2nd Post

Before i began reading my Biology book it did not have idea what to write on my secnd post, but while i was reading i found a sentence that at first sounds wired then i went back and i read it again and i noticed that something is wrong. the sentece was this: Extinction is the death of a species or larger classification category. do you see an error or is just me?... do i have to think that the sentence is fine because is in my Biology book?