Newly Identified Beetle Was Hiding in Plain Sight

Sometimes scientific discoveries aren’t just made in rainforests and oceans. Sometimes they can be made by researchers right in a museum’s own collections.

That’s how a new frog-legged beetle species was identified at the Denver Museum of Nature & Science. The newly discovered fossil had been named for famed naturalist and documentarian David Attenborough. It had been on display in the museum’s “Prehistoric Journey” exhibition since it opened in 1995.

Labeled as a longhorn beetle, the specimen caught the eye of Frank Krell, the museum’s senior curator of entomology, who saw it on exhibit not long after he started his job in January 2007.

“It took me a while to realize that nobody had ever studied this specimen. It does not belong to the group of beetles I normally work on, i.e., the scarab beetles, such as dung beetles, flower chafers, june bugs, but I am the entomologist at the Museum and the beetle is exceptionally pretty. So I saw it as a challenge to get this specimen described, named, and classified,” Krell tells Treehugger.

Krell began researching the species and found that the beetle even appeared in two books—an out-of-print book from the museum on the exhibit and a scientific publication on the Green River Formation, one of the largest accumulations of lake sediments in the world, known for preserved fossil fish. Both times it was also identified as a longhorn beetle.

But there were some features that didn’t seem to match longhorn beetles. “It took me a few years, and when I had everything together and nothing really fit,” Krell says.

So he reached out to Francesco Vitali, invertebrate zoology collections curator at the National Museum of Natural History of Luxembourg, for help. Vitali is an expert in extant and fossil longhorn beetles.

They looked at all the preserved details and were transfixed by the beetle’s curved hind tibiae—its crooked legs. That’s how they eventually determined it was truly a frog-legged leaf beetle. Both groups are closely related.

“For the peer-review of the manuscript, we suggested to the journal to ask the world-leading expert in extant frog-legged leaf beetles as a referee, and the journal followed our suggestion,” Krell says.

“Dr. Chris Reid from the Australian Museum found a few flaws and every little weakness in our interpretation of the fossil. For example, I had considered it a male, but it turned out to be a female. I had misinterpreted the faint remains of the genitalia. That’s why we have peer-review in scientific publications, to have another pair of eyes looking at our work before it is published. Now we can be sure that our paper is pretty water-tight.”

The findings are published in the journal Papers in Palaeontology. 

Choosing a Name

Although beetles are quite hardy when they are alive, they don't typically remain whole when they fossilize. They float on water, then sink and often fall apart when they reach the sediment. So often only wing cases are found in the fossil record.

Some deposits with fine-grained sediment and other positive conditions, however, offer well-preserved, nearly complete fossils. The Green River Formation in northwest Colorado is one such area. This beetle is from that location and lived nearly 49 million years ago.

Ever since he first spotted the fossil, Krell was quite taken with the beetle’s beauty.

“It is the prettiest beetle fossil I have ever seen because of the clear and well preserved circular patterns on the wing cases,” he says.

So, when it was time to choose a name for his discovery, he gave it a lot of thought.

A scientific name has two components: a genus and a species name. The beetle needed a new genus name because it didn’t fit into any existing frog-legged leaf beetle genera. Krell chose the name Pulchritudo, which is Latin for “beauty.”

Because it was a newly discovered species, it needed a new species name, as well. Scientists often dedicate new species to those who are special to them or who have inspired them. Krell chose Attenborough.

Krell reached out to Attenborough to make sure he knew about his beetle namesake. Pulchritudo attenboroughi, or Attenborough’s Beauty, can be seen in Prehistoric Journey, in “The Cenozoic Era” section of the museum.

“Nobody imparts the grandeur and beauty of nature more impressively than Sir David,” he says. “This fossil, unique in its preservation and beauty, is an apt specimen to honor the great man.”