When did the oldest undisputed cycad fossils appear?

The oldest remains of undisputed cycads date from the Triassic Period, which occurred approximately 251.9 to 201.3 million years ago. Examples of these early fossils include the genera Leptocycas and Antarcticycas.1

While some problematic forms have been identified from the Paleozoic Era, and fragmentary fossils suggest their presence as far back as the Carboniferous Period, the Triassic remains are the oldest currently accepted as undisputed.12