Palmlike plants from the Dolores formation (Triassic), southwestern Colorado

Abstract

Plant remains from the Dolores formation in southwestern Colorado include a few small twigs of the conifer Brachyphyllum and large, many-ribbed leaves described as those of an angiosperm, tentatively regarded as a primitive palm and named Sanmiguelia lewisi. This is the earliest known angiospermous flowering plant. Its occurrence in the Middle to Late Triassic, however, indicates that evidence for the origin of the angiosperms should be looked for in the earlier Triassic or late Paleozoic.