Complex sentence: Their results reveal that "Paranthropus boisei" contrary to previous theories, did not eat nuts but dined more heavily on C4 plants than any other human ancestor or human relative studied to date; only an extinct species of grass-eating baboon ate more.
Split into simpler sentences: Their results reveal that "Paranthropus boisei" contrary to previous theories, did not eat nuts but dined more heavily on C4 plants than any other human ancestor or human relative studied to date. Only an extinct species of grass-eating baboon ate more.