Vertebrates and Their Classification

A subphylum of vertebrates characterized by a cranium (skull).

A subphylum of animals with a backbone.

A large placoderm fish from the Devonian period.

An extinct group of armored fishes.

Scavenger fish that live on the ocean floor.

A parasitic fish that feeds on other fish's blood.

A geologic period in Earth's history (380-360 million years ago).

The skull of a vertebrate.

A skull lacking temporal fenestrae (openings) behind the eye sockets.

A skull with one temporal fenestra (opening) behind each eye socket.

A skull with two temporal fenestrae (openings) behind each eye socket.

Openings in the skull behind the eye sockets, allowing for muscle attachment and jaw movement.

Flying reptiles that existed from the late Triassic to the Cretaceous period.

A large pterosaur that likely soared after launching from cliffs.

An armored dinosaur that lived in the Late Cretaceous period.

Early saurischian dinosaurs that lived in the late Triassic period.

Hammerhead sharks exhibit schooling behavior during the day and shift to hunting at night.

Whale sharks are filter feeders, meaning they strain food from the water. They can grow to enormous sizes, exceeding 10 meters in length.

Ovoviviparity is a form of reproduction where eggs develop inside the mother's body. The offspring are born live.

Shark eggs are enclosed in tough, leathery cases that protect the developing embryo. These cases often have tendrils that anchor them to seaweed or other structures.

Stingrays have specialized coloration that helps them blend into the sandy ocean floor.

Spotted ratfish, also known as chimaeras, are cartilaginous fish that inhabit the ocean floor.

Cartilaginous fish have skeletons made of cartilage, a flexible tissue, rather than bone. Sharks and rays are examples.

A filter feeder is an animal that obtains food by straining small organisms or particles from water.

Hollow bones filled with air, commonly found in birds, reducing weight for flight.

The respiratory system of birds, characterized by unidirectional airflow and two breathing cycles for complete air exchange.

Avian respiration requires two complete breathing cycles for fresh air to pass through the lungs.

Air passes from the trachea into the posterior air sacs.

Air from the posterior air sacs moves into the lungs.

Air in the lungs moves to the anterior air sacs.

Air from the anterior air sacs is exhaled from the body.

Specialized types of feathers on a bird's wings; primary feathers are on the wing 'hand' and provide lift, secondary feathers on the 'forearm' provide thrust

An extinct group of reptiles that are considered the ancestors of mammals. They had features like whiskers and holes in their upper jaws, suggesting the possibility of hair.

An extinct, early mammal that may have been nocturnal and insectivorous. They possessed a double hinge in their jaw, which evolved into the middle ear in modern mammals.

A group of mammals that lay eggs instead of giving birth to live young. Platypuses and echidnas are examples.

A monotreme mammal with a leathery beak and webbed feet. It lays eggs and has a venomous spur on its hind legs.

A monotreme mammal with spines, a long snout, and a sticky tongue. They are insectivores and lay eggs.

Mammals that give birth to relatively undeveloped young that complete their development in a pouch. The Tasmanian devil is an example.

A carnivorous marsupial native to Tasmania with a distinctive black fur and a powerful bite.

Cynodonts are important because they are considered to be the direct ancestors of modern mammals. They possessed features like whiskers and holes in their upper jaws, suggesting the possibility of hair. These characteristics paved the way for the evolution of more complex mammals.

A tiny primate with large eyes, about the same size as its brain, and long hind legs; found in Southeast Asia.

A primate native to Central and South America known for its loud, roaring call, similar to a lion.

A group of primates including chimpanzees, gorillas, orangutans, and humans. They share a similar skeletal structure and lack a tail.

A group of primates including gibbons and siamangs. They are smaller than great apes and have long arms for swinging through trees.

A species of lesser ape with distinct white patches on its face; females and infants are buff, while males are black.

A great ape known for its intelligent behavior and close evolutionary relationship to humans

A group of primates that includes modern humans and their extinct ancestors, characterized by bipedalism and larger brains.

The history of how different organisms are related through common ancestors, often depicted using a branching diagram.

Five key features shared by all chordates at some point in their life: notochord, dorsal hollow nerve cord, pharyngeal slits, endostyle, and a post-anal tail.

A type of chordate that retains all five chordate characteristics throughout its life, making it a good example of these features.

A chordate where most adult forms have lost the notochord, nerve cord, and tail, highlighting how these features can be lost during evolution.

A flexible rod that supports the body and provides a framework for muscles to attach.

A tube of nerve tissue running along the back of the animal, forming the basis of the nervous system.

Openings in the throat that function in filter feeding in some chordates, and are modified for gas exchange in others.

A groove in the throat that produces mucus helping to trap food particles in filter-feeding chordates.

A tail extending beyond the anus, used for propulsion in aquatic chordates.

A serpent belonging to the genus Thamnophis, the most widespread reptile genus in North America.

A large tortoise species (Geochelone sulcata) found in the Sahara Desert, known for its distinctive spurs on its legs.

Feathers located at the wing tip that primarily generate thrust during flight, propelling the bird forward.

Feathers located closer to the body on the wing, providing lift and enabling the bird to stay airborne.

The endostyle is a groove in the throat that secretes mucus, helping to trap food particles during filter feeding in some chordates.

During inhalation, air moves into the air sacs, where gas exchange occurs. During exhalation, fresh air is circulated through the lungs and 'used' air is expelled from the body.

Archaeopteryx exhibited both dinosaur and bird characteristics, possessing cuplike teeth like a dinosaur and flight feathers like modern birds.

Shanweiniao cooperorum was a species of Enantiornithes that lived during the Cretaceous period and became extinct at the end of this period.

The bones of the mammalian middle ear evolved from existing bones in reptile jaws and skulls. The stapes is present in other vertebrates, but the malleus and incus are unique to mammals.

A monotreme mammal with a leathery beak and webbed feet. They lay eggs and have a venomous spur on their hind legs.

A monotreme mammal with spines, a long snout, and a sticky tongue. They are insectivores and lay eggs.

The respiratory system of birds is unique, requiring two complete breathing cycles for a complete exchange of fresh air through the lungs.

The middle ear bones in mammals evolved from bones that were part of the jaw and skull in reptiles. This is an example of how structures can change function during evolution.

A carnivorous marsupial native to Tasmania known for its distinctive black fur and a powerful bite.

An extinct group of birds characterized by teeth and claws on their wings.

The skull of Australopithecus afarensis, an early hominid, was similar to modern humans but smaller with a sloped forehead, larger teeth, and a prominent jaw.

An adult female Australopithecus afarensis skeleton, nicknamed Lucy, was discovered in the mid-1970s.

Homo erectus had a prominent brow and a nose that pointed downward rather than forward.

Hominins are a group of primates that includes modern humans and their extinct ancestors, characterized by bipedalism and larger brains.

An early hominid that lived between two and three million years ago, known for its smaller skull and prominent jaw.

An early human species known for its distinctive brow and downward pointing nose.

Lucy is the nickname given to the adult female Australopithecus afarensis skeleton that was discovered in the 1970s.

Lucy is a fossil, providing evidence of a past early hominid species.