Back
Tanyosphaeridium variecalamus
Tanyosphaeridium variecalamus Davey and Williams, 1966
Holotype: Davey and Williams, 1966b, pl.6, fig.7; text-fig.20; Fauconnier and Masure, 2004, pl.80, figs.1–2.
Locus typicus: Lower Chalk, H.M. Geological Survey Borehole, Fetcham Mill, Surrey, England
Stratum typicum: Cenomanian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Tanyosphaeridium variecalamus from Davey and Williams (1966b, p.98-99), diagnosis, elongate central body with granular surface. Processes, moderate in number, cylindrical, expanding slightly distally and terminating with serrate, aculeate or truncated margin. The processes are oval in cross-section, this can be readily seen at their bases. Distally, the processes may be truncated, terminate with one or two spines or splay out, the margin being serrate. The number of processes normally varies between 20 and 31 but one specimen has 38. There are 6 precingular processes, 6 cingular, 3-6 antapical processes, and 5-7 sulcals. Size: length of central body 30-43 µm, width 14-20 µm, process length 12-24 µm
--------------------------------------------------
Original description: Davey and Williams, 1966, p. 98-99
Diagnosis: Elongate central body with granular surface. Processes, moderate in number, cylindrical, expanding slightly distally and terminating with serrate, aculeate or truncated margin.
Dimensions: Holotype: length of central body 34 µm, breadth 14 µm, length of processes, 12-16 µm, number of processes, 26. Range: length of central body 30-43 µm, breadth, 14-20 µm, length of processes 12-24 µm. Number of specimens measured, 13.
Description Davey and Williams, 1966, p. 99
The central body is composed of thin endophragm surrounded by granular periphragm. The processes are composed of smooth periphragm, and have an oval cross-section, there being characteristic oval areas on the surface of the central body beneath the processes, marking the initial divergence of the periphragm from the endophragm. The processes have fairly broad bases and taper distally before expanding slightly before terminating. Distally the processes may be truncated, terminate with one or two spines or splay out the margin being serrate. The number of processes normally varies between 20 and 31, but one specimen has been observed with as many as 38. An apical archaeopyle is always present, surrounded by 6 precingular processes. Medially there is a definite ring of 6 cingular processes and therefore 9-14 processes on the hypotract. The arrangement of the hypotractal processes is difficult to interpret; however there appears to be either 3 or 6 antapical processes. The number of sulcal processes appears to be 5-7. This species is therefore variable in the number of processes it possesses and is able to have either one or two processes per plate in certain areas.
Holotype: Davey and Williams, 1966b, pl.6, fig.7; text-fig.20; Fauconnier and Masure, 2004, pl.80, figs.1–2.
Locus typicus: Lower Chalk, H.M. Geological Survey Borehole, Fetcham Mill, Surrey, England
Stratum typicum: Cenomanian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Tanyosphaeridium variecalamus from Davey and Williams (1966b, p.98-99), diagnosis, elongate central body with granular surface. Processes, moderate in number, cylindrical, expanding slightly distally and terminating with serrate, aculeate or truncated margin. The processes are oval in cross-section, this can be readily seen at their bases. Distally, the processes may be truncated, terminate with one or two spines or splay out, the margin being serrate. The number of processes normally varies between 20 and 31 but one specimen has 38. There are 6 precingular processes, 6 cingular, 3-6 antapical processes, and 5-7 sulcals. Size: length of central body 30-43 µm, width 14-20 µm, process length 12-24 µm
--------------------------------------------------
Original description: Davey and Williams, 1966, p. 98-99
Diagnosis: Elongate central body with granular surface. Processes, moderate in number, cylindrical, expanding slightly distally and terminating with serrate, aculeate or truncated margin.
Dimensions: Holotype: length of central body 34 µm, breadth 14 µm, length of processes, 12-16 µm, number of processes, 26. Range: length of central body 30-43 µm, breadth, 14-20 µm, length of processes 12-24 µm. Number of specimens measured, 13.
Description Davey and Williams, 1966, p. 99
The central body is composed of thin endophragm surrounded by granular periphragm. The processes are composed of smooth periphragm, and have an oval cross-section, there being characteristic oval areas on the surface of the central body beneath the processes, marking the initial divergence of the periphragm from the endophragm. The processes have fairly broad bases and taper distally before expanding slightly before terminating. Distally the processes may be truncated, terminate with one or two spines or splay out the margin being serrate. The number of processes normally varies between 20 and 31, but one specimen has been observed with as many as 38. An apical archaeopyle is always present, surrounded by 6 precingular processes. Medially there is a definite ring of 6 cingular processes and therefore 9-14 processes on the hypotract. The arrangement of the hypotractal processes is difficult to interpret; however there appears to be either 3 or 6 antapical processes. The number of sulcal processes appears to be 5-7. This species is therefore variable in the number of processes it possesses and is able to have either one or two processes per plate in certain areas.