Paleobotany; fossil plants; Alethopteris; coal balls; Iowa Pennsylvanian
Petrified specimens of Alethopteris sullivanti (Lesquereux) Schimper and Alethopteris lesquereuxi Wagner, species of Pennsylvania seed fern leaves, were found in coal balls from the Lovilia locality in south central Iowa. The morphology and anatomy of these leaves are described and are compared with findings of previous workers (Leisman, 1960; Baxter and Willhite, 1969). It is generally accepted that Alethopteris is a foliage type of the Pennsylvania pteridosperm, Medullosa (Scott, 1899; Steidtman, 1944). Evidence cited to support this includes the attachment of seeds to Alethopteris foliage (Halle, 1927), the common association of the genus with Myeloxylon, Dolerotheca, Pachytesta, and other organ genera of medullosan affinity, and the anatomical similarities of the leaves with Myeloxylon petioles (Leisman, 1960; Ramanujam et al., 1974). The genus, Alethopteris, was established by Sternberg in 1825 to describe a fern-like compression foliage. Most subsequent studies of the genus have been confined to compression material. A summary of this work is found in Wagner's comprehensive monograph (1968). Alethopteris sullivanti (Lesquereux) Schimper and Alethopteris lesquereuxi Wagner are the only Pennsylvanian species of which the details of internal anatomy are known from petrified coal ball material (Leisman, 1960; Baxter and Willhite, 1969). Wagner (1968, pp. 16-17) believes that the classification of Carboniferous fern-like foliage into natural genera must be based on several different features. These are 1) the general morphology of the frond and its pinnae, 2) epidermal characteristics as preserved in cuticles, 3) fructifications, 4) pinnule morphology and ontogenetic pattern. Wagner feels that ultimately studies of cuticles will be particularly useful in establishing natural genera. This paper describes the morphology and anatomy of Alethopteris sullivanti and A. lesquereuxi leaves found in Iowa coal balls. It also includes a study of the cuticles of these species.
Proceedings of the Iowa Academy of Science
© Copyright 1976 by the Iowa Academy of Science, Inc.
Reihman, Mary Ann and Schabilion, J. T.
"Two Species of Alethopteris From Iowa Coal Balls,"
Proceedings of the Iowa Academy of Science: Vol. 83:
, Article 4.
Available at: http://scholarworks.uni.edu/pias/vol83/iss1/4