A great ape that roamed Spain 10 million years ago got around like no other hominids known before or since, researchers conclude, based on a unique mosaic of skeletal features that suggest a combination of suspensory and quadrupedal behaviors.
The authors of the study, led by David Alba of the Catalan Paleontology Institute, analyzed bones from the elbow area, shoulder girdle, rib cage, and forelimb of a partial Hispanopithecus laietanus skeleton. They found features suggesting multiple different types of locomotion patterns for the extinct ape, including both swinging through the branches by the arms and walking among the branches on all four feet. The precise combination of features and behaviors, they write, is totally unique among known extinct and extant ape species.
Based on these results, they call the species a “transitional state,” in that the combination of features simultaneously allowed the ape to maintain balance on all fours while also allowing it to move toward more suspensory behavior, which ultimately took over as the predominant mode of locomotion for the lineage.
This study probably doesn’t have immediate implications for the hotly debated question of how and why human bipedalism evolved, but sometimes it’s nice to take a step back from our relentlessly anthropocentric view and simply appreciate our ape cousins for what they are – and what they were millions of years ago. And, in a broader sense, this study also serves as a reminder that we must be careful to remember that we can’t conceptualize extinct species based only on “the biased evidence provided by their few and very specialized remaining living representatives,” as the authors write. The true evolutionary history is simply much too complex.
Citation: Alba DM, Almécija S, Casanovas-Vilar I, Méndez JM, Moyà-Solà S (2012) A Partial Skeleton of the Fossil Great Ape 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