FOSSIL LATICIFERS FROM EOCENE BROWN COAL DEPOSITS OF THE GEISELTAL

Thick mats of cellular remains from Eocene brown coal deposits of the Geiseltal near Halle, DDR, were determined to be fossil nonarticulated laticifers. Nuclear magnetic resonance analyses of intact strands showed they consisted of cis-1,4-configuration rubber representing the polymerized isoprenoid contents of individual laticifers. Only remains of laticifers are present; other cells are absent as a result of biodegradation. The long laticifers, often with a surrounding cell wall, retained a tubular shape during their preservation. The isoprenoid content, which filled the entire lumen, possessed a cribriform structural character. The interstices within the rubber represent areas of former protoplasm of the cell. Various configurations in the protoplasm molded by the rubber during the initial phase of fossilization appear as negative images of former nuclei, organelles, and possibly membrane surfaces. The laticifer axes possess branches of several configurations comparable in morphology to those in branched, nonarticulated laticifers in extant plants. Acetone extracts of the rubber contents analyzed by gas-liquid chromatography identified the presence of several hydrocarbons which form a characteristic profile for the laticifer. It is suggested that the distinctive cellular micromorphology, rubber configuration, and hydrocarbon profile of these laticifers can be employed as markers in comparative studies with extant plants to identify the generic or species origin of these laticifers. FOSSIL remains from Eocene brown coal beds were reported in the classical literature as Milchsaftgefasse, or latex vessels (Hartig, 1848). Available information indicates that these cellular remains are limited in distribution to the Geiseltal, near Halle in central Europe, where they occur along with deposits of diverse flora and fauna (Krumbeigel, Ruffle and Haubold,1983). Gothan (1924,1927) supported the interpretation that these remains represented fossilized laticifers. The density and stiScharacteristics of these hairlike masses and their dark color prompted Jurasky (1928,1930) to refer to them inappropriately as Affenhaar, a term which remains in the literature. Kindscher (1924) interpreted the material to be comparable to rubber. Early studies of its composition indicated that the material decomposed upon ozonization to aldehydes and also that it could be vulcanized (Gothan,1927; Jurasky,l928). The origin of these materials has been controversial even from these few reports, and authors have conjecturally associated them with s Received 23 November 1983; revision accepted 3 April 1984. Research performed at the Colorado State University Regional NMR Center was supported by National Science Foundation Grant CHE 78-18581. the purported remains ofthe Apocynaceae, Euphorbiaceae, Moraceae, and Sapotaceae in the Geiseltal deposits (Hartig, 1848; Kirchheimer, 1935). More recently, Gottwald (1976), in a comparative examination of the fossil lignitecontaining laticifers with extant woods, reported the wood anatomy to be similar to the genus Couma (Apocynaceae) and assigned the remains to the form genus, Coumoxylon har-