Definition
Campsiceras is an extinct genus of ammonoid cephalopods belonging to the subclass Ammonoidea, known from marine sedimentary rocks of the Late Cretaceous period.
Overview
Fossils of Campsiceras are primarily found in Upper Cretaceous strata of Europe, particularly in France, Spain, and the United Kingdom, as well as in parts of North Africa. The genus is used by paleontologists as an index fossil for correlating Late Cretaceous (approximately Turonian to Coniacian, ~90–85 million years ago) marine deposits. Specimens are typically preserved as external shells, which display a range of ornamental features useful for taxonomic identification.
Etymology/Origin
The name Campsiceras derives from Greek roots: “kampso‑” meaning “bent” or “curved” and “‑ceras” meaning “horn,” a common suffix in ammonite nomenclature referring to the coiled, horn‑like shell. The name was established in the early 20th century when the genus was first described in the scientific literature.
Characteristics
- Shell morphology: The shells are generally involute to moderately evolute, with a fairly compressed whorl section. The outer whorls often exhibit pronounced ribbing and occasional tubercles or nodes along the flank.
- Ventral features: A distinct, sometimes keeled, ventral margin is characteristic, aiding in hydrodynamic stability for the living animal.
- Suture pattern: As with other ammonites, the sutures are complex and highly frilled, featuring lobes and saddles typical of the Ammonitida.
- Size: Adult shells range from a few centimeters up to approximately 15 cm in diameter, though size can vary among species.
- Ecology: Like other ammonites, Campsiceras was a nektonic marine predator, likely feeding on small planktonic and nektonic organisms.
Related Topics
- Ammonoidea – the broader subclass encompassing all ammonites.
- Acanthoceratidae – the family to which many Late Cretaceous ammonites, including Campsiceras, are assigned.
- Biostratigraphy – the use of fossil taxa such as Campsiceras to date and correlate sedimentary rock layers.
- Late Cretaceous marine environments – the paleoecological context in which Campsiceras lived.
Note: While the general temporal range and morphological attributes of Campsiceras are well established, precise species-level classifications and detailed phylogenetic relationships remain subjects of ongoing research.