Oh, you wanted more than that? Well, let's see what I can do.
I've been asked this question a couple of times recently, and I was somewhat surprised on both occasions. Yet why should I be? When I conducted a very brief straw poll at work this week, I discovered that most people I spoke to weren't sure, with all but one of those saying "probably not". (I had one response of "definitely not, because they're marsupials", an answer that's wrong on so many levels I'll ignore it from here on in). Only one was confident of the correct answer.
It's all very well for me to say "what else could it be?" because, if I'm honest, I spend a lot of time on this blog pointing out that porpoises aren't dolphins, rabbits aren't rodents, musk deer aren't deer, and so on. If a porpoise can be its own kind of thing, without being a dolphin, then why can't a platypus also be its own kind of thing - albeit at a higher level of strangeness?
