How the mouth of grasshoppers resembles that of mammals

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New research by paleobiologists at the University of Leicester has identified startling similarities between grasshopper mouths and mammalian teeth.

The team of researchers used sophisticated three-dimensional imaging techniques to precisely map the shape of the grasshoppers’ mandibles and present their findings in Methods in ecology and evolutionpublished today (Wednesday).

There are approximately 11,000 known species of grasshoppers. It’s probably surprising that not all grasshoppers eat grass. In fact, they play a range of important roles in grasslands and other ecosystems – some are even carnivorous.

But analyzing the ecological importance of grasshoppers is not straightforward, and finding out what they eat requires detailed study of the contents of their guts or careful, time-consuming observations of how they feed in the wild. There is, however, a better way.

Like animals with teeth, grasshoppers’ mouthparts, called mandibles, differ depending on what they eat: some look like molars and grind hard foods like grass, while others have sharper edges. sharp. Until now, this approach lacked precision, only allowing locusts to be assigned to broad feeding categories.

But the Leicester research – with input from the University of Bristol’s School of Earth Sciences – offers a new way to study the diets of the many species about which scientists have little information, either by either because of their rarity or because they are extinct.

Chris Stockey, a PhD researcher at Leicester, is the corresponding author of the study. He said:

“Knowing what animals eat is fundamental to understanding ecosystems, but it can be difficult and time-consuming, especially if the animals you’re studying are rare, small, or fast-moving.

“One of the advantages of our method is the power of comparisons it provides.

“Amazingly, comparing grasshopper mandible landscapes with mammalian teeth predicts grasshopper diets with 82% accuracy – quite amazing considering that mammalian and grasshopper mouthparts have evolved. independently for 400 million years and were not present in their common ancestor.”

Mark Purnell, Professor of Paleobiology and Director of the Center for Paleobiology at the University of Leicester, said:

“We measured the shapes of grasshopper mouthparts and analyzed them as the topography of a landscape, and found clear differences related to diet.

“The mandibles of carnivorous grasshoppers that eat soft flesh have steeper slopes and sharper cliff edges, while those that eat hard plant matter, such as grass, have mandibles with complex undulating ‘landscapes’ .”

The research was based on museum specimens, part of the huge collections kept behind the scenes for scientists to study – rooms filled with millions of samples below the viewing galleries. Even the most studied collections, such as that of Charles Darwin, produce new species every year.

Without having seen these living organisms, the only way to learn more about their lifestyle and diet was to dissect them thoroughly. Not only is dissection a slow process, but it can damage specimens and limit their usefulness for further study.

Applying this new non-destructive method to museum collections offers an alternative way to learn about the ecology of rare animals while preserving them for future study.

Dr Ben Price, senior curator at the Natural History Museum, who was not involved in the research, added:

“This study is an excellent example of combining modern analytical methods with historical samples from museum collections to help understand the biodiversity of our planet. As technology advances, additional uses of museum collections become possible and this A non-destructive approach could reveal the dietary information of thousands of species, decades after the specimens were collected.”

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