Re-Examination of Triletes Superbus, T. Rotatus, and T. Mamillarius of Bartlett

Abstract

The important contributions to Pleistocene and Post-Pleistocene vegetational history that resulted from studies of pollen in the peat bogs of western Europe during the 1920's led to the belief that valuable information on older floras might be gained through studies of spores preserved in coal and shale. During the decade that began with 1930 several investigators began to examine fossil spores. The result was the beginning of a new phase of paleobotanical research and the development of a considerable body of literature. The modern era of fossil spore research dates from the appearance of two papers by the late Harley H. Bartlett (1929a, 1929b) which appear to have had considerable influence on subsequent developments. In the first paper, entitled Fossils of the Carboniferous Coal Pebbles of the Glacial Drift at Ann Arbor, Bartlett described three species of megaspores that had been obtained from coal pebbles collected from the glacial outwash. These spores were released from the coal by maceration, anld were assigned to Triletes, a name he attributed to Reinsch but which at that time had not formally been designated as a genus. The paper was an impressive demonstration of what might be accomplished with macerative techniques in isolating spores for study, and it established a precedent for naming spores in accordance with standard nomenclatural practice. In the second paper, The Genus Triletes, Reinsch, Bartlett reviewed and evaluated the much ignored works of Paul Reinsch1 who, between 1881 and 1884, came forth with an algal theory of the origin of coal. Reinsch had found in coal a great variety of appendaged megaspores that he described with great accuracy and figured in minute detail, but because he thought they were parasitized algal bodies his works were looked upon with considerable scorn. Though not knowing what he was working with, Reinsch did provide clear and concise descriptions of a number of fossil megaspores. Bartlett maintained that the neglect of Reinsch's works after their publication was not wholly justified; and that because he had used so much care in preparing his descriptiolns aind illustrations he did make a valuable contribution. Bartlett further claimed that Reinsch's term Triletes that had been coilned to designate a certain type of body was available and suitable as a generic name for fossil speres, and that the figures could serve adequately as types even in the absence of the actual specimens. Bartlett's two papers were the initial contributions to the large body of spore literature that began to accumulate after 1929. Before that date the last work of importance to have any bearing on the systematic study of spores was by Bennie and Kidston (1886). Bennie and Kidston had used Triletes to designate a number of spore types to which they attached Roman numerals, as Trletes I, Triletes II, alnd so on through Triletes XVIII. At this time, and throughout the following two or three decades, the opinion was widely held in some quarters that fossil spores were not suitable objects for formal names, and the reasons were similar to those held by some earlier paleobotanists against the liaming of detached plant organs of any kind. Thiessen (1920) in particular was an advocate of this. The majority of paleobotanists, however, realized that