undifferentiated rock units

Paleontology and geology

Heavily-vegetated floodplains covered most of New Mexico during the Triassic. Huge, Mississippi-sized rivers flowed across the state from the southeast to the northwest. One of the earliest dinosaurs, Coelophysis, thrived in this seasonally arid climate, as did cycads, ferns, and the large amphibian Buettneria. This map indicates a broad section of Triassic rock in the northeastern section of the state with additional scattered exposures to the west and south.