New seed cones of Araucaria Juss. 1789 (Araucariaceae) in the Aptian Crato Fossil Lagerstätte, NE Brazil and considerations for whole-plant reconstruction

The Crato Fossil Lagerstätte in the Mesozoic Araripe Basin in northeastern Brazil comprises one of the most important fossil floras in the Early Cretaceous (Aptian) of equatorial Gondwana, distinguished by its preservation, taxonomic diversity and evolutionary significance. Although the taxonomic diversity among gnetophytes and early angiosperms is remarkable, the most frequent macrofossil remains are foliage and reproductive organs of Araucariaceae. Similar to other late Mesozoic ecosystems, it has been assumed that fossil-species of this family were major constituents and canopy-forming trees of the past vegetation. Here, we formally describe ovuliferous cones from this unit and establish Araucaria benignae sp. nov. In order to overcome the uncontrolled fossil sampling in the outcrops of the Crato Formation, Santana Group, we tentatively reallocated the ovuliferous cone specimens to ethnostrata within the C6 carbonate unit of the lacustrine limestone section using the ethnostratigraphic approach. Specimens are probably derived from the “lajão dos sete cortes” and the “lajão branco” ethnostrata, which would mean a minimum time interval of the presence of the new fossil-species of about 79–310 ka. In addition, the previously known fossil-species of Araucariaceae from the Crato Formation flora are supplemented for first considerations about putative whole-plant reconstructions in this assemblage. Although a confident whole-plant association between Araucaria benignae sp. nov. and any of the three known araucariaceous foliage species cannot yet be established, shared epidermal characters suggest a possible affiliation with Brachyphyllum obesum and/or B. sattlerae , highlighting the potential of the Crato Fossil Lagerstätte for future whole-plant reconstructions of Cretaceous Araucariaceae.