After all these strange organisms we've looked at, we finally arrive at mammals, animals that look like us. These are endothermic amniotes, and they have mammary glands. That's what gives them their name. These are milk producing glands that feed the offspring. Mammals also characteristically have hair and 3 middle ear bones. This one seems kind of random. It's just one of the defining features. Don't, you know, I wouldn't stress about it too much. It's, the 3 bones used to convey sound in our ear. And, the last feature of mammals is the neocortex. This one is important. Right? This is what allowed for improved cognition and eventually for us to develop these big noodles that we have. So, we said that mammary glands produce milk to feed the offspring, most of that milk is coming from fat. It or rather, milk is, mostly, water and fat and sugar. So good nutrients to bulk up a baby. Here you can see a bunch of pups nursing on, this mother. Aren't corgis the cutest? I love corgis.
Alright. So let's talk about mammals. First of all, monotremes. These are kind of the weirdest mammals that there are. These are the strangest ones out there. They're egg-laying mammals. Now, generally when we think of mammals, we think that mammals give live birth. These guys don't, they actually lay eggs, that's why they, you know, are often, looked at as sort of an early evolutionary offshoot from mammals. Right? Whereas later mammals would give birth to live offspring, these guys don't. There are very few monotremes in the world. There are platypi. So here we have platypus, and then over here we have an echidna. And there are about 4 species of echidna, if I'm correct, and, only one in existence. So, very few monotremes in the world, and they are all found in Australia.
With that, let's turn the page.