Camptostroma
Extinct genus of marine invertebrates
From Wikipedia, the free encyclopedia
Camptostroma is an extinct genus of echinoderm. Camptostroma roddyi from the Bonnia-Olenellus Zone of the Early Cambrian Kinzers Formation near York and Lancaster, Southeastern Pennsylvania,[3] is the only known species in the genus Camptostroma, as other species referred to this genus "do not appear to be cogeneric."[4]
| Camptostroma Temporal range: | |
|---|---|
| |
| Artist's reconstruction[1] | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | †Edrioasteroidea (?) |
| Order: | †Camptostromatoida |
| Family: | †Camptostromatidae |
| Genus: | †Camptostroma Ruedemann 1933 |
| Type species | |
| †Camptostroma roddyi Ruedemann 1933[2] | |
Anatomy
In life, Camptostroma would have resembled a cupcake, with the mouth in the center of the upper surface, with ambulacra radiating from it in the 2-1-2 pattern common in early echinoderms. The ambulacra are straight in juveniles, but in larger adult specimens, ambulacra A, B, C, and E curve clockwise while ambulacrum D curves counter-clockwise. The anus is near the periphery between ambulacra C and D.[5]
The ambulacra may have extended beyond the upper surface on stubby arms. While this diagnosis is tentative, ongoing work appears to support it.[6]
Classification and relationships
While initially considered to be a scyphozoan due to the fossil's medusoid shape, later investigation detected the presence of stereom plates with the calcitic cleavage pattern diagnostic of echinoderms.[3]
The Treatise on Invertebrate Paleontology accepted Durham's 1966 assignment of Camptostroma to its own class, Camptostromatoidea.[7] However, a later classification based on that of the Treatise omitted this class.[8]
Camptostroma has since been placed in a class of basal echinoderms, the Edrioasteroids,[9] although some recent authors only describe it as "edrioasteroid-like".[6]
Recent research has found weak support for the recovery of Camptostroma as the sister group of the crinoids.[10][11] However, other phylogenies are ambiguous regarding whether it is closer to the crinoids, eocrinoids, or eleutherozoans.[12]
