( ( ( Like ( those ( of ( ( birds and ) mammals ) ) ) ) ( , ( ( this heart ) ( probably ( had ( ( four chambers ) ( with ( ( a ( single ( aorta-a ( large artery ) ) ) ) ( that ( ( carries blood ) ( to ( the body ) ) ) ) ) ) ) ) ) ) ) ) ( , ( ( says Russell ) . ) ) )
(ROOT (SINV (S (PP (IN Like) (NP (NP (DT those)) (PP (IN of) (NP (NNS birds) (CC and) (NNS mammals))))) (, ,) (NP (DT this) (NN heart)) (ADVP (RB probably)) (VP (VBD had) (NP (NP (CD four) (NNS chambers)) (PP (IN with) (NP (NP (DT a) (JJ single) (JJ aorta-a) (JJ large) (NN artery)) (SBAR (WHNP (WDT that)) (S (VP (VBZ carries) (NP (NN blood)) (PP (TO to) (NP (DT the) (NN body))))))))))) (, ,) (VP (VBZ says)) (NP (NNP Russell)) (. .)))
Like those of birds and mammals, this heart probably had four chambers with a single aorta-a large artery that carries blood to the  body, says Russell.
(ROOT (S (PP (IN Like) (NP (NP (DT all) (NNS tetrapods)) (PP (IN except) (NP (NNS birds) (CC and) (NNS mammals))))) (, ,) (NP (NNS frogs)) (VP (VBP possess) (NP (NP (DT a) (NN heart)) (PP (IN with) (NP (CD three) (NNS chambers))))) (. .)))