The Protorthoptera are an extinct order of Palaeozoic insects, and represent a wastebasket taxon and paraphyletic assemblage of basal

Basal (phylogenetics)

In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 neoptera

Neoptera

Neoptera is a classification group that includes almost all the winged insects, specifically those that can flex their wings over their abdomens...

. They appear during the Middle Carboniferous

Carboniferous

The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

 (late Serpukhovian

Serpukhovian

The Serpukhovian is in the ICS geologic timescale the uppermost stage or youngest age of the Mississippian, the lower subsystem of the Carboniferous. The Serpukhovian age lasted from 328.3 Ma tot 318.1 Ma...

 or early Bashkirian

Bashkirian

The Bashkirian is in the ICS geologic timescale the lowest stage or oldest age of the Pennsylvanian, the youngest subsystem of the Carboniferous...

), making them among the earliest known winged insects in the fossil record. Pronotal lobes may be expanded to form a shield. The group includes the ancestors of all other polyneopterous insects.