49 First beetle named from amber in Aotearoa

Coleoptera, Scirtidae: Contacyphon pomahakaensis

Fossils discovered in New Zealand amber include a wide range of invertebrates including mites, spiders, beetles, flies and ants. The first to be found, as recently as 2011, was a tiny mite, just 2 mm across. Previously it was assumed that New Zealand amber, often called ‘kauri gum’, lacked fossils, in contrast to the famous Baltic amber of northern Europe. The reason is that most amber from Aotearoa is dark brown or gold in colour, and almost opaque, full of tiny air bubbles which make it almost impossible to see anything inside it. Everything changed in 2011, when Daphne Lee sent a few small samples to Professor Alexander Schmidt at Göttingen University in Germany. Alexander embedded small pieces of amber in epoxy resin, placed them in a vacuum to stabilise the amber and then polished the embedded amber very carefully to reveal details of the creatures within. This discovery has opened up a huge new window into New Zealand’s past biodiversity.

Fifteen images stacked together provide a three dimensional view of this tiny marsh beetle, Contacyphon pomahakaensis, from amber in a Pomahaka Formation lignite seam (OU 47547). Image credit: U Kaulfuss.

We now know that New Zealand amber hosts a very diverse invertebrate and fungal biota that provides the first glimpses into the fossil ecosystems of the ancient forests that once covered much of Zealandia.

The first beetle from amber to be given a formal name is this well-preserved marsh beetle from a lignite seam near Pomahaka, in South Otago. It is tiny, just 1.7 mm long, with every segment of the antennae visible. As the name suggests, it lived in a coastal kauri forest in a swampy or marshy environment around 27 million years ago. There are 50 species of Contacyphon recorded from New Zealand today and many more still to be described.

Larvae of these tiny beetles are filter-feeding detritivores in shallow stagnant water whereas adults are found on shrubs or trees in wet forests. The finding of this minute marsh beetle in amber tells us that these beetles have had a very long history in the New Zealand region.

—Written by Daphne E Lee and Uwe Kaulfuss