Lunaspis is an extinct genus of armor-plated petalichthyid placoderm fish that lived in shallow marine environments of the Early Devonian period, from approximately 409.1 to 402.5 million year ago.

Like many other petalichthyid fish, Lunaspis are flat and have elongated pectoral spines, shortened thoracic armor, and dorsally oriented eyes.

[4] A typical individual of Lunaspis was a flattened fish with a short trunk and long, curved cornual plates.

The nostrils and the anterior part of the head shield around the orbits is covered by a number of tiny scales, as is the elongated trunk.

Lunaspis were marine bottom dwelling creatures, like many other Devonian placoderm fish, and were nektonic carnivores.

[4] Its body consists of a short trunk shield and elongated cronual plates (the wing-like structures that make up the crescent shape of the moon-like head).

The first specimens of L. broilii were discovered and described through the collaboration of two German palaeontologists, Walter R. Gross and Ferdinand Broili.

The specimen from the Waitahu Outlier was found among a multitude of invertebrate fossils, brachiopods, bivalves, orthocene nautiloids, bryozoans, and isolated crinoid stem ossicles.

[11] "The stratigraphic sequence in the Inangahua and Waitahu Outliers is essentially the same, and includes thick sandstones at the bottom and top of the succession, with an alternation of nearshore limestone and offshore mudstone formations in between.