Chapter 2
Systematic Descriptions
Group: Acritarcha (Evitt 1963).
Genus Schizosporis (Cookson and Dettmann 1959).
Type species: (original designation) Schizosporis reticulatus (Cookson and
Dettmann 1959).
Diagnosis: Outline circular to sub-circular. Test splitting equatorially divided
into two equal parts. Wall smooth, punctate, granulate or reticulate. No outer
membrane is present.
Discussion: Schizosporis was first described and defined by Cookson and
Dettmann (1959), although similar forms have been recorded and described earlier by a number of authors under various other generic names. The equatorial
rupture of the spore test into two equal or almost equal parts places Schizosporis
in the Schizomorphitae which are characterised (Segroves 1967) by an equatorial
zone or line of weakness along which it splits readily. Other forms in the group
are Schizocystia (Cookson and Eisenack 1962), Circulisporites (Norris 1965),
Peltacystia (Balme and Segroves 1966), and possibly Lecaniella (Cookson and
Eisenack 1962) and Brazilea (Tiwari and Navale 1967).
Schizosporis scissus (Balme and Hennelly) (Hart 1960) (Fig. 2.1).
Synonymy: Laevigatosporites scissus (Balme and Hennelly 1956).
Schizosporis scissus (Hart 1965a, b) (Fig. 2.1).
Occurrence: Lower to upper Permian of Collie–Muja Basin, Sue-1 bore.
Description: Diameter about 20 µ. Outline circular to sub-circular or oval. Wall
one-layered, thin not exceeding 1 µ, smooth on lower test. Upper test has a round
thickening which is torn off in greater part in Fig. 2.2b; present in Fig. 2.2a. Test
splitting readily equatorially divided into two parts.
Dimensions: Diameter 16–30 µ (20 specimens measured).
Discussion: The sporeis of very small size, and closely resembles a form described
by Backhouse (1991) from Collie under the generic name Brazilea.
© Springer Nature Switzerland AG 2020
M. Glikson-Simpson, Coal—A Window to Past Climate and Vegetation,
https://doi.org/10.1007/978-3-030-44472-3_2
19
Systematic Descriptions
Group: Acritarcha (Evitt 1963).
Genus Schizosporis (Cookson and Dettmann 1959).
Type species: (original designation) Schizosporis reticulatus (Cookson and
Dettmann 1959).
Diagnosis: Outline circular to sub-circular. Test splitting equatorially divided
into two equal parts. Wall smooth, punctate, granulate or reticulate. No outer
membrane is present.
Discussion: Schizosporis was first described and defined by Cookson and
Dettmann (1959), although similar forms have been recorded and described earlier by a number of authors under various other generic names. The equatorial
rupture of the spore test into two equal or almost equal parts places Schizosporis
in the Schizomorphitae which are characterised (Segroves 1967) by an equatorial
zone or line of weakness along which it splits readily. Other forms in the group
are Schizocystia (Cookson and Eisenack 1962), Circulisporites (Norris 1965),
Peltacystia (Balme and Segroves 1966), and possibly Lecaniella (Cookson and
Eisenack 1962) and Brazilea (Tiwari and Navale 1967).
Schizosporis scissus (Balme and Hennelly) (Hart 1960) (Fig. 2.1).
Synonymy: Laevigatosporites scissus (Balme and Hennelly 1956).
Schizosporis scissus (Hart 1965a, b) (Fig. 2.1).
Occurrence: Lower to upper Permian of Collie–Muja Basin, Sue-1 bore.
Description: Diameter about 20 µ. Outline circular to sub-circular or oval. Wall
one-layered, thin not exceeding 1 µ, smooth on lower test. Upper test has a round
thickening which is torn off in greater part in Fig. 2.2b; present in Fig. 2.2a. Test
splitting readily equatorially divided into two parts.
Dimensions: Diameter 16–30 µ (20 specimens measured).
Discussion: The sporeis of very small size, and closely resembles a form described
by Backhouse (1991) from Collie under the generic name Brazilea.
© Springer Nature Switzerland AG 2020
M. Glikson-Simpson, Coal—A Window to Past Climate and Vegetation,
https://doi.org/10.1007/978-3-030-44472-3_2
19