Sclerotic ring
From Wikipedia, the free encyclopedia
Sclerotic rings are rings of bone found in the eyes of several groups of vertebrate animals, except for mammals and crocodilians.[1] They can be made up of single bones or small bones together.[2] They are believed to have a role in supporting the eye, especially in animals whose eyes are not spherical, or which live underwater.[1] Fossil sclerotic rings are known for a variety of extinct animals, including ichthyosaurs, pterosaurs, and dinosaurs,[3] but are often not preserved.