The right answer is freed the hands for other uses.
bipedality is also more economic than tetrapedality, but it is not as fast and does not offer a high jumping skills.
The standing position has an advantage in reproduction because it has become attractive to females and more or less successful imitation in males, depending on their abilities, but bipedalism is a disadvantage in childbirth.
Answer: Igneous rock forms between sedimentary layers.
This can definitely help in determining relative age because sedimentary rocks will be the older rock than igneous rock as igneous rock has formed between sedimentary rocks
