99-million-year-old beetle discovered trapped in amber

Scientists have discovered a beetle trapped in amber that dates back to 99 million years, a finding that may help better understand the relationship between ancient flowering plants and pollinators.

A group of unusual evergreen gymnosperms, known as cycads, may have been the first insect-pollinated plants.

A study published in the journal Current Biology uncovers the earliest definitive fossil evidence of the relationship between cycads and insects.

Researchers found an ancient boganiid beetle preserved in Burmese amber for an estimated 99 million years along with grains of cycad pollen.

The beetle also shows special adaptations, including mandibular patches, for the transport of cycad pollen.

"Boganiid beetles have been ancient pollinators for cycads since the Age of Cycads and Dinosaurs," said Chenyang Cai, now a research fellow at the University of Bristol in the UK.

"Our find indicates a probable ancient origin of beetle pollination of cycads at least in the Early Jurassic, long before angiosperm dominance and the radiation of flowering-plant pollinators, such as bees, later in the Cretaceous," said Cai.

The researchers also conducted an extensive phylogenetic analysis to explore the beetle's family tree.

Their analysis indicates the fossilised beetle belonged to a sister group to the extant Australian Paracucujus, which pollinate the relic cycad Macrozamia riedlei.

The finding, along with the current disjunct distribution of related beetle-herbivore and cycad-host pairs in South Africa and Australia, support an ancient origin of beetle pollination of cycads, researchers said.

The findings together with the distribution of modern boganiid beetles lead him to suspect that similar beetle pollinators of cycads are yet to be found.