- As early as 2015 paleoanthropologists came across the traces of a previously unknown early human species.
- Now they announce the results of their bone analysis: 50,000 years ago, Homo luzonensis lived in the north of the Philippine island of Luzon.
- The shape of his teeth confused the researchers deeply.
In the Callao Cave in the tropical north of the Philippine island of Luzon, paleoanthropologists have discovered a new, previously unknown human species. Already in 2015, researchers had discovered during excavations on foot and hand bones, a fragment of a femur and several molars – a total of twelve parts of a total of three individuals. After years of analysis, the researchers around Florent Détroit now come in a recent work in the journal Nature concluded that the human remains, because of their unusual characteristics, belong to a new human species that they named after the homo luzonensis.
The new early human species lived on the island about 50,000 years ago, ie at the same time as other species of the human genus such as Homo sapiens, Homo erectus or Denisova man – and also the Neanderthal man in Europe. The Homo luzonensis, on whose physique no statements are possible, the island had probably settled for quite some time. The remains of the Callao Cave probably come from two adults and a teenager. Overall, teeth and bones have a combination of features in terms of size, shape of teeth, and bone curvature that has never been seen in any other hominin species.
There are surprising matches with other human species. For example, the molars of Homo luzonensis are surprisingly small. Other early humans often had significantly larger teeth. The chewing surfaces of the teeth, in turn, and the number of cusps on the teeth are similar to Homo sapiens, the overall shape (except the size) is similar to the teeth of Homo erectus.
For individual toes, the researchers also found matches with the Vormenscheart Australopithecus afarensis, to which Lucy belonged. The finger bones resembled those of this type of human living about three million years ago. Overall, it creates a confusing picture, especially in the teeth. "This strange juxtaposition of features in the jaw of a single individual is completely unexpected and makes it difficult to assess the evolutionary relationships between Homo luzonensis and other hominin species," Canadian anthropologist Matthew Tocheri writes in a companion text in Nature.
A similarly confusing picture was provided by the bones of Homo floresiensis discovered in 2003
The researchers had already found a similar confusing picture years ago when they discovered the new dwarf human species Homo floresiensis on the Indonesian island of Flores in 2003. Also the Hobbitmenschen showed a strange mixture of characteristics of early humans and Vormenschenarten.
One explanation for the strange mix in both Homo floresiensis and the newly discovered Homo luzonensis may be that both are descendants of Homo erectus populations that have developed on their respective islands for hundreds of thousands of years. After all, both islands, Luzon and Flores, were accessible only by sea, even at times when the sea level was still 120 meters lower.
On islands, evolutionary history often takes other paths – one phenomenon is the dwarfing of organisms in long biological isolation that affects both animals and humans alike. In order to be able to assess Homo luzonensis more accurately, the researchers now have to dig further in the caves of Luzon in order to find a skull or jaw, for example, so that conclusions can be drawn about the brain volume.