Hagfish (jawless invert)

Lamprey (jawless vert.)

Cartilaginous fish

Ray-finned bony fish

Lobe-finned bony fish

Amphibians

Reptiles

Birds

Mammals

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• Phylum Chordata • Fishes, amphibians, reptiles, birds and mammals • Four key characteristics: 1. Dorsal, hollow nerve cord 2. A notochord 3. Pharyngeal pouches 4. Tail that extends beyond the anus

• Nerves branch from this cord at regular intervals

• Nerves connect to internal organs, muscles and sense organs

• Long support rod

• Runs through the body just below the nerve cord

• Most chordates only have in the embryonic stage

• Paired structures in the throat (pharynx) region

• Fishes and amphibians: slits develop that connect the pharyngeal pouches to the outside of the body

• The slits may then develop into gills that are used for gas exchange

• All chordates have a tail that extends beyond the anus at some point in their lives

• The tail can contain bone and muscles and is used in swimming by many aquatic species

• More than 99% of all chordates are in the subphylum Vertebrata

• Vertebrae: individual segments that make up the backbone; encloses and protects the spinal cord

• Backbone is part of an endoskeleton, or internal skeleton

• The two groups

• Soft-bodied marine organisms

• Have the four key characteristics at some point in their lives

• Tunicates – Filter feeders

• Lancelets – Small, fish-like creatures

The electric eel is not an eel—it is more closely related to catfish & carp. (It

can emit jolts of over 600 volts & reach

8 feet long!) There are only 2 venomous lizards: (the Gila Monster and the

Mexican Beaded Lizard).

Out of the 2,900 species of snakes in the world, only 725

are venomous. Of those, only 250

can kill humans with one bite.

Chordates Coelomates, bilateral symmetry Highly cephalized Possess a “spinal cord”

(most are vertebrates) Internal bony skeleton Examples:

Fish Amphibians Reptiles Birds Mammals

Leatherback sea turtles may

exceed 2000 lbs. and live for over

100 years.

The largest shark is the whale shark.

It can reach lengths of over 40

feet, but it is a filter-feeder!

When a horned toad is angry, it squirts blood from its eyes.

The sooty tern leaves its nesting

grounds as a youngster and

remains aloft for 3-10 years,

settling on water from time to

time. It returns to land to breed

as an adult.

An ostrich egg is as big as 24 chicken eggs. The Poison

Arrow frog has enough poison to kill 2,200 people.

Cows do not have upper front teeth.

Elephants are the only animals that can't jump.