Homo heidelbergensis was originally known as archaic
Homo sapiens sapiens (basically meaning any
Homo sapiens that didn't look quite
modern). However, because of
mitochondrial DNA evidence, H. heidelbergensis is now used because it is a possible ancestral link to both
Homo neanderthalensis and Homo sapiens.
Fossils of H. heidelbergensis have been dated at 800 000 to 100 000 years old. It was named after the type of specimen found near Heidelberg in Germany in 1907, with an estimated age of 400 000 to 700 000 years. This find consisted of a lower jaw with a receding chin and all of its teeth. The jaw is like that of H. erectus, extremely large and robust, but the teeth are smaller, making Homo ergaster the most likely ancestor. (A much larger jaw than the modern man.)Also some of the specimens found have rather large brow ridges.
The cranal capacity of H. heidelbergensis is about 1300 mL which, compared to H. neanderthalensis is 200 mL less.
H. heidelbergensis appears to represent an intermediate stage between H. ergaster and H. erectus and the two newer species, Homo neanderthalensis and Homo sapiens.
Homo heidelbergensis were more advanced than H. erectus and H. ergaster. These individuals butchered and ate their food on the site of the kill. There is also evidence that, 400,000 years ago, they used throwing spears to kill large prey.
Scientists hypothesize that this new, more advanced tool culture is what led H. heidelbergensis to the domination of Europe. For example, an array of tools were found in southern Italy, which date back to more than 780,000 years ago. This figure suggests that H. heidelbergensis arrived on the scene 180,000 years earlier than previously thought.
The validity of H. heidlebergensis seems to be accepted among many researchers these days, but it is by no means universally accepted.
A photograph of the first H. heidelbergensis found:
http://www.modernhumanorigins.com/mauer1.html
Sources:
http://www.modernhumanorigins.com/heidelbergensis.html
And Biology in Context by Eileen Kennedy and Peter Hickman
Thankyou to Chiisuta.