Orthida is an extinct order of brachiopods which appeared during the Early Cambrian period and became very diverse by the Ordovician, living in shallow-shelf seas.

Specimens from the late Cambrian to the earliest Ordovician exhibit shells with rounded and pointed pedicle valves, with sharp to obtuse extremities and ridges that are fine to course.

Punctate shells appear during the mid-Ordovician, which establish the suborder Dalmanellidina.

The Ordovician is a productive period which gives rise to numerous genera in this order.

However, they started to become greatly reduced by the end of the Ordovician extinction event.