PHYLUM BRACHIOPODA (Lamp Shells)

Characteristics:

• Commonly known as lamp shells.
• One of the lophophorate phyla.
• Possess a "U" shaped lophophore with beating tentacles surrounding the mouth.
• Most common animals of the Paleozoic sea.
• Bilateral symmetry.
• Triploblastic (three germ layers).
• Organs present.
• Tube-in-tube body structure.
• Classified under deuterostomes based on embryological patterns.

PHYLUM ECHINODERMATA

Characteristics:

• Larvae have bilateral symmetry; adults exhibit radial symmetry, with madrepore skewed to one side.
• Possess a water vascular system for feeding, locomotion, gas exchange, and sensory perception.
• Tube feet are present.
• Nerve ring made of nervous cells.
• Ossicles form a calcareous endoskeleton (spines/bumps).
• Separate sexes; all marine.
• Triploblastic (three germ layers) with organ systems present.
• Capable of regeneration (e.g., sea stars and sea cucumbers).

Class Asteroidea

• Includes sea stars (starfish) and sea daisies.
• Star-shaped body with mouth directed toward the substrate.
• Tube feet located on suckers, capable of arm regeneration.

Class Ophiuroidea

• Includes brittle stars.
• Slender body resembling a starved sea star; long, flexible arms.
• No tube feet on suckers.

Class Echinoidea

• Includes regular (sea urchins) and irregular (sand dollars) echinoids.
• Body (test) is made of fused plates; no arms.

Class Holothuroidea

• Commonly known as sea cucumbers.
• Soft-bodied with reduced spines and no arms.
• Capable of regeneration; defense mechanism is evisceration.
• Five rows of tube feet, with modified tube feet near the mouth for feeding.

Class Crinoidea

• Includes feather stars, basket stars, and sea lilies.
• Oldest and most primitive of echinoderms.
• Mouth points upward; fossilizes well in chert rock.

PHYLUM HEMICHORDATA (Acorn Worms)

Characteristics:

• Commonly known as acorn worms.
• Head region shaped like an acorn.
• Possess a dorsal nerve cord and pharyngeal gill slits.
• Gill slits and nerve cord indicate a relationship to chordates.

PHYLUM CHORDATA

Key Characteristics:

1. Presence of pharyngeal gill slits.
2. Presence of a notochord.
3. Presence of a dorsal hollow nerve cord.
4. Presence of a muscular post-anal tail and blocks of muscle.

PHYLUM CHORDATA

General Characteristics:

• Coelomate with bilateral symmetry.
• Tube-in-tube body plan.
• Triploblastic (three germ layers).
• Segmented body with present organ systems.

Subphylum Urochordata

• Includes tunicates and sea squirts.
• Adults are sessile and filter feeders, resembling a bag.
• Possess gill slits but lose other chordate characteristics in adult form; larval forms retain bilateral symmetry and all four chordate characteristics.

Subphylum Cephalochordata

• Commonly known as lancelets (e.g., Amphioxus/Brachiostoma).
• Filter feeders; adults retain all four chordate characteristics.

Subphylum Craniata

• Includes vertebrates (backboned animals).
• Backbone replaces the notochord, can be cartilaginous (e.g., hagfish and chondrichthyes) or calcified (all other vertebrates).
• Segmentation evident in muscles and vertebrae.
• Gill slits may be retained or modified in adult forms; tails may be present or only during embryonic stages.

GROUPING:PISCES (The Fishes)

CLASS MYXINI (Hagfish)

CLASS PETROMYZONTIDA (Lamprey)

GNATHOSTOMES

CLASS PLACODERMI

CLASS CHONDRICHTHYES

CLASS OSTEICHTHYES

Devonian was the

"Age of Fishes."

CLASS MYXINI (Hagfish)

• Characteristics:
• Jawless fish, grouped with lampreys as "cyclostomes."
• Highly reduced vertebrae; cartilage body support.
• Mouth has keratinized tooth-like structures.
• 2-chambered heart (1 atrium, 1 ventricle).
• Marine detritus feeders, secreting slime for defense.

CLASS PETROMYZONTIDA (Lamprey)

• Characteristics:
• Jawless, parasitic; penetrates host skin with teeth and tongue.
• Cartilaginous skeleton without collagen.
• Flexible sheath around notochord, with stiff projections.
• 2-chambered heart (1 atrium, 1 ventricle).

GNATHOSTOMES (Jawed Fishes)

• Characteristics:
• Developed hinged jaws; lateral line system for detecting vibrations.

CLASS PLACODERMI (Armored Fish)

• Characteristics:
• Extinct group known for plated skin.

CLASS CHONDRICHTHYES (Cartilaginous Fishes)

• Characteristics:
• Includes sharks, skates, rays, and ratfish.
• No swim bladder or lungs; retains urea for osmoregulation.
• Modified scales for teeth; 2-chambered heart; internal fertilization.

CLASS OSTEICHTHYES (Bony Fish)

• Characteristics:
• Bone replaces cartilage during development.
• Possesses operculum and may have a swim bladder.
• 2-chambered heart; most exhibit external fertilization.

subclass Sarcopterygii

Includes fleshy-finned fish (e.g., coelacanths).

subclass Actinopterygii

Includes ray-finned fish (e.g., goldfish, catfish).

grouping: tetrapoda

Class Amphibia

Class Reptilia

Class Aves (Birds)

Class Mammalia

Class Amphibia

• Characteristics:
• Evolved from lobe-finned fish; lungs and moist skin for gas exchange.
• 3-chambered heart; primarily external fertilization.
• Undergo metamorphosis; some show neoteny.

orders Class Amphibia

• Anura
• Urodela
• Apoda

Anura

Frogs and toads; observe preserved specimens.

Urodela

Salamanders and newts; observe preserved specimens.

Apoda

Legless, segmented worm-like forms.

Class Reptilia

• Characteristics:
• Ectothermic; 3-chambered heart (except crocodiles).
• Amniotic egg; keratinized, dry skin.

orders of Class Reptilia

• Chelonia
• Rhynchocephalia
• Squamata
• Crocodilia

Chelonia

Turtles and tortoises; observe specimens.

Rhynchocephalia

Tuatara; unique with a 3rd eye.

Squamata

Lizards and snakes; observe specimens.

Crocodilia

Alligators and crocodiles; only crocodiles have a 4-chambered heart.

Class Aves (Birds)

• Characteristics:
• Evolved from thecodonts; 4-chambered heart.
• Air sacs for gas exchange; hollow bones for lighter body.
• Endothermic; care for young; amniotic egg.

Class Mammalia

• Characteristics:
• Evolved from theapsids; hair made of keratin; mammary glands.
• 4-chambered heart; endothermic.

Groups of class mammalia

• Monotremes
• Marsupials
• Placentals

Monotremes

Egg-laying (e.g., platypus).

Marsupials

Immature young develop in pouch.

Placentals

Young nourished via placenta.