Species of Dicroidium, which grew as large trees, were widely distributed and dominant over Gondwana during the Triassic (252 to 201 million years ago).

[5] Dicroidium plants grew as medium-large sized trees,[5] with some preserved trunk sections 10 metres (33 ft) tall and over 50 centimetres (20 in) wide,[4] with the wood assigned to the genera Kykloxylon and Rhexoxylon.

These structures are almost never found in organic connection, and their placement as part of the same plant primarily relies on their repeated co-occurrence with each other, and the similarities in the morphology of their cuticles.

[13] Later Triassic Dicroidium-bearing plants were dominant large canopy forming trees in temperate wetland and forested habitats at mid-high latitudes, extending to the South Pole.

[4][5][6] Dicroidium-dominated ecosystems in Gondwana collapsed during the end-Triassic mass extinction, with Dicroidium surviving in parts of East Antarctica into the Early Jurassic (Sinemurian).