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Plesiosauria

plural noun
Ple·​si·​o·​sau·​ria

Definition of Plesiosauria 

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

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Other Words from Plesiosauria

plesiosaurian \¦⸗⸗⸗¦sȯrēən \ adjective or noun
plesiosauroid \-​ȯˌrȯid \ adjective

History and Etymology for Plesiosauria

New Latin, from plesi- + -sauria

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