What are similarities between lower chordates and higher chordates?

Lower chordates, such as tunicates and lancelets, and higher chordates, including mammals, birds, and reptiles, share several key features. Both groups possess a notochord at some stage of development, a dorsal nerve cord, pharyngeal slits, and a post-anal tail, which characterize the phylum Chordata. Additionally, they both exhibit similar patterns of embryonic development and have a segmented body plan. Despite differences in complexity and habitat, these fundamental traits highlight their shared evolutionary heritage.