Ancient Butterflies Flourished During Triassic-Jurassic Mass Extinction, Didn't Need Flowers, Nectar

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Scientists have accidentally found the oldest ever butterfly or moth fossils

An worldwide team of scientists led by Timo van Eldijk and Bas van de Schootbrugge from Utrecht University, the Netherlands, found fossil remains of moths and butterflies dating back to over 200 million years ago, making them the oldest known fossils of Lepidoptera - the order of insects to which butterflies and moths belong.

Experts say they are the earliest fossilised evidence of the insects, and shed fresh light on their evolution - and also that of their butterfly relatives.

This left behind small fragments including what the team describes as the "perfectly preserved" butterfly scales that covered the wings of early moths and butterflies. "It extends the range to which we know butterflies existed by about 10 million years".

Some of the fossils share features with modern moths in the suborder Glossata, which have a straw-like proboscis that can suck up fluids like nectar.

"These scales are the oldest evidence of moths and butterflies", said Mr. van Eldijk who was an undergraduate at Utrecht University in the Netherlands during the research. "Exceptionally well-preserved specimens were recovered".

In 2012, while searching through ancient slides of leaf litter and sediment - what he calls "pond scum" - Strother found remains of primitive insect wings.

The discovery, published this week in the journal Science Advances, offers new insights into the evolutionary interplay between flowering plants and pollinators.

Microscopic moth scales.     Hossein Rajaei
Microscopic moth scales. Hossein Rajaei

Just about every butterfly and moth that has hollow scales today has a proboscis, Mr. van Eldijk said. Size of the scale bar is 1 cm.

"Development of the proboscis may be regarded as an adaptive innovation to sucking free liquids for maintaining the insect's water balance under arid conditions". Glossatan moths mostly feed on angiosperms - plants that produce flowers.

The shift to angiosperms as a main food source came later - contradicting the idea the sucking proboscis was an adaptive response to the arrival of flowers.

Previous studies had suggested that moths and butterflies with proboscises, which belong to the Glossata group, appeared only about 130 million years ago, when flowers first bloomed on land.

Dr van Eldijk said: "Moths and butterflies represent one of the most admired and studied insect groups - not in the least for their remarkable associations with flowering plants".

Another is that the early Jurassic and late Triassic era was a very dry and arid time and the proboscis of the butterflies was an 'efficient technique to replenish lost moisture and survive desiccation stress, ' the researchers said in the study. The proboscis is a famous tool of this insect group, with some like the Morgan's Sphinx moth, or Darwin's moth, using its foot-long tongue to wiggle deep inside orchids. "But that would be 50 million years later than what the wings were saying".

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