parent_taxon wetherellus
In biology , an organism is any contiguous living system , such as an ___MASK45___ , plant , 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 . 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 " ___MASK88___ " and within this genus to the species " ___MASK88___ 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 . Mackerel is a common name applied to a number of different species of pelagic fish , mostly , but not exclusively , from the family ___MASK6___ . They are found in both temperate and tropical seas , mostly living along the coast or offshore in the oceanic environment . Mackerel typically have vertical stripes on their backs and deeply forked tails . Many species are restricted in their distribution ranges , and live in separate populations or fish stocks based on geography . Some stocks migrate in large schools along the coast to suitable spawning grounds , where they spawn in fairly shallow waters . After spawning they return the way they came , in smaller schools , to suitable feeding grounds often near an area of upwelling . From there they may move offshore into deeper waters and spend the winter in relative inactivity . Other stocks migrate across oceans . The ___MASK6___ family of the mackerels , tunas , and bonitos includes many of the most important and familiar food fishes . The family consists of 51 species in 15 genera and two subfamilies . All species are in the subfamily Scombrinae , except the butterfly kingfish , which is the sole member of subfamily Gasterochismatinae . 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 Eocene Epoch , lasting from , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era . The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch . The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope C in the atmosphere was exceptionally low in comparison with the more common isotope C . The end is set at a major extinction event called the " Grande Coupure " ( the " Great Break " in continuity ) or the Eocene  Oligocene extinction event , which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay . As with other geologic periods , the strata that define the start and end of the epoch are well identified , though their exact dates are slightly uncertain . The Paleogene ( or ; also spelled Palaeogene or Palæogene ; informally Lower Tertiary ) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( ___MASK33___ ) to the beginning of the Neogene Period ___MASK33___ . It is the beginning of the Cenozoic Era of the present Phanerozoic Eon . The Paleogene is most notable for being the time during which mammals diversified from relatively small , simple forms into a large group of diverse animals in the wake of the Cretaceous  Paleogene extinction event that ended the preceding Cretaceous Period . Wetherellus is an extinct genus of mackerel from the Eocene . The transition between the end of the Eocene and the beginning of the Oligocene is marked by large - scale extinction and floral and faunal turnover ( although minor in comparison to the largest mass extinctions ). Most of the affected organisms were marine or aquatic in nature . They included the last of the ancient cetaceans , the ___MASK35___ .