print this page- Citation:Calcidiscus leptoporus (Murray and Blackman, 1898) Loeblich and Tappan, 1978 [Coccosphaera]
Description: Species of Calcidiscus producing circular to sub-circular coccoliths with, closed central-area.
Remarks: This is something of a default name appied to a wide range of morphotypes but in most assemblages there is clearly a separation between slightly sub-cicular forms with a closed central area (leptoporus) and circular froms with an open central area (tropicus).
Range: NN2 to 21.
Variants:
C. fuscus (Backman, 1980) Janin, 1987 - small , broadly elliptical;
C. pataecus (Gartner, 1967) de Kaenel and Villa, 1996 - small , broadly elliptical.
- Citation:Calcidiscus quadriperforatus (Kamptner 1937) Quinn et al. 2004 [Syracolithus]
Description: Coccoliths large sized, 7-11 µm, with 20-35 elements; distal shield sutures smoothly curved on shield then obscured around crest of tube.
Remarks: Separation of this morphotype from the rest of modern Calcidiscus was initially suggested by Kleijne (1993) on morphological grounds and has been strongly supported by culture observations, life-cycle studies (it produces distinctive holococcoliths) and molecular genetics.
References: Geisen et al. 2002, 2004; Saez et al 2003; Quinn et al. 2004.
Range: Recent - fossil range not determined
