Back
Fibrocysta variabilis
Fibrocysta variabilis Mehrota and Sarjeant, 1987, p. 155-156
Taxonomic senior synonym: Wetzeliella (now Apectodinium) paniculatum, according to Garg et al. (1995, p.364) — however, Mehrotra and Singh (2003, p.40–41) retained this species.
Holotype: Mehrotra and Sarjeant, 1987, pl.4, fig.2; Mehrotra and Singh, 2003, pl.15, fig.1.
Paratypes: Mehrota and Sarjeant, 1987
Locus typicus: Narasapur well- 1, Godavari-Krishna basin, Andhra- Pradesh, India
Stratum typicum: Maastrichtian-Palaeocene
Original description: Mehrota and Sarjeant, 1987, p.155
Cyst proximochorate, skolochorate, acavate and cingulotabulate. Ambitus pentagonal to roundedpentagonal. Phragma thin, smooth, sometimes with finely punctate or finely granulate ornamentation. Processes numerous, apparently non-tabular, solid and generally fibrous, but varying markedly in character on each single specimen. The apical and antapical processes are usually most prominent. Each arises from a slight to prominent protuberance; one or both may be branched. Distinctive processes may be present along the line of the cingulum and may be especially prominent in lateral situation; these may be long and acuminate, particularly broad or branched distally. In specimens seen in dorso-ventral view, two lateral processes, each on the anterior side of the cingulum, may be particularly prominent. Elsewhere on the cyst, the processes are slender with expanded distal ends--bifid, trifid, cruciferate, cauliflorate, denticulate, serrate, recurved or secate. The nature of the distal terminations varies greatly, even on single specimens. In branched processes, each major branch has a bifid, trifid, cruciferate or cauliflorate distal extremity. Proximally, the processes are expanded and often exhibit basal connexions.
The cingulum is almost equatorial in situation. Not only is it marked by a marginal line of distinctly longer processes but also typically by low ridges and by lateral inflexures of the phragma. The sulcus is not clearly marked.
Archaeopyle precingular (type P), formed by loss of paraplate 3"". Though no parasutural features are developed, rarely an arrangement of a few processes in groups may suggest an intratabular situation; however, no pattern of paratabulation is apparent.
Dimensions: Holotype: length of central body 63 Ám, breadth 70 Ám, process length between 15 and 35 Ám. Paratype A: length of central body 61 Ám, breadth 50 Ám, process length between 16 and 24 Ám. Paratype B: length of central body 67 Ám, breadth 54 Ám, process length between 18 and 26 Ám.
Range: length of central body 52-75 Ám, breadth 50-70 Ám, process length between 12 and 35 Ám (average 18-22 Ám). Ten specimens measured.
Taxonomic senior synonym: Wetzeliella (now Apectodinium) paniculatum, according to Garg et al. (1995, p.364) — however, Mehrotra and Singh (2003, p.40–41) retained this species.
Holotype: Mehrotra and Sarjeant, 1987, pl.4, fig.2; Mehrotra and Singh, 2003, pl.15, fig.1.
Paratypes: Mehrota and Sarjeant, 1987
Locus typicus: Narasapur well- 1, Godavari-Krishna basin, Andhra- Pradesh, India
Stratum typicum: Maastrichtian-Palaeocene
Original description: Mehrota and Sarjeant, 1987, p.155
Cyst proximochorate, skolochorate, acavate and cingulotabulate. Ambitus pentagonal to roundedpentagonal. Phragma thin, smooth, sometimes with finely punctate or finely granulate ornamentation. Processes numerous, apparently non-tabular, solid and generally fibrous, but varying markedly in character on each single specimen. The apical and antapical processes are usually most prominent. Each arises from a slight to prominent protuberance; one or both may be branched. Distinctive processes may be present along the line of the cingulum and may be especially prominent in lateral situation; these may be long and acuminate, particularly broad or branched distally. In specimens seen in dorso-ventral view, two lateral processes, each on the anterior side of the cingulum, may be particularly prominent. Elsewhere on the cyst, the processes are slender with expanded distal ends--bifid, trifid, cruciferate, cauliflorate, denticulate, serrate, recurved or secate. The nature of the distal terminations varies greatly, even on single specimens. In branched processes, each major branch has a bifid, trifid, cruciferate or cauliflorate distal extremity. Proximally, the processes are expanded and often exhibit basal connexions.
The cingulum is almost equatorial in situation. Not only is it marked by a marginal line of distinctly longer processes but also typically by low ridges and by lateral inflexures of the phragma. The sulcus is not clearly marked.
Archaeopyle precingular (type P), formed by loss of paraplate 3"". Though no parasutural features are developed, rarely an arrangement of a few processes in groups may suggest an intratabular situation; however, no pattern of paratabulation is apparent.
Dimensions: Holotype: length of central body 63 Ám, breadth 70 Ám, process length between 15 and 35 Ám. Paratype A: length of central body 61 Ám, breadth 50 Ám, process length between 16 and 24 Ám. Paratype B: length of central body 67 Ám, breadth 54 Ám, process length between 18 and 26 Ám.
Range: length of central body 52-75 Ám, breadth 50-70 Ám, process length between 12 and 35 Ám (average 18-22 Ám). Ten specimens measured.