TetrapodA tetrapod (; from Ancient Greek (tetra)'four' and (poús)'foot') is any vertebrateanimal of the cladeTetrapoda (). The main diagnostic and defining trait (synapomorphy) of tetrapods is having four limbs, connected to the shoulder- and pelvic girdles, for which the group is named. As a clade, Tetrapoda is defined such that it includes every organism which descended from four-limbed ancestors, including those which have lost some or all of these limbs, e.g. snakes.
AmphibianAmphibians are ectothermic, anamniotic, four-limbedvertebrateanimals that constitute the classAmphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods, but excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals). All extant (living) amphibians belong to the monophyleticsubclassLissamphibia, with three living orders: Anura (frogs and toads), Urodela (salamanders), and Gymnophiona (caecilians).
SarcopterygiiSarcopterygii (; from Ancient Greek (sárx)'flesh' and (ptérux)'wing, fin') is a clade (traditionally a class or subclass) of vertebrateanimals which includes a group of bony fishes and all four legged land animals, including humans. The common name for this clade is lobe-finned fish. Lobe-finned fish have muscular limb buds (lobes) within their fins, which are supported by appendicular skeletons.
ReptileClass of animalsReptiles, as commonly defined, are tetrapodvertebrateanimals with an ectothermic metabolism and amniotic development. Reptiles traditionally comprise four orders: Testudines (turtles), Crocodilia (crocodiles, alligators and gharials), Squamata (lizards and snakes) and Rhynchocephalia (tuatara), with about 12,000 extant species listed in the Reptile Database.
DevonianSubdivision of the Devonian according to the ICS, as of 2024Vertical axis scale: Millions of years agoEtymologyName formalityFormalNickname(s)Age of FishesUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitPeriodStratigraphic unitSystemTime span formalityFormalLower boundary definitionFAD of the GraptoliteLower boundary GSSPKlonk, Czech Republic49°51′18″N13°47′31″E / 49.8550°N 13.7920°E / 49.8550; 13.7920Lower GSSP ratified1972Upper boundary definitionFAD of the ConodontSiphonodella sulcata (discovered to have biostratigraphic issues as of 2006).Upper boundary GSSPLa Serre, Montagne Noire, France43°33′20″N3°21′26″E / 43.5555°N 3.3573°E / 43.5555; 3.3573Upper GSSP ratified1990Atmospheric and climatic dataSea level above present dayRelatively steady around 189 m, gradually falling to 120 m through periodThe Devonian ( ) is a geologic period and system of the Paleozoicera during the Phanerozoiceon, spanning 60.7 million years from the end of the preceding Silurian period at 419.62 million years ago (Ma), to the beginning of the succeeding Carboniferous period at 358.86 Ma.
BirdWarm-blooded animals with wings and feathersBirds are a group of warm-bloodedvertebrateanimals constituting the classAves, 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. They live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich.
MammalClass of animals with milk-producing glandsA mammal (from Latin mamma 'breast') is a vertebrate animal of the classMammalia (). Mammals are characterized by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors diverged in the Carboniferous period over 300 million years ago.
TadpoleA tadpole or polliwog (also porwigle) is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found in adult amphibians, such as a lateral line, gills and swimming tails. As they undergo metamorphosis, they start to develop functional lungs for breathing air, and the diet of tadpoles changes drastically.
Apomorphy and synapomorphyIn phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. In cladistics, synapomorphy implies homology.
Class (taxonomy)In biological taxonomy, class (Latin: classis) is a taxonomic rank, as well as a taxonomic unit (i.e., a taxon) in that rank. It is a group of related taxonomic orders. Other well-known ranks in descending order of size are domain, kingdom, phylum, order, family, genus, and species, with class ranking between phylum and order.
PaleontologyPaleontology or palaeontology is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geologic time, and assess the interactions between prehistoric organisms and their natural environment.*As an Amazon Associate I earn from qualifying purchases.