Camptostroma

Not to be confused with Camptostoma.

Camptostroma Temporal range: Cambrian Stage 4 PreꞒ Ꞓ O S D C P T J K Pg N
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]

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]

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

Camptostroma roddyi fossil on display at the Smithsonian's National Museum of Natural History.

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 revision of the Treatise's classification 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]

References

1. Rahman & Zamora 2024
2. "Camptostroma roddyi". The Paleontology Database. Retrieved November 3, 2024.
3. Durham 1966
4. Durham 1967 , p. S629
5. Paul & Smith 1984 , pp. 450–452
6. Guensburg, Mooi & Mongiardino Koch 2023 , p. 1097
7. Durham 1967
8. Sprinkle 1980 , p. 26
9. Zamora et al. 2017 , p. 484
10. Guensburg et al. 2020 , p. 332
11. Guensburg, Mooi & Mongiardino Koch 2023 , pp. 1104–1106
12. Rahman & Zamora 2024 , pp. 310–311

Works cited

• Durham, J. W. (1 September 1966). "Camptostroma, an Early Cambrian Supposed Scyphozoan, Referable to Echinodermata". Journal of Paleontology. 40 (5): 1009–1255. ISSN   0022-3360. JSTOR   1301996.
• Durham, J. Wyatt (1967). "Addendum: Camptostromatoids". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part S: Echinodermata 1. Vol. 1. University of Kansas Press. pp. S627–S631. Retrieved 29 October 2024.
• Guensburg, Thomas E.; Mooi, Rich; Mongiardino Koch, Nicolás (2023). "Crinoid calyx origin from stem radial echinoderms". Journal of Paleontology. 97 (5): 1092–1115. doi: 10.1017/jpa.2023.14 .
• Guensburg, Thomas E.; Sprinkle, James; Mooi, Rich; Lefebvre, Bertrand; David, Bruno; Roux, Michael; Derstler, Kraig (2020). "Athenacrinus n. gen. and other early echinoderm taxa inform crinoid origin and arm evolution". Journal of Paleontology. 94 (2): 311–333. doi:10.1017/jpa.2019.87.
• Paul, C. R. C.; Smith, A. B. (November 1984). "The early radiation and phylogeny of echinoderms". Biological Reviews. 59 (4): 443–481. doi:10.1111/j.1469-185X.1984.tb00411.x.
• Rahman, Imran A.; Zamora, Samuel (July 2024). "Origin and early evolution of echinoderms". Annual Review of Earth and Planetary Sciences. 52: 295–320. doi:10.1146/annurev-earth-031621-113343. hdl: 10141/623070 .
• Sprinkle, J. (1980). "An Overview of the Fossil Record". Notes for a Short Course: Studies in Geology. 3: 15–26. doi:10.1017/S0271164800000063.
• Zamora, Samuel; Deline, Bradley; Álvaro, J. Javier; Rahman, Imran A. (2017). "The Cambrian Substrate Revolution and the early evolution of attachment in suspension-feeding echinoderms". Earth-Science Reviews. 171: 478–491. doi:10.1016/j.earscirev.2017.06.018.