Amber inclusions from New Zealand
Abstract
Amber is nearly ubiquitous in lignites from Otago and Southland and cornmon throughout New Zealand; however, no amber inclusions have been reported previously. We studied amber from 22 Cretaceous to Miocene sites in southem New Zealand, recovering inclusions at three localities: Cosy Dell (late Oligocene), Roxburgh (early Miocene), and Hyde (?early Miocene). Preparation of New Zealand amber to expose inclusions for study under incident and transmitted light is challenging and time-consuming, with most samples brittle and opaque. Thus, we stabilize and clear the amber lumps using epoxy preparation under vacuum before grinding and imaging under light microscopy. To date we have recovered 63 arthropods, as weIl as plant remains, fungi, and nematodes. Arachnids include diverse mites (Mesostigmata, Oribatida, Astigmata, and Prostigmata), a variety of spiders and web remains with prey, and a pseudoscorpion. Sorne Collembola were identified as belonging to the family Entomobryidae (Entomobryomorpha). Insects include members of the families Dermestidae (Coleoptera), Mymaridae and Scelionidae (Hymenoptera), Veliidae (Heteroptera), Ceratopogonidae (Forcipomyia) and Mycetophilidae (Diptera), as well as Psocoptera, and Lepidoptera. The most abundant fungi in New Zealand amber are hyphomycetes similar to the genus Casparyotorula from European Palaeogene ambers and we discovered similar fungi growing on resin of the extant Agathis australis, the iconic New Zealand Kauri. Furthermore, specimens of the genus Metacapnodium (Capnodiales) represent the first Southem Hemisphere fossil sooty moulds; saprophytic ascomycetes with brown hyphae, often forming extensive subicula on living plant surfaces. These fungi are ubiquitous and diverse in New Zealand today. Many of these new amber fossils represent groups with an otherwise poor fossil record for the entire Southem Hemisphere. The systematic and ecological diversity of the inclusions highlights the potential of New Zealand amber for reconstructing past terres trial ecosystems of Zealandia, one of the biogeographically crucial former Gondwanan landmasses.