Hyperglossal canals close in size to modern Homo sapiens are found in at
least two Neanderthal skulls dated 60-70 kya, in "early" Homo sapiens
dated 90 kya, and unidentified [by the reviewer] Homo species dated
300-400 kya.
In contrast, Australopithecus africanus, >2 Mya, has a canal 1/2 the size
of modern sapiens, and about the same size as chimps.
The reviewer concludes, "This work suggests that fine neurological
control over the vocal tract emerged at a time, around 500,000 to 100,000
years ago, when human ancestors achieved major adaptive feats in social
structure and technology."
Al McCarrick