parent_taxon prodesmodon
The Holarctic is the name for the biogeographic realm that encompasses the majority of habitats found throughout the northern continents of the world , combining Wallace ' s Palearctic zoogeographical region , consisting of North Africa and all of Eurasia ( with the exception of the southern Arabian Peninsula , Southeast Asia , and the Indian subcontinent ), and the Nearctic zoogeographical region , consisting of North America north of Southern Mexico . These regions are further subdivided into a variety of ecoregions . Many ecosystems , and the ___MASK47___ and ___MASK7___ communities that depend on them , are found across multiple continents in large portions of this realm . The continuity of these ecosystems results from the shared glacial history of the realm . The floristic Boreal Kingdom corresponds to the Holarctic realm . The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period million years ago ( ___MASK42___ ) to the beginning of the Paleogene Period ___MASK42___ . It is the last period of the Mesozoic Era . The Cretaceous Period is usually abbreviated K , for its German translation " Kreide " ( chalk ). The Frenchman Formation is stratigraphic unit of Late Cretaceous ( late Maastrichtian ) age in the Western Canada Sedimentary Basin . It is present in southern Saskatchewan and the Cypress Hills of southeastern Alberta . The formation was defined by G . M . Furnival in 1942 from observations of outcrops along the Frenchman River , between Ravenscrag and Highway 37 . It contains the youngest of ___MASK2___ genera , much like the Hell Creek Formation in the United States . Salamanders are a group of amphibians typically characterized by a ___MASK85___ - 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 . All present - day salamander families are grouped together under the scientific name Urodela . Salamander diversity is most abundant in the Northern Hemisphere and most species are found in the Holarctic ecozone , with some species present in the Neotropical zone . A genus ( genera ) is a taxonomic rank used in the biological classification of living and fossil organisms in biology . In the hierarchy of biological classification , genus comes above species and below family . In binomial nomenclature , the genus name forms the first part of the binomial species name for each species within the genus . The Lance ( Creek ) Formation is a division of Late Cretaceous ( dating to about 69 - 66 Ma ) rocks in the western United States . Named after Lance Creek , Wyoming , the microvertebrate fossils and dinosaurs represent important components of the latest Mesozoic vertebrate faunas . The Lance Formation is Late Maastrichtian in age ( Lancian land ___MASK30___ age ), and shares much fauna with the Hell Creek Formation of Montana and North Dakota , the Frenchman Formation of southwest Saskatchewan , and the lower part of the Scollard Formation of Alberta . 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 group , traditionally recognized as the suborder Lacertilia , is defined as all extant members of the ___MASK5___ ( reptiles with overlapping scales ) that are neither sphenodonts ( i . e ., tuatara ) nor snakes  they form an evolutionary grade . While the snakes are recognized as falling phylogenetically within the Toxicofera clade from which they evolved , the sphenodonts are the sister group to the squamates , the larger monophyletic group , which includes both the lizards and the snakes . Vertebrates comprise all species of animals within the subphylum ___MASK76___ ( chordates with backbones ). Vertebrates represent the overwhelming majority of the phylum Chordata , with currently about 64 , 000 species described . Vertebrates include the jawless fish and the jawed vertebrates , which include the cartilaginous fish ( sharks and rays ) and the bony fish . Fauna is all of the ___MASK47___ life of any particular region or time . The corresponding term for plants is " flora ". Flora , fauna and other forms of life such as ___MASK44___ are collectively referred to as biota . Zoologists and paleontologists use " fauna " to refer to a typical collection of animals found in a specific time or place , e . g . the " Sonoran Desert fauna " or the " Burgess Shale fauna ". Paleontologists sometimes refer to a sequence of faunal stages , which is a series of rocks all containing similar fossils . Binomial nomenclature ( also called binominal nomenclature or binary nomenclature ) is a formal system of naming species of living things by giving each a name composed of two parts , both of which use Latin grammatical forms , although they can be based on words from other languages . Such a name is called a binomial name ( which may be shortened to just " binomial "), a binomen or a scientific name ; more informally it is also called a Latin name . The first part of the name identifies the genus to which the species belongs ; the second part identifies the species within the genus . For example , humans belong to the genus " ___MASK6___ " and within this genus to the species " ___MASK6___ sapiens ". The " formal " introduction of this system of naming species is credited to Carl Linnaeus , effectively beginning with his work " Species Plantarum " in 1753 . But Gaspard Bauhin , in as early as 1623 , had introduced in his book " Pinax theatri botanici " ( English , " Illustrated exposition of plants ") many names of genera that were later adopted by Linnaeus . In biology , an organism is any contiguous living system , such as an ___MASK47___ , ___MASK7___ , fungus , archaeon , or bacterium . All known types of organisms are capable of some degree of response to stimuli , reproduction , growth and development and homeostasis . An organism consists of one or more cells ; when it has one cell it is known as a unicellular organism ; and when it has more than one it is known as a multicellular organism . Most unicellular organisms are of microscopic scale and are thus loosely described as microorganisms . Humans are multicellular organisms composed of many trillions of cells grouped into specialized tissues and organs . Prodesmodon is an extinct genus of prehistoric salamander first described from the Lance Formation . Amphibians are ectothermic , tetrapod vertebrates of the class ___MASK68___ . Modern amphibians are all Lissamphibia . They inhabit a wide variety of habitats , with most species living within terrestrial , fossorial , arboreal or freshwater aquatic ecosystems . Thus amphibians typically start out as larvae living in water , but some species have developed behavioural adaptations to bypass this . The young generally undergo metamorphosis from larva with gills to an adult air - breathing form with lungs . Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin . They are superficially similar to lizards but , along with mammals and birds , reptiles are amniotes and do not require water bodies in which to breed . With their complex reproductive needs and permeable skins , amphibians are often ecological indicators ; in recent decades there has been a dramatic decline in amphibian populations for many species around the globe .