Animal Diversity Chapter 34

Chordata

Phylum of bilaterians that include all vertebrates as well as three other groups.

Notochord

Nerve cord

Phrangeal slits

Post-anal Tail

Characteristics of chordates

Notochord

Chordate feature. Long flexible rod between digestive tube and nerve cord that provides support. Became our vertebrae.

Nerve cord

Chordate feature. Cord that developed into our CNS out of a plate of ectoderm. Hollow.

Phrangeal slits

Chordate feature. Became gills or suspension-feeding structures in fish. Became our ears, head and neck.

Post-anal tail

Usually reduced during embryonic development in many species, propels fish. We don't have this, though we're chordates.

Cephalochordata

Subphylum of Chordata. Lancets. Suspension feeders that basically have the full chordate body plan as adults.

Urochordata

Subphylum of chordata. Turnicates. Chordate traits during larval stage, but becomes a sessile filter feeder. Phrangeal slits aid in filter feeding.

Craniata

Non-taxonomic group that basically equates to having a head. Skull, brain, eyes and sensory organs all in one handy dandy place. Have a neural crest exressed during embryonic stages, hearts with at least two chambers, red blood cells and kidneys.

Neural Crest

Feature of a crianate embryo that becomes part of the head, in us our jaw and the front of our skull.

Myxini AKA hagfishes

Basal group of craniates. Create ridiculous amount of slime. Cartilaginous skull etc, no jaws or vertebrae.

Vertebrates

Lineage of craniates that are more efficient at capturing food and avoiding being eaten. We are these.

Enclosed spinal cord

Elaborate skul

Fin rays (in aquatic forms)

Derived characteristics of vertebrates

Lamprey

Jawless fish that feed by clamping onto other live fish.

Conodonts

First vertebrates with skeletal elements in the mouth and pharynx.

Gnathostomes

Infraphylum of Vertebrata. Jawed vertebrates with enlarged forebrains, better sensory organs. First ones were armoured fish.

Chondrichthyes

Class of vertebrata. Fish with cartilaginous skeletons. Sharks and rays and chimeras.

Elasmobranchii

Sharks, rays, skates. Subclass of Chondrichthyes. Short digestive tract with a spiral valve. Acute senses.

Holocephali

Chimeras, or ratfish. Subclass of Chondrichthyes.

Oviparous

Eggs hatch outside of the mother's body.

Ovovivparous

Embryo develops in the uterus and is nourished by the egg yolk.

Vivaparous

Embryo develops within uterus and is nourished through a yolk sac placenta from the mom's blood.

Osteichthyes

Ray and lobe-finned fishes and tetrapods. Class of vertebrata.

Actinopterygii

Ray-finned fish. Subclass of Osteichthyes.

Sarcopterygii

Lobe-finned fish and tetrapods. Subcass of Osteichthyes. Muscular pelvic and pectoral fins (or limbs).

Actinistia

Coelocanths. Subclass of Sarcopterygii.

Dipnoi

Lungfish. Subclass of Sarcopterygii. Capable of air breathing.

Placoid scales

Scales that are very sharp on one end. Sharks have them.

Ganoid scales

Scales that are very flat and kind of like armour. Diamond shaped and very thick.

Cycloid scales

Rounded scales.

Ctenoid scales

Scales that are almost shaped like shells.

Heterocercal

Tails like a shark's, where you have the large upper part and the small lower part. Tips up.

Diphyceral

Tail with only one point. Comes to a point or tip at the end.

Homocercal

A tail with two points that are the same time. Kind of triangular.

Tetrapoda

- Four limbs, feet with digits

- Neck

- Absence of gills

- Sensory skills developed for terrestrial environment

Tiktaalik

"Fishapod", the transitional form from water to land. Found in Nunavut. Had fins, gills, lungs, scales, ribs, a neck, and fins on tetrapod limbs.

Amphibia

Class of tetrapods. Have moist skin, that they breath through as well as through their lungs. Aquatic larvae and terrestrial adults.

Urodela

Subclass of Amphibia. Have tails. Salamanders.

Anura

Subclass of Amphibia. No tails. Froggies.

Apoda

Subclass of Amphibia. Legless, resemble worms.

Amniotes

Class of tetrapods. Includes both reptiles (and birds) and mammals. Characterized by the presence of an amniotic egg with membranes. Most have shells.

Extraembryonic membranes

- Amnion

- Chorion

- Yolk sac

- Allantois

Amnion

Membrane creating a fluid filled membrane around the embryo to cushion against mechanical shock.

Chorion

The membrane outermost of the egg. Allows gas exchange between embryo and the air.

Yolk sac

Membrane containing the yolk.

Allantois

Disposal sac for the embryo's metabolic wastes.

Reptilia

Have scales, lay shelled eggs on the land. Most are ectothermic, though some are endothermic.

Ectothermic

Cold-blooded. Rely on the environmental temperature.

Endothermic

Warm-blooded. Keep the body warm via metabolism.

Parareptiles

Stocky large quadrupedal herbivores that were the first major group of reptiles.

Lepidosaurs

Includes tuataras, lizards, snakes and mososaurs. (Those guys were cool though, too bad they're dead.)

Archosaurs

Contain crocodilians, pterosaurs and dinosaurs.

Tuataras

Two lizard-like reptiles found in New Zealand. Lepidosaurs.

Squamates

Lizards and snakes. Lepidosaurs.

Turtles

Boxlike shell that is fused to their vertebrae. Their phylogeny is seriously confused.

Crocodilians

Alligators and crocodiles. Archosaurs.

Birds

Archosaurs with wings with keratin feathers. Highly adapted for flight.

Adaptations of birds for flight

- No urinary bladder

- Hollow bones

- One ovary

- Small gonads

- Loss of teeth

- Super acute vision

Neornithes

Actual name of birds.

Rattites

Flightless birds. Includes ostritches and kiwis.

Mammals

Have mammary glands, hair, high metabolic rates, large brains and differentiated teeth.

Monotremes

Lineage of mammals. Lay eggs. Echidna and platypus.

Marsupials

Lineage of mammals. Embryo is born very early in development and completes development while nursing in the marsupium.

Eutherian

Lineage of mammals. Most complete embryonic development within the uterus, connected to their mother via placentas.

Primates

Eutherians with large brains, short jaws, forward-looking eyes, complex social behaviours, and hands and feet adapted for grasping.