Back
Alterbia bicavata
Alterbia bicavata, (Jain and Millepied, 1973), Lentin and Williams,1976
Holotype: Jain and Millepied, 1973, pl.1, figs.1-3
Locus typicus: Borehole CM-1, Senegal, northwest Africa
Stratum typicum: Campanian-Maastrichtian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Senegalinium bicavatum: [Jain and Millepied, 1973, p. 23]:
Diagnosis:
Shell ovoid, non tabulate, bicavate; periphragm thin, zone of contact around equator large extending into one apical and two antapical horns leaving behind two or three pericoel areas, surface serrate or smooth. Endophragm thick, dark, granulose with localized verrucose thickening along margins in pericoel areas.
Archaeopyle intercalary, penta to hexagonal, below the apical horn.
Transverse furrow indistinct, indication of longitudinal furrow present.
Description:
Epitract and hypotract nearly equal, epitract conical in outline, apical horn broader than long with apical pore; hypotract rounded antapically with two antapical horns of unequal size, acuminate. Intercalary archaeopyle lies up to or below the capsule margin.
Dimensions/Size:
Holotype: overall length 100 µm, overall width 65 µm, endocyst length 64 µm, endocyst breadth 65 µm, length of apical horn 7 µm, breadth of apical horn 13 µm, length of antapical horn 17 µm, breadth of antapical horn 20 µm.
Range: overall length 90-100 µm, overall breadth 55-70 µm, endocyst length 60-70 µm, endocyst breadth 55-70 µm, length of apical horn 6-22 µm, width of apical horn 13-30 µm, length of antapical horn 6-16 µm, breadth of antapical horn 10-20 µm.
Holotype: Jain and Millepied, 1973, pl.1, figs.1-3
Locus typicus: Borehole CM-1, Senegal, northwest Africa
Stratum typicum: Campanian-Maastrichtian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Senegalinium bicavatum: [Jain and Millepied, 1973, p. 23]:
Diagnosis:
Shell ovoid, non tabulate, bicavate; periphragm thin, zone of contact around equator large extending into one apical and two antapical horns leaving behind two or three pericoel areas, surface serrate or smooth. Endophragm thick, dark, granulose with localized verrucose thickening along margins in pericoel areas.
Archaeopyle intercalary, penta to hexagonal, below the apical horn.
Transverse furrow indistinct, indication of longitudinal furrow present.
Description:
Epitract and hypotract nearly equal, epitract conical in outline, apical horn broader than long with apical pore; hypotract rounded antapically with two antapical horns of unequal size, acuminate. Intercalary archaeopyle lies up to or below the capsule margin.
Dimensions/Size:
Holotype: overall length 100 µm, overall width 65 µm, endocyst length 64 µm, endocyst breadth 65 µm, length of apical horn 7 µm, breadth of apical horn 13 µm, length of antapical horn 17 µm, breadth of antapical horn 20 µm.
Range: overall length 90-100 µm, overall breadth 55-70 µm, endocyst length 60-70 µm, endocyst breadth 55-70 µm, length of apical horn 6-22 µm, width of apical horn 13-30 µm, length of antapical horn 6-16 µm, breadth of antapical horn 10-20 µm.