Раскрыта загадка Плесихи

[demosfer]

В Википедии нашел. https://en.wikipedia.org/wiki/Mrs._Ples

Mrs. Ples is the popular nickname for the most complete skull of an Australopithecus africanus ever found in South Africa.
Mrs. Ples, whose cranial capacity is only about 485 cubic centimetres, was one of the first fossils to reveal that upright walking had evolved well before any significant growth in brain size.

Теперь все понятно!