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SPORANGIAL FRAGMENTS REFERRED TO DICTYOPHYLLUM IN TRIASSIC CHERT FROJVI SARAWAR
Author(s) -
Gastony Gerald J.
Publication year - 1969
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1969.tb09774.x
Subject(s) - sporangium , mesozoic , annulus (botany) , fern , biology , paleontology , spore , botany , structural basin
Sporangial fragments of several Mesozoic fern taxa are organically preserved in a Triassic (Norian) chert from Sarawak. The more nearly entire annuli in the deposit are divided into two size classes. Structural features of the smaller annuli (capsule diam 0.26‐0.3R mm) suggest affinities with the Gleicheniaceae, Matoniaceae, and Dipteridaceae. The three‐dimensional preservation of the larger annuli (capsule diam 0.50‐0.63 mm) reveals features of annular structure and stomial detail which are usually obscured in compressed specimens. Sporangia featuring these larger annuli were probably more‐or‐less pyriform and sessile, and they exhibited an oblique, uninterrupted annulus with greatly reduced induration in the stomial and hypostomial regions. The large size of these sporangia and their probable large spore number indicate that they are not conspecific with the Triassic Clathropteris meniscoides Brongn., also reported from Sarawak. On the basis of general morphology and their unusually large size, these sporangia are tentatively referred to Dictyophyllum exile (Brauns) Nathorst.