Plesiosaurs:The Marine Predator

By Barbara

What is a Plesiosaur?• Plesiosauria is an order of Mesozoic marine reptiles.

• They lived in the Jurassic and Cretaceous Periods• In phylogenetic terms, Plesiosaurs are actually

closely related to living squamate reptiles (lizards and snakes).• Plesiosaurs evolved from the earlier nothosaurs,

who had a more crocodile-like body• The typical plesiosaur had a broad body and a

short tail. • Plesiosaurs’ necks were actually not that flexible

What is a Plesiosaur? (Continued)

• All plesiosaurs had four paddle-shaped 'flipper' limbs.

• It is thought that they were used to propel the animal through the water by a combination of rowing movements and up-and-down movements.

• Their swimming speed has been estimated at 8.2km/h

• Paleontologists have now figured out that Plesiosaurs gave live birth to a single baby

Plesiosauria - Taxonomy• Order Plesiosauria

• Bobosaurus• Suborder Plesiosauroidea

• Family Elasmosauridae• Family Microcleididae• Family Plesiosauridae• Node Cryptoclidia

• (?) Family Aristonectidae• Family Cryptoclididae• Node Leptocleidia

• Family Leptocleididae• Family Polycotylidae

• Suborder Pliosauroidea• (?) Family Rhomaleosauridae• Family Pliosauridae

Had long necks and may have been 'bottom-feeders‘ in shallow waters.

Had shorter necks with a large, elongated head and may have been at home in deeper waters.

Family: Plesiosauridae Genus: Mauisaurus

Family: Plesiosauridae Genus: Styxosaurus

Family: Pliosauridae Genus: Kronosaurus Family: Pliosauridae Genus: Liopleurodon

Family: Pliosauridae Genus: Rhomaleosaurus Family: Pliosauridae Genus: Macroplata

The Discovery• Mary Anning (1799–1847) was

famous for her plesiosaur discoveries at Lyme Regis in Dorset, UK. • She is credited with the first

plesiosaur find recognised as Plesiosaurus dolichodeirus, which has become the 'type fossil' for Plesiosauria

• She was 24 at the time of her discovery

The Bone Wars• The most famous battle in the field of

Paleontology took place over the skeleton of a Plesiosaur.

• In 1868, Edward Draker Cope published a paper on the “Elasmosaurus platyurus” in the American Philosophical Society journal.• In this original restoration, Cope put the

animal's skull on the vertebrate, giving it a short neck and a long tail.

• Not long after publishing it, his rival O.C. Marsh pointed out the flaw, forever damaging Cope’s reputation in the field.

• "when I informed Professor Cope of it, his wounded vanity received a shock from which it has never recovered, and he has since been my bitter enemy." -Marsh

Do they still exist?

That’s up to you to decide!

Works cited• Aquatic reptiles. (n.d.). Natural History Museum. Retrieved January 14, 2013,

from http://www.nhm.ac.uk/nature-online/life/dinosaurs-other-extinct-creatures/non-dino-reptiles/aquatic-reptiles/index.html

• BBC. (n.d.). Plesiosaurs videos, news and facts. BBC Homepage. Retrieved January 13, 2013, from http://www.bbc.co.uk/nature/life/Plesiosaur

• Mary Anning. (n.d.). Natural History Museum. Retrieved January 13, 2013, from http://www.nhm.ac.uk/nature-online/science-of-natural-history/biographies/mary-anning/index.html

• PBS. (n.d.). Pregnant Plesiosaur Fossil May Shed Light on Ancient Animal's Behavior| PBS NewsHour . PBS: Public Broadcasting Service. Retrieved January 14, 2013, from http://www.pbs.org/newshour/rundown/2011/08/pregnant-plesiosaur-fossil-may-shed-light-on-ancient-animals-behavior.html

• PBS. (n.d.). Introduction: Dinosaur Wars. PBS: Public Broadcasting Service. Retrieved January 14, 2013, from http://www.pbs.org/wgbh/americanexperience/features/introduction/dinosaur-intro/

• Sauropterygia: Plesiosauria. (n.d.). Palaeos: Life Through Deep Time. Retrieved January 13, 2013, from http://palaeos.com/vertebrates/sauropterygia/plesiosauria.html