Classification of Lower Mesozoic strata in New Zealand began with the work of Ferdinand von Hochstetter. A geologist with European experience, he recognized Monotis in the field in 1859, and it was his material, collected on a South Island expedition near Nelson, that provided the basis for the variety richmondiana of Monotis salinaria that was described as new by K. A. von Zittel in 1864 – the M. (Entomonotis) richmondiana of later writing.

In an 1864 publication, Hochstetter compared and effectively correlated New Zealand Monotis-bearing strata with the Hallstätt Beds of the Austrian Alps, which in turn were considered to be the lateral equivalents of the Upper Triassic of the Germanic succession (Hochstetter, 1959).

In an early attempt to arrange New Zealand fossiliferous strata in order of age, James Hector (1870) introduced the term “Otapiri Series” for Triassic strata and by 1878 was citing an “Otapiri Series, Upper Trias (Rhaetic)” (Hector, 1878, p. vii). Cox (1878) published a description of Triassic and Jurassic strata in the Hokonui Hills, Southland, that year, noting for the Otapiri Series that “the series [is] either Lower Lias or Rhaetic” (p. 44). The term “Rhaetic” had been used in European writing since 1861. Correlation of the Otapiri Series with the Rhaetic was important. There was considerable agreement in the Old World as to what constituted the Rhaetic, even though the boundary between the Triassic and Jurassic systems was drawn variously at its upper and lower limits.