What is Mammal?
{{Automatic taxobox | name = Mammalia | fossil_range = 225&ndash;0 mya (Kemp)<ref name=Kemp/> <br/>or 167&ndash;0 mya (Rowe)<ref name=Rowe>Rowe T. 1988. Definition, diagnosis, and origin of Mammalia. ''Journal of Vertebrate Paleontology'' '''8''' (3): 241–264.</ref> |image = <imagemap> File:Mammal Diversity 2021.jpg|300px rect 0 0 176 125 [[common vampire bat]] rect 0 120 176 240 [[Tasmanian devil]] rect 0 240 176 380 [[fox squirrel]] rect 0 380 176 500 [[platypus]] rect 0 500 176 600 [[humpback whale]] rect 0 760 176 620 [[giant armadillo]] rect 355 0 176 125 [[Virginia opossum]] rect 355 120 176 240 [[human]] rect 355 240 176 380 [[tree pangolin]] rect 355 380 176 500 [[colugo]] rect 355 500 176 600 [[star nosed mole]] rect 355 760 176 620 [[plains zebra]] rect 530 0 350 125 [[eastern grey kangaroo]] rect 530 120 350 240 [[northern elephant seal]] rect 530 240 350 380 [[African elephant]] rect 530 380 350 500 [[reindeer]] rect 530 500 350 600 [[giant panda]] rect 530 760 350 620 [[black and rufous elephant shrew]] </imagemap> | display_parents = 3 | taxon = Mammalia | authority = [[Carl Linnaeus|Linnaeus]], 1758 | subdivision_ranks = Living subgroups | subdivision = *Subclass [[Prototheria]] **Infraclass [[Australosphenida]] ***Order [[Monotreme|Monotremata]] *Subclass [[Theria]] **Infraclass [[Metatheria]] **Infraclass [[Eutheria]] }} '''Mammals''' are in the [[class (biology)|class]] '''Mammalia'''. They are a group of [[vertebrate]] animals.<ref>Szalay F.S. 1999. Classification of mammals above the species level: Review. ''Journal of Vertebrate Paleontology'' '''19''' (1): 191–195. [[doi:10.1080/02724634.1999.10011133]]. [[JSTOR]] 4523980.</ref> They have [[fur]] or [[hair]] and very precise [[homoiothermy|temperature regulation]]. With the exception of the [[monotreme]]s, all mammals bear live young. Unlike other [[vertebrate]]s, they are the only animals that produce milk for their young through their mammary glands. Parental care of the young is universal among mammals, sometimes for long periods.