Eupteleaceae Papaveraceae Circaeasteraceae Lardizabalaceae Menispermaceae Berberidaceae Ranunculaceae The fossil form Leefructus, described in 2011, has been recognized as a member of this order.

[4] Leefructus mirus shows fully developed leaves; stem and flower that are very similar in structure to those of the modern buttercups.

The fossil is dated to 125 Mya (million years old) and it not only proves that Ranunculales is an ancient group of eudicots but demonstrates that the whole angiosperm clade may be older than expected.

The fact that Leefructus shows a well-developed structure similar to modern ranunculids suggests that this group of eudicots may have developed earlier than the age of the fossil.

[citation needed] The Cronquist system (1981) also recognised the order, but placed it in the subclass Magnoliidae, in class Magnoliopsida [= dicotyledons].

It used this circumscription:[citation needed] In the Cronquist system, the Papaveraceae and Fumariaceae (including the plants in the optional family Pteridophyllaceae) were treated as a separate order Papaverales, placed in this same subclass Magnoliidae.