Plesiosauria

plural noun

Ple·​si·​o·​sau·​ria
ˌplēsēəˈsȯrēə
1
: a suborder of Sauropterygia comprising Mesozoic marine reptiles with dorsoventrally flattened bodies and limbs modified into paddles compare plesiosaurus
2
in some classifications : an order of Reptilia nearly coextensive with Sauropterygia
plesiosaurian
¦⸗⸗⸗¦sȯrēən
adjective or noun
plesiosauroid
-ȯˌrȯid
adjective

Word History

Etymology

New Latin, from plesi- + -sauria

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

  1. Expanded definitions
  2. Detailed etymologies
  3. Advanced search tools
  4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now

Dictionary Entries Near Plesiosauria

Cite this Entry

“Plesiosauria.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Plesiosauria. Accessed 15 Dec. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!