Research in Action South African Journal of Science 104, September/October 2008 337 sublingual fossa is shallow and low down. First hominoid from the Late Miocene This mandible fragment is compatible in size and proportions to medium-sized of Niger hominoids with slender mandibular rami. It is too gracile to belong to an australopithecine, even a small individual a,b* b c Martin Pickford , Brigitte Senut , Jorge Morales and such as AL 288-1 (Lucy)13 from Hadar, José Bragad Ethiopia. Comparisons with several hominoids, both extinct and extant, reveal overall similarities to both Pan troglodytes ince the discovery of Orrorin tugenensis cene taxa are poorly known, and a (Fig. 1) and Homo rather than to any other in the Late Miocene Lukeino Formation, considerable amount of debate has taken genera. The jaw is slightly less deep and STugenHills, Kenya, it is generally admit- place, even concerning some relatively more gracile than that of Orrorin28 and the ted that the origin of bipedal hominids occurred well-preserved specimens.3 Each addi- sublingual fossa is not as deeply excavated. earlier than 6 Myr ago and that the adaptation to bipedal stance and locomotion initially tion to the African Late Miocene We consider that the best match for the occurred in a forested or well-wooded setting. hominoid fossil sample is therefore pre- Niger hominoid fossil is with Pan, but In Africa, eight localities aged between 13 cious. because the fossil is fragmentary, we hesi- and 5.5 Myr have yielded hominoid fossils In 1964, a small collection of vertebrate tate to attribute it to this or to any other belonging to nine species. We here report the fossils from Niger, which includes a frag- hominoid genus. occurrence of a Late Miocene hominoid in ment of hominoid mandible, was sent to Anthracotheriidae: Libycosaurus is repre- Niger, associated with a restricted fauna the Muséum National d’Histoire Naturelle sented at the Niger site by a distal which indicates an age of c. 11–8 Myr. The in Paris by the Bataafse Internationale Niger fossil locality is 940 km north of the metapodial attributed to a medium-sized nearest known extant hominoids, and 1000 km Petroleum Maatshappij (now Shell), species, larger than L. petrocchii and west of the nearest recorded fossil hominoid where it is curated under register No. smaller than the large species from Sahabi from Chad. The scientific value of the Niger 1964-27.885. The precise point of discovery and Chad.16,23 The section of the bone at specimen resides in its discovery locus far is not known, but it is probably close to the break reveals a marked degree of from any other known fossil hominoids, its 5°43’E, 15°32’N, where some Mesozoic dorso-plantar compression which distin- Late Miocene age and the attention that it will Chelonians2 with the register No. 840 guishes this fossil from hippopotamid focus on the Neogene fossil record of West were collected by a Mr Nieuwenhuys, metapodials24 with which it might other- Africa, currently almost unknown. who found the mammals. wise be confused. Introduction Bovidae: The family Bovidae is repre- Palaeontology sented at point N 885 by a left frontal It is now widely accepted that the family The assemblage of fossils from N 885, with horn core, a distal left radius and a Hominidae originated in Africa during Niger, comprises well-mineralized skeletal damaged left calcaneum. The horn core the Late Miocene. However, the African remains of lacustrine and terrestrial ani- belongs to a reduncine antelope, morpho- fossil record for this time period is not mals stained dark brown to black. The logically close to but smaller than Redunca well endowed with hominoid fossils, fauna is restricted, but contains a Nile darti.8,10 making it difficult to trace the transition perch (Lates niloticus), a crocodile (Croco- from pre-hominid to hominid status. dylus cf. niloticus), a chimp-sized homi- Age of the Niger fossils Since 1997, nine hominoid taxa have been noid, a medium-sized species of anthra- Two specimens from the Niger locality reported from eight localities in Africa, cothere (Libycosaurus sp.), and a bovid. are useful for biochronology. The most ranging in age between 13 and 5 Myr: one Pisces: Lates niloticus (Nile perch) is rep- telling evidence is the presence of an species in Namibia [Otavipithecus (12–13 14,25,28 resented at the Niger site by the posterior anthracothere, Libycosaurus sp., equiva- Myr)]; five taxa in Kenya [a chimp- basal part of the skull. lent to the medium-sized species from like hominoid (12.5 Myr), Nakalipithecus Crocodylia: Crocodylus cf. niloticus (Nile Toros-Ménalla, Chad and Sahabi, (9.5–10 Myr), Samburupithecus (9.5 Myr), a crocodile) is represented at locality N 885 Libya.16,23 Secondly, the bovid horn core gorilla-like hominoid (6 Myr), and Orrorin 29 by a brevirostrine mandible with buccal has some resemblances to, but is smaller (6 Myr)]; two in Ethiopia [Chorora- depressions between the teeth, two der- than, material from Sahabi15 (Libya), pithecus (10–10.5 Myr) and Ardipithecus 30 30 11 3 mal scutes, two articulated vertebrae, the Lukeino, Mpesida and Lothagam (5.7 Myr)]; and one in Chad [Sahelan- 9 23 occipital part of a skull and diverse frag- (Kenya) and Langebaanweg (South thropus (6–10 Myr) ]. Despite the draw- ments of skull. Africa). An age of between 11 and 8 Myr is backs of its Late Miocene fossil record, possible for the deposits that yielded Africa has now yielded a respectable Hominoidea is represented at site N 885 these fossils. diversity of hominoids comparable with by a right mandible fragment (Fig. 1) that of Europe and Asia, making it more containing the roots of the first molar. The Palaeoenvironment and likely to be the cradle of hominid evolution mandible is slender and moderately palaeoclimatology than Eurasia.1 All these African Late Mio- deep. The jaw beneath m/1 is 13.2 mm thick, and its depth from the alveolar The presence of Nile perch, Lates niloticus, aCollège de France, 11 place M. Berthelot, 75005, Paris, process to the ventral margin is 31.6 mm. in the Niger deposits indicates the former France. bUMR 5143 du CNRS, Case postale 38, 8 rue Buffon, The preserved part of the tooth measured presence of a freshwater lake or large 75005, Paris, France. at cervix is 9.4 × 9.7 mm, but judging from river in the country. The anthracothere cPaleobiologia, Museo Nacional de Ciencias Naturales, CSIC, José Gutierrez Abascal 2, 28006, Madrid, Spain. the position of the alveoli mesial and Libycosaurus was likely a denizen of dUniversité Paul Sabatier, Toulouse, FRE 2960 CNRS, distal to the preserved roots, the crown shallow swampy parts of a palaeolake, Anthropobiologie et Imagerie Anatomique, 39 Allées Jules Guesde, 31000, Toulouse, France length would originally have been c. 11 mm and the reduncine probably lived close to *Author for correspondence. E-mail: [email protected] and the breadth about 9.9 mm. The water. This evidence, combined with the 338 South African Journal of Science 104, September/October 2008 Research in Action Fig. 1. Hominoid right mandible fragment from Niger (A) compared with a chimpanzee mandible (B): A1) buccal view; A2) sagittal scan, mesial to the left; A3) frontal scan, buccal to the left (arrow points to the mandibular canal). (Scale bars: 10 mm) presence of a hominoid primate, indicates the view that the Sahara is a relatively chimp-like form). In the circumstances, that the region was appreciably more young desert, post-dating the Late Mio- it seems superfluous to invoke a Late humid (at least 750 mm mean annual cene. Recent work in Egypt has revealed Miocene reintroduction of hominoids into rainfall) during the Late Miocene than it is that central Egypt was covered in wood- Africa from Eurasia in order to give rise to today (ranging from sahel to total desert land to forest some 11–10 Myr ago26,27 and hominids,1 a view that was attractive only over large areas of the country). Chad is long known to have been more while the Late Miocene hominoid fossil humid in the past than it is today5,6,20 as record of Africa was poorly known. Discussion were Libya7 and Tunisia.21,22 Apart from humans, hominoids are today At present, the chimpanzees living Conclusions confined to forest and woodland, but the closest to the Niger fossil site occur 940 km A restricted vertebrate fauna of Late common chimpanzee can survive in sub- to the south in Ghana and Nigeria and Miocene age from Niger is of interest on humid environments as long as there are 1700 km to the west in Mali (Fig. 2).4,32 account of its age and the presence within enough trees to supply adequate food and Niger thus joins an increasing list of it of a hominoid primate and an anthra- security.17 This means that the longest dry African countries that have yielded re- cothere. The discovery helps to fill what period should not exceed two months, mains of Late Miocene (c. 11–5.5 Myr ago) was a vast gap in the geographic coverage and that the area should be well endowed hominoids including: Kenya (Lukeino, of fossil hominoids; the nearest known with riparian forest so that there is always 6 Myr, two taxa);19,25,28 (Samburu Hills, fossil specimen of comparable age being a supply of fresh vegetation in the form of 9.5 Myr);12 (Nakali, c. 10 Myr);14 Ethiopia from Chad, over 1000 km to the east and fruit, leaves, pith and bark, even during (Ch’orora, c.