Eocystites is a poorly-known genus of Middle Cambrian echinoderm tentatively assigned to the Eocrinoidea.[1] The type specides, E. primaevus, known only from isolated plates from the Acadian Group of rocks near St. John, New Brunswick,[2] is the only valid species. Of the other two proposed species, E. longidactylus has subsequently been assigned to Gogia by way of its junior synonym Eocrinus,[3] while E. languidocianus has been assigned to Vizcainoia as its type species.[4]
Additional isolated plates belonging to an indeterminate species of Eocystites have been found from the Middle Cambrian of southern Spain.[5]
While various sources including IRMNG credit Hartt for the genus, others including PBDB correctly credit Elkanah Billings. The confusion likely arises from the line “Eocystites primaevus, Billings, Coll. Hartt”, intended to indicate that Hartt collected the specimens. The text further states that the specimens are “regarded by Mr. Billings, to whom the specimens have been submitted, as indicating a new genus of Cystideans.”[6]
Eocystites has been tentatively assigned to the order Ascocystitida,[7] although previous sources have only even considered it an eocrinoid “for lack of a better place to assign it.”[3]
References
- ^ Ubaghs 1967, pp. S492–S493
- ^ Dawson 1868, p. 641
- ^ a b Sprinkle 1973, p. 83
- ^ Zamora & Smith 2011
- ^ Zamora, Gozalo & Liñán 2009, p. 253
- ^ Dawson 1868, p. 643
- ^ Sepkoski 2002, p. 272
Works cited
- Dawson, John William (1868). Acadian Geology. The geological structure, organic remains and mineral resources of Nova Scotia, New Brunswick and Prince Edward Island (Second Edition, Revised and Enlarged ed.). London: MacMillan and Co.
- Sepkoski, John J., Jr. (16 September 2002). “A Compendium of Fossil Marine Animal Genera”. Bulletins of American Paleontology. 362.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - Sprinkle, James (1973). “Morphology and evolution of blastozoan echinoderms”. Special Publication of the Museum of Comparative Zoology, Harvard University. Retrieved 29 October 2024.
- Ubaghs, Georges (1967). “Eocrinoidea”. In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part S: Echinodermata 1. Vol. 1. University of Kansas Press. pp. S455–S495. Retrieved 29 October 2024.
- Zamora, Samuel; Gozalo, Rodolfo; Liñán, Elado (2009). “Middle Cambrian gogiid echinoderms from Northeast Spain: Taxonomy, palaeoecology, and palaeogeographic implications”. Acta Palaeontologica Polonica. 54 (2): 253–265. doi:10.4202/app.2008.0010.
- Zamora, Samuel; Smith, A. B. (2011). “Cambrian stalked echinoderms show unexpected plasticity of arm construction”. Proceedings of the Royal Society B. 279 (1727): 293–298. doi:10.1098/rspb.2011.0777. PMC 3223674. PMID 21653588.