Protopteraspis is an extinct genus of pteraspidid heterostracan agnathan with fossils known from Lower Devonian marine strata in Western Europe.

The animal's somewhat flat build has led some to believe that it was a bottom dweller, living in freshwater areas.

Protopteraspis also did not possess the cornua (horns) found on the headshields of other pterapsids; rather, it had "small points" behind the gill opening.

It is theorized that the headshield formed in youth and that it grew via growth of the plates, which fused in adulthood.

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