the animal kingdom - vertebrates (#15)

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Cambrian period

during this period, Earth’s ocean was teemed with various invertebrate life forms including early vertebrate ancestor Myllokunmingia fengjiaoa

Myllokunmingia fengjiaoa

early vertrebrate ancestor during the Cambrian period;

no protective spikes/appendages & glides through water

phylum Chordata

phylum vertebrates belong to which includes bilaterally symmetrical animals;

under clade deuterostome;

cephalocordata & urochordata

deuterostome

bilaterian animals which form their anus before mouth

• notochord,

• dorsal, hollow nerve cord

• pharyngeal slits/clefts

• muscular, post-anal tail

4 key characs. of phylum Chordata

notochord

4 KEY CHARACS. OF PHYLUM CHORDATA:

flexible rod for structural support;

between digestive tube & nerve chord;

provides skeletal support throughout most of the chordate’s length;

becomes spinal cord

dorsal, hollow nerve cord

4 KEY CHARACS. OF PHYLUM CHORDATA:

nerve cord of the embryo develops to the CNS (brain & spinal cord);

developed from a plate of ectoderm that rolls into a tube

pharyngeal slits or clefts

4 KEY CHARACS. OF PHYLUM CHORDATA:

openings used for filter-feeding or gas exchange;

allow water to exit body w/o passing through digestive tract;

extends from mouth to anus

muscular, post-anal tail

4 KEY CHARACS. OF PHYLUM CHORDATA:

tail extending beyond the digestive tract, aiding in movement;

contains skeletal elements & muscles;

helps propel aquatic species

cephalocordata (lancelets) & urochordata (tunicates)

2 groups of invertebrates

cephalocordata, lancelets

2 GROUPS OF INVERTEBRATES:

basal chordates that retain chordate characteristics (notochord) throughout life;

show segmentation & a swimming motion similar to fish;

start of chordates

(format: answer, common name)

urochordata, tunicates

2 GROUPS OF INVERTEBRATES:

exhibit chordate characteristics mainly in the larval stage;

undergo radical changes upon maturing

• larva settles in a substrate & undergo radical metamorphosis

False; should be lancelets

TRUE OR FALSE:

Lancelets and tunicates are key to understanding vertebrate origins, with

tunicates closely resembling ancestral chordates.

True

TRUE OR FALSE:

Genetic studies in tunicates reveal genes shared with vertebrates, suggesting early chordates had complex organ-related genes.

craniates

chordates that developed heads with brains, sensory organs, & skulls;

distinct traits include multiple sets of Hox genes & the neural crest, which forms various body structures;

hagfishes (class Myxini) & lampreys (Petromyzontida)

• ex. Haikouella

Hox genes, neural crest

UNDER CRANIATES:

1. set of genes in craniates (helps in segmentation)

2. forms various body structures

(separate answers using comma)

hagfishes, Myxini

2 GROUPS OF CRANIATES:

basal invertebrates with cartilage-based skulls, no jaws, & slime glands for defense;

retain notochord in adulthood as a strong, flexible rod of cartilage;

small brain, eyes, ears, nasal opening;

True

TRUE OR FALSE:

Hagfishes have a nasal opening that connects with the pharynx.

True

TRUE OR FALSE:

Vertebrate evolution included additional Hox gene duplications and the formation of a vertebral column.

lampreys, order Petromyzontida

2 GROUPS OF CRANIATES:

basal invertebrates with cartilage skeletons;

notochord persists as main axial skeleton in adult (same in hagfishes)

gnathostomes (jawed vertebrates)

means “jaw mouth”;

superclass which includes groups like sharks, fishes, amphibians, & mammals;

jaws likely evolved from skeletal supports of gill slits

(include more common name in answer)

lateral line system

aquatic gnathostomes possess _____ _____ _____ which is sensitive to water vibrations

chondrichthyes

3 GROUPS/SUPERCLASSES OF GNATHOSTOMES:

cartilage-based skeletons, streamlined for swimming;

repro. strategies: oviparous, ovoviviparous, viviparous

• ex. sharks, rays, & relatives

oviparous

DIFFERENT REPRODUCTIVE STRATEGIES:

development of embryo within an egg outside the mother’s body

ovoviviparous

DIFFERENT REPRODUCTIVE STRATEGIES:

development of embryo inside an egg within the mother’s body until it hatches

viviparous

DIFFERENT REPRODUCTIVE STRATEGIES:

development and nourishment of embryo is within the mother’s body; birth may be followed by a period of parental care

chondrichthyes, osteichthyes, tetrapods

3 groups of gnathostomes

class osteichthyes

3 GROUPS/SUPERCLASSES OF GNATHOSTOMES:

have ossified (bony) endoskeletons with a hard matrix of calcium phosphate;

most breathe through gills covered by an operculum, a protective bony flap;

us a swim bladder for buoyancy

• class Actinopterygii (ray-finned fishes)

calcium phosphate

UNDER OSTEICHTHYES:

they have an ossified (bony) endoskeletons with a hard matrix of this

operculum

UNDER OSTEICHTHYES:

protective bony flap that covers gills which most bony fishes breath through

True

TRUE OR FALSE:

Almost all fishes have bony scales and are oviparous.

Actinopterygii

2 SUBCLASSES OF OSTEICHTHYES:

ray-finned fishes that have modifications in body form and fin structure which aid in maneuvering, defense, and other functions

• ex. trout

Sarcopterygii

2 SUBCLASSES OF OSTEICHTHYES:

lobe-finned fish that have rod-shaped bones surrounded by thick muscles in pectoral and pelvic fins;

many lived in brackish waters (ex. coastal wetlands) during the Devonian period;

some were gigantic predators with lobe-shaped teeth fossils the size of thumbs

• Actinistia (Coelacanths) & Dipnoi (lungfishes)

class Actinistia, coelacanths

UNDER SARCOPTERYGII (LOBE-FINS):

once thought extinct, was rediscovered in 1938

class Dipnoi, lungfishes

UNDER SARCOPTERYGII (LOBE-FINS):

found in freshwater, evolved from ocean species;

breathe through both lungs & gills, surfacing to gulp air;

gills as main organs for gas exchange

False; lobed fins

TRUE OR FALSE:

Sarcopterygii likely used ray fins to swim and "walk" underwater across the substrate.

tetrapods

3 GROUPS/SUPERCLASSES OF GNATHOSTOMES:

evolved from lobe-fins around 365 million years ago;

have limbs with digits instead of fins, allowing movement on land;

early version of this group remain in water similar to amphibians;

has 4 appendages

feet with digits

UNDER SUPERCLASS OF TETRAPODS:

transmit muscle-generated forces to the ground

Tiktaalik

UNDER SUPERCLASS OF TETRAPODS:

fossil showing both fish and tetrapod traits

Amphibia, Reptilia, Aves, Mammalia

4 classes of tetrapods

Amphibia

4 CLASSES OF TETRAPODS:

many amphibians live both in water (early stages) and on land.

typically need water for breeding and have moist, permeable skin for gas exchange;

term derived from “both ways of life” (refers to frog life stages)

• ex. salamanders, frogs, caecilians

Urodela/Caudata, Anura/Salientia, Apoda/Gymnophiona

3 ORDERS OF CLASS AMPHIBIA:

1. salamanders & newts

2. frogs & toads

3. caecilians that are legless and worm-like

(answer respectively)

reptiles, birds, mammals

3 classes that are part of the clade Amniotes

amniotes

adapted to land with the development of the amniotic egg (has specialized membranes);

shells protect eggs, unlike the shell-less eggs of amphibians;

use rib cage to ventilate lungs

warm, moist

Early amniotes were small predators living in _____, _____ environments.

amnion, chorion, yolk sac, allantois

4 specialized membranes of the amniotic egg

Reptilia

4 CLASSES OF TETRAPODS:

have keratin scales for protection and lay shelled eggs on land;

has lungs with extensive folding;

are ectothermic

early kinds (parareptiles) were herbivores;

3-chambered heart (2 atria & 1 ventricle) except for crocodilia (4)

Reptilia

4 CLASSES OF TETRAPODS:

simple teeth with no living tissue, strong and bony skeletons;

has feet with claws

ectothermic/poikilothermic

animals that absorb external heat as their main source of body heat;

associated with being cold-blooded

• ex. reptiles, fish, amphibians, arthropods

diapsids

UNDER CLASS REPTILIA:

included lineages leading to lizards, snakes, & dinosaurs

lepidosaurs

UNDER CLASS REPTILIA:

one lineage includes lizards, snakes, and the ancient tuataras

Rynchocephalia, Squamata, Chelonia, Crocodilia

4 ORDERS OF CLASS REPTILIA:

1. tuatara

2. snakes & lizards

3. turtles & tortoises

4. alligators & crocodiles

snakes

UNDER ORDER SQUAMATA (REPTILIA):

evolved from legged lizards and retain vestigial pelvic bones

turtles

UNDER ORDER CHELONIA (REPTILIA):

boxlike shell fused to skeleton; may have evolved in stages;

fossil evidence suggests possible aquatic origins

crocodilians

UNDER ORDER CROCODILIA (REPTILIA):

evolved from small terrestrial quadrupeds to larger, aquatic animals;

use upturned nostrils to breathe while submerged

Aves (birds)

4 CLASSES OF TETRAPODS:

body covering: feathers

reproduction: internal through hard eggs with shell

breathing: lungs with bronchial tubes

temp.: endothermic;

has hollow bones, toothless beaks, & feathers

True

TRUE OR FALSE:

Birds have extraembryonic membrane consisting of chorion, amnion, yolk sac, & allantois.

Mammalia

4 CLASSES OF TETRAPODS:

amniotes that have hair & mammary glands which produce milk;

endothermic/homeothermic & warm-blooded;

larger brains & diverse range of teeth

hair & fat layer under the skin

UNDER CLASS MAMMALIA:

these help mammals’ bodies to retain heat

monotremes

SUBPHYLUMS OF CLASS MAMMALIA:

lay eggs, have hair, & produce milk but lack nipples;

ancestral for amniotes & retain in most reptiles

• ex. platypus & 4 species of echidnas (spiny anteaters)

marsupials

SUBPHYLUMS OF CLASS MAMMALIA:

possess a placenta, though less complex than eutherians;

live young complete development in a pouch

• ex. kangaroos, koalas

eutherians (placental mammals)

SUBPHYLUMS OF CLASS MAMMALIA:

longer pregnancies, with young developing in the uterus attached to a complex placenta

primates

ORDER IN CLASS MAMMALIA:

earliest known kind were tree-dwellers who had adapted grasping hands/feet & forward-facing eyes;

digits have flat nails instead of narrow claws;

developed social behaviors and parental care

• ex. lemurs, monkeys, apes, humans

True

TRUE OR FALSE:

The head of craniates consist of the brain at anterior end of the dorsal nerve cord, eyes, other sensory organs, & a skull.

jawless fish

earliest vertebrates that had a cranium but no vertebral column;

lived between 500-600 MYA

450-400 MYA

about ____ - ____ MYA the first bony fish with a complete vertebral column evolved;

False; amphibians were the first

TRUE OR FALSE:

First land vertebrates were reptiles.

Gnathostome jaws evolved by modification of the skeletal rods that had previously supported the anterior phrayngeal (gill) slits.

one hypothesis about gnathostomes

benthos

organisms on the seabed

• ex. starfish, corals, crab

nekton

organisms that swim

• ex. fish, squid, shrimp

plankton

organisms that float or drift on water surface

• ex. algae, bacteria, & sea urchin, fish, crustacean larvae (like starfish larvae)

Class Insecta

SUBPHYLUMS OF ARTHROPODA:

6 legs

Class Arachnida

SUBPHYLUMS OF ARTHROPODA:

8 legs

Class Crustacea

SUBPHYLUMS OF ARTHROPODA:

10 or more legs

• ex. crab, lobster, shrimp

Class Diplopoda

SUBPHYLUMS OF ARTHROPODA:

a.k.a. millipedes;

2 pairs of legs per segment

Class Chilopoda

SUBPHYLUMS OF ARTHROPODA:

a.k.a. centipedes;

1 pair of legs per segment