( Antarctica ( ( is ( ( the ( only continent ) ) ( ( on which ) ( ( no Lepidoptera ) ( have ( been found ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Antarctica)) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN continent)) (SBAR (WHPP (IN on) (WHNP (WDT which))) (S (NP (DT no) (NNP Lepidoptera)) (VP (VBP have) (VP (VBN been) (VP (VBN found)))))))) (. .)))
Antarctica is the only continent on which no Lepidoptera have been found.
(ROOT (S (NP (NNP Antarctica)) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN continent)) (PP (IN without) (NP (NNS amphibians))))) (. .)))