The upper Triassic Chinle flora of the Zuni Mountains, New Mexico
— Sidney R. Ash

The Chinle Formation of Late Triassic age in the Zuni Mountains contains a large flora of about 40 species based on petrified wood, compressed leaves, reproductive structures and palynomorphs. Most of the plant fossils occur in the Monitor Butte Member of the Chinle, but some also occur in the Sonsela Sandstone Bed in the overlying Petrified Forest Member. The flora, which has been known for over a century, contains representatives of most major groups of plants including the horsetails, ferns, seed ferns, conifers, cycads, bennettitales and ginkgoes. It also includes several forms which cannot be classified with certainty at this time and several undescribed taxa. The flora indicates that the climate was warm and moist when the Monitor Butte Member was being deposited in the Zuni Mountains area of New Mexico.