 Okay, what do you think this is? Dude, what does it look like? How about a hollow ball of cells? Hmm, that's what it is. This is a picture of a Blaschula. And if you remember, the Blaschula was that thing that defines all animals. I'm going to try to make one animal cladogram and include everybody that I want you to know on it, and I'm going to build it out in four little clips here. So the Blaschula defines everybody that we're going to look at next. And let's go ahead and scroll down here and try to draw this out in a way that is sort of hopefully helpful. So we know that the sister protest of all animals is the Coeniflagellate. Coen, and I'd never figure out if it's two ends or one in. We'll do one end here, and we did two on the last one. Fla-g-l-ate. Awesome, and I'm going to show you a picture of a Coeniflagellate in just a second. But first of all, I want to show you that yes, Blaschula comes next. That's the character that defines all the critters beyond this point. That's the character that defines this ancestor that gave rise to all the critters beyond this point. The first and most primitive animal actually has a lot in common with Coeniflagellates, and that is the sponge. Sponges, and sponges are also known as perifera. That's their family. That's not their family. It's their phylum, which is just a classification level. So I'm going to show you some pictures of some sponges, I think. But maybe I'm going to show you a Coeniflagellate first. Look at how cool that thing is. That's my single cell protest Coeniflagellate. I'm going to show you why sponges are, I think Coeniflagellates gave rise to sponges and all other animals. This is a sponge. It's a filter feeding organism in the ocean. They are pretty unorganized. There's not a whole lot of structure to them. There's a lot of, you can actually see a whole bunch of holes in this particular sponge, and they just filter the water and eat the food out of it. And here's how they filter the water. They use these collar cells, which are also called coenicites. Coincidence? I think not. Doesn't the coenicite or the collar cell look exactly like a coeniflagellate? The hypothesis is that a group of coeniflagellates were like, dude, we might as well start hanging out. Like if we join forces, we actually will be more likely to reproduce and pass on our genes and get more food so that we can reproduce and pass on our genes. So it was a successful strategy that gave rise to this whole group of organisms. Now, sponges are pretty primitive. The next level up is a group of organisms that have everybody beyond this has tissues. Now, that is not Kleenex, my friends. No, no, no. The most primitive animal with a blastula that also has tissues is a group of... The common thing you can think of them as is jellyfish, but it includes other critters and they're Nidorians. And they're Nidorians because they have this, like, phenomenal, amazing structure called a nidocyte, which I'll tell you about in a second. Jellyfish also include C. anemones, or the Nidorians also include C. anemones, and C. anemones are stingy-type things, but all of these guys have tissues. So let's check it out. I mean, how cool is that? Just don't go hang out with it. Check this out. These nidocytes are cellular organelles that are basically poisoned arrows. There's poison on the tip of these arrows. Check that out. That have strings attached to them, and the jellyfish or C. anemone or coral will shoot this poison arrow at their prey. And since it's attached to a string, it will paralyze their prey and then wind in that string and, like, reel in their prey and eat it. If you've ever been to a tide pool and you stuck your finger nicely and gently and kindly, not your tongue, into a C. anemone, you'll notice that you kind of stick to it. Have you done that before? You stick to it because the C. anemone is like, yeah, I'll eat that, and it sticks all of its poison barbs into your finger. And then you are a little bit stronger than a C. anemone, probably. And so you pull your finger away and all those little threads break. So the C. anemone was not successful at eating you, but it tried to. I say, don't stick your tongue in it. Who would stick their tongues in a C. anemone? But it has happened. And you can imagine that your tongue is less tough. Like, this skin is thinner. Like, the tissue on your tongue is like, yeah, don't stick your tongue in something that is going to poison you because, of course, it was a Y chromosome who stuck his tongue into a C. anemone and then, like, had an allergic reaction to it and his tongue swelled up because it was poison in there and he had to go to the emergency room and I was not present for that, but it was a story that stuck in my brain. Like, what? That's crazy. This is a C. anemone, so don't stick your tongue in that thing. I think that's all I have for this section. I totally, it is. Okay, so we're at Clay-to-Gram Land. There's something, something new is going to happen here, right? Like, something different is going to happen that's going to define the next group of organisms. Don't you want to know what it is? What is that word? Yeah, I'll tell you in a second.