Palaeobiogeographical links within the Triassic of Gondwana: Umkomasia fleurdelysia, a new cupule (pteridosperm megasporophyll) and a comparison of allied species

A new species of fossil cupule (megasporophyll), Umkomasia fleurdelysia sp. nov., is described from South America, Africa and Australia. The Brazilian specimens from the Passo das Tropas locality of the Santa Maria Formation (Ladinian–Carnian, Middle–Upper Triassic) are represented by eight well-preserved cupules showing a developmental sequence from closed to open cupules with extended lobes. Large ovoid seeds are associated with these cupules. These cupules and seeds bear clear markings made by the piercing mouthparts of an insect belonging to the Hemiptera. The South African specimens are from the Hlatimbe Valley locality of the Molteno Formation (Carnian), and one cupule has detailed sculpturing that suggests a fleshy structure and possible dispersal by animals. The single Australian cupule is from the Ottaba locality of the Esk Formation (Ladinian–Carnian), and has five rather than four lobes. The new cupules are compared with all known and accepted Umkomasia species and new specimens from Brazil are described. The closely similar Umkomasia feistmantelii from the Lorne and Sydney Basins, Australia, is reviewed and new specimens are illustrated. The possible affiliation of U. fleurdelysia with particular Dicroidium species (such as Dicroidium zuberi) is discussed. Greater knowledge of Umkomasia and other cupules is important in resolving the question of angiosperm origins in the pre-Cretaceous and for understanding the early evolutionary experiments with enclosed seeds, such as those that occurred in Umkomasiaceae and other families in the Triassic.Heidi M Anderson* [hmsholmes@googlemail.com], Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg 20150, South Africa; Ronaldo Barboni [ronaldobarboni@hotmail.com], Pesquisador Convidado, Museu de História Geológica do Rio Grande do Sul, MHGEO-UNISINOS, São Leopoldo, Brazil; Andrew C. Rozefelds [andrew.rozefelds@qm.qld.gov.au], Collection and Research Centre, Queensland Museum, 122 Gerler Road, Hendra, Queensland 4011, Australia, and School of Engineering and Technology, Central Queensland University, Rockhampton, Queensland 4702, Australia.