Nannotax3 - Coccolithophores

Citation: Calciosolenia Gran, 1912

Type species: Calciosolenia murrayi Gran 1912

Synonyms:

Acanthosolenia Bernard 1939
Anoplosolenia Deflandre 1952
Scapholithus Deflandre 1954

NB The monomorphic species C. brasiliensis has often been placed in a separate genus, Anoplosolenia, leaving the dimorphic species C. murrayi in Calciosolenia. Following Young et al. (2003) we prefer to include both species in a single genus, since the coccolith structure of the two species is identical and their affinity is not in dispute. Including the two species in one genus makes this affinity clearer, reduces the number of monospecific genera, and avoids the problem of having generic concepts which cannot be applied to isolated coccoliths in the fossil record. As a result, the artificial genus Scapholithus, which has often been used by palaeontologists for isolated scapholiths, is redundant, all such specimens can be included in Calciosolenia.
Since fossil specimens cannot usually be confidently assigned to either C. murrayi or C. brasiliensis the best identification is usually Calciosolenia sp.

Distinguishing features: Coccosphere with rhombic muroliths with central area floored by transverse laths (scapholiths); varimorphic or dimorphic.

Morphology remarks: Coccolith structure and optics discussed in Bown et al. 2017

Size: Coccolith size typically small (2-5 µm) exceptionally up to 7 µm. Some size variation depending on postion on coccosphere but within species size of the main body coccolithsseemsto be a useful taxonomic criterion (see Malinverno 2004).

Geological Range:
Last occurrence (top): Extant Data source: Total of range of species in this database
First occurrence (base): at base of Danian Stage (0% up, 66Ma, in Danian stage). Data source: Total of range of species in this database

References:

Bernard, F. (1939). Coccolithophorides nouveaux ou peu connus observes à Monaco en 1938. Archives de Zoologie Expérimentale et Générale, Paris. 81: 33-44. gs :: ::

Bown, P. R., Lees, J. A. & Young, J. R. (2017). On the Cretaceous origin of the Order Syracosphaerales and the genus Syracosphaera. Journal of Micropalaeontology. 36(2): 153-165. gs :: view :: open

Deflandre, G. & Fert, C. (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie. 40: 115-176. gs :: ::

Deflandre, G. (1952). Classe des Coccolithophoridés. (Coccolithophoridae. Lohmann, 1902). In, Grassé, P. P. (ed.) Traité de Zoologie. Masson, Paris 439-470. gs :: ::

Gran, H. H. (1912). Pelagic plant life. In, Murray, J. & Hjort, J. (eds) The Depths of the Ocean. Macmillan, London 307-386. gs :: ::

Malinverno, E. (2004). Morphological variability within the genus Calciosolenia (coccolithophorids) from the eastern Mediterranean Sea. Micropaleontology. 50(supl. 1): 81-91. gs :: ::

Young, J. R., Geisen, M., Cros, L., Kleijne, A., Probert, I. & Ostergaard, J. B. (2003). A guide to extant coccolithophore taxonomy. Journal of Nannoplankton Research, Special Issue. 1: 1-132. gs :: view :: open

Daughter taxa: (blue => in age window 0-800Ma)
				Calciosolenia alternans Small Calciosolenia with a relatively broad central-area filled by a plate-like structure that displays a four-fold, alternating light-dark birefringence image.
				Calciosolenia aperta Broad, rhomboidal scapholith with broad flaring rim and central area spanned by transverse bars and thick, distal longitudinal bar.
				Calciosolenia brasiliensis Coccosphere without spines, coccoliths >5µm long
				Calciosolenia corsellii Coccosphere without spines, coccoliths 3-4µm long, with spurs at the ends
				Calciosolenia murrayi Dimorphic - terminal liths have one end extended into spine
				Calciosolenia sp. Calciosolenia specimens which cannot be assigned to established species

Tags	LITHS: murolith, tubular, quadrate, CA: grill, R-UNITS: R-prominent, DETAILS: ca_disjunct, rim-bicyclic,
Metrics	Lith size: 2->7µm; Coccosphere size: 20->95µm; Sources:

Calciosolenia

References:

Comments (0)

Add Comment