A recently discovered prehistoric species of scorpion may have been one of the first creatures to leave the sea and venture on to land, a new study claims.
Researchers from Otterbein University, USA say the creature would have lived about 437 million years ago during the Siluarian period.
It’s called Parioscorpio venator and is the oldest-known scorpion so far discovered by scientists. It was found in Waukesha, a county in Winsconsin, USA.
As the fossil record is limited for the period it lived, researchers say it is unclear exactly how or when it adapted to life on dry land.
Palaeontologist Andrew Wendruff, an author on the study, said the discovery of two very well preserved fossils was an exciting development.
On close examination of the fossils they found that they were both a member of a previously-unknown scorpion species.
The newly found marine arachnids shows some primitive characteristics present in other early marine organisms, said Mr Wendruff.
The creatures have compound eyes, as well as characteristics found in present-day scorpions, such as a tail terminating in a stinger.
It also shows details of internal anatomy, including narrow, hourglass-shaped structures that extend along much of the middle part of the body.
These structures are very similar to the circulatory and respiratory systems in present-day scorpions, as well as those of modern horseshoe crabs, the authors say.
The new study into the prehistoric creatures says they had no lungs or gills, which is evidence that they may not have been ‘fully terrestrial’ but did spend time on land.
Their similarity to horseshoe crabs, which can breathe on land, suggests they may have forayed onto land for extended periods of time, the authors claim.
‘Anatomical details preserved in P. venator suggest that the physiological changes necessary to accommodate a marine-to-terrestrial transition in arachnids occurred early in their evolutionary history.
‘The close similarity of its preserved pulmonary-cardiovascular structures with those of extant scorpions hint at the possibility of extended stays on land.’
The research has been published in the journal Scientific Reports.