Camptostroma
Extinct genus of marine invertebrates From Wikipedia, the free encyclopedia
Camptostroma roddyi is an extinct echinoderm from the Bonnia-Olenellus Zone of the Early Cambrian Kinzers Formation near York and Lancaster, Southeastern Pennsylvania.[2] It is the only known species in the genus Camptostroma, as other species referred to this genus "do not appear to be cogeneric."[3]
| Camptostroma Temporal range: Early Cambrian | |
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| Artist's reconstruction | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Genus: | †Camptostroma |
| Species: | †C. roddyi |
| Binomial name | |
| Camptostroma roddyi Ruedemann 1933[1] | |
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.[4]
The ambulacra may have extended beyond the upper surface on stubby arms. While this diagnosis is tentative, ongoing work appears to support it.[5]
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.[2]
The Treatise on Invertebrate Paleontology accepted Durham's 1966 assignment of Camptostroma to its own class, Camptostromatoidea.[6] However, a later revision of the Treatise's classification omitted this class.[7]
Camptostroma has since been placed in a class of basal echinoderms, the Edrioasteroids,[8] although some recent authors only describe it as "edrioasteroid-like".[5]
Recent research has found weak support for the recovery of Camptostroma as the sister group of the crinoids.[9][10] However, other phylogenies are ambiguous regarding whether it is closer to the crinoids, eocrinoids, or eleutherozoans.[11]
References
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