( ( Ingrowths ( of ( ( the ( arthropod exoskeleton ) ) ( known ( as apodemes ) ) ) ) ) ( ( serve ( as ( ( attachment sites ) ( for muscles ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Ingrowths)) (PP (IN of) (NP (NP (DT the) (JJ arthropod) (NN exoskeleton)) (VP (VBN known) (PP (IN as) (NP (NNS apodemes))))))) (VP (VBP serve) (PP (IN as) (NP (NP (NN attachment) (NNS sites)) (PP (IN for) (NP (NNS muscles)))))) (. .)))
Ingrowths of the arthropod exoskeleton known as apodemes serve as attachment sites for muscles.
(ROOT (S (NP (NNS Apodemes)) (VP (VBP are) (ADJP (JJ ingrowths) (PP (IN on) (NP (NP (JJ arthropod) (NNS exoskeletons)) (SBAR (WHPP (TO to) (WHNP (WDT which))) (S (NP (NNS muscles)) (VP (VBP attach)))))))) (. .)))