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Cobricosphaeridium hebes
Cobricospbaeridium hebes, Harland and Sarjeant, 1970
Holotype: Harland and Sarjeant, 1970, pl.21, fig.1-2, text-fig.2
Locus typicus: Cobrico Swamp, Victoria, Australia
Stratum typicum: Holocene
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Original description: [Harland and Sarjeant, 1970, p. 217-218]:
Diagnosis:
Spherical to sub-spherical proximate cyst, ornamented with granules and bearing two types of processes. Processes of the first type are relatively short, wart-like, digitate to foliate, sometimes stellate in plan. Processes of the second type are even shorter than the first, slender and not easily seen.
Sulcus and cingulum are poorly defined.
Archaeopyle apical (A) with a well-marked sulcal notch.
Description:
Cyst spherical to sub-spherical, made up of two body layers.
The periphragm gives rise to both granules and processes. The body wall has a total thickness in the order of 1 µm. The first type of processes are short, blunt, wart-like, digitate to foliate, sometimes stellate in plan; they appear to be solid and not to connect to the interior of the cyst. They are sparsely ornamented with granules. In some cases the processes are made up from the convergence of a number of radiating ridges, giving rise to a complex stellate arrangement. Ten processes may be counted around the periphery of the holotype. Process arrangement on the central body appears irregular: no tabulation has been deciphered. The shorter processes are not very easily distinguishable but can be seen to be short, solid, slender and distally closed.
Sulcus and cingulum may be seen only with difficulty, but in one or two cases they are distinguished by an alignment of the longer processes, and a slight reduction in the granular ornament.
The archaeopyle is apical, apparently formed by the loss of the equivalents of two or four apical plates. Its margin is zig-zag and a number of slits were observed to extena posteriorly from the angles.
Dimensions:
Holotype: Length 46 µm, breadth 46 µm, length of longer processes 3 µm, length of shorter processes 1 µm.
Range: Length 42 (47.5) 55 µm, breadth 34 (44.5) 53 µm, longer processes range in length from 2 (3.3) 5 µm; smaller processes range from less than 1 µm to 1 µm. (In all cases, the figure in parenthesis is the arithmetic mean.) Nine specimens were measured; these make up the total available material.
Affinities:
This species is quite well represented in the assemblages; the individual specimens are well preserved and show the nature of the archaeopyle very clearly. It was therefore chosen as type species for the genus. Cobricosphaeridium hebes is characterized by process form, the granular nature of the central body and by the archaeopyle. It resembles Organism No. 2 of Churchill and Sarjeant (1963, p. 50, Figs. 8, 35), especially in the similarity of the process type, but differs in the nature of the archaeopyle.
Holotype: Harland and Sarjeant, 1970, pl.21, fig.1-2, text-fig.2
Locus typicus: Cobrico Swamp, Victoria, Australia
Stratum typicum: Holocene
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Original description: [Harland and Sarjeant, 1970, p. 217-218]:
Diagnosis:
Spherical to sub-spherical proximate cyst, ornamented with granules and bearing two types of processes. Processes of the first type are relatively short, wart-like, digitate to foliate, sometimes stellate in plan. Processes of the second type are even shorter than the first, slender and not easily seen.
Sulcus and cingulum are poorly defined.
Archaeopyle apical (A) with a well-marked sulcal notch.
Description:
Cyst spherical to sub-spherical, made up of two body layers.
The periphragm gives rise to both granules and processes. The body wall has a total thickness in the order of 1 µm. The first type of processes are short, blunt, wart-like, digitate to foliate, sometimes stellate in plan; they appear to be solid and not to connect to the interior of the cyst. They are sparsely ornamented with granules. In some cases the processes are made up from the convergence of a number of radiating ridges, giving rise to a complex stellate arrangement. Ten processes may be counted around the periphery of the holotype. Process arrangement on the central body appears irregular: no tabulation has been deciphered. The shorter processes are not very easily distinguishable but can be seen to be short, solid, slender and distally closed.
Sulcus and cingulum may be seen only with difficulty, but in one or two cases they are distinguished by an alignment of the longer processes, and a slight reduction in the granular ornament.
The archaeopyle is apical, apparently formed by the loss of the equivalents of two or four apical plates. Its margin is zig-zag and a number of slits were observed to extena posteriorly from the angles.
Dimensions:
Holotype: Length 46 µm, breadth 46 µm, length of longer processes 3 µm, length of shorter processes 1 µm.
Range: Length 42 (47.5) 55 µm, breadth 34 (44.5) 53 µm, longer processes range in length from 2 (3.3) 5 µm; smaller processes range from less than 1 µm to 1 µm. (In all cases, the figure in parenthesis is the arithmetic mean.) Nine specimens were measured; these make up the total available material.
Affinities:
This species is quite well represented in the assemblages; the individual specimens are well preserved and show the nature of the archaeopyle very clearly. It was therefore chosen as type species for the genus. Cobricosphaeridium hebes is characterized by process form, the granular nature of the central body and by the archaeopyle. It resembles Organism No. 2 of Churchill and Sarjeant (1963, p. 50, Figs. 8, 35), especially in the similarity of the process type, but differs in the nature of the archaeopyle.