Extinct species

Elasmosaurus

Elasmosaurus platyurus (Cope, 1868)

Taxonomy

Range: Kansas and the Western Interior Seaway, North America
Habitat: Marine waters of the Western Interior Seaway, which covered parts of central North America.
Lived: Late Cretaceous · about 83–72 million years ago

Trait: Had one of the longest necks of any known animal, built from an extraordinary number of neck vertebrae.
Source
Trait: Its long neck was likely too rigid to curve sharply, more like a long pole than a flexible snake-like structure.
Source
Diet: Likely hunted by swimming slowly toward schools of fish and snapping sideways with its head.
Source
Discovery: Its original scientific description famously placed its skull on the wrong end of its body, a mistake later corrected.
Source
Movement: Propelled itself with four large flippers rather than tail movement, unusual among marine reptiles.
Source
Earth Context: Represents an extreme evolutionary experiment in neck length among marine reptiles.
Source
Time Context: Fossils from western Kansas place it in the Campanian, a stage of the Late Cretaceous.
Source