Overview

• Sven Sachs and Daniel Madzia formally described the new genus and species Plesionectes longicollum in PeerJ Life & Environment.
• The species is based on specimen SMNS 51945, a nearly complete skeleton unearthed in 1978 from a Holzmaden quarry.
• The fossil preserves soft tissue around the neck, tail and hindlimbs and exhibits an unusually long neck of at least 43 cervical vertebrae alongside a high dorsal count.
• Dating to about 183 million years ago, Plesionectes longicollum is now recognized as the earliest plesiosaur from the Posidonia Shale.
• The discovery sheds light on marine ecosystem evolution during the early Toarcian oceanic anoxic event and underscores the Posidonia Shale’s role as a premier Early Jurassic fossil repository.