Assertion: plesiosaur's neck | /r/PartOf | the suborder
Facets:
Source sentences:
text: Early in their evolutionary history, the plesiosaurs split into two main lineages: the pliosaurs (or pliosauroids, which belong to the suborder Pliosauroidea), in which the neck was short and the head elongated; and the plesiosauroids (which belong to the suborder Plesiosauroidea), in which the head remained relatively small and the neck assumed snakelike proportions and became very flexible.