Cycadales

Basic information from Wikipedia:

Cycadales, known as cycads, are an ancient group of gymnosperms with a high extinction risk. Considering the unique morphological characters of cycads and their phylogenetic position as the earliest extant group of seed plants with a minimum age in the Early Permian, they have been relevant for the study of phenotypic evolution between gymnosperms and angiosperms, origin of the seed, neurotoxins, as well as studies on coevolution. Today, 10 genera with a total of 368 species are recognized within Cycadales.