Coastal Quechua
Coastal Quechua, also called Maritime Quechua or Chincha Quechua, is a hypothesized variety of Classical Quechua spoken in coastal region of the modern Peruvian departments of Lima and Ica. It would have been widespread in coastal valleys located between the Rímac and Ica rivers, bordering the Quingnam language in the north and a language from the Aymaran family in the south, with which it shared a transition zone in the valleys of Pisco and Ica. Like other non-southern varieties of Quechua, it would have been considered a quechua chinchaisuyo during the colonial period. It went extinct due to the depopulation of the southern Peruvian coast, part of the Andean demographic collapse.
Today, there is no surviving variety that can be considered a descendant of Coastal Quechua, and even its existence is debated among specialists. There are indications in certain chronicles suggesting that the Chincha culture spoke a Quechua language. In the late 20th century, Peruvian linguist Alfredo Torero proposed that Quechua, and specifically a variety particular to the Chincha was spread and used as a lingua franca as a result of their commercial activity, as well as the religious importance of the oracle of Pachacámac. According to Torero, it is possible that this variety was the ancestor of the modern Kichwa language spoken in Ecuador. However, this hypothesis has been heavily criticized by later investigators.
There is also a lack of a consensus on which colonial documents would reflect this so-called Coastal Quechua. In a famous article published in 1990, Rodolfo Cerrón-Palomino proposed a series of phonological and grammatical characteristics of Coastal Quechua from the first Quechua dictionary and grammar, written by the missionary Domingo de Santo Tomás and published in Valladolid in 1560. However, Santo Tomás does not mention in either work the source of his linguistic data, and the attribution of both to coastal Quechua is based on information about his pastoral work in the 1540s. The features attributed by Cerrón-Palomino to Coastal Quechua include: the absence of aspirated and ejective plosives, the sonorization of occlusives following nasal sounds, and the fricativization of occlusives in coda position, among others. Studies published in the 21st century have seriously questioned the placement of the Quechua described by Santo Tomás in the Chincha region, while Cerrón-Palomino has affirmed the existence of this coastal variety.