Middle Triassic megafossil plants from Long Gully, near Otematata, north Otago, New Zealand

Abstract

The Long Gully Formation of the Corbies Creek Group contains abundant remains of the low-diversity coastal vegetation characteristic of the Middle and Late Triassic Pacific margins of Gondwana. The plant-bearing rocks in Long Gully conformably overlie fossiliferous deltaic and marine Ladinian rocks (Kaihikuan local stage).

A variety of fossil fructifications were found, allowing better understanding of the botanical affinities of the plants. Fertile remains referred to Todites maoricus sp. nov., indicate osmundalean affinities for one common kind of sphenopterid fern frond. Townrovia petasata gen. et sp. nov. is the likely microsporophyll and ? Peltaspermum sp. indet. the likely megasporophyll of seed fern leaves referred to Pachydermophyllum, represented at Long Gully by P. dubium (Burges) comb. nov. and P. praecordillerae (Frenguelli) comb. nov. The ovulate voltziacean conifer cone Telemachus lignosus sp. nov. and “unidentified cone B” may be fructifications of a species also producing leaves referred to Heidiphyllum elongatum (Morris) gen. et comb. nov., including leaves widespread in Triassic rocks of Gondwana formerly referred to Phoenicopsis, Podozamites and Desmiophyllum. The ginkgoalean ovulate cone Karkenia fecunda sp. nov. and “unidentified cone A” may have been produced by the same species as the leaves Sphenobaiera robusta (Arber) Florin.