ALGIROSPHAERA TAXONOMY
Annelies Kleijne(1), Joerg Bollmann(2), Vita Pariente(3),Ian Probert (4), Jeremy Young(5)
1 Faculty of Earth Sciences, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
2 Geologisches Institut, ETH-Zentrum, 8092 Zürich, Switzerland
3 Texas A&M, College station, Texas, USA
4 Laboratoire de Biologie et Biotechnologies Marines, Universite de Caen Basse Normandie, Caen, France
5 Palaeontology Department, The Natural History Museum, Cromwell Road, London
Algirosphaera robusta has recently been maintained in culture (Probert et al. in prep.) and TEM study of it has revealed has much new information on the structure of this species.and indicates that it has many unique features. This has in turn prompted a review of possibly related rhabdosphaeraceae, and of diversity in Algirosphaera. From this we recognise the following 5 species, two of which are new.
Algirosphaera robusta (Lohmann, 1902) Norris, 1984 [Syracosphaera]
Prominent flagellar opening surrounded by 3 polar coccoliths with higher & wider protrusion. Synonyms A. oryza Schlauder, 1945, A. quadricornu (Schiller) Norris, 1984 [Syracosphaera], A. aurea (Bernard & Lecal 1960) [Anthosphaera], Anthosphaera bicornu Schlauder 1945, and others, see Kleijne (1992). Mostly distinguished on nature of circum-flagellar coccoliths and shape of body coccoliths.
Algirosphaera meteora (Muller 1972) Norris 1984 [Anthosphaera]
Broadly elliptical form with constriction around base of the spine, also baseplate lacks central irregular cycle. N.B. Forms assignable to this species are illustrated by Mara Corttes and Jorg Bollmann on EMIDAS (as Cyrtosphaera cucullata.) and I have another from Vita Pariente.
Algirosphaera cucullata (Lecal-Schlauder 1951) n. comb [Acanthoica]
Domal protrusion, "bowler hat" shaped. Like Algirosphaera robusta but vari-monomorphic (no polar coccoliths) and less elongate. Placed in Cyrtosphaera by Kleijne 1992 on the basis of varimorphism but the coccolith structure is arguably closer to A. robusta than to C. aculeata. ...?Possibly an unusual form of A. meteora but seems to show different ultrastructure in the SEMs of Kleijne 1993 and lacks constriction.
Algirosphaera sp. 1 "emidasiensis"
Small form; dimorphic. (a) Equatorial coccoliths with sub-rectangular protrusions and quadrate base. (b) weakly calcified (?) elliptical body coccoliths without protrusions. Observed by Bollmann in Canaries (?), illustrated on EMIDAS.
Algirosphaera sp. 2 "pteriformis"
Small form; dimorphic. (a) Equatorial coccoliths with elongate triangular-shaped protrusions and quadrate bases. (b) weakly calcified (?) elliptical body coccoliths without protrusions. Observed by Vita Pariente in the Gulf of Mexico.
Small Algirosphaera from Gulf of Mexico (sample from VP)
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