In 1869, Harry Govier Seeley, based on a fossil found at Haslingfield, Cambridgeshire, named Ptenodactylus nasutus, at the same time disclaiming the name which makes it invalid by modern standards. In 1870, Seeley had realised that the generic name Ptenodactylus had been preoccupied and renamed the species into Ornithocheirus nasutus. The specific name means "with a long nose" in Latin. In 2001 David Unwin made this species a junior subjective synonym of Anhanguera fittoni. However, in 2013 Taissa Rodrigues and Alexander Wilhelm Armin Kellner concluded firstly that Pterodactylus fittoni Owen 1859 was not a part of the genus Anhanguera and secondly that Ornithocheirus nasutus was not identical to it regardless. They decided to name a separate genus for the species: Camposipterus. The generic name combines that of the Brazilian paleontologist Diogenes de Almeida Campos with a Latinised Greek πτερόν, pteron, "wing". The resulting new combination name, the combinatio nova, is Camposipterus nasutus, the type species remains Ornithocheirus nasutus.
The holotype, CAMSM B 54556, had been found in a layer of the Cambridge Greensand dating from the Cenomanian but probably containing reworked fossils from the older Albian. It consists of the front part of a snout.
Rodrigues & Kellner in 2013 moved two more species to the genus. They renamed Pterodactylus sedgwickii Owen 1859 into Camposipterus(?) sedgwickii and Ornithocheirus colorhinus Seeley 1870 into Camposipterus(?) colorhinus. The question marks indicate the uncertainty of the authors about the correctness of the move.
Pterodactylus sedgwickii had in 1859 been named by Richard Owen based on specimen CAMSM B54422, the front part of a snout from the Cambridge Greensand. Its specific name honours Adam Sedgwick. It was in 1869 renamed by Seeley into a Ptenodactylus sedgwickii and in 1870 into a Ornithocheirus sedgwickii. In 1874, Owen again renamed it into Coloborhynchus sedgwickii. Owen in 1859 also referred a front of the lower jaws, specimen CAMSM B54421. However, this piece is not of the same individual as the holotype and there is no proof for any connection with Pterodactylus sedgwickii.
In 1869, Seeley also named a Ptenodactylus colorhinus, in 1870 a Ornithocheirus colorhinus based on the syntypes CAMSM B54431 and CAMSM B54432, both front snouts from the Cambridge Greensand. Its specific name means "with a docked nose" from the Greek κόλος, kolos, "docked", and ῥίς. rhis, "nose". In 2001, Unwin considered this species to be a junior synonym of Anhanguera cuvieri. However, this was not accepted by Rodrigues & Kellner, who, rejecting any identity between the Brazilian and English pterosaur material, named a separate Cimoliopterus cuvieri.
Rodrigues & Kellner treated Camposipterus as a group or clade. No synapomorphies could be established but a unique combination of themselves not unique traits was present. In side view the snout is rounded. The snout bears no crest. The front part of the snout is expanded. The palate curves upwards. The first tooth pair is located in the snout tip.
Each of the species of Camposipterus has its own unique derived traits, autapomorphies, and a unique combination of traits.
Rodrigues & Kellner established two autapomorphies of Camposipterus nasutus. At the front of the jaw edge there is a density of three teeth per three centimetres, at the rear a density of 2.5 teeth. The snout tip is flat, in front view wider than tall. There is a unique combination of traits: the upper profile of the snout is straight or lightly curved; the midline ridge on the palate is extended forwards until the level of the rear margins of the second tooth pair; to the rear the distance between the teeth gradually increases; the senond and third tooth pairs are obliquely pointed sideways; the front of the snout is slightly expanded.
Rodrigues & Kellner established two autapomorphies of Camposipterus(?) sedgwickii. The expanded section of the front snout is suddenly constricted behind the third tooth pair. The tooth sockets of the third tooth pair are much larger than those of the fourth pair. There is a unique combination of traits: the snout is deep; the midline ridge on the palate towards the front reaches a position behind the third tooth pair.
Rodrigues & Kellner established a single autapomorphy of Camposipterus(?) colorhinus: the depression above the first tooth pair is obliquely directed to below. There is a unique combination of traits: the frontal expansion of the snout is well-developed, without a constriction at its end; there is a depression above the first tooth pair; the second and third tooth sockets have a large diameter; the fourth tooth socket is much smaller than the second and third.
Camposipterus(?) colorhinus has a robust snout tip forming a large rosette to catch slippery prey such as fishes, indicating an animal of considerable size. The depression above the first tooth pair is shared with Uktenadactylus wadleighi, but in this form the depression is horizontally oriented. Seeley speculated that it was the attachment area for a lip but pterosaurs had horny beaks.
Rodrigues and Kellner assigned Camposipterus to a new clade Anhangueria, but incertae sedis, thus in an unknown position. Some cladistic analyses published in the naming article suggested a position in the evolutionary tree above Cimoliopterus and below Cearadactylus atrox.