According to phylogenic trees, there are actually two distinct lineages of Neanderthals. One split from Homo Sapiens around 500,000 years ago, and the other split from Denisovans around 600,000 years ago.

This lineage that split from Denisovans, called the proto-Neanderthals, is known only from fossils found in Spain, and died out or was absorbed into the later Neanderthals group. Did the last common ancestor originate in Spain?

Most likely, this common ancestor was an offshoot of Homo erectus, which in one of my previous videos you learned is known as Homo sapiens erectus. This phylogenic tree shows the relationship between these groups, which split up around 850,000 years ago. Previous analyses of the 'Sima de los Huesos hominins' showed that their maternally inherited mitochondrial DNA was distantly related to Denisovans, but not closely related to other Neanderthals.

The new results show that the hominins were a more ancient lineage of proto-Neanderthals, but distantly related to other Neanderthals.