Rodents make up the largest order of mammals, with over 40% of mammalian species. They have two
incisors in the upper and lower jaw which grow continually and must be kept short by gnawing.
The lagomorphs comprise two families,
Leporidae (
hares and
rabbits), and Ochotonidae (
pikas). Though they can resemble
rodents, and were classified as a
superfamily in that order until the early 20th century, they have since been considered a separate order. They differ from rodents in a number of physical characteristics, such as having four incisors in the upper jaw rather than two.
Order:
Eulipotyphla (shrews, hedgehogs, gymnures, moles and solenodons)
Eulipotyphlans are insectivorous mammals.
Shrews and
solenodons resemble mice,
hedgehogs carry spines,
gymnures look more like large rats, while
moles are stout-bodied burrowers.
The bats' most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals capable of flight. Bat species account for about 20% of all mammals.
The order Cetacea includes
whales,
dolphins and
porpoises. They are the mammals most fully
adapted to aquatic life with a spindle-shaped nearly hairless body, protected by a thick layer of blubber, and forelimbs and tail modified to provide propulsion underwater.
There are over 260 species of carnivorans, the majority of which eat meat as their primary dietary item. They have a characteristic skull shape and dentition.
The even-toed ungulates are
ungulates whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in
perissodactyls. There are about 220 artiodactyl species, including many that are of great economic importance to humans.
^McDonald, R. A.; Abramov, A. V.; Stubbe, M.; Herrero, J.; Maran, T.; Tikhonov, A.; Cavallini, P.; Kranz, A.; Giannatos, G.; Kryštufek, B. & Reid, F. (2019).
"Mustela nivalis". IUCN Red List of Threatened Species. 2019: e.T70207409A147993366.
^Skumatov, D.; Abramov, A.V.; Herrero, J.; Kitchener, A.; Maran, T.; Kranz, A.; Sándor, A.; Stubbe, M.; Saveljev, A.; Savour-Soubelet, A.; Guinot-Ghestem, M.; Zuberogoitia, I.; Birks, J.D.S.; Weber, A.; Melisch, R. & Ruette, S. (2016).
"Mustela putorius". IUCN Red List of Threatened Species. 2016: e.T41658A45214384.
^Anderwald, P.; Ambarli, H.; Avramov, S.; Ciach, M.; Corlatti, L.; Farkas, A.; Papaioannou, H.; Peters, W.; Sarasa, M.; Šprem, N.; Weinberg, P. & Willisch, C. (2021) [amended version of 2020 assessment].
"Rupicapra rupicapra". IUCN Red List of Threatened Species. 2021: e.T39255A195863093.
Rodents make up the largest order of mammals, with over 40% of mammalian species. They have two
incisors in the upper and lower jaw which grow continually and must be kept short by gnawing.
The lagomorphs comprise two families,
Leporidae (
hares and
rabbits), and Ochotonidae (
pikas). Though they can resemble
rodents, and were classified as a
superfamily in that order until the early 20th century, they have since been considered a separate order. They differ from rodents in a number of physical characteristics, such as having four incisors in the upper jaw rather than two.
Order:
Eulipotyphla (shrews, hedgehogs, gymnures, moles and solenodons)
Eulipotyphlans are insectivorous mammals.
Shrews and
solenodons resemble mice,
hedgehogs carry spines,
gymnures look more like large rats, while
moles are stout-bodied burrowers.
The bats' most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals capable of flight. Bat species account for about 20% of all mammals.
The order Cetacea includes
whales,
dolphins and
porpoises. They are the mammals most fully
adapted to aquatic life with a spindle-shaped nearly hairless body, protected by a thick layer of blubber, and forelimbs and tail modified to provide propulsion underwater.
There are over 260 species of carnivorans, the majority of which eat meat as their primary dietary item. They have a characteristic skull shape and dentition.
The even-toed ungulates are
ungulates whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in
perissodactyls. There are about 220 artiodactyl species, including many that are of great economic importance to humans.
^McDonald, R. A.; Abramov, A. V.; Stubbe, M.; Herrero, J.; Maran, T.; Tikhonov, A.; Cavallini, P.; Kranz, A.; Giannatos, G.; Kryštufek, B. & Reid, F. (2019).
"Mustela nivalis". IUCN Red List of Threatened Species. 2019: e.T70207409A147993366.
^Skumatov, D.; Abramov, A.V.; Herrero, J.; Kitchener, A.; Maran, T.; Kranz, A.; Sándor, A.; Stubbe, M.; Saveljev, A.; Savour-Soubelet, A.; Guinot-Ghestem, M.; Zuberogoitia, I.; Birks, J.D.S.; Weber, A.; Melisch, R. & Ruette, S. (2016).
"Mustela putorius". IUCN Red List of Threatened Species. 2016: e.T41658A45214384.
^Anderwald, P.; Ambarli, H.; Avramov, S.; Ciach, M.; Corlatti, L.; Farkas, A.; Papaioannou, H.; Peters, W.; Sarasa, M.; Šprem, N.; Weinberg, P. & Willisch, C. (2021) [amended version of 2020 assessment].
"Rupicapra rupicapra". IUCN Red List of Threatened Species. 2021: e.T39255A195863093.