[SOUND] [MUSIC] So the next piece of information that you can deduce from the body plan, the symmetry, the special characters, the functional morphology, of an organism, is the feeding mode. So, all that means is what did the organism eat when it was alive. So, the first one is called filter feeding, okay. So, our sponges are a great example of a filter feeder. The reason why or how we can identify a sponge as a filter feeder is that, we'll use our terminology, is that it's a Benthic organism,it's epifaunal and it's sessile. So if you think about that, it's a sessile organism living on top of that sea floor. So it can't chase it's food. [LAUGH] So you can rule out carnivory and possibly scavengers. Because they can't really chase down their food. So that's what can clue you into the idea that an organism is a filter feeder. If it can't really actively move in a direction it's probably a filter feeder. If it's sessile then it's probably a filter feeder, okay. So you can at least make a really great guess. So the first one is filter feeding and to be a great filter feeder, to succeed at filter feeding, you have to basically pump a lot of water through your body. So a sponge is great at that. It's very porous, that's why it's called Porifera. And it can actually squish the water through there, so it can pump in water from the sides, and squish it out the top. And it can move a lot of water through it's system, so that's a great filter feeder. All right, the next one is an herbivore, okay. Herbivores eat primarily plant material. So a great example, [LAUGH] one of my favorites, one of my favorite herbivores is an echinoderm. So we have our little echinoderms moving along the bottom of the sea floor in the Benthic region. It's a vagrant organism, so it can move. It's epifaunal, it's on the top of that seafloor, and it uses this awesome little tool called Aristotle's lantern. And it scrapes off algae off of other things, or rocks, or the bottom of the seafloor, and that is an herbivore. So just keep in mind, herbivores are going to be eating plant material primarily. The next type of feeding mode is carnivory or are carnivores. So carnivores are actively hunting meat eaters. I'm a carnivore. [LAUGH] All right, so carnivores. Some things that you can use to identify a carnivore is that its vagrant or nectonic, okay. So it needs to be moving and chasing after its prey or lurking in the murk and ambushing its prey, so it needs to vagrant or nectonic, so actively moving. So those are our carnivores, okay, they're going to be primarily eating meat. Another good indicator of carnivores is a well developed jaw, we'll talk about that later, and are teeth. All right, [LAUGH] so they look like they have meat shredding teeth. That's a great tip or tip off to you that that's a carnivore. So in contrast the next group is our scavengers. So scavengers are like carnivores in that they do eat meat, okay, if you will. They do eat animal material, but they're not active hunters. So that's the primary difference between carnivores and scavengers. Some functional morphology that you can use to identify a scavenger is, for example antenna, how about that? So, antenna kind of protruding out of the front of the organism, in the head region, often indicate that, that organism is trying to feel out, if you will, different chemicals in its environment. So if it can detect the chemicals of a decaying carcass, If you will then that might indicate that's a great scavenger. So shrimp are often times, a coral banded shrimp is actually a scavenger and they have those long antenna sticking out front. And the can sense those chemicals in the environment and it will tip that organism off to a decaying carcass. A feast nearby. [LAUGH] So that's one morphological feature that will help you identify a scavenger. Secondly, you want to consider that a scavenger does need to cover some ground. So it needs to be a vagrant organism. So it's definitely moving through the water column. Or moving on the sea floor. So it's a vagrant or nectonic organism. Lastly, in contrast to a carnivore, how you could maybe make that distinction, is that a carnivore generally has to have well developed eyes. Usually, I would say, well developed eyes. Think of an octopus, an awesome carnivore. They have those big eyes. They're well developed, they have sharp vision there. But a scavenger doesn't necessarily need to have as sharp vision to chase down its prey, because its prey is already dead. So that's another thing that can make, can help you make that distinction between a carnivore and a scavenger. Last feeding mode that you can assign to an organism or that you can think about here is our detrital feeders. So they're eating detritus or detrital if you will. And what these organisms do is they basically have to, they're like filter feeders in a way but they have to filter a nutritive material from actual sediment. So, they have to eat dirt. All right, [LAUGH] that's a detrital feeder. So, generally they're kind of scooping through or sifting through on that Benthic region on the sea floor. They're sifting a bunch of sediment and they're collecting all the nutritive material out of that sediment. So, that's our detrital feeders. So, just to run through them real quick we have our filter feeders, we have our herbivores, carnivores, scavengers, or our detrital feeders, [LAUGH] all right? So just to reiterate, you can deduce a lot of information just from looking at a fossil that you find, which I think is just really awesome. So consider that symmetry, look at the overall body plan. Does it look like its flat and that it would be comfortable on the bottom of the sea floor or is it kind of streamlined and looks like it might live in the water column? So look at that body plan. Look at the functional morphology, the different features. Maybe it has complex eyes so it looks like it could hunt something down pretty easily. So look at those functional morphological features and use that information how that organism lived and ate. [MUSIC]
