The evolution that led toanthropomorphic apes(gibbons, orangutans, gorillas and chimpanzees) amaintain an upright torso position when climbing treesoccurred during theMiocene in two places independently, one in Europe and the other in Africa, according to a study carried out by a team of scientists from the Catalan Institute of Paleontology (ICP), which has carried out a critical review of the dates of all hominoids (who lived between 23 and 5 million years ago) in the West Eurasian.
In addition, the unpublished results of specimens recently found in the set of fossil deposits of Hostalets de Pierola (Barcelona, northeast Spain), one of the three most important of this period, together with those of Kenya and those found on the border between Pakistan and India.
Hominoids, a group that includes all anthropomorphic apes, began their history in Africa about 23 million years ago. From there they were expanding towards Europe and Asia (14 million years ago), although in these territories they were disappearing (7-6 million years) possibly due to the deterioration of the climate, with the exception of the orangutans. Of the thirteen Miocene hominoid species described in Eurasia, five are found in Catalonia, specifically in the Vallès-Penedes Basin, where the ICP has been carrying out a continuous series of studies.
The study released today, as explained by Isaac Casanovas, co-author of the work, points out that the hominoids discovered in European deposits and especially in Catalonia -where they lived between 12 and 9 million years ago-, were part of the subfamily of the driopithecines ( forest apes), which would be related to the ponginos, a group that includes the current orangutans. Some of thefossil remains of driopithecines found in Catalonia have advanced characteristics: they could climb trees maintaining a vertical posture of the torso and hang using only their arms, which still occurs in the great anthropomorphs of today, such as ponginos and “hominins” (gorillas, chimpanzees and humans).
In this sense, the study concludes that it is likely that these adaptations occurred independently in driopithecines and hominins, although it remains to be determined whether the African hominins had any link with the European homineids or evolved directly from the African forms. The new dates thus allow ordering an important set of evolutionary events and suggests thatthe change in body design from the quadruped model towards the current structure of those great anthropomorphs also took place in the Mediterranean area.
The work, which is published today in the magazineProceedings of the National Academy os Sciences(PNAS), is also signed by the director of the ICP, Salvador Moyà, and the researchers of this institute David M. Alba and Josep M. Robles, and Miguel Garcés (UB). Moyà highlighted thevalue of the Catalan fossil record, which covers the first part of hominid evolution. “It is the most complete and of the highest quality in the world. That is why it isessential to understand the origin of our family“, explained the director of the ICP.
