Protostomes & Deuterostomes

lophotrochozoan

group of protosomes

lophophore

rings the mouth of these animals and functions in suspension feeding

Trochophores

larval common to several phyla of lophotrochozoa

Difference between a lophotrochozoans and a ecdysozoan?

lophotorochozoans grow incrementally, ecdysozoans grow by molting

How do ecdysozoans grow

molting-shedding of the soft cuticle or hard exoskeleton

prominent of the ecdysozan phyla

roundworms (nematoda) and arthropods (arthropoda)

Lophotrochozoans: Rotifera

damp soils & marine environments
have a coelom, but no lophophore or trochophore larvae
corona- cluster of cilia that is used for suspension feeding

Lophotrochozoans: Platyhelminthes (flatworms)

three major subgroups: free-living flatworms, endoparasitic, ectoparasitic flukes
Lack a lophophore and have a digestive tract with only one opening for ingestion and waste

Lophotrochozoans: Annelida (Segmented Worms)

segmented body and have a coelom that functions as a hydrostatic skeleton
divided into Polychaeta and Citellata
synapomorphy: numerous bristlelike extensions called chaetae that extend from appendages called parapodia

Annelid phylogeny

Two groups: Oligochaeta (earthworms) and Hirudinea (leeches)
chaetae- bristle like structures

Lophotrochozoans: Mollusca (mollusks)

four important lineages: Bivalves, Gastropods, Chitons, Cephalopods
Bivalves are suspension feeders, the other groups are herbivores or predators

The Molluscan Body Plan

1. the foot, a large muscle located at the based of the animal (movement)

2. visceral mass, contains most of the internal organs

3. mantle, tissue layer that covers the visceral mass and forms the mantle cavity (secretes calcium carbonate shells)

Key lineages of Ecdysozoans

segmented body, but lack jointed limbs and an exoskeleton
Onychophora (velvet worms)
Tardigrades (water bears)

Ecdysozoans: Nematoda (roundworms)

unsegmented worms with a coelom, a tube-within-a-tube body plan, no appendages

Ecdysozoans: Arthropoda (arthropods)

segmented bodies, jointed exoskeletons, reduced coelom, body cavity called a hemocoel

Arthropoda: Myriapods (millipedes & centipedes)

short segments, with one or two pairs of legs
detrivores & carnivores
sexes are separate & fertilization is internal

Insects defining characteristics

1. Three tagmata: head, thorax, and abdomen

2. Three pairs of walking legs on the ventral thorax

3. One or two pairs of wings attached to the dorsal thorax

Arthropoda: Chelicerata (chelicerates)

spiders, ticks
most prominent lineage is the arachnids

Arthropoda: Crustaceans

lobsters, shrimps
segmented body divided into the cephalothorax (head and thorax) and the abdomen
carapace- platelike section of their exoskeleton that protects the cephalothorax

Four phyla of Deuterostomes

Echinodermata- sea stars
Hemichordata- burrowing acorn worms
Xenoturbellida- wormlike species
Chordata- vertebrates

Echinoderms

spines or spikes
marine animals
starfish
deuterostome

Echinoderm Body plan

tube feet- water vascular system (fluid-filled structures)
Podia- tube feet that project outside the body that are involved in motion
Radial symmetry, endoskeleton of calcium carbonate, and water vascular system = synapomorphies

What are the two groups protostomes are divided into?

Lophotrochozoa and ecdysozoa

What does the head of an insect have

A pair of antenna, a pair of compound eyes, and four sets of mouthparts: Labrium, Mandible, Maxilla, and labium

What are the four morphological features of chordata?

1. openings into the throat called pharyngeal gill slits

2. hollow nerve cord that runs the length of the body

3. flexible rod called the notochord that runs the length of the body

4. muscular post-anal tail

What are the two synapomorphies of vertebrates

-column of cartilaginous called vertebrae, which protects the spinal cord

-cranium (skull) is a bony, cartilaginous case that encloses and protects the brain

The vertebrate jaw

Jaws evolved from the cartilage in the anterior gill arch
different feeding methods = modifications to jaws

The tetrapod limb

lungfish have fins supported by bones and are capable of walking short distance
lungfish are the earliest land-dwelling vertebrates
natural selection turned fins into limbs as the first tetrapods became more dependent on terrestrial habitats

Amniotic Egg

1. Fish and amphibians must lay their eggs, which only have a single membrane in water

2. reptiles and birds are able to lay their amniotic eggs, which have an external membrane and three internal membranes on land

3. watertight shell with a membrane-bound food, water, and waste repository

Parts of the Amniotic Egg

embryo (amnion)

yolk sac (from mother)

allantois (waste storage)

albumen (cushions embryo, provides nutrients)

membranes (including chorion- support + gas exchange)

shell

What are egg-laying animals called

Oviparous- female produce an egg with a yolk, and retains it within her body, yolk nourishes the developing embryo

What are species that give birth called

viviparous

what do viviparous mammals have

the placenta that is rich in blood vessels that facilitates the flow of oxygen and nutrients from mother to embryo

what is after the development called

the gestation, then the offspring emerges from the mother’s body

Chordata: Vertebrata (Hagfish & Lampreys)

only vertebrates that lack jaws but have a crania
hagfish lack a vertebral column
lampreys- collum + hollow nerve cord

Chordata: Vertebrata (Chondrichthyes)

sharks, rays
cartilaginous skeleton, jaws, paired fins
predators
internal fertilization
fertilized eggs are shed into the water or retained until young are hatched

Chordata: Vertebrata (actinopterygii)

ray-finned fishes with fins that have long bony rods arranged in a ray pattern
most successful vertebrate lineage

Chordata: Vertebrata (actinistia and dipnoi)

coelacanths and lungfish = lobe-finned fishes
link between tetrapods and ray-finned fishes

Chordata: Vertebrata (amphibia)

most ancient tetrapods
three clades: Frogs, salamanders, caecilians
gas exchange through skin

Chordata: Mammalia (mammals)

three lineages: monotremata, marsupiala, and eitheria

Three distinguishing characters of mammals

insulating hair or fur
endothermy- regulate their body temps with internally generated heat
mammary glands for lactation

Chordata: Mammalia- Monotremata

ancient mammals
lay eggs and have low metabolic rates
leathery beak
platypus and echidna

Chordata: Mammalia (marsupiala)

placenta, young are born poorly developed and continue to develop while attached to their mothers nipple
Opossum, Koala

Chordata: Mammalia (Eutheria)

structure of the teeth and the digestive tract correlate closely with the diet
placental mammals
young are developed at birth
humans

Chordata: Reptilia

1. number and placement of openings in the side of the skull (distinguishes between reptilian and mammalian)

2. adapted for terrestrial life because of:
   scales, well developed lungs, amniotic eggs

3. Four lineages: Lizards, turtles, crocodiles, birds

4. except for birds, ectothermic, do not use internally generated heat to regulate their body temp
   regulate behaviorally

Secondary radial symmetry

presence of both radial and bilateral symmetry in the life period of an organism

Radiata

group of radially symmetric organisms