The biology of extinct trees that grew in high-latitude forests during warmer geological periods is of major interest to understand past and future ecosystem dynamics. Decombeix et al. describe a detailed anatomical study of new fossil gymnosperms from the Triassic (ca. 240 my) of Antarctica.

Disrupted growth in the wood of a Triassic trunk
Disrupted growth in the wood of a Triassic (ca. 240 my) trunk from the Central Transantarctic Mountains. These new Antarctic fossils document the first co-occurrence of traumatic growth zones and epicormic shoots in an extinct plant, and provide new information on the biology of trees that grew in high-latitude forests under past greenhouse climates.

The Triassic trees formed epicormic shoots and had traumatic growth zones in their wood indicating that they were subjected to environmental stresses not seen previously from this region. This study provides new insights into aspects of tree growth and response to disturbance in these warm high-latitude forests that have no equivalent today.