Endophytic ovipositions on leaves from the Late Triassic, northern Chile: Ichnotaxonomic, palaeobiogeographical and palaeoenvironmetal considerations

Abstract

This paper reports the first record of Triassic insect oviposition scars from southern South America. These scars are found on Late Triassic leaves and leaf fragments from Heidiphyllum elongatum Retallack and Pseudoctenis harringtoniana Bonetti, from the La Ternera Formation, and Taeniopteris sp. B from the Las Breas Formation, in northern Chile. The morphology of these traces is described in detail and comparisons are made with other worldwide records. The identified scars from the Triassic of Chile are: Paleoovoidus contactus isp. nov., P. megaovoidum isp. nov. and P. rectus (Vasilenko) Sarzetti, Labandeira, Muzón, Wilf, Cuneo, Johnson, Genise. Additionally, P. midribum isp. nov., P. marginatum isp. nov., and P. oppositum isp. nov. are established, based upon a detailed analysis of descriptions in the literature. A synthesis of the geological records and ichnotaxonomic considerations is given. The five new species are defined based on the ichnotaxonomic characters suggested by various authors, with the objective of standardizing the different schemes under a single binomial ichnotaxonomical proposal, including all records from the Carboniferous to the Cenozoic, and establishing the corresponding synonymy. Ichnofossils from the Triassic of Chile are tentatively assigned to the Order Odonatoptera based upon morphological characteristics their host plants, and palaeoenvironmetal interpretations.