A new species of human, Homo luzonensis, discovered in the Philippines
An international multidisciplinary team, involving France's National Museum of Natural History, the CNRS and the Pacea Laboratory, has discovered a new species of hominin, Homo luzonensis (contemporaneous with Homo sapiens), at excavations in Callao Cave, located on the island of Luzon in the Northern Philippines.
Published in Nature on April 11th, 2019, the study of the 50 to 67,000-year-old fossils reveals a patchwork of singular morphological characteristics differentiating Homo luzonensis from other species of the Homo genus and underscores the importance of island Southeast Asia in the evolutionary history of hominins.
This new species, Homo luzonensis, has been described from a set of fossil bones and teeth belonging to at least 3 different individuals discovered at excavations in Callao cave in 2007, 2011, and 2015. Two of these fossils have been dated directly to 50,000 and 67,000 years ago using the Uranium series method. They are some of the oldest known human remains in the Philippines, preceding the first Homo sapiens dated to 30 to 40,000 years ago and discovered on the island of Palawan, in the Southwest part of the archipelago.
The comparative analyses performed on the fossils, particularly using 3D imaging and morphometric methods, show that the Homo luzonensis species has very primitive features or characteristics, resembling Australopithecus, and other, very modern, features, similar to our own species, Homo sapiens.
The team of scientists, co-led by Florent Détroit*, involving France's National Museum of Natural History and CNRS** and particularly CNRS researcher Clément Zanolli from the Pacea Laboratory - From Prehistory to Modern Times: Culture, Environment and Anthropology (CNRS unit, French Ministry for Culture and the University of Bordeaux) discovered two particularly informative examples.
These included teeth: the premolars and molars shown in the figure are understood to have belonged to the same individual. The premolars have 2 to 3 roots, whereas in Homo sapiens, only one or sometimes two roots are found. With this characteristic and the morphology of the enamel and dentine, Homo luzonensis premolars are therefore more similar to those of Australopithecus and ancient species of the Homo genus, such as Homo habilis and Homo erectus. However, the molars are very small and have a very simple morphology, closer to those of Homo sapiens. Therefore, an individual possessing these combined characteristics cannot be classified in any of the species known to date.
In addition, the researchers also studied foot bones (figure h and i), particularly noting that the proximal phalanx has a very pronounced curvature and highly developed insertions for plantar flexion muscles. This characteristics are not found in Homo sapiens. Instead, this phalanx bears a strong resemblance to those in Australopithecus, found only in Africa from much older periods (approximately 2 to 3 million years).
This quite singular combination of characteristics clearly differentiates the species from other representatives of the Homo genus, particularly the contemporaneous species discovered in Southeast Asia, such as Homo sapiens and Homo floresiensis.
* Lecturer at the French National Museum of Natural History and member of the Human and Environment Department.
** The laboratories involved in this discovery are "Natural History of Prehistoric Man" (HNHP, MNHN/CNRS /UPVD), the Laboratory of Paleontology Evolution Paleoecosystems Paleoprimatology (PALEVOPRIM, CNRS /University of Poitiers), "From Prehistory to Modern Times: Culture, Environment and Anthropology" (PACEA, CNRS /University of Bordeaux/French Ministry of Culture) and "Molecular Anthropology and Computer-Generated Imaging" (AMIS, CNRS /University Toulouse III - Paul Sabatier/University Paris Descartes).
A new species of Homo from the Late Pleistocene of the Philippines, Florent Détroit, Armand Salvador Mijares, Julien Corny, Guillaume Daver, Clément Zanolli, Eusebio Dizon, Emil Robles, Rainer Grün & Philip J. Piper.
Paleoanthropologist at the Pacea laboratory