Overview

• The study by Sven Sachs and Daniel Madzia published August 4 in PeerJ Life & Environment formally names Plesionectes longicollum based on specimen SMNS 51945 from Holzmaden’s Posidonia Shale.
• Plesionectes longicollum exhibits an exceptionally long neck with at least 43 cervical vertebrae and a higher dorsal vertebral count than other Early Jurassic plesiosaurs.
• Remnants of soft tissues preserved around its neck, tail and hindlimbs provide rare anatomical details of marine reptiles from the Toarcian.
• At roughly 183 million years old, this species is the oldest known plesiosaur from the Posidonia Shale and represents the formation’s sixth named plesiosaur.
• The discovery underscores the importance of museum archives in revealing hidden biodiversity and offers new perspectives on marine ecosystems during the early Toarcian anoxic event.