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Trabeculidium elegantulum
Trabeculidium elegantulum (Drugg, 1967) Duxbury, 1980
Originally Cannosphaeropsis, subsequently Cannosphaeropsis?, thirdly (and now) Trabeculidium, fourthly Nematosphaeropsis. Stover and Williams, 1987 transferred this species to Nematosphaeropsis Deflandre and Cookson, 1955. In Lentin and Williams 1993 the species is retained in Trabeculidium, following Sarjeant, 1989, who maintained that Trabeculidium is a separate genus.
Holotype: Drugg, 1967, pl.4, fig.17
Locus typicus: Escarpado Canyon, California
Stratum typicum: Danian
Original diagnosis: Drugg, 1967, p.24: Cannosphaeropsis elegantula
Test small, more or less oval, covered with about 15 to 20 processes supporting an external network of fine threads. The wall is thin and devoid of visible structure. The processes are about 14 µm in length and branch at the tips into 4 or 5 branches which may branch again. At times one or two of the processes on one pole may be broader than the rest suggesting some sort of symmetry. The interconnecting filaments are fine and sometimes bear a few tiny beads or barbs. A noticeable feature of these threads is that they tend to project in fairly straight lines between the processes and that they tend to occur in pairs as parallel strands. The overall pattern formed by these parallel interconnections is vaguely reminiscent of the polygonal fields of Hystrichosphaera. This pattern is limited only to the interconnections at the process tips, there being no equivalent ridges or interconnections at the bases of the processes.
Dimensions: Holotype, body 37 x 53 µm, overall 61 x 72 µm; range of test size 28--37 µm wide, 33--53 µm long.
Affinities:
Drugg, 1967, p.25: Cannosphaeropsis elegantula
This species bears a general resemblance to Cannosphaeropsis tutulosa Cookson and Eisenack 1960. It differs most noticeably in the absence of the outloops of C. tutulosa and in the possession of the parallel threads described above.
Originally Cannosphaeropsis, subsequently Cannosphaeropsis?, thirdly (and now) Trabeculidium, fourthly Nematosphaeropsis. Stover and Williams, 1987 transferred this species to Nematosphaeropsis Deflandre and Cookson, 1955. In Lentin and Williams 1993 the species is retained in Trabeculidium, following Sarjeant, 1989, who maintained that Trabeculidium is a separate genus.
Holotype: Drugg, 1967, pl.4, fig.17
Locus typicus: Escarpado Canyon, California
Stratum typicum: Danian
Original diagnosis: Drugg, 1967, p.24: Cannosphaeropsis elegantula
Test small, more or less oval, covered with about 15 to 20 processes supporting an external network of fine threads. The wall is thin and devoid of visible structure. The processes are about 14 µm in length and branch at the tips into 4 or 5 branches which may branch again. At times one or two of the processes on one pole may be broader than the rest suggesting some sort of symmetry. The interconnecting filaments are fine and sometimes bear a few tiny beads or barbs. A noticeable feature of these threads is that they tend to project in fairly straight lines between the processes and that they tend to occur in pairs as parallel strands. The overall pattern formed by these parallel interconnections is vaguely reminiscent of the polygonal fields of Hystrichosphaera. This pattern is limited only to the interconnections at the process tips, there being no equivalent ridges or interconnections at the bases of the processes.
Dimensions: Holotype, body 37 x 53 µm, overall 61 x 72 µm; range of test size 28--37 µm wide, 33--53 µm long.
Affinities:
Drugg, 1967, p.25: Cannosphaeropsis elegantula
This species bears a general resemblance to Cannosphaeropsis tutulosa Cookson and Eisenack 1960. It differs most noticeably in the absence of the outloops of C. tutulosa and in the possession of the parallel threads described above.