Category «Polycotylidae»

Polycotylidae

Polycotylids have been traditionally classified as pliosaurs because of their short necks and relatively large heads. However, cladistic analyses that take into account a broader suite of anatomical characters have revealed that they are probably plesiosauroids, and therefore more closely related to the long-necked elasmosaurids and cryptoclidids than to pliosaurs. All polycotylids share a number …

Thililua

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 the first four …

An old debate settled – plesiosaurs gave birth to live young

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 & Chiappe, 2011). Whether plesiosaurs laid eggs or gave birth to live young has been a topic of speculation for nearly 200 years. …

Two new species of polycotylid plesiosaurs

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 and species, Palmula …

New plesiosaur mount unveiled at plesiosaur mini-symposium, Rocky Mountain Dinosaur Resource Centre

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 (February 25th). Five Speakers presented talks at the event, discussing their research into plesiosaurs in the USA (pictured below alongside the new mount). The plesiosaur on display was discovered …