Endophytic oviposition on leaves from the Late Triassic of northern Chile: Ichnotaxonomic, palaeobiogeographic and palaeoenvironment considerations

This paper reports the first record of Triassic insect oviposition scars from southern South America. Oviposition scars are found on Late Triassic leaves and leaf fragments from Heidiphyllum elongatum (Morris) 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 fossil traces is described in detail and comparisons are made with other worldwide records. The identified scars from the Triassic of Chile are: Paleoovoidus contactus nov. isp., P. megaovoidius nov. isp., and P. rectus Vasilenko. Additionally, P. midribus nov. isp., P. marginatus nov. isp., and P. suboppositus nov. isp. are established, based upon a detailed analysis of descriptions in the literature. A synthesis of the fossil record and ichnotaxonomic considerations is given. The five new ichnotaxa are defined based on characters suggested by previous authors, with the objective of standardizing the different schemes under a single binomial ichnotaxonomical proposal, including most records from the Carboniferous to the Cenozoic, and establishing corresponding synonymy. Ichnofossils from the Triassic of Chile are tentatively assigned to the order Odonatoptera based upon morphological characteristics of scars on their host plants, and palaeoenvironmetal interpretations.