Editing Mammal classification (section)

{{Short description|Taxonomy of mammals}}
{{Pie chart
|caption=Over 70% of mammal species are in the orders [[Rodent]]ia, [[Chiroptera]], and [[Eulipotyphla]].
|label1=[[Rodentia]] |value1=40.5 |color1=#63aafe
|label2=[[Chiroptera]] |value2=22.2 |color2=#dd2d32
|label3=[[Eulipotyphla]] |value3=8.8 |color3=#fff58c
|label4=[[Primates]] |value4=7.8 |color4=#4ee257
|label5=[[Artiodactyla]] |value5=5.4 |color5=#fea746
|label6=[[Carnivora]] |value6=4.7 |color6=#6711ff
|label7=[[Diprotodontia]] |value7=2.3 |color7=#865357
|label8=[[Didelphimorphia]] |value8=1.9 |color8=#00ccff
|label9=[[Lagomorpha]] |value9=1.7 |color9=#a2bd90
|label10=[[Dasyuromorphia]] |value10=1.3 |color10=#ccffcc
|label11=[[Afrosoricida]] |value11=0.8 |color11=#ffff99
|label12=[[Cingulata]] |value12=0.3 |color12=#ff99cc
|label13=[[Macroscelidea]] |value13=0.3 |color13=#33cccc
|label14=[[Peramelemorphia]] |value14=0.3 |color14=#cc99ff
|label15=[[Perissodactyla]] |value15=0.3 |color15=#3366ff
|label16=[[Pilosa]] |value16=0.3 |color16=#99cc00
|label17=[[Scandentia]] |value17=0.3 |color17=#ffcc99
|label18=[[Paucituberculata]] |value18=0.1
|label19=[[Pholidota]] |value19=0.1
|label20=[[Hyracoidea]] |value20=0.09 |color20=#99ccff
|label21=[[Monotremata]] |value21=0.08 |color21=#ff6600
|label22=[[Sirenia]] |value22=0.06
|label23=[[Proboscidea]] |value23=0.05 |color23=#003366
|label24=[[Dermoptera]] |value24=0.03 |color24=#ccffff
|label25=[[Notoryctemorphia]] |value26=0.03
|label26=[[Microbiotheria]] |value25=0.03
|label27=[[Tubulidentata]] |value27=0.02
}}

{{Mammals by population sidebar}}
[[Mammalia]] is a class of animal within the phylum [[Chordata]]. '''Mammal classification''' has been through several iterations since [[Carl Linnaeus]] initially defined the class. No classification system is universally accepted; McKenna & Bell (1997) and Wilson & Reader (2005) provide useful recent compendiums.<ref name=Mammalogy>{{cite book |title=Mammalogy|edition=Sixth|date=2015|last1=Vaughan|first1=Terry A.|last2=Ryan|first2=James M.|last3=Czaplewski|first3=Nicholas J.|isbn=9781284032093|chapter=Chapter 4: Classification of Mammals |publisher=Jones & Bartlett Learning |chapter-url=http://samples.jbpub.com/9781284032093/9781284032093_CH04_Secure.pdf}}</ref> Many earlier ideas from Linnaeus et al. have been completely abandoned by modern taxonomists, among these are the idea that [[bat]]s are related to [[bird]]s or that [[human]]s represent a group outside of other living things.<ref>{{cite book|last1=Marks|first1=Jonathan M.|title=Human Biodiversity: Genes, Race, and History|date=1995|publisher=Transaction Publishers |isbn=9780202366562}}</ref> Competing ideas about the relationships of mammal orders do persist and are currently in development. Most significantly in recent years, [[cladistics|cladistic]] thinking has led to an effort to ensure that all taxonomic designations represent [[monophyletic]] groups. The field has also seen a recent surge in interest and modification due to the results of [[molecular phylogeny|molecular phylogenetics]].

[[George Gaylord Simpson]]'s classic "Principles of Classification and a Classification of Mammals" ([[#References|Simpson, 1945]]) [[Taxonomy (biology)|taxonomy]] text laid out a [[systematics]] of [[mammal]] origins and relationships that was universally taught until the end of the 20th century.

Since Simpson's 1945 [[scientific classification|classification]], the [[fossil record|paleontological record]] has been recalibrated, and the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself, partly through the new concept of [[cladistics]]. Though field work gradually made Simpson's classification outdated, it remained the closest thing to an official classification of mammals. See [[List of placental mammals]] and [[List of monotremes and marsupials]] for more detailed information on mammal genera and species.