Vertebrates

What are the derived characters of chordates?

1. Notochord

2. Dorsal Nerve Cord

3. Pharyngeal Slits and Clefts

4. Muscular, Post-Anal Tail

Urochordata

A phylum of non-vertebrate chordates

Example of a Urochordata

Tunicates

What are some characteristics of Urochordata?

Larvae use tail and notochord to swim, but as adults they are sessile; Adults keep the pharyngeal slit but lose all other derived characters

Cephalochordata

Invertebrate phylum of chordata

Example of a Cephalochordata

Lancelets

What are some characteristics of Cephalochordata?

Swim using a simplified form of the mechanism used by fish; Maintain all 4 characters throughout their lives

Operculum

It covers a fish’s gills and allows for stationary breathing

What is something that sharks DO NOT have and some fish do have that acts as an advantage?

A swim bladder this allows organism to remain stationary, paired with operculum

What organisms are Chondrichthyes?

Sharks, rays and relatives

Gnathostomes

Clade of animals with hinged jaws

Ovoviviparous

Fertilized eggs are retained in the oviduct and are nourished by the egg yolk. The young are born after the eggs are hatched within the uterus (they are hatched in uterus and born alive)

Oviparous

Eggs hatch outside the mother’s body

Viviparous

Embryo develops within the uterus and is nourished from the mother’s blood through the placenta (live birth)

Osteichthyes

Clade of the bony and ray-finned fishes. Largest clade of vertebrates.

Amphibian

Both ways of life (land and marine)

Anura

A clade of amphibians that lack tails but have powerful hind legs (Frogs)

Urodela

Experience paedomorphosis (retention of larval features when sexually mature)

Reptilia

Includes Lizards, Snakes, Turtles, Crocodiles, and Birds

Endothermic

Able to maintain an internal body temperature that is different from the external environment; birds and mammal trait

Amniotes

tetrapods whose living members are reptiles and mammals (named after the amniotic egg)

Diapsids

Animals which have a pair of holes on either side of the skull where the muscles attach to the jaw

Hominoids

Amniote clade that includes humans

Bipedal

Walking on two legs as hominins do

Hair

A derived character of mammals

Placental

Only type of mammal that has completely internal embryonic development

Head

Region where sensory structures are often found

Spiracles

Grasshoppers breathe through these small pores that are part of the tracheal system

Amniotic

Type of egg that allows development in dry environments