Wikipedia says “Paranthropus boisei or Australopithecus boisei was an early hominin, described as the largest of the Paranthropus genus (robust australopithecines).
It lived in Eastern Africa during the Pleistocene epoch from about 2.3 until about 1.2 million years ago.”

Dan Baker writes “It’s said that Paranthropus Boisei had very powerful arms, but you can see in these photos, the artists depict powerful looking pectoral muscles as well as very powerful trapezoid muscles, attached about half way up the back of the skull.
The trapezoid muscles being attached in this manner would make it difficult for the creature to turn its head in the same way that we do as humans. They would share the same problems as gorillas AND our favorite lady “Patty”. In the Patterson film, we see Patty turn her entire upper body when looking back at Bob Gimlin. Gorillas raise their heads and then turn back. Paranthropus would most likely have done something similar.
There are interesting parallels that can be seen when studying paleoanthropology and Primatology and comparing some of the attributes of Bigfoot. Of course,this is for the most part, speculation on my behalf. I hope you find it interesting.”