Image credit Wikimedia Commons; original image– https://www.nature.com/articles/s41586-019-1067-9
Homo luzonensis, named “luzonensis” after Luzon, an island in the Philippines, is a recently discovered extinct hominin species found in what is today the Philippines. The species was named in 2019 with a little over a dozen specimens representing at least three individuals, all found in Callao Cave in the Philippines and dated to around 67,000 years ago. The specimens are mostly either teeth or bones of the hands and feet. The young age of the species, relative to other hominin species, suggests that the species existed at the same time as numerous other hominin groups: e.g., Homo sapiens, Homo floresiensis, Neandertals, and Denisovans.
The original researchers noted the unique combination of primitive and derived features of the various specimens that differentiate it from other known species. The teeth, compared to other hominin species, are small, and the molars are even smaller than those of H. floresiensis, another small, contemporaneous hominin species found on an island (Flores, Indonesia). The maxillary (upper) molars decrease in size from front to back (M1 > M2 > M3), which is a trait similar to H. sapiens and Asian Homo erectus. Some of traits of the bones of the hands and feet are more primitive, similar to Australopithecus.
The overall combination of traits seen in H. luzonensis is unique, and some affinities are seen to Asian H. erectus and to the older Australopithecus. This, coupled with the limited fossil sample, makes determining the origin of H. luzonensis difficult. The exact phylogenetic relationship of H. luzonensis is still undetermined as well, further complicated by the failure to extract DNA from the remains (most likely due to the hot and humid climate—which degrades DNA—where they were found).
The few specimens assigned to H. luzonensis are fragmentary, making it difficult to estimate the height of the species. The original researchers estimated a height just under five feet, with males being slightly taller on average than females. Similar to H. floresiensis (see H. floresiensis article) from the island of Flores, H. luzonensis may be another example of insular dwarfism (reduction in body size when in a small environment, like an island), although more fossils are needed to get a more accurate idea of the size of H. luzonensis.
Another intriguing element of the discovery of Homo luzonensis is how the species got to the island of Luzon. Like the island of Flores, Luzon is (and was) not connected to any mainland, and consequently the presence of hominins on both of those islands suggests that both species made sea crossings.
