all the evidence points to this being a cat

book in public domain

Say you have a Cat in one basket and a Dog in the other.  How may your strict factual observation tell you which Critter you are currently manhandling?  This page from a 1901 children's natural science reader may help. (Click on image to get a bit bigger view.)  Please pay attention to the illustration of "A Cat's Mouth."  What kind of a cat did they have there?  A panther?
From Frederick William Hackwood, Chatty object lessons in nature knowledge: being companion object lessons to Longman's Chatty readings in elementary science (Longmans, Green, 1901) page 108.