Earliest Bennettitalean Cone from the Triassic of Australia

A newly discovered fossil cone from the Early Triassic (early Spathian) Wentworth Falls Claystone at Mt Piddington is the oldest known bennettitalean reproductive structure. The new remains are here referred to Williamsonia runnegari sp. nov. and consist of a terminal cone with long interseminal scales, overreaching about 520 ovules, which were deeply seated and small (2.2 × 3.6 mm). Mature seeds were about twice the size of the ovules (4.3 × 6.4 mm) and had greater preserved relief from a presumed woody endocarp. Its leaf may have been Taeniopteris lentriculiformis , found in the same bed and also from other late Early and early Middle Triassic localities of southeastern Australia and New Zealand. The fossil flora of the Mt Piddington locality is dominated by the seed fern Dicroidium zuberi and its reproductive structures ( Umkomasia feistmantelii and Pteruchus barrealensis ) and marattialean ferns ( Cladophlebis carnei ). New records of plants from the Mt Piddington locality include a polypore bracket fungus ( Eopolyporopsis sp.), an equisetalean ( Phyllotheca etheridgei ) and conifers ( Voltziopsis wolganensis and Walkomiella australis ). This vegetation and its sedimentary setting have been reconstructed as a warm temperate shrubland of anabranches of sandy braided streams.