The Steinheim skull is a fossilized skull of a Homo heidelbergensis found in 1933 near Steinheim an der Murr (20 km north of Stuttgart, Germany). It is estimated to be 250,000–350,000 years old. The skull is slightly flattened and has a cranial capacity from 1110–1200 cc. Others give volumes of (950), 1179±30 and 1270±10 cc. Sometimes referred to as Homo steinheimensis, the original fossil is housed in the State Museum of Natural History in Stuttgart, Germany. Some believe that the Steinheim skull may have belonged to an adult female due to its gracile nature.
The "primitive man of Steinheim" is a single find. The designation "Steinheim skull" can be seen as a reference to the location of the fossil, but in no way identifies with a certain taxon. The skull shows characteristics of both H. heidelbergensis and Neanderthals. It is therefore classified by most paleoanthropologists to H. heidelbergensis and is believed to be a transitional form of H. heidelbergensis to Neanderthals. This has sometimes been referred to as "pre-Neanderthal.” The inner ear of the fossil has a feature in which Neanderthals and H. sapiens differ. The location of the semicircular canals of the inner ear in the temporal bone of the skull base is similar to the situation in Neanderthals, while the semicircular canals of the older H. erectus, as with H. sapiens, are closer.
Until the late 1980s, the fossil was sometimes referred to as H. sapiens steinheimensis. During this time Neanderthals were also referred to as H. sapiens neanderthalensis. Today, however, paleoanthropologists assume that Neanderthals and humans emerged independently from a common ancestor, usually this is called H. erectus, and therefore that two distinct species are to be considered: H. neanderthalensis and H. sapiens.
Prior to discovery of the Steinheim skull in the gravel pit, many objects such as bones of elephants, rhinos and wild horses had been unearthed. Therefore, the archaeologists excavating the site were already sensitized to possible skeletal remains in the quarry. Fritz Berckhemer traveled on the same day of the skull's discovery and reviewed the still hidden skull in the wall. The next day, together with Max Bock, he began the careful excavation. It was clear, on the basis of the shape and dimensions of the skull, that it was not a monkey, as had initially been suspected. It turned out to be a human skull from the Pleistocene. The skull was roughly cleaned, hardened and plastered so it would arrive safe and sound in the Museum of Natural History.