Review of Animalia: Chordates and Beyond

This set of flashcards covers key vocabulary and concepts related to the characteristics and classifications of various animal phyla, particularly focusing on Chordates, their subphyla, and their importance in evolutionary biology.

Notochord

A supportive rod, present in chordates, dorsal to the body cavity, often replaced by cartilage or bone in adult vertebrates.

Dorsal tubular nerve cord

A nerve cord that runs along the longitudinal axis of the body, dorsal to the notochord, which can expand anteriorly as the brain.

Pharyngeal slits

Openings in the pharyngeal region between the digestive tract and outside of the body, used for feeding and gas exchange in some chordates.

Postanal tail

A tail that extends beyond the anal opening, often used in locomotion.

Endostyle

A structure found in chordates that secretes mucus for trapping food particles during filter feeding.

Urochordata

Subphylum of Chordata that includes sea squirts and tunicates.

Cephalochordata

Subphylum of Chordata that includes lancelets, exhibiting all four chordate characteristics as adults.

Craniata

Subphylum that includes all chordates with a skull.

Hyperotreti

Infraphylum within Craniata that contains hagfishes, characterized by their non-vertebrate status.

Vertebrata

Infraphylum that includes vertebrates characterized by having vertebrae.

Chondrichthyes

Class of cartilaginous fishes, including sharks, skates, and rays.

Actinopterygii

Class of bony fishes that includes the ray-finned fishes.

Sarcopterygii

Class of lobe-finned fishes that gave rise to amphibians.

Amniotic egg

An egg that contains an amnion, allowing for a more terrestrial lifestyle and embryonic development.

Ectothermic

Organisms that obtain heat from external sources (environment).

Endothermic

Organisms that generate heat internally (warm-blooded).

Homocercal

Symmetrical tail structure found in most bony fishes.

Heterocercal

Asymmetrical tail structure found in some fishes, especially sharks.

Oviparous

A reproductive strategy where eggs are laid outside of the body.

Viviparous

A reproductive strategy where the young are born live.

Altricial

Young that are born in an undeveloped state and require significant parental care.

Precocial

Young that are relatively developed at hatching and can care for themselves.

Ichthyology

The study of fishes.

Amphibia

Class of vertebrates that typically have a two-stage life cycle, starting as aquatic larvae and maturing into terrestrial adults, characterized by moist skin and metamorphosis.

Reptilia

Class of vertebrates characterized by dry, scaly skin and often laying amniotic eggs, comprising snakes, lizards, turtles, and crocodiles.

Aves

Class of endothermic vertebrates characterized by feathers, wings, a beak with no teeth, and the laying of hard-shelled eggs.

Mammalia

Class of endothermic vertebrates characterized by the presence of mammary glands, hair or fur, and a neocortex in the brain.

Tetrapod

A superclass of vertebrates that includes all land-dwelling vertebrates having four limbs, encompassing amphibians, reptiles, birds, and mammals.

Chordata

Phylum characterized by a notochord, dorsal hollow nerve cord, pharyngeal slits, postanal tail, and endostyle at some point in their life cycle.

Vertebrae

Series of bones or cartilages that form the backbone, protecting the spinal cord and providing support to the body.

Agnatha

Superclass of jawless fishes, including hagfishes and lampreys.

Gnathostomata

Group of vertebrates characterized by the presence of jaws.

Amniota

Clade of tetrapod vertebrates that lay their eggs on land or retain the fertilized egg within the mother, characterized by the presence of an amnion.

Anamniota

Paraphyletic group of vertebrates that lack an amnion, including fishes and amphibians.

Notochord

A supportive rod, present in chordates, dorsal to the body cavity, often replaced by cartilage or bone in adult vertebrates.

Dorsal tubular nerve cord

A nerve cord that runs along the longitudinal axis of the body, dorsal to the notochord, which can expand anteriorly as the brain.

Pharyngeal slits

Openings in the pharyngeal region between the digestive tract and outside of the body, used for feeding and gas exchange in some chordates.

Postanal tail

A tail that extends beyond the anal opening, often used in locomotion.

Endostyle

A structure found in chordates that secretes mucus for trapping food particles during filter feeding.

Urochordata

Subphylum of Chordata that includes sea squirts and tunicates.

Cephalochordata

Subphylum of Chordata that includes lancelets, exhibiting all four chordate characteristics as adults.

Craniata

Subphylum that includes all chordates with a skull.

Hyperotreti

Infraphylum within Craniata that contains hagfishes, characterized by their non-vertebrate status.

Vertebrata

Infraphylum that includes vertebrates characterized by having vertebrae.

Chondrichthyes

Class of cartilaginous fishes, including sharks, skates, and rays.

Actinopterygii

Class of bony fishes that includes the ray-finned fishes.

Sarcopterygii

Class of lobe-finned fishes that gave rise to amphibians.

Amniotic egg

An egg that contains an amnion, allowing for a more terrestrial lifestyle and embryonic development.

Ectothermic

Organisms that obtain heat from external sources (environment).

Endothermic

Organisms that generate heat internally (warm-blooded).

Homocercal

Symmetrical tail structure found in most bony fishes.

Heterocercal

Asymmetrical tail structure found in some fishes, especially sharks.

Oviparous

A reproductive strategy where eggs are laid outside of the body.

Viviparous

A reproductive strategy where the young are born live.

Altricial

Young that are born in an undeveloped state and require significant parental care.

Precocial

Young that are relatively developed at hatching and can care for themselves.

Ichthyology

The study of fishes.

Amphibia

Class of vertebrates that typically have a two-stage life cycle, starting as aquatic larvae and maturing into terrestrial adults, characterized by moist skin and metamorphosis.

Reptilia

Class of vertebrates characterized by dry, scaly skin and often laying amniotic eggs, comprising snakes, lizards, turtles, and crocodiles.

Aves

Class of endothermic vertebrates characterized by feathers, wings, a beak with no teeth, and the laying of hard-shelled eggs.

Mammalia

Class of endothermic vertebrates characterized by the presence of mammary glands, hair or fur, and a neocortex in the brain.

Tetrapod

A superclass of vertebrates that includes all land-dwelling vertebrates having four limbs, encompassing amphibians, reptiles, birds, and mammals.

Chordata

Phylum characterized by a notochord, dorsal hollow nerve cord, pharyngeal slits, postanal tail, and endostyle at some point in their life cycle.

Vertebrae

Series of bones or cartilages that form the backbone, protecting the spinal cord and providing support to the body.

Agnatha

Superclass of jawless fishes, including hagfishes and lampreys.

Gnathostomata

Group of vertebrates characterized by the presence of jaws.

Amniota

Clade of tetrapod vertebrates that lay their eggs on land or retain the fertilized egg within the mother, characterized by the presence of an amnion.

Anamniota

Paraphyletic group of vertebrates that lack an amnion, including fishes and amphibians.

Osteichthyes

A superclass of bony fishes, characterized by a bony skeleton and often the presence of a swim bladder or lung. It includes ray-finned fishes and lobe-finned fishes.

Swim bladder

An internal gas-filled organ in most bony fishes that helps control buoyancy.

Placoid scales

Tough, tooth-like scales characteristic of cartilaginous fishes (Chondrichthyes), providing protection and reducing drag.

Monotremes

A subclass of mammals that lay eggs, such as the echidna and platypus, but still possess mammary glands to feed their young.

Marsupials

A subclass of mammals, typically characterized by giving birth to undeveloped young that continue their development in a pouch on the mother's body, e.g., kangaroos and koalas.

Placental Mammals

The largest subclass of mammals characterized by a prolonged gestation period and the development of the embryo within the mother's uterus, nourished by a placenta, e.g., humans, dogs, whales.

Diaphragm

A sheet of internal muscle in mammals that extends across the bottom of the thoracic cavity, vital for breathing.