Prehistoric pair of fornicating flies that became frozen in amber 41 million years ago discovered
Nature & Science

Prehistoric pair of fornicating flies that became frozen in amber 41 million years ago discovered

A pair of fornicating flies that became frozen in amber 41 million years ago are among the oldest fossilised mating animals ever to be discovered.

The frisky insects appear to have been in the very throes of passion when they got trapped in gluey tree resin and preserved — unparted, even in death.

Over time, the resin hardened into amber hardened, entombing the amorous pair with their legs still entwined.

The fact than flies typically only take a few seconds to copulate makes the fossil find from Victoria, Australia even more rare and remarkable.

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A pair of fornicating flies that became frozen in amber 41 million years ago are among the oldest fossilised mating animals ever to be discovered. The frisky insects appear to have been in the very throes of passion when they got trapped in gluey tree resin and preserved

WHAT IS AMBER?

Amber has been used in jewelry for thousands of years, and is often found to hold remarkably well-preserved materials from eras long since passed.

The golden-coloured translucent substance is formed when resin from extinct coniferous trees became hardened and then fossilised.

Often insects, plant material, pollen and other creatures became trapped in the resin, causing them to be entombed within after it solidified.

‘You could say these long-legged flies were “caught in the act” 41 million years ago – which is astounding,’ said paper author and palaeontologist Jeffrey Stilwell of the Monash University, in Melbourne.

He was certain this was the scenario when the specimen was first analysed — a fact which co-author Dan Bickel, a fly expert from the Australian Museum, then confirmed.

‘The flies could have accidentally landed on the tree resin to mate, and then got stuck forever together, literally,’ Professor Stilwell said.

‘You can imagine all of the statements by my amber student volunteers, one being “Doin’ it Gondwana style”, etc.’

Gondwana was an ancient supercontinent that eventually split into separate land masses — including Australia.

Mating has been captured in amber unearthed from other parts of the world, but is nevertheless ‘very rare’, Professor Stilwell said.

In Steven Spielberg’s 1993 film Jurassic Park, dinosaurs are reintroduced to the world by extracting their DNA from a mosquito that had been preserved in amber.

Most biologists agree that such a scenario would no be possible. But many experts do believe that DNA can be preserved in amber for millions of years.

‘This is one of the greatest discoveries in palaeontology for Australia,’ Professor Stilwell said. ‘Amber is considered to be the “Holy Grail” in the discipline, as organisms are preserved in a state of suspended animation in perfect 3D space, looking just like they died yesterday’

‘This is one of the greatest discoveries in palaeontology for Australia,’ Professor Stilwell said.

‘Amber is considered to be the “Holy Grail” in the discipline, as organisms are preserved in a state of suspended animation in perfect 3D space, looking just like they died yesterday.’

‘But, in fact, [they] are many millions of years old, providing us with an enormous amount of information on ancient terrestrial ecosystems.’

Professor Stilwell and colleagues stumbled upon the flies while trawling through almost 6,000 pieces of fossilised amber.

The material was unearthed from rocks dating back from 54–40 million years ago found at two sites — one in Western Tasmania and the other in Victoria.

Among them were the two mating specimens of long-legged flies, known to the scientific community as ‘Dolichopodidae’.

These bugs are commonly found across Britain and the rest of the world today.

Other finds from the amber collection included a flake of amber containing a beautifully preserved biting midge and a larger piece with a long-legged fly and and another biting midge

‘This may be the first example of “frozen behaviour” in the fossil record of Australia,’ said Professor Stilwell.

‘Frozen behaviours are rarely recorded in the fossil record, but can be quite diverse, including defence, parasitism, feeding, swarms, and so on.’

Dolichopodidae comprise mainly small metallic flies. The adult males wave their legs when courting potential suitors.

Other finds from the amber collection included a flake of amber containing a beautifully preserved biting midge and a larger piece with a long-legged fly and and another biting midge.

Both specimens are about 41 million years old and were found in Anglesea, Victoria.

The team also analysed amber deposits unearthed by the team at other spots in southeastern Australia, Tasmania and New Zealand  that date back 230 million years.

There were fossilised ants, the first Australian fossils of ‘slender springtails’, a tiny, wingless arthropod and an insect called a felt scale (Eriococcidae) — all around 53 million years old.

There was also a cluster of juvenile spiders, biting midges (Ceratopogonidae), two liverwort and two moss species.

They are the oldest known animals and plants preserved in amber from Southern Gondwana.

The researchers also analysed amber deposits unearthed by the team at other spots in southeastern Australia, Tasmania and New Zealand – dating back 230 million years. There were fossilised ants, the first Australian fossils of ‘slender springtails’, a tiny, wingless arthropod and an insect called a felt scale. Pictured, an artist’s impression of ants getting stuck in resin

‘Finding Triassic, Cretaceous and Paleogene fossils from ancient tree resin in Australia and eastern New Zealand is a dream come true,’ said Professor Stilwell.

‘We now have our first definite glimpses of ancient subpolar greenhouse Earth ecosystems, when Australia and Antarctica were attached and situated much further south in higher latitudes.’

‘Many discoveries are the first ever for their respective groups of animals and plants, including the first ever ants, springtails and others, including the first recorded evidence for “frozen behaviour” in the fossil record of mating flies.’

‘There has never been a fossil ant recorded in Australia before, but we can now state for the first time that ants have been a significant part of the Australian ecosystem for over 40 million years.’

Most amber records are from the Northern Hemisphere. The study has confirmed it was abundant in the ancient supercontinents of Southern Pangea and Southern Gondwana.

‘The research furthers our understanding of prehistoric southern ecosystems in Australia and New Zealand during the Late Triassic to mid-Paleogene periods — 230 to 40 million years ago,’ added Profezzor Stilwell.

The full findings of the study were published in the journal Scientific Reports.