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Kleithriasphaeridium secatum
Kleithriasphaeridium secatum Schiøler and Wilson, 1998, Plate 6, figs. 1-6
Holotype: Schiøler and Wilson, 1998, Plate 6, Fig. 5
Paratypes: Schiøler and Wilson, 1998, Plate 6, Fig. 3, 4
Repository: The palynological type collection, Institute of Geological and Nuclear Sciences, Lower Hutt, New Zealand.
Type locality: Ben More section, south Marlborough, New Zealand.
Type stratum: Paton Formation at 43.8 m on log P30c6. Teratan (upper Coniacian).
Derivation of name: After its secate process terminations.
Diagnosis: Skolochorate two-layered intratabulate gonyaulacoid cyst with smooth peri- and endophragm. Pericyst bears 24 large hollow processes, one per major paraplate. Processes taper slightly to their narrowest point close to the endophragm, distally they widen gently to form funnel-shaped secate to crenulate terminations. Processes usually fenestrate in their distal half, sometimes also proximally, at contact with endophragm. Paracingulum is indicated by intratabulate processes, parasulcus indicated by a few small hollow processes. Archeopyle is precingular, type P(3), operculum free. Paratabulation: 4', 6'', 6c, ?s, 6''', 1p, 1''''.
Description: Skolochorate two-layered gonyaulacoid cyst. The peri- and endophragm are smooth. The endophragm is thin (thickness: <0.5 µm), the periphragm is relatively thick (thickness: 1-2 µm). On complete specimens 24 large hollow intraplate processes arise from the periphragm. The processes are smooth or very faintly striate. From a relatively narrow base the processes taper to their narrowest diameter one quarter to one third out from the base. They then widen and terminate broadly funnel-shaped to trumpate. The process terminations are irregularly crenulate to secate. In most cases the processes are fenestrate in their upper third, and a few processes may have perforations at their base (Plate 6, Fig. 3). The fenestration is concentrated near the process tip. Most processes appear open, but some, including the antapical process, are closed with a perforate phragm. The paracingulum is indicated by six processes. The parasulcus is indicated by a few small solid and trumpate processes. The archeopyle is precingular, type P(3), the operculum is free. The paratabulation is expressed by intratabular processes; in Kofoid notation the paratabulation is: 4', 6'', 6c, ?s, 6''', 1p, 1''''.
Dimensions (in µm):
holotyperange
Length of cyst body 82 80 (93) 107
Width of cyst body 71 71 (86) 101
Length of processes 22-36 20 (40) 60
Number of specimens measured: 10
Stratigraphic occurrence: 1.1 m (base of section)-43.8 m in the Ben More section, 37.5-78 m in the Kekerengu section. Teratan (middle to upper Coniacian, Upper Cretaceous) in the Paton Formation, south Marlborough, New Zealand.
Remarks: K. secatum sp. nov. differs from all other species of Kleithriasphaeridium by having secate to crenulate process terminations combined with a smooth endo- and periphragm. Most specimens of the new taxon differ further by having fenestrate processes. K. secatum sp. nov. differs from Kleithriasphaeridium loffrense Davey and Verdier, 1976, which also has spiny to secate process terminations, in having broad and widening processes. The processes of Kleithriasphaeridium eoinodes (Eisenack, 1958) Davey, 1974 emend. Sarjeant, 1985 are similar in shape to those of K. secatum sp. nov., but longer, relative to radius of cyst body (longer than radius rather than shorter than radius), and are without fenestrae. Furthermore, K. eoinodes is much smaller (c half size) than the new species. Kleithriasphaeridium corrugatum Davey, 1974 differs in having radial ribs on the central body. Kleithriasphaeridium fasciatum (Davey and Williams, 1966) Davey, 1974 differs in having denticulate process tips and fibrous processes. Kleithriasphaeridium porosospinum Davey, 1982 differs in having perforate and strongly striate processes. Kleithriasphaeridium readei (Davey and Williams, 1966) Davey and Verdier, 1976 emend. Davey and Verdier, 1976 differs in having ribs extending from the processes to the surface of the cyst body. Kleithriasphaeridium truncatum (Benson, 1976) Stover and Evitt, 1978 differs in having broad adcingular processes and a large antapical process and furthermore has a variety of differently shaped process tips. Kleithriasphaeridium sp. of Mohr and Gee (1992b, plate 8, fig. 8) resembles the new species and the two taxa may be conspecific.
Holotype: Schiøler and Wilson, 1998, Plate 6, Fig. 5
Paratypes: Schiøler and Wilson, 1998, Plate 6, Fig. 3, 4
Repository: The palynological type collection, Institute of Geological and Nuclear Sciences, Lower Hutt, New Zealand.
Type locality: Ben More section, south Marlborough, New Zealand.
Type stratum: Paton Formation at 43.8 m on log P30c6. Teratan (upper Coniacian).
Derivation of name: After its secate process terminations.
Diagnosis: Skolochorate two-layered intratabulate gonyaulacoid cyst with smooth peri- and endophragm. Pericyst bears 24 large hollow processes, one per major paraplate. Processes taper slightly to their narrowest point close to the endophragm, distally they widen gently to form funnel-shaped secate to crenulate terminations. Processes usually fenestrate in their distal half, sometimes also proximally, at contact with endophragm. Paracingulum is indicated by intratabulate processes, parasulcus indicated by a few small hollow processes. Archeopyle is precingular, type P(3), operculum free. Paratabulation: 4', 6'', 6c, ?s, 6''', 1p, 1''''.
Description: Skolochorate two-layered gonyaulacoid cyst. The peri- and endophragm are smooth. The endophragm is thin (thickness: <0.5 µm), the periphragm is relatively thick (thickness: 1-2 µm). On complete specimens 24 large hollow intraplate processes arise from the periphragm. The processes are smooth or very faintly striate. From a relatively narrow base the processes taper to their narrowest diameter one quarter to one third out from the base. They then widen and terminate broadly funnel-shaped to trumpate. The process terminations are irregularly crenulate to secate. In most cases the processes are fenestrate in their upper third, and a few processes may have perforations at their base (Plate 6, Fig. 3). The fenestration is concentrated near the process tip. Most processes appear open, but some, including the antapical process, are closed with a perforate phragm. The paracingulum is indicated by six processes. The parasulcus is indicated by a few small solid and trumpate processes. The archeopyle is precingular, type P(3), the operculum is free. The paratabulation is expressed by intratabular processes; in Kofoid notation the paratabulation is: 4', 6'', 6c, ?s, 6''', 1p, 1''''.
Dimensions (in µm):
holotyperange
Length of cyst body 82 80 (93) 107
Width of cyst body 71 71 (86) 101
Length of processes 22-36 20 (40) 60
Number of specimens measured: 10
Stratigraphic occurrence: 1.1 m (base of section)-43.8 m in the Ben More section, 37.5-78 m in the Kekerengu section. Teratan (middle to upper Coniacian, Upper Cretaceous) in the Paton Formation, south Marlborough, New Zealand.
Remarks: K. secatum sp. nov. differs from all other species of Kleithriasphaeridium by having secate to crenulate process terminations combined with a smooth endo- and periphragm. Most specimens of the new taxon differ further by having fenestrate processes. K. secatum sp. nov. differs from Kleithriasphaeridium loffrense Davey and Verdier, 1976, which also has spiny to secate process terminations, in having broad and widening processes. The processes of Kleithriasphaeridium eoinodes (Eisenack, 1958) Davey, 1974 emend. Sarjeant, 1985 are similar in shape to those of K. secatum sp. nov., but longer, relative to radius of cyst body (longer than radius rather than shorter than radius), and are without fenestrae. Furthermore, K. eoinodes is much smaller (c half size) than the new species. Kleithriasphaeridium corrugatum Davey, 1974 differs in having radial ribs on the central body. Kleithriasphaeridium fasciatum (Davey and Williams, 1966) Davey, 1974 differs in having denticulate process tips and fibrous processes. Kleithriasphaeridium porosospinum Davey, 1982 differs in having perforate and strongly striate processes. Kleithriasphaeridium readei (Davey and Williams, 1966) Davey and Verdier, 1976 emend. Davey and Verdier, 1976 differs in having ribs extending from the processes to the surface of the cyst body. Kleithriasphaeridium truncatum (Benson, 1976) Stover and Evitt, 1978 differs in having broad adcingular processes and a large antapical process and furthermore has a variety of differently shaped process tips. Kleithriasphaeridium sp. of Mohr and Gee (1992b, plate 8, fig. 8) resembles the new species and the two taxa may be conspecific.