Polycotylus latipinnis was the first short-necked plesiosaur to be recognised in North America (Carpenter 1996), and the first polycotylid to be described and named (Cope 1869). It was established in the same volume that coined the name Elasmosaurus and contained the infamous 'head on the wrong end' reconstruction (Cope 1869). However, despite…
Polycotylids are a clade of relatively small-bodied, typically snort-necked, long-snouted plesiosauroids, from the Cretaceous Period. Martinectes bonneri They were traditionally classified as pliosaurs because of their short necks and relatively large heads. However, cladistic analyses taking into account a broader suite of anatomical characters have shown they are plesiosauroids, more closely related…
Thililua has 30 cervical vertebrae. Each cervical has a longitudinal ridge on its lateral surfaces, this is a convergent feature with elasmosaurids. The skull of Thililua is relatively large with a short postorbital region and elongate rostrum. The type specimen (MHNGr.PA.11710) consists of a complete skull, entire cervical and pectoral series, and…
Edgarosaurus is a basal polycotylid (Druckenmiller 2002) from the Thermopolis Shale
An exciting new paper published this week in the journal Science (Vol. 333, p.870-873) provides the first direct evidence for live birth in plesiosaurs, and may have implications for plesiosaur behaviour (O'Keefe and Chiappe 2011). The plesiosaur Polycotylus giving birth to a single large baby. Based on new fossil evidence. Image by…
The discovery of a new plesiosaur specimen was recently announced by the South Dakota School of Mines and Technology, South Dakota, USA. 11-year-old Devon Zimmerman noticed the skull and part of the backbone on the bank of the Missouri River, near Pickstown, South Dakota, during a vacation with parents Duane and DeeAnn…
The newest film offering from National Geographic opened to 78 IMAX theaters across the United States, the largest ever opening for an IMAX movie. ‘Sea Monsters’ is set in the Late Cretaceous Western Interior Sea, and follows the journey of a growing Dolichorhynchops. The official website is now complete and up and…
The second paper in the two-part report on by Albright et al. on plesiosaurs from the Upper Cretaceous Tropic Shale of southern Utah (Journal of Vertebrate Palaeontology, Volume 27(1) p. 41-58), introduces two new genera and species of polycotylid plesiosaur and contributes to the systematics of polycotylid plesiosaurs. The first new genus…
The unveiling of a new plesiosaur mount formed the highlight of a Mini-Symposium dedicated to plesiosaurs, held at the Rocky Mountain Dinosaur Resource Centre, USA, last month (25 February 2006). Five Speakers presented talks at the event, discussing their research into plesiosaurs in the USA (pictured below alongside the new mount). The plesiosaur…