Laetoli Site S: articoli scientifici

New footprints from Laetoli (Tanzania) provide evidence for marked body size variation in early hominins

Insight di William L. Jungers:

Autori
Fidelis T. Masao, Department of Archaeology and Heritage Studies, University of Dar es Salaam, P.O. Box 35050, Dar es Salaam, Tanzania
Elgidius B. Ichumbaki, Department of Archaeology and Heritage Studies, University of Dar es Salaam, P.O. Box 35050, Dar es Salaam, Tanzania
Marco Cherin, Dipartimento di Fisica e Geologia, Università di Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy; PaleoFactory, Sapienza Università di Roma, Piazzale A. Moro 5, 00185 Roma, Italy
Angelo Barili, Galleria di Storia Naturale, Centro d’Ateneo per i Musei Scientifici, Università di Perugia, Via del Risorgimento, 06051 Deruta, Italy
Giovanni Boschian, Dipartimento di Biologia, Università di Pisa, Via Derna, 56126 Pisa, Italy
Dawid A. Iurino, Dipartimento di Scienze della Terra, Sapienza Università di Roma, Piazzale A. Moro 5, 00185 Roma, Italy; PaleoFactory, Sapienza Università di Roma, Piazzale A. Moro 5, 00185 Roma, Italy
Sofia Menconero, Studio Associato Grassi, Via Luigi Salvatorelli 33, 06125 Perugia, Italy
Jacopo Moggi-Cecchi, Dipartimento di Biologia, Università di Firenze, Via del Proconsolo 12, 50122 Firenze, Italy
Giorgio Manzi, Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Piazzale A. Moro 5, 00185 Roma, Italy

Abstract
Laetoli is a well-known palaeontological locality in northern Tanzania whose outstanding record includes the earliest hominin footprints in the world (3.66 million years), discovered in 1978 at Site G and attributed to Australopithecus afarensis. Here, we report hominin tracks unearthed in the new Site S at Laetoli and referred to two bipedal individuals (S1 and S2) moving on the same palaeosurface and in the same direction as the three hominins documented at Site G. The stature estimates for S1 greatly exceed those previously reconstructed for Au. afarensis from both skeletal material and footprint data. Combined with a comparative reappraisal of the Site G footprints, the evidence collected here embodies very important additions to the Pliocene record of hominin behaviour and morphology. Our results are consistent with considerable body size variation and, likely, degree of sexual dimorphism within a single species of bipedal hominins as early as 3.66 million years ago.