Other animal coverings such as the arthropod exoskeleton have different developmental origin, structure and chemical composition.

The developmental origin of the insect wing remains in dispute, as does the purpose prior to true flight.

In contrast, the cerebellum has a distinct developmental origin, as well as a unique cellular composition, compared to all the other regions assayed.

Many anatomical features of the adult testis reflect its developmental origin in the abdomen.

A similar developmental origin suggests they are the same structure, and thus likely derived from a common ancestor.

As these cells are from an independent developmental origin, they are typically unaffected by the genetic cause of leucism.

A rigorous exploration of their developmental origin and their relationship to the other well-known cell types in skeletal muscle should be forthcoming.

Inflammatory origin Cysts of developmental origin may be either:

The developmental origin has been disputed.

The developmental origin is unclear, though they may be of endodermal origin, which would explain the mucin-producing, ciliated cell type.