255 relations: Academic Press, Acanthostega, Acetabulum, Actinistia, Actinopterygii, Adelospondyli, Aistopoda, Alfred Romer, Alligator, Allotheria, Amniote, Amphibamidae, Amphibian, Amphisbaenia, Anamniotes, Anatomy, Ancient Greek, Anomodont, Anthracosauria, Aquatic animal, Archegosaurus, Aristotle, Baphetidae, Basal (phylogenetics), Bat, Batrachomorpha, Beelarongia, Biological membrane, Bird, Body plan, Branchiosauridae, Buccal pumping, Buoyancy, Caecilian, Caiman, Canowindridae, Carboniferous, Carboniferous rainforest collapse, Carl Linnaeus, Carpal bones, Cenozoic, Cetacea, Chemoreceptor, Choristodera, Clade, Cladistics, Cladogram, Class (biology), Clavicle, Cleithrum, ..., Coelacanth, Colosteidae, Coral snake, Crassigyrinus, Cretaceous, Crocodile, Crocodilia, Crown group, Cutaneous respiration, Cynodont, Density, Dentition, Devonian, Diadectomorpha, Diapsid, Dinosaur, Dissorophoidea, Dolphin, Elapidae, Elginerpeton, Elpistostegalia, Elpistostege, Embolomeri, Emsian, Eotetrapodiformes, Euramerica, Eusthenodon, Eusthenopteron, Euteleostomi, Evolution, Evolutionary history of life, Exoskeleton, Eyelid, Femur, Fibula, Fin, Focal length, Frequency, Frog, Geologic time scale, Gephyrostegidae, Gharial, Gill, Glenoid cavity, Gogonasus, Gondwana, Gyroptychius, Habitat, Hand, Hangenberg event, Heart, Herpetology, Hexapoda, Hoatzin, Holocene, Hominidae, Homology (biology), Human, Humerus, Hydrophiinae, Hyoid bone, Hyomandibula, Hypercapnia, Ichthyostega, Ichthyostegalia, Ilium (bone), Inertia, Interclavicle, International Union for Conservation of Nature, Ischium, IUCN Red List, Jarvikina, Joint, Journal of Iberian Geology, Jurassic, Kenichthys, Koharalepis, Late Devonian extinction, Lateral line, Lens (anatomy), Lepidosauria, Lepospondyli, Lineage (evolution), Lissamphibia, Lizard, Lung, Lungfish, Lysorophia, Mammal, Mandageria, Marsdenichthys, Matrix (biology), Megalichthyidae, Metabolic alkalosis, Michael Benton, Microsauria, Middle ear, Moa, Mouse, Nasolacrimal duct, Natural environment, Nectridea, Neontology, North China Craton, Notochord, Obruchevichthys, Octopus, Odor, Operculum (fish), Orbit (anatomy), Organ (anatomy), Oscillation, Osteichthyes, Osteolepidae, Osteolepiformes, Osteolepis, Otic notch, Palate, Paleontology, Panderichthys, Pelvis, Penguin, Pennsylvanian (geology), Permian, Permian–Triassic extinction event, Phylogenetic nomenclature, Phylogenetic tree, Physical strength, Physiology, Pierre André Latreille, Pinniped, Platycephalichthys, Polypterus, Pregnancy, Pressure, Primate, Prototheria, Pubis (bone), Pulse (signal processing), Radius (bone), Refractive index, Reptile, Reptiliomorpha, Respiration (physiology), Respiratory acidosis, Rhipidistia, Rhizodontida, Rib, Right angle, Robert L. Carroll, Rock (geology), Romer's gap, Salamander, Sarcopterygii, Sauripterus, Sauropsida, Seymouriamorpha, Sirenia, Skink, Skull, Snake, Spiracle, Stapes, Stegocephalia, Stem tetrapoda, Synapsid, Tadpole, Tarsus (skeleton), Taxonomy (biology), Temnospondyli, Terrestrial animal, Tetrapod, Tetrapodomorpha, Theria, Therocephalia, Theropoda, Threatened species, Tibia, Tiktaalik, Tinirau (genus), Toad, Tongue, Tortoise, Tournaisian, Trackway, Transitional fossil, Triassic, Tristichopteridae, Tristichopterus, Tuatara, Turtle, Tympanal organ, Ulna, Valentia Island, Ventastega, Vertebrate, Vertebrate Palaeontology (Benton), Vertebrate paleontology, Vertebrate Paleontology (Romer), Water bird, Western Kentucky University, Whale, Whatcheeriidae, Zachełmie, Świętokrzyskie Voivodeship, 10th edition of Systema Naturae. Expand index (205 more) » « Shrink index
Academic Press is an academic book publisher.
Acanthostega (meaning "spiny roof") is an extinct genus of stem-tetrapod, among the first vertebrate animals to have recognizable limbs.
The acetabulum (cotyloid cavity) is a concave surface of a pelvis.
Actinistia is a subclass of mostly fossil lobe-finned fishes.
Actinopterygii, or the ray-finned fishes, constitute a class or subclass of the bony fishes.
Adelospondyli is an order of elongate, presumably aquatic, Carboniferous amphibians.
Aïstopoda (Greek for " not-visible feet") is an order of highly specialised snake-like amphibians known from the Carboniferous and Early Permian of Europe and North America, ranging from tiny forms only, to nearly in length.
Alfred Sherwood Romer (December 28, 1894 – November 5, 1973) was an American paleontologist and biologist and a specialist in vertebrate evolution.
An alligator is a crocodilian in the genus Alligator of the family Alligatoridae.
Allotheria (meaning "other beasts", from the Greek αλλός, –other and θήριον, –wild animal) is an extinct branch of successful Mesozoic mammals.
Amniotes (from Greek ἀμνίον amnion, "membrane surrounding the fetus", earlier "bowl in which the blood of sacrificed animals was caught", from ἀμνός amnos, "lamb") are a clade of tetrapod vertebrates comprising the reptiles, birds, and mammals.
The Amphibamidae are an extinct family of dissorophoid euskelian temnospondyls.
Amphibians are ectothermic, tetrapod vertebrates of the class Amphibia.
Amphisbaenia (called amphisbaenians or worm lizards) is a group of usually legless squamates, comprising over 180 extant species.
The anamniotes are an informal group comprising the fishes and the amphibians, the so-called "lower vertebrates", which lay their eggs in water.
Anatomy (Greek anatomē, “dissection”) is the branch of biology concerned with the study of the structure of organisms and their parts.
The Ancient Greek language includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD.
Anomodontia is an extinct group of non-mammalian therapsids containing many species from the Permian and Triassic periods (possibly continuing into the Early Cretaceous), most of which were toothless, possibly endothermic herbivores.
Anthracosauria is an order of extinct reptile-like amphibians that flourished during the Carboniferous and early Permian periods, although precisely which species are included depends on one's definition of the taxon.
A aquatic animal is an animal, either vertebrate or invertebrate, which lives in the water for most or all of its lifetime.
Archegosaurus is a genus of temnospondyl amphibian which lived during the Asselian to Wuchiapingian stages of the Permian, around 299-253 million years ago.
Aristotle (Ἀριστοτέλης Aristotélēs,; 384–322 BC) was an ancient Greek philosopher and scientist born in the city of Stagira, Chalkidiki, in the north of Classical Greece.
Baphetidae is an extinct family of early tetrapods.
In phylogenetics, basal is the direction of the base (or root) of a rooted phylogenetic tree or cladogram.
Bats are mammals of the order Chiroptera; with their forelimbs adapted as wings, they are the only mammals naturally capable of true and sustained flight.
Batrachomorpha ("frog form") is a name traditionally given to recent and extinct amphibians that are more closely related to modern amphibians than they are to reptiles.
Beelarongia is a genus of prehistoric lobe-finned fish which lived during the Late Devonian period (Frasnian stage, about 375 to 385 million years ago).
A biological membrane or biomembrane is an enclosing or separating membrane that acts as a selectively permeable barrier within living things.
Birds, also known as Aves, are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.
A body plan, Bauplan (German plural Baupläne), or ground plan is a set of morphological features common to many members of a phylum of animals.
Branchiosauridae is an extinct family of temnospondyl amphibians.
Buccal pumping is "breathing with one's cheeks": a method of ventilation used in respiration in which the animal moves the floor of its mouth in a rhythmic manner that is externally apparent.
In physics, buoyancy or upthrust, is an upward force exerted by a fluid that opposes the weight of an immersed object.
Caecilians (New Latin for "blind ones") are a group of limbless, serpentine amphibians.
A caiman is an alligatorid crocodilian belonging to the subfamily Caimaninae, one of two primary lineages within Alligatoridae, the other being alligators.
The Canowindridae are a family of prehistoric lobe-finned fishes which lived during the Devonian period (Famennian stage, about 374 to 359 million years ago).
The Carboniferous is a geologic period and system that spans 60 million years from the end of the Devonian Period million years ago (Mya), to the beginning of the Permian Period, Mya.
The Carboniferous rainforest collapse (CRC) was a minor extinction event that occurred around 305 million years ago in the Carboniferous period.
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after his ennoblement as Carl von LinnéBlunt (2004), p. 171.
The carpal bones are the eight small bones that make up the wrist (or carpus) that connects the hand to the forearm.
The Cenozoic Era meaning "new life", is the current and most recent of the three Phanerozoic geological eras, following the Mesozoic Era and, extending from 66 million years ago to the present day.
Cetacea are a widely distributed and diverse clade of aquatic mammals that today consists of the whales, dolphins, and porpoises.
A chemoreceptor, also known as chemosensor, is a specialized sensory receptor cell which transduces (responds to) a chemical substance (endogenous or induced) and generates a biological signal.
Choristodera is an extinct order of semiaquatic diapsid reptiles that ranged from the Middle Jurassic, or possibly Late Triassic, to at least the early Miocene.
A clade (from κλάδος, klados, "branch"), also known as monophyletic group, is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single "branch" on the "tree of life".
Cladistics (from Greek κλάδος, cládos, i.e., "branch") is an approach to biological classification in which organisms are categorized in groups ("clades") based on the most recent common ancestor.
A cladogram (from Greek clados "branch" and gramma "character") is a diagram used in cladistics to show relations among organisms.
In biological classification, class (classis) is a taxonomic rank, as well as a taxonomic unit, a taxon, in that rank.
The clavicle or collarbone is a long bone that serves as a strut between the shoulder blade and the sternum or breastbone.
The cleithrum is a membrane bone which first appears as part of the skeleton in primitive bony fish, where it runs vertically along the scapula.
The coelacanths constitute a now rare order of fish that includes two extant species in the genus Latimeria: the West Indian Ocean coelacanth (Latimeria chalumnae) primarily found near the Comoro Islands off the east coast of Africa and the Indonesian coelacanth (Latimeria menadoensis).
The Colosteidae are a family of tetrapod-like vertebrates that lived in the Carboniferous period.
Coral snakes are a large group of elapid snakes that can be subdivided into two distinct groups, Old World coral snakes and New World coral snakes.
Crassigyrinus (meaning "thick tadpole") is an extinct genus of carnivorous stem tetrapod from the Early Carboniferous of Scotland and possibly Greer, West Virginia.
The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period million years ago (mya) to the beginning of the Paleogene Period mya.
Crocodiles (subfamily Crocodylinae) or true crocodiles are large aquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia.
Crocodilia (or Crocodylia) is an order of mostly large, predatory, semiaquatic archosaurian reptiles, known as crocodilians.
In phylogenetics, the crown group of a collection of species consists of the living representatives of the collection together with their ancestors back to their most recent common ancestor as well as all of that ancestor's descendants.
Cutaneous respiration, or cutaneous gas exchange, is a form of respiration in which gas exchange occurs across the skin or outer integument of an organism rather than gills or lungs.
The cynodonts ("dog teeth") (clade Cynodontia) are therapsids that first appeared in the Late Permian (approximately 260 Ma).
The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume.
Dentition pertains to the development of teeth and their arrangement in the mouth.
The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya.
Diadectomorpha are a clade of large reptile-like amphibians that lived in Euramerica during the Carboniferous and Early Permian periods and in Asia during Late Permian (Wuchiapingian), and are very close to the ancestry of the Amniota.
Diapsids ("two arches") are a group of amniote tetrapods that developed two holes (temporal fenestra) in each side of their skulls about 300 million years ago during the late Carboniferous period.
Dinosaurs are a diverse group of reptiles of the clade Dinosauria.
Dissorophoideans are a clade of medium-sized, temnospondyl amphibians that appeared during the Moscovian in Euramerica, and continued through to the Late Permian and even possibly the Early Triassic of Gondwana (if Micropholis belongs here).
Dolphins are a widely distributed and diverse group of aquatic mammals.
The Elapidae (ἔλλοψ éllops, "sea-fish") are a family of venomous snakes found in the tropics and subtropics around the world, with terrestrial forms in Asia, Australia, Africa, North America, and South America as well as marine forms in the Pacific and Indian oceans.
Elginerpeton is a monotypic genus of early tetrapod, the fossils of which were recovered from Scat Craig, Scotland, in rocks dating to the late Devonian Period (Late Frasnian stage, 375 million years ago).
Elpistostegalia or Panderichthyida is an order of prehistoric lobe-finned fishes which lived during the Late Devonian period (about 385 to 374 million years ago).
Elpistostege is an extinct genus of tetrapod-like vertebrate that lived in the Late Devonian period (Late Givetian to Early Frasnian).
Embolomeri is a suborder of Reptiliomorpha.
The Emsian is one of three faunal stages in the Early Devonian epoch.
Eotetrapodiformes is a clade of sarcopterygian fish including tetrapods (four-limbed vertebrates) and their immediate ancestors, two groups of stem tetrapods called tristichopterids and elpistostegalids.
Euramerica (also known as Laurussia – not to be confused with Laurasia, – the Old Red Continent or the Old Red Sandstone Continent) was a minor supercontinent created in the Devonian as the result of a collision between the Laurentian, Baltica, and Avalonia cratons during the Caledonian orogeny, about 410 million years ago.
Eusthenodon is a genus of prehistoric lobe-finned fish.
Eusthenopteron is a genus of prehistoric sarcopterygian (often called lobe-finned fishes) which has attained an iconic status from its close relationships to tetrapods.
Euteleostomi is a successful clade that includes more than 90% of the living species of vertebrates.
Evolution is change in the heritable characteristics of biological populations over successive generations.
The evolutionary history of life on Earth traces the processes by which both living organisms and fossil organisms evolved since life emerged on the planet, until the present.
An exoskeleton (from Greek έξω, éxō "outer" and σκελετός, skeletós "skeleton") is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton (endoskeleton) of, for example, a human.
An eyelid is a thin fold of skin that covers and protects the human eye.
The femur (pl. femurs or femora) or thigh bone, is the most proximal (closest to the hip joint) bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles including lizards, and amphibians such as frogs.
The fibula or calf bone is a leg bone located on the lateral side of the tibia, with which it is connected above and below.
A fin is a thin component or appendage attached to a larger body or structure.
The focal length of an optical system is a measure of how strongly the system converges or diverges light.
Frequency is the number of occurrences of a repeating event per unit of time.
A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (Ancient Greek ἀν-, without + οὐρά, tail).
The geologic time scale (GTS) is a system of chronological dating that relates geological strata (stratigraphy) to time.
Gephyrostegidae is an extinct family of reptiliomorph tetrapods from the Late Carboniferous including the genera Gephyrostegus, Bruktererpeton, and Eusauropleura.
The gharial (Gavialis gangeticus), also known as the gavial or fish-eating crocodile, is a crocodilian in the family Gavialidae, and is native to the northern part of the Indian Subcontinent.
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water and excretes carbon dioxide.
The glenoid cavity or glenoid fossa of scapulaThe word glenoid is pronounced or (both are common) and is from gléne, "socket", reflecting the shoulder joint's ball-and-socket form.
Gogonasus (meaning "snout from Gogo") was a lobe-finned fish known from 3-dimensionally preserved 380 million-year-old fossils found from the Gogo Formation in Western Australia.
Gondwana, or Gondwanaland, was a supercontinent that existed from the Neoproterozoic (about 550 million years ago) until the Carboniferous (about 320 million years ago).
Gyroptychius is an extinct genus of osteolepiform lobe-finned fish from the Devonian period.
In ecology, a habitat is the type of natural environment in which a particular species of organism lives.
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs.
The Hangenberg event is a bioevent that occurred at the end of the Famennian epoch (late Devonian) associated with the Late Devonian extinction (roughly 358.9 ± 0.4 million years ago); it was an anoxic event marked by a black shale.
The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system.
Herpetology (from Greek "herpein" meaning "to creep") is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians (gymnophiona)) and reptiles (including snakes, lizards, amphisbaenids, turtles, terrapins, tortoises, crocodilians, and the tuataras).
The subphylum Hexapoda (from the Greek for six legs) constitutes the largest number of species of arthropods and includes the insects as well as three much smaller groups of wingless arthropods: Collembola, Protura, and Diplura (all of these were once considered insects).
The hoatzin (Opisthocomus hoazin), also known as the reptile bird, skunk bird, stinkbird, or Canje pheasant, is a species of tropical bird found in swamps, riparian forests, and mangroves of the Amazon and the Orinoco basins in South America.
The Holocene is the current geological epoch.
The Hominidae, whose members are known as great apes or hominids, are a taxonomic family of primates that includes eight extant species in four genera: Pongo, the Bornean, Sumatran and Tapanuli orangutan; Gorilla, the eastern and western gorilla; Pan, the common chimpanzee and the bonobo; and Homo, which includes modern humans and its extinct relatives (e.g., the Neanderthal), and ancestors, such as Homo erectus.
In biology, homology is the existence of shared ancestry between a pair of structures, or genes, in different taxa.
Humans (taxonomically Homo sapiens) are the only extant members of the subtribe Hominina.
The humerus (plural: humeri) is a long bone in the arm or forelimb that runs from the shoulder to the elbow.
The Hydrophiinae, commonly known as sea snakes or coral reef snakes, are a subfamily of venomous elapid snakes that inhabit marine environments for most or all of their lives.
The hyoid bone (lingual bone or tongue-bone) is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage.
The hyomandibula, commonly referred to as hyomandibular (os hyomandibulare, from hyoeides, "upsilon-shaped" (υ), and Latin: mandibula, "jawbone") is a set of bones that is found in the hyoid region in most fishes.
Hypercapnia, also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood.
Ichthyostega (Greek: "fish roof") is an early tetrapodomorph genus that lived at the end of the Upper Devonian period.
Ichthyostegalia is an order of extinct amphibians, representing the earliest landliving vertebrates.
The ilium (plural ilia) is the uppermost and largest part of the hip bone, and appears in most vertebrates including mammals and birds, but not bony fish.
Inertia is the resistance of any physical object to any change in its position and state of motion.
An interclavicle is a bone which, in most tetrapods, is located between the clavicles.
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources.
The ischium forms the lower and back part of the hip bone (os coxae).
The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List), founded in 1964, has evolved to become the world's most comprehensive inventory of the global conservation status of biological species.
Jarvikina is a genus of prehistoric lobe-finned fish which lived during the Devonian period.
A joint or articulation (or articular surface) is the connection made between bones in the body which link the skeletal system into a functional whole.
Journal of Iberian Geology (formerly Cuadernos de Geología Ibérica) is a triannual peer-reviewed scientific journal published by the Universidad Complutense de Madrid.
The Jurassic (from Jura Mountains) was a geologic period and system that spanned 56 million years from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period Mya.
Kenichthys is a genus of sarcopterygian fish from the Devonian period, and a member of the clade tetrapodomorpha.
Koharalepis is a prehistoric lobe-finned fish which lived during the Devonian period.
The Late Devonian extinction was one of five major extinction events in the history of the Earth's biota.
The lateral line is a system of sense organs found in aquatic vertebrates, used to detect movement, vibration, and pressure gradients in the surrounding water.
The lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina.
The Lepidosauria (from Greek meaning scaled lizards) are reptiles with overlapping scales.
Lepospondyli is a diverse taxon of reptiliomorph tetrapods.
An evolutionary lineage is a temporal series of organisms, populations, cells, or genes connected by a continuous line of descent from ancestor to descendent.
The Lissamphibia are a group of tetrapods that includes all modern amphibians.
Lizards are a widespread group of squamate reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains.
The lungs are the primary organs of the respiratory system in humans and many other animals including a few fish and some snails.
Lungfish are freshwater rhipidistian fish belonging to the subclass Dipnoi.
Lysorophia is an order of aquatic Carboniferous and Permian amphibians within the extinct subclass Lepospondyli.
Mammals are the vertebrates within the class Mammalia (from Latin mamma "breast"), a clade of endothermic amniotes distinguished from reptiles (including birds) by the possession of a neocortex (a region of the brain), hair, three middle ear bones, and mammary glands.
Mandageria (Pronunciation: Man-daj-ee-ree-a fair-fax-i) is an extinct genus of lobe-finned fish.
Marsdenichthys is an extinct genus of Devonian tetrapodomorph.
In biology, matrix (plural: matrices) is the material (or tissue) in animal or plant cells, in which more specialized structures are embedded, and a specific part of the mitochondrion.
The Megalichthyidae are a family of prehistoric lobe-finned fishes which lived from the late Devonian to the early Permian period.
Metabolic alkalosis is a metabolic condition in which the pH of tissue is elevated beyond the normal range (7.35–7.45).
Michael James "Mike" Benton FRS (born 8 April 1956) is a British palaeontologist, and professor of vertebrate palaeontology in the School of Earth Sciences at the University of Bristol.
Microsauria ("small lizards") is an extinct order of amphibians from the late Carboniferous and early Permian periods.
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the inner ear.
The moa were nine species (in six genera) of flightless birds endemic to New Zealand.
A mouse (Mus), plural mice, is a small rodent characteristically having a pointed snout, small rounded ears, a body-length scaly tail and a high breeding rate.
The nasolacrimal duct (sometimes called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity.
The natural environment encompasses all living and non-living things occurring naturally, meaning in this case not artificial.
Nectridea is the name of an extinct order of lepospondyl tetrapods from the Carboniferous and Permian periods, including animals such as Diplocaulus.
Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, recent) organisms.
The North China Craton is a continental crustal block with one of Earth's most complete and complex record of igneous, sedimentary and metamorphic processes.
In anatomy, the notochord is a flexible rod made out of a material similar to cartilage.
Obruchevichthys is an extinct genus of tetrapod from Latvia during the Late Devonian.
The octopus (or ~) is a soft-bodied, eight-armed mollusc of the order Octopoda.
An odor, odour or fragrance is always caused by one or more volatilized chemical compounds.
The operculum is a series of bones found in bony fish that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding.
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated.
Organs are collections of tissues with similar functions.
Oscillation is the repetitive variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states.
Osteichthyes, popularly referred to as the bony fish, is a diverse taxonomic group of fish that have skeletons primarily composed of bone tissue, as opposed to cartilage.
Osteolepidae is a family of prehistoric lobe-finned fishes which lived during the Devonian period.
Osteolepiformes, also known as megalichthyiformes, are a group of prehistoric lobe-finned fishes which first appeared during the Devonian period.
Osteolepis ('bone scale') is an extinct genus of lobe-finned fish from the Devonian period.
Otic notches are invaginations in the posterior margin of the skull roof, one behind each orbit.
The palate is the roof of the mouth in humans and other mammals.
Paleontology or palaeontology is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene Epoch (roughly 11,700 years before present).
Panderichthys is a genus of extinct sarcopterygian (lobe-finned fish) from the late Devonian period, about 380 Mya.
The pelvis (plural pelves or pelvises) is either the lower part of the trunk of the human body between the abdomen and the thighs (sometimes also called pelvic region of the trunk) or the skeleton embedded in it (sometimes also called bony pelvis, or pelvic skeleton).
Penguins (order Sphenisciformes, family Spheniscidae) are a group of aquatic, flightless birds.
The Pennsylvanian (also known as Upper Carboniferous or Late Carboniferous) is, in the ICS geologic timescale, the younger of two subperiods (or upper of two subsystems) of the Carboniferous Period.
The Permian is a geologic period and system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic period 251.902 Mya.
The Permian–Triassic (P–Tr or P–T) extinction event, colloquially known as the Great Dying, the End-Permian Extinction or the Great Permian Extinction, occurred about 252 Ma (million years) ago, forming the boundary between the Permian and Triassic geologic periods, as well as the Paleozoic and Mesozoic eras.
Phylogenetic nomenclature, often called cladistic nomenclature, is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below.
A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the evolutionary relationships among various biological species or other entities—their phylogeny—based upon similarities and differences in their physical or genetic characteristics.
Physical strength is the measure of an animal's exertion of force on physical objects.
Physiology is the scientific study of normal mechanisms, and their interactions, which work within a living system.
Pierre André Latreille (29 November 1762 – 6 February 1833) was a French zoologist, specialising in arthropods.
Pinnipeds, commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic marine mammals.
Platycephalichthys is a genus of tristichopterid lobe-finned fish which lived during the middle Devonian, upper Givetian stage.
Polypterus is a genus of freshwater fish in the bichir family (Polypteridae) of order Polypteriformes.
Pregnancy, also known as gestation, is the time during which one or more offspring develops inside a woman.
Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.
A primate is a mammal of the order Primates (Latin: "prime, first rank").
Prototheria (from Greek πρώτος, prōtos, first, + θήρ, thēr, wild animal) is the subclass to which the order Monotremata belongs.
In vertebrates, the pubic bone is the ventral and anterior of the three principal bones composing either half of the pelvis.
A pulse in signal processing is a rapid, transient change in the amplitude of a signal from a baseline value to a higher or lower value, followed by a rapid return to the baseline value.
The radius or radial bone is one of the two large bones of the forearm, the other being the ulna.
In optics, the refractive index or index of refraction of a material is a dimensionless number that describes how light propagates through that medium.
Reptiles are tetrapod animals in the class Reptilia, comprising today's turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives.
Reptiliomorpha is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians).
In physiology, respiration is defined as the movement of oxygen from the outside environment to the cells within tissues, and the transport of carbon dioxide in the opposite direction.
Respiratory acidosis is a medical emergency in which decreased ventilation (hypoventilation) increases the concentration of carbon dioxide in the blood and decreases the blood's pH (a condition generally called acidosis).
The Rhipidistia, also known as dipnotetrapodomorphs (formally Dipnotetrapodomorpha) are a clade of lobe-finned fishes which include the tetrapods and lungfishes.
Rhizodonts (order Rhizodontida) are an extinct group of predatory tetrapodomorph fishes known from many areas of the world from the Givetian through to the Pennsylvanian - the earliest known species is about 377 million years ago (Mya), the latest around 310 Mya.
In vertebrate anatomy, ribs (costae) are the long curved bones which form the rib cage.
In geometry and trigonometry, a right angle is an angle of exactly 90° (degrees), corresponding to a quarter turn.
Robert Lynn Carroll (born May 5, 1938) is a vertebrate paleontologist who specialises in Paleozoic and Mesozoic amphibians and reptiles.
Rock or stone is a natural substance, a solid aggregate of one or more minerals or mineraloids.
Romer's gap is an example of an apparent gap in the tetrapod fossil record used in the study of evolutionary biology.
Salamanders are a group of amphibians typically characterized by a lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults.
The Sarcopterygii or lobe-finned fish (from Greek σαρξ sarx, flesh, and πτερυξ pteryx, fin) – sometimes considered synonymous with Crossopterygii ("fringe-finned fish", from Greek κροσσός krossos, fringe) – constitute a clade (traditionally a class or subclass) of the bony fish, though a strict cladistic view includes the terrestrial vertebrates.
Sauripterus is a genus of rhizodont lobe-finned fish that lived during the Devonian period.
Sauropsida ("lizard faces") is a group of amniotes that includes all existing birds and other reptiles as well as their fossil ancestors and other extinct relatives.
Seymouriamorpha were a small but widespread group of limbed vertebrates (tetrapods).
The Sirenia, commonly referred to as sea cows or sirenians, are an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters.
Skinks are lizards belonging to the family Scincidae and the infraorder Scincomorpha.
The skull is a bony structure that forms the head in vertebrates.
Snakes are elongated, legless, carnivorous reptiles of the suborder Serpentes.
Spiracles are openings on the surface of some animals, which usually lead to respiratory systems.
The stapes or stirrup is a bone in the middle ear of humans and other mammals which is involved in the conduction of sound vibrations to the inner ear.
Stegocephalia is a name used for four-limbed stem-tetrapods, and their amphibian-grade descendants, and in phylogenetic nomenclature for all tetrapods.
The Stem Tetrapoda are a cladistically defined group, consisting of all animals more closely related to extant four-legged vertebrates than to their closest extant relatives (the lungfish), but excluding the crown group Tetrapoda.
Synapsids (Greek, 'fused arch'), synonymous with theropsids (Greek, 'beast-face'), are a group of animals that includes mammals and every animal more closely related to mammals than to other living amniotes.
A tadpole (also called a pollywog) is the larval stage in the life cycle of an amphibian, particularly that of a frog or toad.
The tarsus is a cluster of seven articulating bones in each foot situated between the lower end of tibia and fibula of the lower leg and the metatarsus.
Taxonomy is the science of defining and naming groups of biological organisms on the basis of shared characteristics.
Temnospondyli (from Greek τέμνειν (temnein, "to cut") and σπόνδυλος (spondylos, "vertebra")) is a diverse subclass of extinct small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian, and Triassic periods.
Terrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, spiders), as compared with aquatic animals, which live predominantly or entirely in the water (e.g., fish, lobsters, octopuses), or amphibians, which rely on a combination of aquatic and terrestrial habitats (e.g., frogs, or newts).
The superclass Tetrapoda (from Greek: τετρα- "four" and πούς "foot") contains the four-limbed vertebrates known as tetrapods; it includes living and extinct amphibians, reptiles (including dinosaurs, and its subgroup birds) and mammals (including primates, and all hominid subgroups including humans), as well as earlier extinct groups.
The Tetrapodomorpha (also known as Choanata) are a clade of vertebrates consisting of tetrapods (four-limbed vertebrates) and their closest sarcopterygian relatives that are more closely related to living tetrapods than to living lungfish.
Theria (Greek: θηρίον, wild beast) is a subclass of mammals amongst the Theriiformes (the sister taxa to Yinotheria).
Therocephalia is an extinct suborder of eutheriodont therapsids from the Permian and Triassic.
Theropoda (or, from Greek θηρίον "wild beast" and πούς, ποδός "foot") or theropods are a dinosaur suborder characterized by hollow bones and three-toed limbs.
Threatened species are any species (including animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future.
The tibia (plural tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia), and it connects the knee with the ankle bones.
Tiktaalik is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the late Devonian period, about 375 MYA (million years ago), having many features akin to those of tetrapods (four-legged animals).
Tinirau is an extinct genus of sarcopterygian fish from the Middle Devonian of Nevada.
Toad is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands.
The tongue is a muscular organ in the mouth of most vertebrates that manipulates food for mastication, and is used in the act of swallowing.
Tortoises are a family, Testudinidae. Testudinidae is a Family under the order Testudines and suborder Cryptodira.
The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous.
A trackway is an ancient route of travel for people or animals.
A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group.
The Triassic is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.9 million years ago (Mya), to the beginning of the Jurassic Period Mya.
Tristichopterids (Tristichopteridae) were a diverse and successful group of tetrapodomorph fishes living throughout the Middle and Late Devonian.
Tristichopterus is a genus of prehistoric lobe-finned fish which lived during the Devonian period.
Tuatara are reptiles endemic to New Zealand.
Turtles are diapsids of the order Testudines (or Chelonii) characterized by a special bony or cartilaginous shell developed from their ribs and acting as a shield.
A tympanal organ is a hearing organ in insects, consisting of a membrane (tympanum) stretched across a frame backed by an air sac and associated sensory neurons.
The ulna is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm.
Valentia Island (Dairbhre, meaning "The Oak Wood") is one of Ireland's most westerly points.
Ventastega is a basal tetrapod that lived during the Famennian subdivision of the Late Devonian period approximately 372.2 to 359.2 million years ago, though Ventastega origins as a tetrapod lineage are probably seated in the preceding Frasnian period of the Late Devonian (385.3 to 374.5 million years ago) when a surge of morphological diversification of tetrapods began.
Vertebrates comprise all species of animals within the subphylum Vertebrata (chordates with backbones).
Vertebrate Palaeontology is a basic textbook on vertebrate paleontology by Michael J. Benton, published by Blackwell's.
Vertebrate paleontology is the subfield of paleontology that seeks to discover, through the study of fossilized remains, the behavior, reproduction and appearance of extinct animals with vertebrae or a notochord.
Vertebrate Paleontology is an advanced textbook on vertebrate paleontology by Alfred Sherwood Romer, published by the University of Chicago Press.
The term water bird, waterbird or aquatic bird (not to be confused with wading birds) is used to refer to birds that live on or around water.
Western Kentucky University is a public university in Bowling Green, Kentucky, United States.
Whales are a widely distributed and diverse group of fully aquatic placental marine mammals.
Whatcheeriidae is an extinct family of tetrapods which lived in the Mississippian sub-period, a subdivision of the Carboniferous period.
Zachełmie is a village in the administrative district of Gmina Zagnańsk, within Kielce County, Świętokrzyskie Voivodeship, in south-central Poland.
The 10th edition of Systema Naturae is a book written by Carl Linnaeus and published in two volumes in 1758 and 1759, which marks the starting point of zoological nomenclature.