Heterophylly in Cordaites-like foliage from western Gondwana

• Presence of heterophylly in Cordaites is described for the first time from Gondwana.
• Specimens are preserved as imprints of foliage.
• Twigs exhibit heterophylly represented by spathulate and needle-like leaves.
• Leaf scars are comparable to the species Cordaicladus.
• Associated fertile organ bear Cordaicarpus seeds.

Cordaitalean plants are an important component of upper Palaeozoic Gondwanan plant fossil assemblages. New fossil axes from western Argentina exhibit the first examples of heterophylly in Gondwanan cordaitaleans. Cordaites bifolius sp. nov. was probably a large tree, with its largest branches reaching 17 cm in diameter and leaves reaching at least 55 cm in length. Heterophylly is expressed by the co-attachment of spathulate and needle-like leaves in the twigs. The branches that preserve leaf scars are similar to species of Cordaicladus. Associated stout fertile organs are similar to Cordaitanthus and bear seeds of Cordaicarpus-type.