New Species of Scorpion From 240 Million Years Ago Discovered in Museum

Researchers have identified a previously unknown scorpion species that lived around 240 million years ago.

The discovery came after a team of paleontologists examined in detail a fossil that was being kept in the Milan Museum of Natural History in Italy, according to a statement.

The fossil itself was originally found in the Besano Formation—a geological formation in the southern Alps—at Monte San Giorgio, a mountain on the border between Italy and Switzerland.

The formation is known for being one of the richest sites for fossils dated to the Middle Triassic—the geological era between around 247-237 million years ago—in the world.

Scorpions are arachnids, a group of eight-legged invertebrates that includes spiders and other creatures, such as ticks and mites. Scorpions also belong to the larger group of animals known as arthropods, which all possess an exoskeleton, a segmented body, and other distinguishing characteristics.

The latest find, which has been documented in a study published in the journal PalZ, is significant because terrestrial arthropods are among the rarest fossils in the paleontological record, and arachnids represent only a small part of this record, according to the study authors.

In fact, the newly described species, which has been named Protobuthus ziliolii, is the first known scorpion from the Mesozoic Era (about 252 to 66 million years ago) found in Italy. It is also only the second species discovered in the world from the genus (group of species) Protobuthus.

The new species is described based on only one specimen, that was encased in a small piece of rock.

The scorpion measures just 4.4 centimeters (1.7 inches) in length and has been preserved almost intact, complete with eyes, legs and stinging tail.

With the help of UV light and a scanning electron microscope in the laboratories of the museum, researchers were above to determine that the fossil represents the body of the scorpion itself and not simply a discarded exoskeleton, known as the exuvia.

Arthropods have a hard shell known as an exoskeleton. They must go through stages of molting to keep growing, in which they shed their old exoskeleton to reveal a new one. The abandoned exoskeleton is known as the exuvia. Usually, these have more chance to fossilize, than the original body, the researchers said.

The fossil was extracted from the upper layers of the Besano deposit on the Italian side of Monte San Giorgio. The fossils of the mountain are known for their variety and exceptional state of conservation. The scorpion find has not yet been exhibited to the public at the museum.