Actually, it does in many ways. As ridiculous and ludicrous as it seems to modern types like us today, Guido, as well-traveled and knowledgable as scientists or naturalists were in ancient classical antiquity, what they knew about hard sciences, physics, astrology, astronomy, natural sciences and what Pliny knew about plant and animal species in other regions of the world like Far East, or sub-Saharan Africa or even the Hindu Kush, regions most Greeks or Romans never travelled to much less knew a lot about, someone like Pliny might as well believe that snarks, and grumpkins COULD exist as much as dragons because he couldn't prove they didn't exist, either. Remember, many people in medieval Europe believed unicorns once existed and were wiped out by the Flood.
I know it sounds ridiculous but the extent of what many ancient philosophers, scientists, or naturalists knew was extremely limited so even if Pliny the Elder or someone like Ptolemy likely thought the existence of dragons was asinine, well, no one had ever proven they didn't exist, so who knows?