Original sentence: Cryptozoology is the study of rumored animals  that are presumed (at least by the researcher) to exist, but for which conclusive proof does not exist, or for animals which are generally considered extinct, but are occasionally reported
Edited sentence: Cryptozoology is the study of rumored animals  that are presumed (at least by the researcher) to exist, but for which conclusive proof does not yet exist, or for animals which are generally considered extinct, but are occasionally reported