Lusonectes is a poorly known microcleidid the Toarcian (Lower Jurassic) of Portugal. It is known from a single holotype specimen (MG33), a partial skull in the Museu Geológico, Lisbon, Portugal. It was described and named by Smith et al. (2012) as the first diagnostic plesiosaur species from Portugal, and the westernmost occurrence…
Microcleidus is a medium (4.27 m) to large (5.03 m) plesiosauroid with a small head and a long neck containing 38–39 cervical vertebrae. Watson (1909) erected Microcleidus to accommodate fossil material belonging to 'P.' homalospondylus and 'P.' macropterus (Watson 1911). Both species were considered valid by Seeley (1865), Blake (1876) and Watson (1911) on…
Hauffiosaurus is a basal pliosaurid known from the Lower Jurassic (Toarcian) of the UK and Germany. Hauffiosaurus is a medium to large sized plesiosaur (H. zanoni = 3.4 m, H. tomistomimus, 4.23 m, H. longirostris = 4.83 m) (Smith and Lomax 2019), with a relatively long neck for a pliosaur, and an…
Rhomaleosaurus is the largest known Lower Jurassic pliosaur and was the top predator in early Jurassic marine ecosystems. It has a reinforced skull to help resist torsion and a ferocious set of teeth, a combination of characters perfect for snatching and killing cephalopods, fish, and other marine reptiles. Historically, the genus Rhomaleosaurus…
'Occitanosaurus' was described by Sciau et al. (1990) and Bardet et al. (1999). The genus name was erected for 'Plesiosaurus' tournemirensis by Bardet et al. (1999). The taxon was originally regarded as an early elasmosaurid but is now considered a member of the Microcleididae. 'Occitanosaurus' was approximately 3.9 meters long. The type…
M. victor was originally described and figured by Fraas (1910). Historically, M. victor has been regarded as a species of Rhomaleosaurus and is often associated in the literature under the defunct name 'Thaumatosaurus'. See my article about this history of 'Thaumatosaurus' here. Smith and Vincent (2010) identified M. victor as generically distinct from…