Paleontologists Find Frog-Legged Beetle Fossil in Colorado

Wednesday, August 11, 2021

Pulchritudo attenboroughi. Image credit: Krell & Vitali, doi: 10.1002/spp2.1398.

A new species of leaf beetle that lived nearly 49 million years ago (Eocene epoch) in what is now the United States has been named after Sir David Attenborough.

Beetles are sturdy when they are alive, but they do not easily fossilize as a whole beetle. They float on water, and when they sink and reach the sediment, they often fall apart.

Usually, only single wing cases are found in the fossil record.

Some deposits with a fine-grained sediment and particularly favorable conditions provide us with very well preserved, often almost complete fossils. These deposits are called Lagerstätten.

The Eocene-epoch Green River Formation in northwest Colorado is one of them.

“I was delighted to have the opportunity to work on such a magnificent and unique fossil,” said Dr. Francesco Vitali, a curator at the Luxembourg’s National Museum of Natural History.

“We looked at all the preserved details. It was the beetle’s crooked legs — its curved hind tibiae — that gave away its true identity: a frog-legged leaf beetle (subfamily Sagrinae).”

The new beetle species is the second known fossil representative of the subfamily Sagrinae from North America.

“This is one of the most magnificent beetle fossils ever found,” said Dr. Frank-Thorsten Krell, a curator at the Denver Museum of Nature & Science.

“The patterning is preserved in unsurpassed clarity and contrast, making this one of the best-preserved beetle fossils. It is most definitely deserving of its name.”

Digital reconstruction of Pulchritudo attenboroughi, based on part and counterpart of holotype. Image credit: Krell & Vitali, doi: 10.1002/spp2.1398.

The beetle needed a new genus name, because it did not fit in any existing frog-legged leaf beetle genera.

Because of its beauty, Dr. Krell and Dr. Vicente chose the name Pulchritudo, which is Latin for beauty.

Scientists often dedicate new species to colleagues who have contributed significantly to science, or to people who are special to them.

For Dr. Krell, one person immediately came to mind: Sir David Attenborough, English broadcaster and naturalist, who has inspired him, his family and millions of others through his documentaries on the natural world.

“Nobody imparts the grandeur and beauty of nature more impressively than Sir David,” Dr. Krell said.

“This fossil, unique in its preservation and beauty, is an apt specimen to honor such a great man.”

The discovery of Pulchritudo attenboroughi is reported in the journal Papers in Palaeontology.


Frank-Thorsten Krell & Francesco Vitali. Attenborough’s beauty: exceptional pattern preservation in a frog-legged leaf beetle from the Eocene Green River Formation, Colorado (Coleoptera, Chrysomelidae, Sagrinae). Papers in Palaeontology, published online August 5, 2021; doi: 10.1002/spp2.1398