Neanderthals had a brain at birth of a similar size to that of modern-day babies. However, after birth, their brain grew more quickly than it does for Homo sapiens and became larger too. Nevertheless, the individual lifespan ran just as slowly as it does for modern human beings.
The oldest "nuclear DNA" from a human has identified some early representatives of the Neanderthal lineage. The well-preserved ancient remains from the "Pit of Bones" site in Spain have been known for more than three decades. They are about 400,000 years old, but their relationships to Neanderthals and other ancient relatives has been hotly debated. Photo: Cranium 5 from Sima de los Huesos
Recently discovered skeletal remains in Italy, which date 30,000 to 40,000 years old, are possibly those of a hybrid between a Neanderthal (Homo neanderthalensis or Homo sapiens neanderthalensis) and human (Homo sapiens)! The individual's lower jaw is currently being examined, and it seems to indicate a hominin which had a face that looked intermediate between a Neanderthal and modern human. Genetic analysis -> female Neanderthal and a male Homo sapiens.
HOMO ERGASTER (Wikipedia.org) 'The Working Man' (aka African Homo erectus) is a chronospecies of Homo that lived in eastern and southern Africa during the early Pleistocene, between 1.8 million and 1.3 million years ago.
7V. From site: Durc was a mixture of both Neanderthal and Modern Man -- "Figuratively, Durc was the only son of the Clan. After Creb saw a glimpse of the Clan's doom at the Clan Gathering, Creb came to believe that Durc was Ayla's gift to the Clan. Children like Durc (and their descendents) would carry on some part of the dying Clan." There are implications, both in "Clan of the Cave Bear" and in Ayla's dreams in later books, that Durc will become the future leader.