Sweep-feeding food strategies involve specialized appendages with blades that could be used by the animals to rake through the substrate of their living environments in search for small prey items.

The sole known fossil remains of C. permianus, a massive incomplete carapace, suggests a very large eurypterid, potentially reaching lengths of 1.4 metres (4.6 feet).

Citing similarities with members of the modern genus in the appearance and anatomy of the somewhat incomplete fossil, Kutorga named it Limulus oculatus.

[6] Scottish naturalist John Scouler described the genus Eidothea in 1831 based on a single fossil prosoma from Scotland, but did not grant it any specific name.

[5] Fossils of Eurypterus scouleri were compared to the carapace described by Kutorga in 1838 by Norwegian paleontologist Leif Størmer in 1951, who concluded that the two were clearly congeneric.

[9] English paleontologist Charles D. Waterston was the first to suggest that C. scouleri perhaps shouldn't be considered as congeneric with Campylocephalus, raising the issue in a 1958 paper.

Though Ponomarenko had mentioned several features that also distinguished C. permianus from the then currently recognized species of Campylocephalus, including a different carapace shape and some thickening of the exoskeleton around the eyes, Lamsdell determined that these distinctions were not valid.

In the view of Lamsdell, specimens of the type species C. oculatus are not well preserved enough to determine the precise structure of the eyes and because fossils of its carapace are either flattened or incomplete, its shape can not be ascertained with complete accuracy.

[5] The hibbertopterids are united as a group by being large mycteropoids with broad prosomas, a hastate (e.g. shaped like a gladius, a Roman sword) telson (which was the posteriormost division of the body) with paired keels on the ventral side, ornamentation consisting of scales or other similar structures on the exoskeleton, the fourth pair of appendages possessing spines, the more posterior tergites of the abdomen possessing tongue-shaped scales near their edges and there being lobes positioned posterolaterally (posteriorly on both sides) on the prosoma.

The cladogram below is adapted from Lamsdell (2012),[1] collapsed to only show the superfamily Mycteropoidea.Drepanopterus pentlandicus Drepanopterus abonensis Drepanopterus odontospathus Woodwardopterus scabrosus Mycterops mathieui Hastimima whitei Megarachne servinei Campylocephalus oculatus Hibbertopterus scouleri Hibbertopterus wittebergensis Hibbertopterids such as Campylocephalus were sweep-feeders, having modified spines on their forward-facing prosomal appendages that allowed them to rake through the substrate of their living environments.

Some species of the closely related Hibbertopterus had specialized comb-like rachis (shafts) that were able to entrap small prey and other organic food particles.

[11] Though they would have been slow owing to their massive size and robust form, studies on Hibbertopterus footprints discovered in Scotland have demonstrated that hibbertopterids would have been able to walk on land for at least short periods of time.

The tracks discovered indicate that they would have utilized a lumbering, jerking and dragging movement and that the keeled belly and the telson left a central groove behind.

[13] C. salmi is known from the Ostrava Formation of the Czech Republic and would have lived during the Arnsbergian age (326.4–318.1 million years ago) of the Carboniferous period.

[15] It is difficult to make any statements on the paleoecology of the type species, C. oculatus, as the precise location and dating of the fossil specimen remains somewhat unclear.

Most accounts place the fossil as having been found at a location named Dourasovo in Russia[10][13] and being from the Guadalupian epoch (272.3–259.8 million years ago) of the Permian period.