Let the species die. ~ Spanish paleoanthropologist Juan Luis Arsuaga
While a cogent description can be made for H. heidelbergensis, the attribution has a history of controversy. The species is based upon a single 600,000-year-old lower jaw found in Mauer Germany in 1907. Nothing quite like it has been found since.
It took decades for the species designation to catch on. Disparate finds of roughly similar archeological age – skulls with distinctive thick brow ridges and large faces – convinced numerous paleoarcheologists to lump the specimens together under the H. heidelbergensis banner.
H. heidelbergensis was conceived as having a large brain, and having mastered complex tools, based upon bones and wooden spears found at a dig in Schöningen Germany.
Another faction was never convinced. They thought H. heidelbergensis was a concept, not a species. Some of the fossils attributed to H. heidelbergensis were instead Neanderthal, they contended.
Lumping into H. heidelbergensis creates the monogenesis that Darwin dreamed of. In contrast, the demise of H. heidelbergensis would mean a plethora of hominin intermediary specimens, with no clear single-species lineage to humankind. If all the finds attributed to H. heidelbergensis are not a single species, the descent of humans becomes even more of a tangle. That may well be.
The H. heidelbergensis controversy is far from being a singular example that hominin evolution appears an exercise in adaptive radiation spread across continents, with occasional interbreeding that entangled the Homo genus as a mosaic of species.