Ichthyosaur

Bloat and float

These are the scattered bones, vertebrae and ribs from a very large ichthyosaur. These animals were active hunters and therefore were likely to be negatively buoyant (didn’t float) in order to be fast and agile in the water. When they died, they would have sunk to the sea floor but, particularly in shallower seas, as the body decomposed, gasses built up and floated the bloated body back to the surface. There it would be scavenged upon by other animals and broken up, which could well be the case here.

Find out more on the reptiles pages.

Common name

Ichthyosaur

Scientific name

Opthalmosaurus

Type

Vertebrates > Reptiles > Ichthyosaurs


Strata

Kimmeridge Clay Formation

Time period

Upper Jurassic

Age

152 million years

Where found

Freshwater Bay, Portland

Found by

Dr Drury in 1930

Museum

Dorset County Museum, Dorchester

Accession number

DCM.G.00008