The first arthropods from New Zealand amber
Résumé
Amber is nearly ubiquitous in lignites from Otago and Southland, and elsewhere throughout New Zealand; however, until now no arthropod inclusions have been reported from these fossil tree resins. We have examined amber from several Cretaceous to Miocene sites in southern New Zealand and recovered inclusions of arthropods in three localities: Cosy Dell (Late Oligocene), Roxburgh (Early Miocene), and Hyde (Early Miocene). Preparation of New Zealand amber and exposing its inclusions for study under incident and transmitted light is challenging and time-consuming, since most amber samples are brittle and opaque. Thus, we apply epoxy preparation under vacuum before grinding and imaging in order to stabilize the amber lumps and to clear the fossil resin for light-microscopy. To date we have recovered about 50 arthropods, as well as plant remains, fungi, and nematodes. Arachnids include diverse mites from the Mesostigmata, Oribatida, Astigmata, and Prostigmata, a variety of spiders and their web remains with prey, and a pseudoscorpion. Some Collembola were identified as belonging to the family Entomobryidae. Inclusions of insects comprise members of the families Dermestidae (Coleoptera), Mymaridae and Scelionidae (Hymenoptera), Veliidae (Heteroptera), as well as Nematocera (Diptera), Psocoptera, and Lepidoptera. Many of the new fossils represent groups with an otherwise poor fossil record in the entire Southern Hemisphere. The systematic and ecological diversity of the inclusions highlights the potential of New Zealand amber for reconstructing past terrestrial ecosystems of Zealandia, one of the biogeographically crucial Gondwanan landmasses.