The journal PLoS ONE published last week the discovery of fossil remains of the hominid Hispanopithecus laietanus at the paleontological site of Can Feu (Sant Quirze del Vallès, Barcelona), in a paper coauthored by several researchers from the Institut Català de Paleontologia Miquel Crusafont (ICP). This research confirms that this hominid from about 10 million years ago had a different locomotion compared to the remaining known apes, both fossil and extant.During the construction of an industrial building in Can Feu, Sant Quirze del Vallès (Barcelona), in 2001, remains of a fossil primate, later identified as Hispanopithecus laietanus, were discovered. This site is located just 4 km from Can Llobateres (Sabadell, Barcelona), where the most complete remains from this ape, the individual known as Jordi, are known.
The paper published in the journal PLoS ONE, led by the ICP researcher David M. Alba describes the fifteen remains of an adult female skeleton of Hispanopithecus laietanus, with a body mass between 22 and 25 kg, recovered at the paleontological site of Can Feu, dating from the late Miocene, about 10 million years ago. The body mass estimate agrees well with the sex inferred from the morphology of the fossil remains, and in particular from the size and shape of several teeth. In the case of Jordi, an adult male specimen, a mass of about 39 kg was estimated. This evidence shows that H. laietanus displayed a significant size dimorphism, with males being 50% larger than females. This is also the case in extant non-human hominids, with a moderate dimorphism displayed by chimpanzees and bonobos (about one-third larger) and a higher dimorphism displayed by gorillas and orang-utans (more than twice as heavy).
The locomotion of this taxon was well known thanks to the skeleton of Jordi, and especially to the abundant remains of the hand. These indicate that H. laietanus not only had an orthograde (erect) posture suitable for vertical climging along tree trunks and adaptations to suspend from the branches like orangutans do today, but also retained adaptations for moving quadrupedally above the branches. This combination of suspension and arboreal quadrupedalism had not been documented in any other hominid, extant or fossil, and had been questioned by some members of the international scientific community.
The remains of Can Feu, however, include fragments of the chest, shoulder and forearm that strengthen the hypothesis that H. laietanus locomotor repertoire was different from that of other known apes. Specifically, the first rib and the clavicle remains show a mixture of primitive features, such as those of monkeys, and more derived ones, such as those of modern hominids. Especially important is the morphology of the ulna, very characteristic of extant hominids, and which in Hispanopithecus shows a combination of suspensory adaptations with some features that confirm the retention of arboreal quadrupedal behaviors.
+ info Alba, D.M., Almécija, S., Casanovas-Vilar, I., Méndez, J.M., Moyà-Solà, S.(2012). A partial skeleton of Hispanopithecus laietanus from Can Feu and the mosaic evolution of crown-hominoid positional behaviors. PLoS ONE 7(6): e39617. doi:10.1371/journal.pone.0039617.+ info Casanovas-Vilar, I., Furió, M., Alba, D.M., Moyà-Solà, S. & Méndez, J.M. (2012). Rodents and insectivores from the hominoid-bearing site of Can Feu (Vallès-Penedès Basin, Catalonia, Spain). Journal of Vertebrate Paleontology 32(1): 225-230.