The spermatophytes first evolved by the end of the Middle Devonian, some 390 million years ago. The Famenian deposits record what has been interpreted as the first seed plant radiation. In these levels, a surprisingly large seed plant diversity is observed. Indeed, up to seventeen ovule species are found occupying a wide morphological spectrum. In Belgium, ovules are associated in nearly all localities to sporangiate axes presenting a very similar vegetative morphology. They consist un a dichotomous branchin system bearing terminally a group of sporangia. Sporangia are small and round to oval in shape. They are borne on the recurved tips of a small dichotomous organ. This communication will focus on the description and discussion of the evolutionary implications of these sporangia that we consider as the microsporangiate organs of Late Devonian spermatophytes.

Abstract of an Oral Presentation or a Poster