Animal Evolution & Diversity Chapter 26

Nonchordate Invertebrates Sponges Cnidarians Phyla- Porifera (have pores) Multicellular Heterotrophic No cell walls Few specialized cells Clade- Meazoa Phyla- Cnidaria Include: Jellyfishes, sea fans, sea anemones, hydras, corals carnivores Radial symmetry Stinging tenticles

Nonchordate Invertebrates Arthropods Nematodes (roundworms) Phylum- Arthropoda (joint feet) Includes: spiders; centipedes; insects; and crustaceans (crabs) Segmented body Exoskeleton Cephalization Jointed appendages Phylum- Nematoda Include: nematodes, roundworms, unsegmented worms (pseudocoeloms) Specialized tissues, organ systems

Nonchordate Invertebrates Flatworms Annelids Phylum- Platyhelminthes Soft Unsegmented Flattened worms Have tissues and internal organ systems Bilateral symmetry cephalization Phylum- Annelida Includes: earthworms, marine worms, parasites, bloodsucking leeches Segmented True coelom

Nonchordate Invertebrates Mollusks Echinoderms Phylum- Mollusca Includes: snail, slugs, clams, squids, octopus Soft-bodied Internal or external shell True coeloms Complex organs Produce larvae Phylum- Echinodermata Includes: sea stars, urchins, and san dollars Spiny skin Internal skeleton Water vascular system Five-part radial symmetry

Chordates 26.2

Reptiles Evolved from ancient amphibians First to evolve to dry conditions Have dry, scaly skin Well-developed lungs Strong limbs Shelled eggs that do NOT develop in water Four groups of reptiles: lizards, snakes, crocodilians, turtles and tortoises, and tuatara Related to dinosours

Amphibians Live in water as larva, and land as adults Vertebrates Require water for reproduction Have lungs (adults) Moist skin (mucus glands) No scales or claws

Bony Fish Have skeletons Two groups of bony fish : Ray-finned and Lobe- Finned Ray-finned Lobe-finned Internal skeleton Paired fins Scales Gills Example: eels, goldfish, and catfish Fleshy fins Include: lungfish and coelacants Tetrapods are four-limbed vertebrates

Birds Considered reptiles that regulate their internal body temperature. Have feathers Two legs Lightweight bones Front limbs are wings

Jawless fish No jaws or teeth Skeletons are made of cartilage Include: lampreys and hagfishes Lack vertebra Have notochord

Mammals Mammary glands (produce milk) Hair Breathe air Four-chambered heart Maintain homeostasis (regulation of body temperature)

Primate Evolution 26.3

What is a Primate? A mammal that has relatively long fingers and toes with nails instead of claw Arms can rotate around the shoulder joints Strong clavicle Binocular vision (combine images from both eyes, providing 3D views ) Well-developed cerebrum (“thinking” part of the brain allows complex behaviors)

Hominie Evolution Homonoids (include orangutans, gorillas, chimpanzee, and humans) Hominines (hominoids that led to humans) Skull, neck, spinal column, hip bones, and leg bones of early hominine species changed shape in ways that enabled later species to walk upright (BIPEDAL) Hand evolved an OPPOSABLE THUMB that can touch the tips of the fingers (enables grasping) Evolved larger brains