Ladinian

Ladinian is a division of the Middle Triassic epoch in the international geologic timescale. It follows the Anisian stage and precedes the Carnian stage. The name Ladinian is derived from the Ladin region of northern Italy, where rocks of this age were studied in the development of stratigraphic correlations. In the modern ICS chart, the Ladinian is dated to roughly 242 to 235 million years ago, representing a middle portion of the Triassic period.

Geology and boundaries

The Ladinian is defined within the broader framework of the Triassic, formed after the end-Permian mass extinction and during a broad recovery and diversification of life. The stage’s lower and upper boundaries are established by global stratigraphic markers that rely on characteristic fossil assemblages rather than a single absolute date, in line with international standards for correlating rock sequences across different regions. Rocks of Ladinian age are found in various parts of Europe, Asia, and other paleogeographic areas that were influenced by the central Tethys Ocean and the supercontinent Pangaea.

Environment and life

During the Ladinian, marine ecosystems supported diverse invertebrates such as ammonoids and conodonts, along with reef-builders in suitable shallow seas. Terrestrial ecosystems saw the ongoing evolution and diversification of reptiles, including early archosauromorphs, as landmasses remained largely connected. The climate was generally warm, with sea levels fluctuating in ways that produced both transgressive and regressive cycles affecting sedimentation and faunal distributions.

significance

As a middle subdivision of the Triassic, the Ladinian helps scientists understand post-extinction recovery, early Mesozoic biotic radiations, and the spatial and climatic dynamics of a world dominated by Pangaea. Further refinements in boundary definitions and regional stratigraphy continue to illuminate its precise temporal and ecological context.

See also: Triassic, Middle Triassic, Anisian, Carnian.