Back
Pulchrasphaera
From Williams et al., 2017:
[Pulchrasphaera, Schiøler et al., 1997, p. 89
Type species: Pulchrasphaera minuscula, Schiøler et al., 1997 (pl.1, figs.1–3)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Schiøler et al., 1997]:
Diagnosis:
Spherical to subspherical proximate autocyst with low atabulate ornament. Numerous short solid and atabulate processes arise from the phragm. The archeopyle is precingular, type 2P. The operculum is typically free, and is formed by the loss of paraplates 3" and 4".
Discussion:
Bitectatodinium Wilson, 1973 and Gongylodinium Fenton et al., 1980 resemble Pulchrasphaera in size and shape and invariably also have a 2P archeopyle. However, both the former genera differ in lacking processes. Bitectatodinium differs further in being two-layered. Specimens of Filisphaera Bujak, 1984 may have a 2P archeopyle, but the genus differs from Pulchrasphaera in lacking processes. Xenicodinium Klement, 1960 is covered by low atabulate ornament, but lacks processes and has an uncertain archeopyle type. Pulchrasphaera differs from all other small round proximate and atabulate/cryptotabulate genera by its archeopyle type. Pulchrasphaera differs from the skolochorate genera Kiokansium Stover & Evitt, 1978, emend. Duxbury, 1983; Pervosphaeridium Yun, 1981 and Taleisphaera Duxbury, 1979, emend. Masure, 1986, which also have a 2P archeopyle, in being proximate and spherical to subspherical rather than skolochorate and ellipsoidal.
[Pulchrasphaera, Schiøler et al., 1997, p. 89
Type species: Pulchrasphaera minuscula, Schiøler et al., 1997 (pl.1, figs.1–3)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Schiøler et al., 1997]:
Diagnosis:
Spherical to subspherical proximate autocyst with low atabulate ornament. Numerous short solid and atabulate processes arise from the phragm. The archeopyle is precingular, type 2P. The operculum is typically free, and is formed by the loss of paraplates 3" and 4".
Discussion:
Bitectatodinium Wilson, 1973 and Gongylodinium Fenton et al., 1980 resemble Pulchrasphaera in size and shape and invariably also have a 2P archeopyle. However, both the former genera differ in lacking processes. Bitectatodinium differs further in being two-layered. Specimens of Filisphaera Bujak, 1984 may have a 2P archeopyle, but the genus differs from Pulchrasphaera in lacking processes. Xenicodinium Klement, 1960 is covered by low atabulate ornament, but lacks processes and has an uncertain archeopyle type. Pulchrasphaera differs from all other small round proximate and atabulate/cryptotabulate genera by its archeopyle type. Pulchrasphaera differs from the skolochorate genera Kiokansium Stover & Evitt, 1978, emend. Duxbury, 1983; Pervosphaeridium Yun, 1981 and Taleisphaera Duxbury, 1979, emend. Masure, 1986, which also have a 2P archeopyle, in being proximate and spherical to subspherical rather than skolochorate and ellipsoidal.