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Hystrichosphaeridium cantharellus
Hystrichosphaeridium cantharellus Brosius, 1963
Now Cordosphaeridium. Originally Hystrichosphaeridium, subsequently (and now) Cordosphaeridium, thirdly Tityrosphaeridium.
Holotype: Brosius, 1963, pl.6, fig.1
Age: Late Oligocene
Original description: Brosius 1963, p. 40-41. Hystrichosphaeridium cantharellum
Diagnosis: A species of the genus Hystrichosphaeridium with the following special characteristics: The spherical to ovoidal, smooth inner body bears about 15-20 hollow tree-like processes. These are mostly broad and cylindrical, narrow slightly in the middle and broaden weakly distally. They are composed of fibres, that are split distally and strongly combed backwards. Sometimes net-like openings occur. At the ends, the processes always seem felt-like, but upon high magnification their fibrous character is revealed. Within a single specimen narrow and wide processes occur. As a hatch, a calotte may be split off.
Dimensions: holotype: shell diameter 54 µm, process length 30 µm. Mean shell diameter 50-57 µm, process length 15-28 µm, proces diameter 2-8 µm (10 specimens measured).
Gocht, 1969, p. 45-46:
Cordosphaeridium cantharellum (annotated) The body is relatively delicate. Also the processes, the shafts of which appear massive as a result of the bundled fibres, are relatively loosely striated. The central body is spherical and very thin-walled. The processes are of variable thickness, mostly slightly more slender or more strongly branched on the ventral side. They are constructed of thin, parallel fibre strings, which can already be discerned near the process bases, approaching them radially, then uniting to form the shaft. Distally they fan out, forming a more or less flat funnel. In the distal membrane of the funnel they become evenly fibrous or split into single bundles. Ideally, this membrane is rather smooth-edged, and has an oval to polygonal outline. However, they are often torn or frayed, the ends running down parallel to the shaft. The width of the funnel often exceeds that of the bases, whereas the shafts may be strongly constricted in the middle. Hence the name: cantharellum.
The archaeopyle is relatively small, but has, like C. inodes, the characteristical notch towards the girdle. Accordingly, the process distribution is similar. The narrow ventral processes vary in number and size. The antapical process E is often particularly strongly developed.
Some specimens have very short processes, causing the funnels to touch one another, occasionally giving the impression to be interconnected by an outer membrane.
Affinities:
Brosius, 1963, p. 41
There are some relations with the Cretaceous species Hystrichosphaeridium truncigerum Deflandre. The arrangement of slender and broad, longitudinally striate processes in some specimens are mutual. However, our forms are larger and less squat. The central body is smooth and the split ends characteristically strongly bent backwards and felted.
The construction of the processes also reminds of Hystrichosphaeridium inodes Klumpp.
Now Cordosphaeridium. Originally Hystrichosphaeridium, subsequently (and now) Cordosphaeridium, thirdly Tityrosphaeridium.
Holotype: Brosius, 1963, pl.6, fig.1
Age: Late Oligocene
Original description: Brosius 1963, p. 40-41. Hystrichosphaeridium cantharellum
Diagnosis: A species of the genus Hystrichosphaeridium with the following special characteristics: The spherical to ovoidal, smooth inner body bears about 15-20 hollow tree-like processes. These are mostly broad and cylindrical, narrow slightly in the middle and broaden weakly distally. They are composed of fibres, that are split distally and strongly combed backwards. Sometimes net-like openings occur. At the ends, the processes always seem felt-like, but upon high magnification their fibrous character is revealed. Within a single specimen narrow and wide processes occur. As a hatch, a calotte may be split off.
Dimensions: holotype: shell diameter 54 µm, process length 30 µm. Mean shell diameter 50-57 µm, process length 15-28 µm, proces diameter 2-8 µm (10 specimens measured).
Gocht, 1969, p. 45-46:
Cordosphaeridium cantharellum (annotated) The body is relatively delicate. Also the processes, the shafts of which appear massive as a result of the bundled fibres, are relatively loosely striated. The central body is spherical and very thin-walled. The processes are of variable thickness, mostly slightly more slender or more strongly branched on the ventral side. They are constructed of thin, parallel fibre strings, which can already be discerned near the process bases, approaching them radially, then uniting to form the shaft. Distally they fan out, forming a more or less flat funnel. In the distal membrane of the funnel they become evenly fibrous or split into single bundles. Ideally, this membrane is rather smooth-edged, and has an oval to polygonal outline. However, they are often torn or frayed, the ends running down parallel to the shaft. The width of the funnel often exceeds that of the bases, whereas the shafts may be strongly constricted in the middle. Hence the name: cantharellum.
The archaeopyle is relatively small, but has, like C. inodes, the characteristical notch towards the girdle. Accordingly, the process distribution is similar. The narrow ventral processes vary in number and size. The antapical process E is often particularly strongly developed.
Some specimens have very short processes, causing the funnels to touch one another, occasionally giving the impression to be interconnected by an outer membrane.
Affinities:
Brosius, 1963, p. 41
There are some relations with the Cretaceous species Hystrichosphaeridium truncigerum Deflandre. The arrangement of slender and broad, longitudinally striate processes in some specimens are mutual. However, our forms are larger and less squat. The central body is smooth and the split ends characteristically strongly bent backwards and felted.
The construction of the processes also reminds of Hystrichosphaeridium inodes Klumpp.