Taxonomy:
Taxa described by Varol & Houghton (1996) for Ascidian spicules
Fossil taxa which are probably based on ascidian spicules include the following [all based on my interpretation unless otherwise noted JRY]
Durand (1948) first recognised fossil ascidian spicules and following this Deflandre & Delfandre-Rigaud (1956) proposed the new genus and species Micrascidites vulgaris for them. This name has often been used. Buge & Monniot (1972) provide further documentartion of French Eocen specimens
Varol & Girgis (1994) discussed ascidian spciules, suggested several Mesozoic nannoofssil were likely to be Ascidian spicules and assigned them to the genus Didemnum, which isthe most common extant genus of Ascidians.. Varol & Houghton (1996) provide a useful overview for nannofossil specialists and also propose Linnean names for various different morphotypes. Varol (2006) developed this approach further, proposing names for many different Mesozoic morphotypes.
Lukowiak (2012) and Lukowiak et al. (2016) record fossil specimens from the Eocene of Australia and Miocene of Moldova respectively and assign spicules to ascidian taxa as far as possible, in prefernce to using the parataxonomy of Varol & Houghton (1996). They also give modern references.
Distinguishing features:
Parent taxon (other groups): Other nannoplankton and microplankton groups
This taxon: Typically spherically-radiate calcite bodies, formed of largish tapering, radiate elements with radial c-axes. Larger and less regularly-shaped than typical nannofossils.
Farinacci & Howe catalog pages: Angulolithina * , Angulolithina arca * , Discoaster athanasiui * , Discoaster irregularis * , Discoaster mrazeci * , Discoaster multinucleatus * , Discoaster olteniae * , Discoaster pentaradiatus communis * , Discoaster pentaradiatus flosculoides * , Discoaster sabbae * , Discoaster slatiorensis * , Gongylis * , Gongylis salzwedelensia * , Heliodiscoaster cayeuxi * , Heliodiscoaster cernaensis * , Heliodiscoaster concentricus * , Heliodiscoaster deflandrei * , Heliodiscoaster irregularis * , Heliodiscoaster rumanus * , Hemidiscoaster triradiatus aquitanicus * , Micrascidites [no catalog entry yet], Micrascidites vulgaris [no catalog entry yet], Perforocalcinella * , Perforocalcinella fusiformis * , Perforocalcinella petali * , Tansinius * , Tansinius angularis * , Tansinius irregularis * , Tansinius olteniae * , Tansinius rectangularis * , Tansinius stefanescui *
Search data:
Lith size: 0->0µm; |
Geological Range:
Last occurrence (top): at top of (100% up, 0Ma, in "Holocene" stage). Data source: Total of ranges of the species in this database
First occurrence (base): within (-Ma, base in "Holocene" stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Bona, J. (1964). Coccolithophorida-vizsgalatok a meceski retegekben (Coccolithopohriden-Unntersuchungen in der neogen Schichtenfolge des Meeskggerbirges). Földtani Közlöny - Bulletin of the Hungarian Geological Society. 94: 121-131. gs Bonet, F. & Benveniste-Velasquez, N. (1971). Espiculas de asicidias fosiles y actuales. Revista del Instituto Mexicano del Petroleo. 3(4): 8-35. gs Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gs O Bown, P. R. (2010). Calcareous nannofossils from the Paleocene/Eocene Thermal Maximum interval of southern Tanzania (TDP Site 14). Journal of Nannoplankton Research. 31(1): 11-38. gs O Deflandre, G. & Deflandre-Rigaud, M. (1956). Micrascidites manip. nov., sclerites de Didemnides (Ascidies, Tuniciers) fossiles due Lutétian du Bassin Parisien et du Balcombien d'Australia. Compte Rendu Sommaire des Séances de la Société Géologique de France. 1956: 47-48. gs O Durand, S. (1948). Ascidians. Comptes rendus de l'Académie des sciences, Paris. 227: 683-684. gs Filipescu, M. & Hanganu, E. (1960). Sur les Discoastérides du Tertiare du N-O de l'Olténie. Revue Roumaine de Géologie Géophysique et Géographie. 4(2): 217-232. gs Hoffmann, N. (1970e). Taxonomische Untersuchungen an Coccolithen aus der Kreide Norddeutchlands anhand elektronenmikroskopischer Aufnamen. Hercynia. 7(1-3): 163-198. gs Lukowiak, M. (2012). First record of Late Eocene Ascidians (Ascidiacea, Tunicata) from Southeastern Australia . Journal of Paleontology. 86(3): 521-526. gs Lukowiak, M., Dumitriu, S. & Ionesi, V. (2016). First fossil record of early Sarmatian didemnid ascidian spicules (Tunicata) from Moldova. Geobios. 49: 201-209. gs Menini, A., Mattioli, E., Spangenberg, J. E., Pittet, B. & Suan, G. (2018). New calcareous nannofossil and carbon isotope data for the Pliensbachian/Toarcian boundary (Early Jurassic) in the western Tethys and their paleoenvironmental implications. Newsletters on Stratigraphy. -. gs Perch-Nielsen, K. (1988). New Lower Cretaceous calcareous nannofossil species from England. INA Newsletter. 10(1): 30-37. gs Varol, O. & Girgis, M. (1994). New taxa and taxonomy of some Jurassic to Cretaceous calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 192: 221-253. gs Varol, O. & Houghton, S. D. (1996). A review and classification of fossil didemnid ascidian spicules. Journal of Micropalaeontology. 15: 135-149. gs Varol, O. (2006). Didemnid ascidian spicules from the Arabian Peninsula. Journal of Nannoplankton Research. 28(1): 35-56. gs O Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 225-265. gs Missing or ambiguous references: Savigny 1816; References:
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Ascidian spicules compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-7-2025
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Comments (3)
If any of you want a pdf of this paper, please, do not hesitate to write to me. Cheers!