Mammals on 'sky islands' may be threatened by climate change, human development
A new study sheds light on how climate change and human development threaten mammal species living in isolated biodiversity hotspots known as "sky islands."
A new study sheds light on how climate change and human development threaten mammal species living in isolated biodiversity hotspots known as "sky islands."
Plants & Animals
Apr 29, 2024
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Research published in the Proceedings of the National Academy of Sciences identifies how gentrified parts of a city have notably more urban wildlife than ungentrified parts of the same city, further limiting marginalized ...
Ecology
Apr 15, 2024
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A mysterious parasite from Asia is infecting snakes over most of Florida, and researchers believe it was likely brought here by invasive Burmese pythons.
Plants & Animals
Apr 3, 2024
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In a study published in Biology Letters, researchers at Queen Mary University of London have cracked a centuries-old philosophical question about sight and touch. Led by Dr. Elisabetta Versace, the team used chicks to finally ...
Plants & Animals
Apr 2, 2024
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As habitat loss and fragmentation continues, many in the scientific community view landscape corridors as important for connecting habitat fragments to maintain biodiversity.
Ecology
Apr 2, 2024
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Interstate 90 fractures the spine of the Cascades at its midpoint.
Plants & Animals
Apr 1, 2024
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Killer whales foraging in deep submarine canyons off the coast of California represent a distinct subpopulation that uses specialized hunting techniques to catch marine mammals, Josh McInnes at the University of British Columbia ...
Ecology
Mar 20, 2024
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One of the largest studies on wildlife activity—involving more than 220 researchers, 163 mammal species and 5,000 camera traps worldwide—reveals that wild animals react differently to humans depending on where the animals ...
Plants & Animals
Mar 18, 2024
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It sounds like a crime show episode at sea: In late January 2024, federal regulators learned that a dead female North Atlantic right whale had been sighted near Martha's Vineyard, Massachusetts. The whale was towed to shore, ...
Plants & Animals
Mar 13, 2024
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62
New research is cutting male mammals down to size.
Plants & Animals
Mar 13, 2024
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Mammals (formally Mammalia) are a class of vertebrate animals whose females are characterized by the possession of mammary glands while both males and females are characterized by sweat glands, hair, three middle ear bones used in hearing, and a neocortex region in the brain.
Mammals are divided into three main categories depending how they are born. These categories are, monotremes, marsupials and placentals. Except for the five species of monotremes (which lay eggs), all mammal species give birth to live young. Most mammals also possess specialized teeth, and the largest group of mammals, the placentals, use a placenta during gestation. The mammalian brain regulates endothermic and circulatory systems, including a four-chambered heart.
There are approximately 5,400 species of mammals, distributed in about 1,200 genera, 153 families, and 29 orders (though this varies by classification scheme). Mammals range in size from the 30–40-millimetre (1.2–1.6 in) Bumblebee Bat to the 33-metre (110 ft) Blue Whale.
Mammals are divided into two subclasses, the prototheria, which includes the oviparous monotremes, and the theria, which includes the placentals and live-bearing marsupials. Most mammals, including the six largest orders, belong to the placental group. The three largest orders, in descending order, are Rodentia (mice, rats, and other small, gnawing mammals), Chiroptera (bats), and Soricomorpha (shrews, moles and solenodons). The next three largest orders include the Carnivora (dogs, cats, weasels, bears, seals, and their relatives), the Cetartiodactyla (including the even-toed hoofed mammals and the whales) and the Primates to which the human species belongs. The relative size of these latter three orders differs according to the classification scheme and definitions used by various authors.
Phylogenetically, Mammalia is defined as all descendants of the most recent common ancestor of monotremes (e.g., echidnas and platypuses) and therian mammals (marsupials and placentals). This means that some extinct groups of "mammals" are not members of the crown group Mammalia, even though most of them have all the characteristics that traditionally would have classified them as mammals. These "mammals" are now usually placed in the unranked clade Mammaliaformes.
The mammalian line of descent diverged from an amniote line at the end of the Carboniferous period. One line of amniotes would lead to reptiles, while the other would lead to synapsids, including mammals. The first true mammals appeared in the Triassic period. Modern mammalian orders appeared in the Palaeocene and Eocene epochs of the Palaeogene period.
This text uses material from Wikipedia, licensed under CC BY-SA