( ( ( ( ( ( ( Two types ) ( of ( skeletal systems ) ) ) : ) ( ( Exoskeleton - ) ( arthropods Endoskeleton ) ) ) - ) ( vertebrates ( B. ( Internal ( Skeletons 1 ) ) ) ) ) . )
(ROOT (NP (NP (NP (CD Two) (NNS types)) (PP (IN of) (NP (JJ skeletal) (NNS systems)))) (: :) (NP (NP (NNP Exoskeleton)) (: -) (NP (NNP arthropods) (NNP Endoskeleton))) (: -) (NP (NP (NNS vertebrates)) (NP (NNP B.) (NNP Internal) (NNP Skeletons) (CD 1))) (. .)))
Two types of skeletal systems: Exoskeleton - arthropods Endoskeleton - vertebrates B. Internal Skeletons 1.
(ROOT (S (NP (NNS Humans)) (VP (VBP possess) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN endoskeleton))) (. .)))