Deriving Phylogenies from Synthesis Trees // Provides tools to derive species-level phylogenies from large synthesis mega- trees for a wide range of taxonomic groups, including plants, birds, mammals, amphibians, reptiles, fish, bees, butterflies, and sharks. When a queried species is absent from the mega- tree, it is grafted onto the tree using one of two placement strategies: attachment at the basal node of the most closely related genus or family ('at_basal_node'), or random attachment below that basal node with probability proportional to branch length ('random_below_basal'). See Li (2023) doi:10.1111/ecog.06643 for details. Multiple species from a genus not represented in the mega-tree are placed as a polytomy to preserve clade coherence. The package interfaces with the 'megatrees' data package, which bundles or downloads on demand curated mega-trees. Users can also provide their own mega- trees.