Deuterostomes pt 2

Echinoderms

A group of marine animals that includes sea urchins, starfish, and sea cucumbers, characterized by their radial symmetry.

Water Vascular System

A network of water-filled canals unique to echinoderms, used for locomotion, feeding, and gas exchange.

Madreporite

The sievelike structure through which water enters the water vascular system of echinoderms.

Stone canal

The canal that connects the madreporite to the ring canal in echinoderms.

Ring canal

The circular canal that encircles the mouth of echinoderms and connects to radial canals.

Radial canals

Canals that extend from the ring canal down each arm of the echinoderm, aiding in locomotion and feeding.

Major groups of Echinoderms

Includes sea urchins, starfish, and sea cucumbers, each with distinct characteristics.

Sea Urchins

Echinoderms characterized by a hard shell and spines, often found on the ocean floor.

Starfish

Also known as sea stars, echinoderms known for their ability to regenerate lost limbs.

Sea Cucumbers

Echinoderms with a soft body and leathery skin, often burrowed in the sea floor.

Bilateral Symmetry

Body plan in which equal halves are found on either side of a central axis, unlike the radial symmetry of echinoderms.

Dorsal

The back or upper side of an organism.

Ventral

The belly or lower side of an organism.

Anterior

The front end of an organism.

Posterior

The back end of an organism.

Pharyngeal Gill Slits

Developing structures in the embryos of chordates; can develop into gills in aquatic species.

Notochord

A flexible rod-like structure found in the embryos of chordates, providing support.

Postanal tail

An extension of the body found in chordates, extending beyond the anus.

Nerve Cord

A hollow tube above the notochord in chordates that develops into the brain and spinal cord.

Lancelets

Small, fish-like marine animals of the subphylum Cephalochordata that retain all four key chordate features.

Tunicates

Marine animals in the subphylum Urochordata that exhibit chordate features only in their larval stage.

Vertebrates

Animals in the subphylum Vertebrata that have a vertebral column and well-defined head region.

Derived Traits

Characteristics that have evolved in a group from a common ancestor.

Vertebral Column

The spine, made of vertebrae, that surrounds and protects the nerve cord in vertebrates.

Cyclostomes

Jawless fish, such as hagfishes and lampreys, characterized by a round mouth.

Myxini

The class of jawless fish that includes hagfishes, known for their slime production.

Petromyzontida

The class of jawless fish that includes lampreys, which are known for their parasitic feeding habits.

Gnathostomes

Jawed vertebrates, including all fish and tetrapods.

Chondrichthyes

A class of jawed fish characterized by a cartilaginous skeleton, including sharks and rays.

Sharks

Cartilaginous fish known for their sharp teeth and predatory behaviors.

Skates

Flat-shaped cartilaginous fish related to rays, known for their ability to glide through the water.

Rays

Cartilaginous fish distinguished by their flattened bodies and wing-like pectoral fins.

Lobe-finned fish

A group of fish with paired fleshy lobed fins, which may have given rise to terrestrial vertebrates.

Dipnoi

Lungfish characterized by their ability to breathe air using lungs.

Actinistia

Coelacanths, ancient lobe-finned fish thought extinct until discovered alive.

Ray-finned fish

Class Actinopterygii, characterized by bony rays supporting the fins.

Amphibians

Tetrapod vertebrates that begin life in water and usually transition to land, featuring moist skin.

Legs

Limbs adapted for locomotion in terrestrial amphibians.

Lungs

Respiratory organs allowing for gas exchange in amphibians and other tetrapods.

Cutaneous respiration

Breathing through the skin, which is vital for amphibians due to their moist skin.

Pulmonary veins

Veins transporting oxygenated blood from the lungs to the heart.

Divided Heart

An amphibian heart structure allowing for separation of oxygenated and deoxygenated blood.

No amnion

Characteristic of amphibians; they do not possess an amniotic membrane surrounding the embryo.

Tiktaalik

An early tetrapod considered a transitional fossil between fish and land animals.

Ichthyostega

One of the first amphibians, showcasing features adapted for both land and water.

Anura

The order of amphibians that includes frogs and toads.

Frogs vs Toads

Frogs generally have smooth skin and live near water, while toads have dry, warty skin and prefer drier environments.

Caudata

The order of amphibians that includes salamanders and newts.

Apoda

The order of amphibians that are legless and resemble worms or snakes.

Reptilia

Class of ectothermic, scaly vertebrates that include snakes, lizards, turtles, and birds.

Amniotic Eggs

Eggs that have a protective amniotic membrane, allowing for development in a terrestrial environment.

Chorion

The outermost membrane surrounding the embryo in amniotic eggs, facilitating gas exchange.

Amnion

A membrane that encloses the amniotic fluid, protecting the embryo.

Yolk Sac

The structure in the egg that provides nutrients to the developing embryo.

Allantois

A membrane that collects waste products and aids in gas exchange in the egg.

Thoracic Breathing

A breathing mechanism involving the expansion of the ribcage, typical in reptiles and mammals.

Dry, scaly skin

A characteristic of reptiles that prevents water loss and adapts them for terrestrial life.

Ectothermic

Animals that depend on external sources to regulate their body temperature.

Improved circulatory system

Reptiles have a more advanced circulatory system than amphibians but not as efficient as that of mammals and birds.

Anapsids

Group of reptiles characterized by having no temporal fenestrae; includes turtles.

Chelonia

The order of reptiles that includes all turtles and tortoises.

Synapsid

An early group of reptiles that evolved into mammals, characterized by temporal fenestrae.

Therapsids

The group of synapsids considered to be ancestors of mammals, showing mammal-like characteristics.

Diapsids

Reptiles with two temporal fenestrae; includes most reptiles and birds.

Archosaurs

A clade of diapsid reptiles that includes dinosaurs, crocodiles, and birds.

Dinosaurs

Diverse group of reptiles that dominated land during the Mesozoic era.

Tuataras

A group of reptiles that are the only surviving members of the order Rhynchocephalia.

Squamata

The largest order of reptiles, which includes lizards and snakes.

Crocodylia

Order of reptiles that includes alligators and crocodiles.

Similarities to birds

Reptiles share many characteristics with birds, such as scales and egg-laying.

Aves

Class of warm-blooded vertebrates known for feathers, beaks, and laying eggs.

Keratinized Feathers

Feathers made of keratin that provide insulation and aid in flight among birds.

Hollow bones

Adaptation in birds that reduce weight for flight.

Endothermy

The ability to maintain a constant body temperature independent of the environment.

Other adaptations for flight

Includes wings, a lightweight body, and specialized respiratory systems.

Archaeopteryx

An extinct genus of bird-like dinosaurs, demonstrating features of both birds and reptiles.

Connection to theropod dinosaurs

Birds are descended from a group of theropod dinosaurs, sharing many anatomical features.

Mammalia

Class of animals characterized by mammary glands, hair, and three middle ear bones.

Derived characteristics of mammals

Includes presence of fur or hair, mammary glands, and more complex brain structures.

Hair

A key characteristic of mammals that provides insulation and protection.

Mammary glands

Glands in female mammals that produce milk to nourish young.

Specialized teeth and skulls

Adaptations in mammals allowing for diverse diets and efficient feeding mechanisms.

General evolutionary history of mammals

Mammals evolved from synapsid ancestors during the late Triassic period.

Monotreme

Egg-laying mammals, including the echidna and platypus.

Marsupialia

Group of mammals that give birth to underdeveloped young, which mature in a pouch.

Eutheria

Also known as placental mammals, which have a complex placenta.

What is the placenta?

An organ in eutherians that supports the developing fetus with nutrients and waste removal.

Primates

A group of mammals including humans, apes, monkeys, and prosimians, characterized by flexible limbs.

Prosimians

The most primitive primates, including lemurs and tarsiers.

Anthropoids

Higher primates, including monkeys, apes, and humans.

New world primates

Primates found in the Americas, characterized by prehensile tails.

Old world primates

Primates found in Africa and Asia, which do not have prehensile tails.

Gibbons

Small apes known for their brachiating motion and long arms.

Hominids

A family of primates that includes great apes and humans.

Orangutans

Large, tree-dwelling apes native to Indonesia and Malaysia.

Gorillas

The largest primate species, known for their strong social structures.

Chimpanzees

Primates closely related to humans, known for their advanced social behaviors.

Hominins

Branch of the hominid family that includes humans and their ancestors.

Bipedalism

The ability to walk on two legs, a key trait of hominins.

Changes in landscape

Environmental changes that affected the evolution and behaviors of hominins.