A 1.3 million years old phalanx discovered in Atapuerca shows that the morphology of the modern human hand was already defined at that time

The features observed on it confirm that those hominids were capable of producing and using stone tools in a complex way

This human fossil, along with the mandible found in the same site and the Orce teeth, is one of the oldest in Europe

As it is revealed in an article now published by the Journal Human Evolution, being an IPHES researcher, Carlos Lorenzo, the main author

fotoscatalà – españolarticle

The Equipo de Investigación de Atapuerca (EIA) has recently published in the Journal of Human Evolution, a study based on the analysis of a human phalanx found in 2008 in the Sima del Elefante, Atapuerca (Burgos), 1.3 million years old, it shows that our hands morphology was already defined at the time.

The main author of the article is Carlos Lorenzo, a researcher of the IPHES (Institut Català de Paleoecologia Humana i Evolució Social) and URV (Universitat Rovira i Virgili of Tarragona), who has led this work along with Adrián Pablos, a postdoctoral researcher of  the Universidad de Burgos (UBU) and the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), in collaboration with other scientists of these institutions and the Centro Mixto UCM-ISCIII de Evolución y Comportamiento Humanos. Also as authors of the IPHES and the URV had participated Rosa Huguet, Josep Vallverdú and Eudald Carbonell.

The analyzed fossil, scientifically identified as ATE9-2, is the first (proximal) phalanx of the left fifth finger of an adult and was found at the same level as the mandible published in the Nature journal as the oldest hominid in Europe, 1.2-1.3 million years old.

Comparisons that have been established with the lacking fossil global record for this anatomical part, and two samples of modern humans, indicate that the fossil ATE9-2 don´t greatly differ from these or the neanderthals, in morphologic terms. “It means, that the phalanx, and therefore the hand, has changed little in morphology over 1.3 million years to the present”, explains Carlos Lorenzo.

“The only observed differences -he continues- have to do with the robustness of the fossil, which shared with neandertals and the Sima de los Huesos homind bones. This robustness, or width of the distal joint, seems like a primitive character already detected in other skeletal parts and the oldest hominids. This confirms the fact that the species Homo sapiens differs from other fossil species in its graceful body”

Until the appearance of this phalanx, there is no fossil record of the genus Homo for this anatomical element older than neanderthals and Sima de los Huesos hominid remains. There are only proximal phalanges of the hand of an Australopithecus fifth finger, and some other fragmentary remains but is still unknown if they belong to the genus Homo or Australopithecus.

“The phalanges of Australopithecus are curved, a fact that some researchers have linked to the difficulty or impossibility of producing and using stone tools”, says Carlos Lorenzo. “The fossil of the Sima del Elefante is straight as in modern humans”. However, “The procedure of manufacturing stone tools has changed a lot from 1.3 million years ago”. This fact led the researchers to conclude that the phalanges (and thus the hand) of the hominids had every morphological characteristics to produce very advanced stone tools at least 1.3 million years ago”.

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