Siouan languages
Siouan languages can be grouped into the Western Siouan languages and Catawban languages. The Western Siouan languages can be divided into Missouri River languages (such as Crow and Hidatsa), Mandan, Mississippi River languages (such as Dakotan, Chiwere-Winnebago, and Dhegihan languages), and Ohio Valley Siouan branches. The Catawban languages consist only of Catawban and Woccon.
Siouan languages
Many of the consonant clusters proposed by Wolf (19501951) can be accounted for due to syncopation of short vowels before stressed syllables. For example, Matthews (1958: 129) gives *wróke as the proto-form for 'male.' With added data from a larger set of Siouan languages since the middle of the twentieth century, Rankin et al. (2015) give *waroː(-ka) as the reconstructed form for 'male.'