The unknown protist would be placed near the base of the branch leading to the diplomonad since gene sequences place it closest to that taxon, but the fully functional mitochondria would be an ancestral state given that diplomonads have highly reduced mitochondria.
Work Step by Step
Review earlier chapters on phylogenetics and review Fig. 28.2, noting how reduction of mitochondria defines the modern diplomonads. The gene sequence data places the unknown taxon very close to the diplomonads, but it clearly lacks one of their most clearly defining features.