( Thus ( ( having ( four limbs ) ) ( ( is ( ( a ( derived feature ) ) ( that ( ( ( separates tetrapods ) ( -LRB- ( ( ( ( ( ( ( ( ( mammals , ) birds ) , ) amphibians ) , ) reptiles ) and ) ( some fish ) ) -RRB- ) ) ) ( from ( all ( other organisms ) ) ) ) ) ) ) . ) ) )
(ROOT (S (RB Thus) (S (VP (VBG having) (NP (CD four) (NNS limbs)))) (VP (VBZ is) (NP (NP (DT a) (JJ derived) (NN feature)) (SBAR (WHNP (WDT that)) (S (VP (VBZ separates) (NP (NNS tetrapods)) (PRN (-LRB- -LRB-) (NP (NP (NNS mammals)) (, ,) (NP (NNS birds)) (, ,) (NP (NNS amphibians)) (, ,) (NP (NNS reptiles)) (CC and) (NP (DT some) (NN fish))) (-RRB- -RRB-)) (PP (IN from) (NP (DT all) (JJ other) (NNS organisms)))))))) (. .)))
Thus having four limbs is a derived feature that separates tetrapods (mammals, birds, amphibians, reptiles and some fish) from all other organisms.
(ROOT (S (NP (NNP Birds)) (VP (VBP have) (NP (CD four) (NNS limbs))) (. .)))