76
2 Systematic Descriptions
Remarks and comparison: Illinites tectus is distinguished by its thick and rigid
nexine and finely structured thin sacci. I. tectus has no nexine folds under distal
roots, a phenomenon common in other species of Illinites.
Genus Alisporites (Daugherty) (Nilsson 1958).
Diagnosis: Disaccate, haploxylonoid to slightly diploxylonoid. Sacci distally
inclined, same size or slightly larger than corpus. Nexine folded under distal
roots. Cappula tenuinexinous.
Known distribution: Widespread in Permian in Northern and Southern hemispheres.
Discussion: The form genus Alisporites was erected and used by Daugherty
(detailed in Potonie and Kremp 1956) for large disaccate pollen with a distal
sulcus, ‘a single fusiform furrow’ as described by Daugherty. Potonie and Kremp
(1956) designated a type species, namely Alisporites opii. Potonie and Kremp
followed Daugherty in interpreting the torn cappula as a sulcus. Nilsson (1958)
was not in the opinion that Alisporites possesses a sulcus in the true sense of a
sharply delimited furrow. Nilsson observed in similar forms a distal tenuitas and
on occasion exine was missing altogether due to bad preservation.
Sulcatisporites is distinct from Alisporites by its vaguely distinguishable corpus
and narrow cappula.
Platysaccus has larger sacci than corpus.
Alisporites milvinus (Balme and Hennelly 1955) (Fig. 2.54).
Occurrence: Upper Permian of Collie–Muja Basin.
Description: Disaccate. Diploxylonoid. Sacci as large as or smaller than corpus.
Ektexine detached equatorially on proximal face and sub-equatorially on distal
face. Cappula about 1/3 corpus width, tenuinexinous. Exine thick, nexine folds
under distal roots, forming a sharp outline for cappula. Exine smooth on attached
parts and intra-microreticulate on sacci.
Exine tends to split along the central, presumably thinnest part of cappula.
Dimensions: Total width: 60–75 µ. Corpus width: 30–54 µ (10 specimens
measured).
Remarks: Alisporites closely resembling the Collie Basin species was recorded
from the Permian of Antarctica (Faebee et al. 1990).
Sub-turma: Striatites (Pant 1954).
Pollen grains belonging to the Striatites, having characteristic taeniate/striate corpus, have been isolated from sporangia of the Glossopterids (Lindstrom et al.
1997). The glossopteris flora is the dominant group of plants in the Permian sediments, and a major contributor to the coal deposits of Gondwana. Glossopterids
are a cold climate vegetation and shed their leaves in winter. McLaughlin (1992)
stated that “different parts of the plants were often fossilised separately. As a
result many different names have been applied to various fossilised organs of this
group.” The same applies to the pollen of the Glossopterids. In this book I make
an attempt in combining names of pollen to what appears to be the same plant
by comparing the fossil pollen/spore to genera of similar living plants. This is
2 Systematic Descriptions
Remarks and comparison: Illinites tectus is distinguished by its thick and rigid
nexine and finely structured thin sacci. I. tectus has no nexine folds under distal
roots, a phenomenon common in other species of Illinites.
Genus Alisporites (Daugherty) (Nilsson 1958).
Diagnosis: Disaccate, haploxylonoid to slightly diploxylonoid. Sacci distally
inclined, same size or slightly larger than corpus. Nexine folded under distal
roots. Cappula tenuinexinous.
Known distribution: Widespread in Permian in Northern and Southern hemispheres.
Discussion: The form genus Alisporites was erected and used by Daugherty
(detailed in Potonie and Kremp 1956) for large disaccate pollen with a distal
sulcus, ‘a single fusiform furrow’ as described by Daugherty. Potonie and Kremp
(1956) designated a type species, namely Alisporites opii. Potonie and Kremp
followed Daugherty in interpreting the torn cappula as a sulcus. Nilsson (1958)
was not in the opinion that Alisporites possesses a sulcus in the true sense of a
sharply delimited furrow. Nilsson observed in similar forms a distal tenuitas and
on occasion exine was missing altogether due to bad preservation.
Sulcatisporites is distinct from Alisporites by its vaguely distinguishable corpus
and narrow cappula.
Platysaccus has larger sacci than corpus.
Alisporites milvinus (Balme and Hennelly 1955) (Fig. 2.54).
Occurrence: Upper Permian of Collie–Muja Basin.
Description: Disaccate. Diploxylonoid. Sacci as large as or smaller than corpus.
Ektexine detached equatorially on proximal face and sub-equatorially on distal
face. Cappula about 1/3 corpus width, tenuinexinous. Exine thick, nexine folds
under distal roots, forming a sharp outline for cappula. Exine smooth on attached
parts and intra-microreticulate on sacci.
Exine tends to split along the central, presumably thinnest part of cappula.
Dimensions: Total width: 60–75 µ. Corpus width: 30–54 µ (10 specimens
measured).
Remarks: Alisporites closely resembling the Collie Basin species was recorded
from the Permian of Antarctica (Faebee et al. 1990).
Sub-turma: Striatites (Pant 1954).
Pollen grains belonging to the Striatites, having characteristic taeniate/striate corpus, have been isolated from sporangia of the Glossopterids (Lindstrom et al.
1997). The glossopteris flora is the dominant group of plants in the Permian sediments, and a major contributor to the coal deposits of Gondwana. Glossopterids
are a cold climate vegetation and shed their leaves in winter. McLaughlin (1992)
stated that “different parts of the plants were often fossilised separately. As a
result many different names have been applied to various fossilised organs of this
group.” The same applies to the pollen of the Glossopterids. In this book I make
an attempt in combining names of pollen to what appears to be the same plant
by comparing the fossil pollen/spore to genera of similar living plants. This is