wide

Not

proj.

Not

proj.

Not

proj.

Infraorbitalforamen

height

(32)

High

?Varia

ble

High

High

?High

Low

Low

Low

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Characters

Au.

afarensis

Au.

garhi

Au.

africanu

sAu

.sediba

H.

habilis

H.

rudo

lfensis

H.

erectus

Au.

aethiopicus

Au.

boisei

Au.

robu

stus

Canine

juga

prom

inence/anterior

pillars

Prom

inent

Prom

inent

Varia

ble

Prom

inent

Varia

ble

Weak

Weak

Weak

Weak

Pillars

Patencyof

prem

axillary

suture

Obliterated

?Occasional

Trace

Obliterated

Obliterated

Obliterated

Obliterated

Obliterated

Occasional

Inferolateralnasal

aperture

margin

Sharp

Sharp

Varia

ble

Blunt

Varia

ble

Sharp

Blunt

Blunt

Varia

ble

Blunt

Eversion

ofsuperio

rnasal

aperture

margin

??

None

Slight

Slight

Slight

Slight

Slight

Varia

ble

None

Nasoalveolartriangular

fram

e/gutter

Triangular

?Triangular

Triangular

Triangular

Triangular

Triangular

Gutter

Gutter

Gutter

Nasal

cavity

entrance

Stepped

Stepped

Stepped

Stepped

Varia

ble

Stepped

Stepped

Smooth

Smooth

Smooth

Nasoalveolarclivus

contourin

coronalplane

Convex

Convex

Straight

Straight

Straight

Straight

Straight

Concave

Concave

Concave

Subnasal

projectio

n(38)

Marked

Marked

Varia

ble

Weak

Varia

ble

Weak

Weak

Marked

Moderate

Moderate

Canine

fossa

Present

Present

Present

Present

Present

Absent

Absent

Absent

Absent

Absent

Maxillaryfossula

Absent

Absent

Absent

Absent

Absent

Absent

Absent

Absent

Absent

Present

Incisorprocum

bency

Procum

b.Procum

b.Varia

ble

Vertical

Varia

ble

Vertical

Vertical

Vertical

Vertical

Vertical

Anterio

rnasalspinerel.to

nasalaperture

Absent

?An

terio

rAn

terio

rAn

terio

r?

Enlarged

Posterior

Posterior

Posterior

Expansionof

frontal

processof

zygomaticbone

Med.andlat.

?Med.andlat.

Medial

Medial

Medial

Medial

Med.andlat.

Med.andlat.

Med.andlat.

Angularindentationof

lateralorbitalmargin

??

Indented

Curved

Curved

Curved

Curved

?Curved

Curved

Zygomaticprom

inence

developm

ent

Prom

inent

?Prom

inent

Slight

Slight

?Slight

Prom

inent

Prom

inent

Prom

inent

Lateralflarin

gof

zygomaticarches

Marked

?Marked

Slight

Slight

Slight

Slight

Marked

Marked

Marked

Outlin

eof

superio

rfacial

mask

Tapered

?Tapered

Squared

Squared

Squared

Squared

Tapered

Tapered

Tapered

Zygomaticoalveolar

crest/m

alar

notch

Straight

?Straight

Straight

Notch

Notch

Notch

Straight

Straight

Straight

Infraorbitalplateangle

relativeto

alveolar

plane

Obtuse

?Obtuse

Right

Right

Right

Right

Obtuse

Obtuse

Obtuse

Zygomaticom

axillary

stepsandfossae

present

No

?No

No

No

No

No

No

No

Yes

Heightof

masseter

origin

(35)

Low

Low

High

High

Low

Low

Low

High

High

High

Malar

thickness(31)

Thin

?Thin

Thin

Thin

?Thin

Thick

Thick

Thick

Projectio

nof

zygomatics

relativeto

nasalbones

Posterior

Posterior

Varia

ble

Posterior

Posterior

Level

Posterior

Anterio

rAn

terio

rAn

terio

r

Facial

prognathism

(7)

(sellion-prosthionangle)

Prognathic

Prognathic

Varia

ble

Mesognath.

Mesognath.

Mesognath.

Orthogn.

Prognathic

Mesognath.

Mesognath.

Masseteric

positio

nrelativeto

sellion

Anterio

r?

Posterior

Posterior

Posterior

?Posterior

Anterio

rAn

terio

rAn

terio

r

Lateralanterio

rfacial

contour

Bipartite

Bipartite

Varia

ble

Straight

Varia

ble

Straight

Straight

Straight

Straight

Straight

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Characters

Au.

afarensis

Au.

garhi

Au.

africanu

sAu

.sediba

H.

habilis

H.

rudo

lfensis

H.

erectus

Au.

aethiopicus

Au.

boisei

Au.

robu

stus

Palate

Protrustionof

incisors

beyond

bi-caninelin

eYes

Yes

Yes

Yes

Yes

No

Yes

No

No

No

Anterio

rpalataldepth

Shallow

Shallow

Deep

Deep

Varia

ble

Deep

Varia

ble

Shallow

Deep

Shallow

Dentalarcade

shape

Rectangle

Rectangle

Varia

ble

Parabolic

Parabolic

Parabolic

Parabolic

Rectangle

Parabolic

Parabolic

MaxillaryI2/C

diastema

Present

Present

Absent

Absent

Varia

ble

Absent

Absent

Absent

Absent

Absent

Man

dible

Orie

ntationof

mandibular

symphysis

Receding

?Receding

Vertical

Vertical

Vertical

Vertical

Vertical

Vertical

Vertical

Bony

chin

(mentum

osseum

)Ab

sent

?Slight

Slight

Slight

Slight

Slight

Slight

Slight

Slight

Dire

ctionof

mental

foramen

opening

Varia

ble

?Varia

ble

Lateral

Lateral

Lateral

Lateral

Lateral

Lateral

Lateral

Post-in

cisive

planum

Prom

inent

?Prom

inent

Weak

Prom

inent

Weak

Weak

Prom

inent

Prom

inent

Prom

inent

Torusmarginalis

and

marginaltubercles

Prom

inent

?Moderate

Moderate

Moderate

Prom

inent

Prom

inent

?Prom

inent

Prom

inent

Mandibularcorpus

cross-sectionalarea

atM1(50)

Small

?Sm

all

Small

Small

Varia

ble

Small

Large

Large

Large

Teeth

Incisor-to-postcanineratio

(maxillary)

(60)

Large

Moderate

Moderate

Moderate

Moderate

Moderate

Large

?Sm

all

Small

Canine-to-postcanine

ratio

(maxillary/mandibular)(61,

62)

Large

Large

Large

Large

Large

Large

Large

?Sm

all

Small

Postcanine

crow

narea

(maxillary/mandibular)(57,

59)

Moderate

Large

Large

Moderate

Moderate

Large

Small

Large

Large

Large

MaxillaryI1:MMR

developm

ent,lin

gual

face

Moderate

?Moderate

Moderate

Weak

Weak

Weak

?Moderate

Moderate

MaxillaryC:

developm

ent

oflin

gual

ridges

Marked

Marked

Marked

Weak

Weak

Marked

Marked

?Marked

Weak

Maxillaryprem

olar

molarization

None

Minor

Minor

None

Minor

Minor

None

Marked

Marked

Marked

Maxillaryprem

olars:

buccal

grooves

Marked

Marked

Marked

Weak

Weak

Marked

Weak

?Weak

Weak

Medianlin

gual

ridge

ofmandibularcanine

Prom

.?

Prom

.Weak

Weak

Weak

Weak

?Weak

Weak

MandibularP 3

root

number

2?

22

12

1?

22

Protoconid/metaconid

moremesialcusp

(molars)

Equal

?Equal

Protoconid

Protoconid

Protoconid

Protoconid

?Equal

Equal

Peak

ofenam

elform

sbetweenrootsof

molars

No

?Yes

Yes

No

No

No

?No

Yes

Relativeenam

elthickness

Thick

Thick

Thick

Thick

Thick

Thick

Thick

Hyper

Hyper

Hyper

Positio

nsof

apices

oflin

gual

(LC)

andbuccal

(BC)

cuspsof

prem

olars

andmolarsrelativeto

occlusal

margin

LCat

margin,

BCslightly

lingual

LCat

margin,

BCslightly

lingual

LCslightly

buccal,BC

moderately

lingual

LCslightly

buccal,BC

moderately

lingual

LCat

margin,

BCslightly

lingual

LCat

margin,

BCslightly

lingual

LCat

margin,

BCslightly

lingual

LCmod.

buccal,BC

strongly

lingual

LCmod.

buccal,BC

strongly

lingual

LCmod.

buccal,BC

strongly

lingual

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Table2.

Craniodental

measurementsforearly

homininsin

Africa.

Au.sediba

isrepresentedby

MH1.

Unlessotherwise

defin

ed,measurements

are

based

on(6).

Some

measureswere

unavailableforspecimensof

Au.a

farensisandAu.g

arhi,inwhich

case

thecharacterstates

inTable1wereestim

ated.S

everal

characterstates

inTable1arerecorded

asvaria

ble,

although

only

speciesaveragevalues

arepresented

here.Measurements

arein

millimetersunless

otherwiseindicated.

Descriptio

nsof

characterstates

presentedin

Table1that

arebasedon

measurements

from

thistableareprovided

inSO

Mtext

S3.Ab

breviatio

nsareas

follows:br,

bregma;ek,ectoconchion;

ekm,ectom

olare;fm

t,frontomolaretemporale;ft,frontotemporale;

g,glabella;mf,

maxillofrontale;

n,nasion;ns,nasospinale;

or,orbitale;po,porio

n;pr,

prosthion;

rhi,rhinion;

zm,zygomaxillare;

zy,zygion;zyo,

zygoorbitale.

Item

Measure

ment

descr

iption

in(6)

Measure

ment

Au.

afaren

sisAu

.afr

icanu

sAu

.sed

ibaH.

habil

isH.

rudolf

ensis

H.ere

ctus

Au.

aethi

opicu

sAu

.bo

isei

Au.

robustus

1Cranialcapacity

(cm3 )

415

442

420

631

751

900

419

515

530

29

Maximum

parie

talbreadth

9099

100

103

114

126

9499

100

311

Bi-porionicbreadth(po-po)

126

9910

410

412

712

112

511

6—

4Postorbitalconstrictio

n(narrowestpointbehind

theorbits)

7769

7376

8589

6564

735

Postorbitalconstrictio

nindex(4/14×10

0)66

7185

7072

8065

6168

6Horizontaldistance

betweenTM

JandM2 /M3

8361

4551

5857

9482

817

Facial

prognathism

(sellion-prosthionangle)

6361

6565

6872

4166

698

75Infratem

poralfossadepth

–31

2127

–37

5150

369

8Minimum

frontalbreadth(ft-ft)

4054

7066

7276

3336

3510

17Glabella

tobregma(g-br)

101

8075

8386

103

–87

–11

Frontalchord(n-br)

–84

7480

9399

–84

–12

62Supraorbitaltorusvertical

thickness

–8

88

1012

1012

913

43Superio

rfacial

height

(n-pr)

8778

6868

9076

9910

080

1449

Superio

rfacial

breadth(fmt-fm

t)11

797

8610

011

710

710

010

810

715

50Bi-orbitalbreadth(ek-ek)

8984

7889

100

9910

193

8216

52Bizygomaticbreadth(zy-zy)

157

126

102

117

–13

515

316

514

317

Zygomaticbreadthindex(14/16

×10

0)75

7484

85–

84–

6574

1853

Bimaxillarybreadth(zm-zm)

–10

384

9711

310

512

611

910

619

55Interorbitalbreadth(m

f-mf)

1819

2027

2425

2324

2420

56Orbitalbreadth(m

f-ek)

3836

3133

3939

3637

3321

57Orbitalheight

(perpendicular

to20

)34

3231

3133

3641

3330

2271

Nasal

bridge

length

(n-rhi)

–27

2618

2018

3530

2823

73Nasal

bridge

breadthsuperio

r–

58

88

1312

1411

24Nasal

bridge

breadthat

anterio

rlacrimal

crests

–11

510

–24

1911

–25

74Nasal

bridge

breadthinferio

r–

1113

1110

1811

78

26Nasal

bridge

height

(nasionsubtense

atanterio

rlacrimal

crests)

–4

98

–9

45

–27

69Nasal

height

(n-ns)

5850

4945

5752

7264

5428

70Nasal

aperture

height

(rhi-ns)

2926

2228

3930

3835

2429

68Maximum

nasalaperture

width

2323

2625

2732

3031

2530

Orbito

alveolar

height

(or-alveolar

plane)

5553

4447

5951

5369

5731

60Malar

thickness

1413

138

–12

2018

1832

Infraorbitalforamen

height

(toinferio

rorbitalmargin)

–12

1515

1416

3025

2633

Prosthionto

zygomaxillare(pr-zm

)–

6757

5569

6780

8271

34Prosthionto

zygoorbitale

(pr-zyo)

–60

5057

7570

7381

6935

Masseterorigin

height

index(33/34

×10

0)–

112

104

9692

9611

010

110

336

47Subnasaleto

prosthion(horizontalprojectio

n)28

2313

1917

1623

2726

3748

Subnasal

toprosthion(vertical

projectio

n)15

2117

1830

2112

2522

38Subnasaleprojectio

nindex(36/37

×10

0)18

710

876

106

5779

192

108

122

3994

Incisoralveolar

length

–13

1615

1416

1515

1340

96Prem

olar

alveolar

length

–15

1816

1613

2122

17

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to the facial plane. The face is mesognathic.The palate is consistently deep along its entireextent, with a parabolic dental arcade.

Mandible. Descriptions apply to the morecomplete juvenile (MH1) mandible unless other-wise stated. The nearly vertical mandibular sym-physis presents a weak lateral tubercle, resultingin a slight mental trigone, and a weak man-dibular incurvation results in a slight mentumosseum. The post-incisive planum is weaklydeveloped and almost vertical. Both mandibularcorpora are relatively gracile, with a low heightalong the alveolar margin. The extramolar sulcusis relatively narrow in both mandibles. In MH1,a moderate lateral prominence displays itsgreatest protrusion at the mesial extent of M2,with a marked decrease in robusticity to P4; inMH2 the moderate lateral prominence showsits greatest protrusion at M3, with a markeddecrease in robusticity to M2. The alveolar prom-inence is moderately deep with a notable medialprojection posteriorly. The anterior and posteriorsubalveolar fossae are continuous. The ramusof MH1 is tall and narrow, with nearly parallel,vertically oriented anterior and posterior bor-ders; the ramus of MH2 is relatively broader,with nonparallel anterior and posterior borders(fig. S2). The mandibular notch is relatively deepand narrow in MH1 and more open in MH2.The coronoid extends farther superiorly thanthe condyle. The condyle is mediolaterally broadand anteroposteriorly narrow. The endocondyloidbuttress is absent in MH1, whereas in MH2 aweak endocondyloid buttress approaches thecondyle without reaching it.

Dental size and proportions. The dentitionof the juvenile (MH1) is relatively small, whereaspreserved molars of the adult (MH2) are evensmaller (Fig. 3 and fig. S4). For MH1, themaxillary central incisor is distinguishable onlyfrom the reduced incisors of Au. robustus. Themaxillary canine is narrower than all canines ofAu. africanus except TM 1512, whereas themandibular canine falls well below the range ofAu. africanus. Premolars and molars are at thelower end of the Au. africanus range and withinthat of H. habilis–H. rudolfensis and H. erectus.Molar dimensions of the adult individual (MH2)are smaller than those of Au. africanus, areat or below the range of those of H. habilis–H. rudolfensis, and are within the range of thoseofH. erectus. Au. sedibamirrors the Au. africanuspattern of maxillary molars that increase slightlyin size posteriorly, though it differs in that themolars tend to be considerably larger in the lattertaxon. Conversely, the Au. sediba pattern variesslightly from that seen in specimens KNM-ER1813, OH 13, and OH 65 andH. erectus, where-in the molars increase from M1 to M2 but thendecrease to M3. In broad terms, the teeth ofAu. sediba are similar in size to teeth of speci-mens assigned to Homo but share the closelyspaced cusp apices seen in Australopithecus.

Postcranium. Preserved postcranial remainsof Au. sediba (table S1) denote small-bodiedIte

mMe

asure

ment

descr

iption

in(6)

Measure

ment

Au.

afaren

sisAu

.afr

icanu

sAu

.sed

ibaH.

habil

isH.

rudolf

ensis

H.ere

ctus

Au.

aethi

opicu

sAu

.bo

isei

Au.

robustus

4198

Intercaninedistance

2630

3030

3331

–29

2742

88Palate

breadth(ekm

-ekm

)68

6463

7080

6683

8267

4314

1Mandibularsymphysisheight

3938

3227

3634

–47

4244

142

Mandibularsymphysisdepth

6020

1919

2419

–28

2545

147

Mandibularcorpus

height

atP 4

3433

2830

3830

–42

3846

148

Mandibularcorpus

depthat

P 419

2118

2022

19–

2824

4714

9Cross-sectionalarea

atP 4

(calculatedas

anellipse)

511

558

382

427

653

458

–91

070

948

150

Mandibularcorpus

height

atM1

3332

2829

3630

3541

3749

151

Mandibularcorpus

depthat

M1

1921

1820

2320

2628

2650

152

Cross-sectionalarea

atM1(calculatedas

anellipse)

488

532

396

421

667

469

715

913

759

5115

4Mandibularcorpus

height

atM2

3131

2531

3630

–41

3552

155

Mandibularcorpus

depthat

M2

2225

2223

2621

–31

2853

156

Cross-sectionalarea

atM2(calculatedas

anellipse)

536

612

436

537

745

504

–98

077

054

162

Heightof

mentalforamen

relativeto

alveolar

margin

2019

1313

1713

–20

2055

Maxillaryincisorcrow

narea

(I1+I2)

143

135

109

132

137

136

–11

710

956

Maxillarycanine

crow

narea

107

104

7995

118

96–

7679

57Maxillarypostcanine

crow

narea

713

868

731

755

829

617

–10

1294

158

Mandibularcanine

crow

narea

8795

6883

–79

–72

6159

Mandibularmolar

crow

narea

550

651

536

565

668

466

–78

167

860

Maxillaryincisorto

postcanine

ratio

20.0

15.6

14.9

17.4

16.6

22.1

–11

.511

.661

Maxillarycanine

topostcanine

ratio

15.0

11.9

10.8

12.6

14.2

15.5

–7.5

8.4

62Mandibularcanine

tomolar

ratio

15.8

14.6

12.7

14.6

–16

.7–

9.2

9.0

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hominins that retain an australopith pattern oflong upper limbs, a high brachial index, andrelatively large upper limb joint surfaces(table S2). In addition to these aspects of limband joint proportions, numerous other featuresin the upper limb are shared with sibling speciesof Australopithecus (to the exclusion of laterHomo), including a scapula with a craniallyoriented glenoid fossa and a strongly developedaxillary border; a prominent conoid tubercle onthe clavicle, with a pronounced angular margin;low proximal-to-distal humeral articular propor-tions; a distal humerus with a marked crest forthe brachioradialis muscle, a large and deepolecranon fossa with a septal aperture, and amarked trochlear/capitular keel (19); an ulnawith a pronounced flexor carpi ulnaris tubercle;and long, robust, and curved manual phalangesthat preserve strong attachment sites for theflexor digitorum superficialis muscle.

Numerous features of the hip, knee, and ankleindicate that Au. sediba was a habitual biped. Interms of size and morphology, the proximal anddistal articular ends of the femur and tibia fallwithin the range of variation of specimensattributed to Au. africanus. However, severalderived features in the pelvis link the Malapaspecimens with later Homo. In the os coxa (Fig.4), Au. sediba shares with Homo a pronouncedacetabulocristal buttress; a more posterior posi-tion of the cristal tubercle; a superoinferiorlyextended posterior iliac blade, with an expandedretroauricular area; a sigmoid-shaped anterior in-ferior iliac spine; a reduced lever arm for weighttransfer between the auricular surface and theacetabulum; an enlarged and rugose iliofemoralligament attachment area; a tall and thin pubicsymphyseal face; and a relatively short ischiumwith a deep and narrow tuberoacetabular sulcus.These features are present in taxonomically un-

assigned postcranial remains from Koobi Fora(KNM-ER 3228) and Olduvai Gorge (OH 28),which have been argued to represent earlyHomo(20), as well as in earlyHomo erectus (21). An oscoxa from Swartkrans (SK 3155) has been con-sidered by some to also represent early Homo(22) but can be seen to possess the australopithpattern in most of these features. In addition,Au. sediba shares with later Homo the human-like pattern of low humeral-to-femoral diaph-yseal strength ratios, in contrast to the ape-likepattern seen in the H. habilis specimen OH 62(table S2).

Although aspects of the pelvis are derived, thefoot skeleton is more primitive overall, sharingwith other australopiths a flat talar trochleaarticular surface with medial and lateral marginswith equal radii of curvature, and a short, stout,and medially twisted talar neck with a highhorizontal angle and a low neck torsion angle

Fig. 3. Dental size of a selection of Au. sediba teeth compared to other earlyhominin taxa; see fig. S4 for additional teeth. Dental measurements weretaken as described by Wood (6). Owing to small sample sizes, H. habilis andH. rudolfensis were combined. (A) Upper central incisor mesiodistal (MD)length. (B) Upper canine MD length. (C) Lower canine MD length. (D) Squareroot of calculated [MD × BL (BL, buccolingual)] upper third premolar area.(E) Square root of calculated (MD × BL) upper second molar area. (F)Square root of calculated (MD × BL) lower second molar area. Measureswere taken on original specimens by D.J.D. for Au. africanus, Au. robustus,

and Au. sediba. Measurements for Au. afarensis, H. habilis, H. rudolfensis,and H. erectus are from (6). P4 is not fully erupted on the right side of MH1,therefore measures of the maxillary postcanine dentition are presented forthe left side only. Dental metrics for Au. sediba are as follows (MD, BL, inmillimeters): Maxillary: MH1: RI1 10.1, 6.9; LI2 7.7 (damaged), 5.1; RC9.0, 8.8; LP3 9.0, 11.2; LP4 9.2, 12.1; LM1 12.9, 12.0; LM2 12.9, 13.7;LM3 13.3, 14.1; MH2: RM3 11.3, 12.9. Mandibular: MH1: LC 8.0, 8.5; RM112.5, 11.6; RM2 14.4, 12.9; RM3 14.9, 13.8; MH2: RM1 11.8, 11.1; RM214.1, 12.2; RM3 14.2, 12.7; LM3 14.1, 12.5.

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(table S2 and fig. S5). The calcaneus is markedlyprimitive in its overall morphology: the bone isstrongly angled along the proximodistal axis,with the point of maximum inflexion occurring atan enlarged peroneal trochlea; the lateral plantartubercle is lacking; the calcaneal axis is set about45° to the transverse plane; and the calcaneocu-boid facet is vertically set and lacks an expandedposterior projection for the beak of the cuboid(23).

Discussion. The age and overall morpholo-gy of Au. sediba imply that it is most likelydescended from Au. africanus, and appears morederived toward Homo than do Au. afarensis, Au.garhi, and Au. africanus. Elsewhere in SouthAfrica, the Sterkfontein cranium Stw 53, dated to2.0 to 1.5Ma, is generally considered to representeither H. habilis (10, 24, 25) or perhaps anundiagnosed form of early Homo (26). It playedan important role in the assignment of OH 62 toH. habilis (27). However, the derived cranioden-tal morphology of Au. sediba casts doubt on theattribution of Stw 53 to early Homo [see also(28)]: Stw 53 appears to be more primitive thanMH1 in retaining closely spaced temporal lines;marked postorbital constriction; a weakly devel-oped supraorbital torus; narrow, nonprojectingnasal bones; anterior pillars; marked nasoalveolarprognathism; medial and lateral expansion of thefrontal process of the zygomatic bone; andlaterally flared zygomatics. If Stw 53 insteadrepresents Au. africanus, the assignment of OH62 to H. habilis becomes tenuous. Attribution ofthe partial skeleton KNM-ER 3735 to H. habiliswas tentatively based, in part, on a favorablecomparison with OH 62 and on the hypothesisthat there were no other contemporaneous non-

robust australopith species to which it could beassigned in East Africa (29). As a result, theinterpretation of KNM-ER 3735 as H. habilisalso becomes uncertain.

The phylogenetic significance of the co-occurrence of derived postcranial features inAu. sediba,H. erectus, and a sample of isolatedfossils generally referred to Homo sp. indet.(table S2) is not clear: The latter might repre-sent early H. erectus, it might sample the post-cranium of H. rudolfensis (which would thenimply an evolutionary pathway fromAu. sediba toH. rudolfensis to H. erectus), or it might representthe postcranium of H. habilis [which would sug-gest that OH 62 and KNM-ER 3735 (two speci-mens with ostensibly more primitive postcranialskeletons) do not belong in this taxon]. If the lat-ter possibility holds, it could suggest a phyloge-netic sequence from Au. sediba to H. habilis toH. erectus. Conversely, although the overall post-cranial morphology of Au. sediba is similar to thatof other australopiths, a number of derived featuresof the os coxa align the Malapa hominins withlater Homo (H. erectus) to the exclusion of otheraustralopiths. Additionally, Au. sediba shares asmall number of cranial traits with H. erectus thatare not exhibited in the H. habilis–H. rudolfensishypodigm, including slight postorbital constrictionand convexity of the infraorbital region (18).Following on this, MH1 compares favorably withSK 847 (H. erectus) in the development of thesupraorbital torus, nasal bones, infraorbital region,frontal process of the zygomatic, and subnasalprojection. However, MH1 differs from SK 847 inits relatively smaller size, the robust glabelar re-gion, the weakly developed supratoral sulcus, thesteeply inclined zygomaticoalveolar crests with a

high masseter origin, and the moderate caninejuga, all features aligning MH1 with Australopith-ecus. It is thus not possible to establish the precisephylogenetic position of Au. sediba in relation tothe various species assigned to early Homo. Wecan conclude that combined craniodental and post-cranial evidence demonstrates that this new spe-cies shares more derived features with earlyHomothan does any other known australopith species(Table 1 and table S2) and thus represents a candi-date ancestor for the genus, or a sister group to aclose ancestor that persisted for some time after thefirst appearance of Homo.

The discovery of a <1.95-million-year-old(16) australopith that is potentially ancestral toHomo is seemingly at odds with the recovery ofolder fossils attributed to the latter genus (5) or ofapproximately contemporaneous fossils attribut-able to H. erectus (6, 30). However, it is unlikelythat Malapa represents either the earliest or thelatest temporal appearance of Au. sediba, nordoes it encompass the geographical expanse thatthe species once occupied. We hypothesize thatAu. sediba was derived via cladogenesis fromAu. africanus (≈3.0 to 2.4 Ma), a taxon whosefirst and last appearance dates are also uncertain(31). The possibility that Au. sediba split fromAu. africanus before the earliest appearance ofHomo cannot be discounted.

Although the skull and skeleton of Au. sedibado evince derived features shared with earlyHomo, the overall body plan is that of a homininat an australopith adaptive grade. This supportsthe argument, based on endocranial volume andcraniodental morphology, that this species ismost parsimoniously attributed to the genusAustralopithecus. The Malapa specimens dem-

Fig. 4. Representative ossa coxae, in lateral view, from left to right, of Au.afarensis (AL 288-1), Au. africanus (Sts 14), Au. sediba (MH1), and H. erectus(KNM-WT 15000). The specimens are oriented so that the iliac blades all lie in theplane of the photograph (which thus leads to differences between specimens inthe orientation of the acetabula and ischial tuberosities). MH1 possesses derived,Homo-like morphology compared to other australopithecines, including a relativereduction in the weight transfer distance from the sacroiliac (yellow) to hip (circle)

joints; expansion of the retroauricular surface of the ilium (blue arrows)(determined by striking a line from the center of the sphere representing thefemoral head to the most distant point on the posterior ilium; the superior arrowmarks the terminus of this line, and the inferior arrow marks the intersection ofthis line with the most anterior point on the auricular face); narrowing of thetuberoacetabular sulcus (delimited by yellow arrows); and pronouncement of theacetabulocristal (green arrows) and acetabulosacral buttresses.

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onstrate that the evolutionary transition from asmall-bodied and perhaps more arboreal-adaptedhominin (such as Au. africanus) to a larger-bodied, possibly full-striding terrestrial biped(such asH. erectus) occurred in a mosaic fashion.Changes in functionally important aspects ofpelvic morphology, including a reduction of thesacroacetabular weight-bearing load arm andenhanced acetabulosacral buttressing (reflect-ing enhancement of the hip extensor mecha-nism), enlargement of the iliofemoral ligamentattachment (reflecting a shift in position of theline of transfer of weight to behind the center ofrotation of the hip joint), enlargement of theacetabulocristal buttress (denoting enhancementof an alternating pelvic tilt mechanism), and re-duction of the distance from the acetabulum tothe ischial tuberosity (reflecting a reduction in themoment arm of the hamstring muscles) (20, 32)occurred within the context of an otherwise aus-tralopith body plan, and seemingly before anincrease in hominin encephalization [in contrastto the argument in (33)]. Relative humeral andfemoral diaphyseal strength measures (table S2)also suggest that habitual locomotor patterns inAu. sediba involved a more modern human-likemechanical load-sharing than that seen in theH. habilis specimen OH 62 (34, 35). Mosaic evo-lutionary changes are mirrored in craniodentalmorphology, because the increasinglywide spacingof the temporal lines and reduction in post-orbital constriction that characterize Homo firstappeared in an australopith and before significantcranial expansion. Moreover, dental reduction,particularly in the postcanine dentition, precededthe cuspal rearrangement (wide spacing of post-canine tooth cusps) that marks early Homo.

The pattern of dental eruption and epiphysealfusion exhibited by MH1 indicates that its age atdeath was 12 to 13 years by human standards,whereas inMH2 the advanced degree of occlusalattrition and epiphyseal closure indicates that ithad reached full adulthood (SOM text S1). Al-though juvenile, MH1 exhibits pronounced devel-opment of the supraorbital region and canine juga,eversion of the gonial angle of the mandible, andlarge rugose muscle scars in the skeleton, all in-dicating that this was a male individual. And, al-though fully adult, the mandible and skeleton ofMH2 are smaller than in MH1, which, combinedwith the less rugose muscle scars and the shape ofthe pubic body of the os coxa, suggests that MH2was a female. In terms of dental dimensions,MH1has mandibular molar occlusal surface areas thatare 10.7% (M1) and 8.1% (M2) larger than thoseof MH2. Dimorphism in the postcranial skeletonlikewise is not great, though the juvenile status ofMH1 tends to confound efforts to assess adultbody size. The diameter of the proximal epiphysisfor the femoral head of MH1 (29.8 mm) is ap-proximately 9.1% smaller than the superoinferiordiameter of MH2's femoral head (32.7 mm). It islikely that MH1 would have experienced someappositional increase in joint size before matu-rity, thus this disparity would probably have de-

creased somewhat. The distal humeral epiphysisof MH1 is fully fused and its articular breadth(35.3 mm) is only marginally larger than that ofMH2 (35.2 mm). Thus, although the dentitionand postcranial skeleton are at odds in the de-gree of apparent size differences, the overalllevel of dimorphism, if these sex attributions arecorrect, appears slight in the Malapa homininsand was probably similar to that evinced by mod-ern humans.

References and Notes1. R. A. Dart, Nature 115, 195 (1925).2. D. C. Johanson, T. D. White, Science 203, 321

(1979).3. B. Asfaw et al., Science 284, 629 (1999).4. M. G. Leakey et al., Nature 410, 433 (2001).5. W. H. Kimbel, D. C. Johanson, Y. Rak, Am. J. Phys. Anthropol.

103, 235 (1997).6. B. Wood, Koobi Fora Research Project, Volume 4:

Hominid Cranial Remains (Clarendon Press, Oxford,1991).

7. G. P. Rightmire, Am. J. Phys. Anthropol. 90, 1(1993).

8. R. J. Blumenschine et al., Science 299, 1217(2003).

9. B. Wood, M. Collard, Science 284, 65 (1999).10. P. V. Tobias, Olduvai Gorge Volume 4: The Skulls,

Endocasts and Teeth of Homo habilis (Cambridge Univ.Press, Cambridge, 1991).

11. D. S. Strait, F. E. Grine, J. Hum. Evol. 47, 399(2004).

12. D. E. Lieberman, Nature 410, 419 (2001).13. The H. erectus hypodigm includes African specimens that

are referred to the taxon H. ergaster by some. Unlessotherwise stated, we collectively refer to H. habilis,H. rudolfensis, H. erectus, and H. ergaster materials as“early Homo.”

14. F. Spoor et al., Nature 448, 688 (2007).15. P. V. Tobias, The Brain in Hominid Evolution (Columbia

Univ. Press, New York, 1971).16. P. H. G. M. Dirks et al., Science 328, 205 (2010).17. D. M. Bramble, D. E. Lieberman, Nature 432, 345

(2004).18. Rak (36) describes a feature in the infraorbital region of

Au. boisei that he refers to as a nasomaxillary basin: aconcave depression that is surrounded by a moreelevated topography. We see a similar concavity in theinfraorbital region of specimens of H. habilis–H.rudolfensis (KNM-ER 1470, KNM-ER 1805, KNM-ER1813, and OH 24), although it is not clear whetherthey represent homologous structures. In specimens ofAu. africanus, Au. sediba, and H. erectus, we recognize aslight convexity in this area.

19. Some humeri that are probably best attributed toAustralopithecus lack marked development of thetrochlear/capitular keel [or “lateral crest”: see (37)], andthus the absence of a marked crest does not reliablydifferentiate Australopithecus from Homo. However,although some specimens of early Homo (such asKNM-WT 15000) have crests that are more stronglydeveloped than those of modern humans, none exhibitthe marked crests of the australopiths. Thus, the markedcrest seen in the Malapa humeri can be seen to be sharedwith Australopithecus rather than Homo.

20. M. D. Rose, Am. J. Phys. Anthropol. 63, 371 (1984).21. A. Walker, C. B. Ruff, in The Nariokotome Homo erectus

Skeleton, A. Walker, R. E. F. Leakey, Eds. (Harvard Univ.Press, Cambridge, MA, 1993), pp. 221–233.

22. C. K. Brain, E. S. Vrba, J. T. Robinson, Ann. Transv. Mus.29, 55 (1974).

23. L. C. Aiello, C. Dean, An Introduction to HumanEvolutionary Anatomy (Academic Press, London, 1990).

24. A. R. Hughes, P. V. Tobias, Nature 265, 310(1977).

25. D. Curnoe, P. V. Tobias, J. Hum. Evol. 50, 36(2006).

26. F. E. Grine, W. L. Jungers, J. Schultz, J. Hum. Evol. 30,189 (1996).

27. D. C. Johanson et al., Nature 327, 205 (1987).28. R. J. Clarke, S. Afr. J. Sci. 104, 443 (2008).29. R. E. F. Leakey, A. Walker, C. V. Ward, H. M. Grausz, in

Hominidae, G. Giacobini, Ed. (Jaca Books, Milano, Italy,1989), pp. 167–173.

30. L. Gabunia, A. Vekua, Nature 373, 509 (1995).31. T. D. White, in Paleoclimate and Evolution with Emphasis

on Human Origins, E. S. Vrba, G. H. Denton,T. C. Partridge, L. H. Burckle, Eds. (Yale Univ. Press,New Haven, CT, 1995), pp. 369–384.

32. J. T. Stern Jr., R. L. Susman, Am. J. Phys. Anthropol. 60,279 (1983).

33. C. O. Lovejoy, Gait Posture 21, 113 (2005).34. C. Ruff, Am. J. Phys. Anthropol. 138, 90 (2009).35. It is possible that the more Homo-like humeral-to-femoral

diaphyseal strength ratios in Au. sediba reflect arelative reinforcement of the femoral diaphysis in thecontext of femoral elongation (resulting in longerbending-moment arms) without a change in locomotorbehavior. At present, we are unable to directly assessthe absolute and relative length of the femur inAu. sediba.

36. Y. Rak, The Australopithecine Face (Academic Press,New York, 1983).

37. M. R. Lague, W. L. Jungers, Am. J. Phys. Anthropol. 101,401 (1996).

38. R. R. Skelton, H. M. McHenry, J. Hum. Evol. 23, 309(1992).

39. M. Collard, B. Wood, Proc. Natl. Acad. Sci. U.S.A. 97,5003 (2000).

40. H. F. Smith, F. E. Grine, J. Hum. Evol. 54, 684(2008).

41. We thank the South African Heritage Resources Agencyfor the permits to work at the Malapa site; the Nashfamily for granting access to the Malapa site andcontinued support of research on their reserve; the SouthAfrican Department of Science and Technology, the SouthAfrican National Research Foundation, the Institute forHuman Evolution, the Palaeontological Scientific Trust,the Andrew W. Mellon Foundation, the AfricaArrayProgram, the U.S. Diplomatic Mission to South Africa,and Sir Richard Branson for funding; the University of theWitwatersrand’s Schools of Geosciences and AnatomicalSciences and the Bernard Price Institute forPalaeontology for support and facilities; the GautengGovernment, Gauteng Department of Agriculture,Conservation and Environment and the Cradle ofHumankind Management Authority; E. Mbua, P. Kiura,V. Iminjili, and the National Museums of Kenya for accessto comparative specimens; Optech and Optron; DukeUniversity; the Ray A. Rothrock Fellowship of TexasA&M University; and the University of Zurich 2009 FieldSchool. Numerous individuals have been involved in theongoing preparation and excavation of these fossils,including C. Dube, B. Eloff, C. Kemp, M. Kgasi,M. Languza, J. Malaza, G. Mokoma, P. Mukanela,T. Nemvhundi, M. Ngcamphalala, S. Jirah, S. Tshabalala,and C. Yates. Other individuals who have givensignificant support to this project include B. de Klerk,C. Steininger, B. Kuhn, L. Pollarolo, B. Zipfel, J. Kretzen,D. Conforti, J. McCaffery, C. Dlamini, H. Visser,R. McCrae-Samuel, B. Nkosi, B. Louw, L. Backwell,F. Thackeray, and M. Peltier. T. Stidham helped constructthe cladogram in fig. S3. J. Smilg facilitated computedtomography scanning of the specimens. R. Clarke andF. Kirera provided valuable discussions on these andother hominin fossils in Africa.

Supporting Online Materialwww.sciencemag.org/cgi/content/full/328/5975/195/DC1SOM Text 1 to 4Figs. S1 to S5Tables S1 and S2References

19 November 2009; accepted 26 February 201010.1126/science.1184944

9 APRIL 2010 VOL 328 SCIENCE www.sciencemag.org204

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www.sciencemag.org sCiEnCE erratum post date 17 deCemBer 2010

ErratumResearch Articles: “Australopithecus sediba: A new species of Homo-like Australopith from South Africa” by L. R. Berger et al. (9 April, p. 195). In the legend of Fig. 3, the mesiodistal diameter of the RM2 of the mandible of the adult individual MH2 should be 13.1 mm (not 14.1 mm). In Fig. 4, the specimen number of the pelvis of Australopithe-cus afarensis (Lucy) should be A.L. 288-1 (not A.L. 228-1). These errors do not affect the Research Article’s conclusions.

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