Mesocephaly is the most common ratio of skull length to skull width in the world today, but was rarer in prehistoric times. It is characterised by the skull width reaching less than 81 and at least 76 percent of the skull breadth. Mesocephalic groups are common on all continents except Australia. In Africa, many forest groups and some savannah groups like Bobo and Shari show mesocephaly, but also people of Madagascar. It is common in Northern Europe and the Mediterranean, South Arabia, West India, much of China, Japan, Indonesia, and Siberia. It occurs in Western Polynesians and New Guineans. In North America, Silvid groups as well as those of the Mexican steppes show mesocephaly. It is common in the Amazon rainforest and in Fuegians.