What Came First: The Butterfly Or The Flower? 236-Million-Year-Old “Latrine” Discovery Yields Surprising Answer

Two hundred and thirty-six million years ago, an ancient herbivore took a dump that would blow 21^st-century minds. You see, that poop contained what would become the oldest-known evidence of butterflies and moths, preserved in tiny hexapod scales still detectable in coprolites (fancy word for fossil poop). Most perplexing of all is that, if the scales did indeed belong to a butterfly, it would indicate that these winged insects and their long feeding snoots predate flowers.

This discovery takes us to a communal latrine shared by the herbivorous therapsids, dicynodonts. Like some animals alive today, these animals appear to have gathered to all poop in the same place. Doesn’t sound like fun, but it has many benefits, including reducing the risk of predation and even sending signals to your buddies.

It was within one of these pits in Talampaya National Park, Argentina, that our story unfolds. Here, researchers from Argentina’s Regional Center for Scientific Research and Technology Transfer of La Rioja (CRILAR) discovered samples in 2011 that raised eyebrows.

Looking more closely at the coprolites, they discovered minuscule hexapod scales – scales that we know can be found on the wings of lepidopterans like butterflies and moths. About the width of two human hairs, the scales are minute, but still they were unique enough for the team to name a new butterfly species: Ampatiri eloisae.

The discovery marks the oldest hexapod scales ever found, and if they are indeed a lepidopteran’s, that pushes back the emergence of this group by around 35 million years.

“Our butterfly is the oldest known, but it’s not the first butterfly," CRILAR palaeontologist Lucas Fiorelli told Science. "That original form is practically impossible to find – it would be like discovering the common ancestor of humans and chimpanzees. Even so, Ampatiri is the closest we’ve come to that origin.”

That origin raises interesting questions because, by the team’s latest estimates, it puts the emergence of the proboscis to around 260 million and 244 million years ago. Like a silly straw attached to their face, modern butterflies unroll their proboscis to access nectar in tubular flowers, but this new discovery suggests the appendage appeared around 100 million years before flowers did.

It’s possible that the trait emerged following the Permian-Triassic extinction event 252 million years ago as a way to capitalize on a rapidly changing botanical environment. Back then, nonflowering plants were producing nectar secretions known as pollination drops, and the proboscis may have become even more specialist as flowering took off.

The study is published in the Journal of South American Earth Sciences.