 Hi, hi out there. Is anyone feeling sad? This is our last general biology lecture. We're going to talk about vertebrates today. You've been here, you've seen this cladogram. We've been like dealing with this cladogram for like eight lectures now, or 32 or something like that. And in the last lecture, we dove into the animal scene. In fact, we fleshed out our cladogram, our animal aspect of our cladogram here. So today, we're going to focus in just on the chordates, and we're going to flesh out, just like we fleshed out all the previous ones, we're going to flesh out the chordates, which include vertebrates, which dog pound, you are a vertebrate. We could do cheers. We could do, we are vertebrates, cheers. Or we are chordates, because then we get to include some really cool critters in the chordate clan. So let's start by knowing that we're going to build another cladogram. And in fact, we could probably start our cladogram. I think I'll wait and start it in the next one. But we'll look at the characteristics that define chordates, and then slowly flesh out all the other critters that are included in chordate land. So let's go talk about them, because chordates are cool.