Back
Amphorulacysta delicata
Amphorulacysta delicata, (van Helden, 1986, p.188, pl. 4, figs.4–7), Williams and Fensome 2016, p.139.
This combination was not validly published in Chen (2013, p.295), since that author did not fully reference the basionym.
Holotype: van Helden, 1986, pl.4, fig.4.
Locus typicus: Jeanne d'Arc sub-basin
Stratum typicum: Amphorula metaelliptica assemblage zone (Portlandian to early Berriasian)
Age: Portlandian–early Berriasian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [van Helden 1986, p. 188]:
Diagnosis:
Proximochorate cyst, body subspherical; paratabulation gonyaulacacean, indicated by high penitabular septa, united distally by ring-trabeculae, and incomplete septa along the paracingulum; the latter possessing small rectilinear septa.
Archeopyle apical, type (A). Individual septa formed by a delicate complex of processes often interconnected and distally joined, forming a slightly flaring septum, open towards the paracingular area..
Description:
Shape: subspherical to slightly elongate cyst body; length of septa uniform, approximately one quarter of body diameter.
Wall structure: thin-walled, acavate proximochorate cyst.
Wall features: no parasutural features; high, straight, penitabular septa, incomplete and open towards paracingulum, distally slightly flaring and joined by trabeculae; length of septa approximately 10 µm; paracingular septa small, rectilinear.
Archeopyle: apical, type (A); operculum free.
Paratabulation: indicated by the position of the penitabular and rectilinear septa only.
Paracingulum: difficult to discern; S.E.M. photograph shows small, rectilinear septa in the paracingular area (Plate 4, fig. 6).
Dimensions:
intermediate; length of overall cyst 56 µm to 85 µm (holotype 73 µm); width of overall cyst 55 µm to 74 µm (holotype 69 µm); five specimens measured.
Remarks:
Amphorula delicata sp. nov. differs from Amphorula metaelliptica in having a complex of delicate, often interconnecting processes which form the septa. In A. metaelliptica the septa are distinctly perforated and fan-shaped. Age and occurrence. Amphorula delicata sp. nov. occurs in the Jeanne d'Arc subbasin in the Amphorula metaelliptica assemblage zone (rare to common), dated as Portlandian to early Berriasian, where its range is concurrent with that of Amphorula metaelliptica. Amphorula delicata sp. nov. has been recorded in the following wells: Mobil et al. Ben Nevis I-45, and Mobil et al. Hebron I-13.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Amphorula delicata van Helden, 1986 has a tabulation indicated by high penitabular septa, united distally by ring-trabeculae, and incomplete septa along the cingulum; the latter possessing small rectilinear septa. Individual septa formed by a delicate complex of processes often interconnected and distally joined, forming a slightly flaring septum, open towards the cingular area. Amphorula delicata differs from Amphorula metaelliptica in having a complex of delicate, often interconnecting processes which form the septa. In A. metaelliptica the septa are distinctly perforated and fan-shaped.
Size: overall length 56-85 µm, width 55-74 µm.
This combination was not validly published in Chen (2013, p.295), since that author did not fully reference the basionym.
Holotype: van Helden, 1986, pl.4, fig.4.
Locus typicus: Jeanne d'Arc sub-basin
Stratum typicum: Amphorula metaelliptica assemblage zone (Portlandian to early Berriasian)
Age: Portlandian–early Berriasian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [van Helden 1986, p. 188]:
Diagnosis:
Proximochorate cyst, body subspherical; paratabulation gonyaulacacean, indicated by high penitabular septa, united distally by ring-trabeculae, and incomplete septa along the paracingulum; the latter possessing small rectilinear septa.
Archeopyle apical, type (A). Individual septa formed by a delicate complex of processes often interconnected and distally joined, forming a slightly flaring septum, open towards the paracingular area..
Description:
Shape: subspherical to slightly elongate cyst body; length of septa uniform, approximately one quarter of body diameter.
Wall structure: thin-walled, acavate proximochorate cyst.
Wall features: no parasutural features; high, straight, penitabular septa, incomplete and open towards paracingulum, distally slightly flaring and joined by trabeculae; length of septa approximately 10 µm; paracingular septa small, rectilinear.
Archeopyle: apical, type (A); operculum free.
Paratabulation: indicated by the position of the penitabular and rectilinear septa only.
Paracingulum: difficult to discern; S.E.M. photograph shows small, rectilinear septa in the paracingular area (Plate 4, fig. 6).
Dimensions:
intermediate; length of overall cyst 56 µm to 85 µm (holotype 73 µm); width of overall cyst 55 µm to 74 µm (holotype 69 µm); five specimens measured.
Remarks:
Amphorula delicata sp. nov. differs from Amphorula metaelliptica in having a complex of delicate, often interconnecting processes which form the septa. In A. metaelliptica the septa are distinctly perforated and fan-shaped. Age and occurrence. Amphorula delicata sp. nov. occurs in the Jeanne d'Arc subbasin in the Amphorula metaelliptica assemblage zone (rare to common), dated as Portlandian to early Berriasian, where its range is concurrent with that of Amphorula metaelliptica. Amphorula delicata sp. nov. has been recorded in the following wells: Mobil et al. Ben Nevis I-45, and Mobil et al. Hebron I-13.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Amphorula delicata van Helden, 1986 has a tabulation indicated by high penitabular septa, united distally by ring-trabeculae, and incomplete septa along the cingulum; the latter possessing small rectilinear septa. Individual septa formed by a delicate complex of processes often interconnected and distally joined, forming a slightly flaring septum, open towards the cingular area. Amphorula delicata differs from Amphorula metaelliptica in having a complex of delicate, often interconnecting processes which form the septa. In A. metaelliptica the septa are distinctly perforated and fan-shaped.
Size: overall length 56-85 µm, width 55-74 µm.