ARTICLE doi:10.1038/nature10922 A new hominin foot from Ethiopia shows multiple Pliocene bipedal adaptations Yohannes Haile-Selassie.2,Beverly Z.Saylor2,Alan Deino3,Naomi E.Levin4,Mulugeta Alenes Bruce M.Latimer2 A newly discovered partial hominin foot skeleton from eastern Africa indicates the presence of more than one hominin locomotor adaptation at the beginning of the Late Pliocene epoch.Here we show that new pedalelements,dated to about 3.4 million years ago,belong to a species that does not match the contemporaneous Australopithecus afarensis in its morphology and inferred locomotor adaptations,but instead are more similar to the earlier Ardipithecus ramidus in possessing an opposable great toe.This not only indicates the presence of more than one hominin species at the beginning of the Late Pliocene of eastern Africa,but also indicates the persistence of a species with Ar.ramidus-like locomotor adaptation into the Late Pliocene. Woranso-Mille is a relatively new palaeontological site located in the of other metatarsal ratios(Fig.4,see Supplementary Information for central Afar region of Ethiopia'.The fossiliferous horizons identified at discussions).Principal components analysis(PCA;correlation matrix, the site range in age from approximately 3.2 to 3.8 million years(Myr) varimax rotation with Kaiser normalization)was conducted on 11 ago.More than 54,000 fossil specimens sampling diverse mammalian metatarsal ratios(Supplementary Table 1).Although some metatarsal taxa have been collected thus far (Supplementary Information). length proportions of BRT-VP-2/73 are more similar to those of Geological and palaeontological work in the past five years has concen- cercopithecids (for example,MT2 length MT4 length)than those trated on sediments radiometrically dated to between 3.57+0.014 and 3.8+0.18 Myr ago'.These sediments have yielded numerous early hominin remains,induding a partial skeleton of Au.afarensis'-s Slightly younger deposits have subsequently yielded hominin fossils 112900 Mille R including a well-preserved,~3.4-Myr-old partial foot skeleton(BRT- VP-2/73).The detailed geological context,dating and palaeoenviron- ment ofBRT-VP-2/73 are presented in the Supplementary Information. The hominin forefoot(metatarsals and phalanges)is characteristically under-represented in the fossil record as a consequence ofits fragility in 1128 the face of predators and taphonomic processes.Previously described hominin pedal fossils-12 have not included associated and well- preserved metatarsals and phalanges.Here we describe a partial BRT-VP-2 hominin forefoot (BRT-VP-2/73)recovered from Burtele locality 2 (BRT-VP-2),one of the vertebrate localities of the Woranso-Mille 1128 study area (see Fig.1).This partial pedal skeleton is unique in provid- ing important evidence bearing on the functional morphology and proportions of several early hominin foot elements.It also presents the opportunity to draw morphological and functional comparisons between earlier (Ar.ramidus,~4.4 Myr ago)and contemporaneous 11270 (Au.afarensis,~2.9-3.6 Myr ago)hominins,and test whether there was diversity in hominin bipedalism in the earlier phases of hominin Mille-Chifra road evolutionary history3. BRT-VP-2/73 consists of eight mostly intact bony elements of a right foot:complete first,second,fourth metatarsals;head of third metatarsal;three proximal phalanges(rays 1,2 and 4);and one middle 40r3230” 4033r00r 403320” 4034700 Quatemsry sediments River ★ BRT-VP-2/73 phalanx(ray 2)(Fig.2a-fand Table 1).Detailed comparative descrip- 意Nommal fault WM07/B-1.WM10/B- tions are provided in Supplementary Information.The lack of Strike and dip 入/Messured section anatomical redundancy,spatial distribution,individual age status, morphological compatibility and preservation of the specimens indi- cate that they are from a single foot. Figure 1 Location map ofthe Burtele(BRT)vertebratelocalities(BRT-VP. 1 and BRT-VP-2)in the Woranso-Mille study area.The path ofthe measured BRT-VP-2/73 clearly differs from cercopithecids by its dorsoplantarly section through the sandstone ridges and the location of the mesa section with tall hallucal base relative to the bone's length(Fig.3a)and also relative to the dated Burtele tuff are shown.The measured basalt section is off the map the height ofthe second metatarsal base(Fig.3b),in addition to a number The study area is located about 30 miles north of Hadar and Gona. The Cleveland Museum of Natural History,Cleveland,Ohio44106,USA2Case Western Reserve University.Cleveland,Ohio 44106,USABerkeley Geochronology Center,Berkeley,California94720.USA Johns Hopkins University.Baltimore.Maryland 21218,USA.Addis Ababa University.PO Box 1176 Addis Ababa,Ethiopia. 29 MARCH 2012 VOL 483 NATURE 565 2012 Macmillan Publishers Limited.All rights reservedARTICLE doi:10.1038/nature10922 A new hominin foot from Ethiopia shows multiple Pliocene bipedal adaptations Yohannes Haile-Selassie1,2, Beverly Z. Saylor2 , Alan Deino3 , Naomi E. Levin4 , Mulugeta Alene5 & Bruce M. Latimer2 A newly discovered partial hominin foot skeleton from eastern Africa indicates the presence of more than one hominin locomotor adaptation at the beginning of the Late Pliocene epoch. Here we show that new pedal elements, dated to about 3.4 million years ago, belong to a species that does not match the contemporaneous Australopithecus afarensis in its morphology and inferred locomotor adaptations, but instead are more similar to the earlier Ardipithecus ramidus in possessing an opposable great toe. This not only indicates the presence of more than one hominin species at the beginning of the Late Pliocene of eastern Africa, but also indicates the persistence of a species with Ar. ramidus-like locomotor adaptation into the Late Pliocene. Woranso-Mille is a relatively new palaeontological site located in the central Afar region of Ethiopia1 . The fossiliferous horizons identified at the site range in age from approximately 3.2 to 3.8 million years (Myr) ago. More than 54,000 fossil specimens sampling diverse mammalian taxa have been collected thus far (Supplementary Information). Geological and palaeontological work in the past five years has concen￾trated on sediments radiometrically dated to between 3.57 6 0.014 and 3.86 0.18 Myr ago2 . These sediments have yielded numerous early hominin remains, including a partial skeleton of Au. afarensis3–5. Slightly younger deposits have subsequently yielded hominin fossils including a well-preserved, ,3.4-Myr-old partial foot skeleton (BRT￾VP-2/73). The detailed geological context, dating and palaeoenviron￾ment of BRT-VP-2/73 are presented in the Supplementary Information. The homininforefoot (metatarsals and phalanges) is characteristically under-represented in the fossil record as a consequence of its fragility in the face of predators and taphonomic processes. Previously described hominin pedal fossils6–12 have not included associated and well￾preserved metatarsals and phalanges. Here we describe a partial hominin forefoot (BRT-VP-2/73) recovered from Burtele locality 2 (BRT-VP-2), one of the vertebrate localities of the Woranso-Mille study area (see Fig. 1). This partial pedal skeleton is unique in provid￾ing important evidence bearing on the functional morphology and proportions of several early hominin foot elements. It also presents the opportunity to draw morphological and functional comparisons between earlier (Ar. ramidus, ,4.4 Myr ago) and contemporaneous (Au. afarensis, ,2.9–3.6 Myr ago) hominins, and test whether there was diversity in hominin bipedalism in the earlier phases of hominin evolutionary history13. BRT-VP-2/73 consists of eight mostly intact bony elements of a right foot: complete first, second, fourth metatarsals; head of third metatarsal; three proximal phalanges (rays 1, 2 and 4); and one middle phalanx (ray 2) (Fig. 2a–f and Table 1). Detailed comparative descrip￾tions are provided in Supplementary Information. The lack of anatomical redundancy, spatial distribution, individual age status, morphological compatibility and preservation of the specimens indi￾cate that they are from a single foot. BRT-VP-2/73 clearly differs from cercopithecids by its dorsoplantarly tall hallucal base relative to the bone’s length (Fig. 3a) and also relative to the height of the secondmetatarsal base (Fig.3b), in addition to a number of other metatarsal ratios (Fig. 4, see Supplementary Information for discussions). Principal components analysis (PCA; correlation matrix, varimax rotation with Kaiser normalization) was conducted on 11 metatarsal ratios (Supplementary Table 1). Although some metatarsal length proportions of BRT-VP-2/73 are more similar to those of cercopithecids (for example, MT2 length , MT4 length) than those 1 The Cleveland Museum of Natural History, Cleveland, Ohio 44106, USA. 2 Case Western Reserve University, Cleveland, Ohio 44106, USA. 3 Berkeley Geochronology Center, Berkeley, California 94720, USA. 4 Johns Hopkins University, Baltimore, Maryland 21218, USA. 5 Addis Ababa University, PO Box 1176 Addis Ababa, Ethiopia. Sudan Ethiopia WORMIL Red Sea Somalia Mille R. BRT-VP-2 Waytaleyta R. Mille-Chifra road BRT-VP-1 Ridge section Offset along palaeosol Quaternary sediments Pliocene volcano sediments Pliocene basalt River Normal fault Strike and dip BRT-VP-2/73 WM07/B-1, WM10/B-1 Measured section Locality boundary 40°32′30′′ 40°33′00′′ 40°33′30′′ 40°34′00′′ 11°27′00′′ 11°27′30′′ 11°28′00′′ 11°28′30′′ 11°29′00′′ Mesa section Figure 1 | Location map of the Burtele (BRT) vertebrate localities (BRT-VP- 1 and BRT-VP-2) in theWoranso-Mille study area. The path of the measured section through the sandstone ridges and the location of the mesa section with the dated Burtele tuff are shown. The measured basalt section is off the map. The study area is located about 30 miles north of Hadar and Gona. 29 MARCH 2012 | VOL 483 | NATURE | 565 ©2012 Macmillan Publishers Limited. All rights reserved