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Hystrichodinium lanceatum
Hystrichodinium? lanceatum Davies, 1983
Davies, 1983, questionably included this species in Hystrichodinium.
Holotype: Davies, 1983, pl.7, figs.1-2, text-fig.18B
Locus typicus: Amund Ringnes Island, District of Franklin, Northwest Territories, Canada
Stratum typicum: Late callovian-Tithonian
Original diagnosis: Davies, 1983, p.22
An ellipsoid, spiniferate dinoflagellate cyst with a short teat-like apical horn and one or occasionally two antapical horns. Long ribbon-like processes arise from low sutural crests, tapering to sharp, lance-like terminations. rarely bifurcate. Surface
granulate. Tabulation: ?4", 6", 6""", ?0p, 1"""". Archeopyle: (AP(3)).
Size: length 32(49)59 Ám; breadth 25(36)43 Ám.
Original description: Davies, 1983, p.22-23
The number of processes is variable. The processes (up to 24 Ám long) are concentrated around the cingulum and the antapex, often developed over the antapical horn(s) as extensions to it. The periphragm is granulate to finely pitted giving a spongy appearance; the endophragm is thick and smooth. Processes arise from the periphragm and some may be penitabular on the operculum (Plate 7. fig. 9-11 ). A precise apical tabulation could not be determined due to the folding of the processes and the spongy surface, however, isolated apical opercula indicate that four plates are involved. Poorly preserved specimens often have some of the periphragm and processes removed.
Davies, 1983, p. 23: ?Hystrichodinium lanceatum is tentatively placed in the genus Hystrichodinium because the apical series is removed along with the 3" plate in archeopyle formation. Hystrichodinium voigtii (Alberti, 1961 ) Davey, 1974 is similar but differs by its well developed apical horn, low crests bordering the cingulum and processes arising from the apical horn position. Hystrichodinium patriciae (Neale and Sarjeant, 1962) Lentin and Williams, 1975 differs by its ovoidal endoblast and longer, more numerous processes.
Davies, 1983, questionably included this species in Hystrichodinium.
Holotype: Davies, 1983, pl.7, figs.1-2, text-fig.18B
Locus typicus: Amund Ringnes Island, District of Franklin, Northwest Territories, Canada
Stratum typicum: Late callovian-Tithonian
Original diagnosis: Davies, 1983, p.22
An ellipsoid, spiniferate dinoflagellate cyst with a short teat-like apical horn and one or occasionally two antapical horns. Long ribbon-like processes arise from low sutural crests, tapering to sharp, lance-like terminations. rarely bifurcate. Surface
granulate. Tabulation: ?4", 6", 6""", ?0p, 1"""". Archeopyle: (AP(3)).
Size: length 32(49)59 Ám; breadth 25(36)43 Ám.
Original description: Davies, 1983, p.22-23
The number of processes is variable. The processes (up to 24 Ám long) are concentrated around the cingulum and the antapex, often developed over the antapical horn(s) as extensions to it. The periphragm is granulate to finely pitted giving a spongy appearance; the endophragm is thick and smooth. Processes arise from the periphragm and some may be penitabular on the operculum (Plate 7. fig. 9-11 ). A precise apical tabulation could not be determined due to the folding of the processes and the spongy surface, however, isolated apical opercula indicate that four plates are involved. Poorly preserved specimens often have some of the periphragm and processes removed.
Davies, 1983, p. 23: ?Hystrichodinium lanceatum is tentatively placed in the genus Hystrichodinium because the apical series is removed along with the 3" plate in archeopyle formation. Hystrichodinium voigtii (Alberti, 1961 ) Davey, 1974 is similar but differs by its well developed apical horn, low crests bordering the cingulum and processes arising from the apical horn position. Hystrichodinium patriciae (Neale and Sarjeant, 1962) Lentin and Williams, 1975 differs by its ovoidal endoblast and longer, more numerous processes.