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STUDIES OF PALEOZOIC MARATTIALEANS: THE MORPHOLOGY AND PHYLOGENETIC POSITION OF EOANGIOPTERIS GOODII SP. N.
Author(s) -
Millay Michael A.
Publication year - 1978
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.1537-2197.1978.tb06111.x
Subject(s) - sporangium , pennsylvanian , biology , spore , phylogenetic tree , botany , dryopteridaceae , fern , type locality , genus , paleozoic , phyletic gradualism , paleontology , biochemistry , structural basin , gene
Eoangiopteris goodii sp. n. is described from Upper Pennsylvanian coal balls from Ohio (Shade locality) containing isolated pecopterid pinnules approx. 7 × 9 mm that bear up to 20 linear synangia on the lower surface. The synangia extend at right angles from the midrib to the downturned pinnule margins and measure 2.0–3.5 mm in length. Individual synangia are compact and are composed of 10–19 sporangia that have their bases embedded in an elongate parenchymatous pad. In longitudinal section sporangia measure 0.4 × 2.0 mm and have acute elongate, curved apices. Spores average 70 μm in diam and are most similar to the dispersed spore genus Verrucosisporites. Eoangiopteris goodii differs from the generitype E. andrewsii Mamay in its greater size, pinnule histology, and spore type. Sporangium wall complexity and spore type of the two presently known species of Eoangiopteris are considered to be at about the same evolutionary level as the more primitive species of Scolecopteris . Construction of the synangia in Eoangiopteris is different from that of Scolecopteris and indicates that at least two evolutionary lines are recognizable within the Pennsylvanian Marattiales.