How many mammals are in the Chordate phylum?
SELECT DISTINCT COUNT(?uri) WHERE {?uri <http://dbpedia.org/property/phylum> <http://dbpedia.org/resource/Chordate>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Mammal>}
Chordate