Dr Rolf Oberpieiler ‘Unique Weevil Fauna Preserved in Burmese Amber (100 Million Years Old)’

Rolf, a weevil taxonomist at the Australian National Insect Collection, CSIRO, will speak about this fascinating phenomenon, which dates back to early Upper Cretaceous deposits.   Like the plants, the weevil fauna in Burmese amber also exhibits distinct affinities to modern-day Gondwana taxa that are relictual in Australia.

Abstract

Among the many thousands of beetles recovered from Burmese amber to date, only nine weevils (Coleoptera: Curculionoidea) have been described, suggesting the existence of a depauperate weevil fauna in this early Upper Cretaceous deposit.  However, more than 100 weevil specimens have now been found, making the fauna one of the richest known from the Mesozoic Era and rivalling that of the famous Upper Jurassic Karatau site in Kazakhstan.  The Burmite weevil fauna is highly diverse at genus and species level but only represents three families, the vast majority of taxa belonging to a unique, extinct family characterised by a suite of features incongruent with any of the eight extant ones. The full extent of its taxic and morphological diversity remains to be discovered, but it includes many highly specialised phytophages evidently adapted to exploit the diversity of early angiosperms present at the time.  The unusual combination of generally long and thin oviposition rostrums, geniculate antennae, exodont mandibles and slender tarsi with sharp claws suggests that these weevils were well suited to an arboreal life attacking the flowers and ovules of these plants, possibly also to pollinating them.  Given the diversity of this family in the middle Cretaceous, it likely represents the earliest diversification of weevils on angiosperms.  Like the plants, the weevil fauna in Burmese amber also exhibits distinct affinities to modern-day Gondwanan taxa that are relictual in Australia.  As more family-level taxa are confirmed from this deposit, knowledge of the early evolution of weevils and their intimate associations with plants will increase, as will prospects of using Burmite weevils in phylogenetic dating analyses, especially considering the generally exceptional preservation of these fossils.

Biography

Dr Rolf Oberprieler is the weevil taxonomist at the Australian National Insect Collection at CSIRO in Canberra.  He did his PhD on the systematics of cycad weevils in Africa but works on the taxonomy of several other Australian weevils as well as on the phylogeny and evolution of weevils internationally.