Buried deep beyond the veil of extinction: Euphyllophyte relationships at the base of the spermatophyte clade.

Our results support the groups defined by traditional taxonomy, resolve Stenokoleales nested among the lignophytes, and indicate that seed plants may share a closer ancestor with Stenokoleales than with aneurophytes. Additionally, our trees suggest a Givetian minimum age for the seed plant ancestor, a late Emsian minimum age for the Stenokoleales, and early Emsian minimum ages for lignophytes, the bilateral clade, and the aneurophyte ancestor.