No, squirrels are not marsupials. Squirrels belong to the order Rodentia and family Sciuridae, while marsupials belong to the order Didelphimorphia, Dasyuromorphia, Diprotodontia, Microbiotheria, Notoryctemorphia, Peramelemorphia, and Paucituberculata.
Squirrels and marsupials are very different types of mammals. The most noticeable difference is that marsupials have pouches where their young develop, while squirrels do not have pouches. Additionally, squirrels give birth to relatively mature young, while marsupial young are extremely undeveloped when they are born and complete their development attached to a nipple inside the mother’s pouch.
Some key differences between squirrels and marsupials:
Taxonomy
Squirrels are rodents belonging to the family Sciuridae. There are over 200 species divided into three subfamilies:
| Subfamily | Genera |
|---|---|
| Sciurinae | Funambulus, Heliosciurus, Protoxerus, Ratufa, Sciurus, and many others |
| Xerinae | Atlantoxerus, Spermophilopsis, Spermophilus, Xerus, and others |
| Callosciurinae | Callosciurus, Dremomys, Glyphotes, Nannosciurus, and others |
Marsupials belong to the order Didelphimorphia in the Americas or the orders Dasyuromorphia, Diprotodontia, Microbiotheria, Notoryctemorphia, Peramelemorphia, and Paucituberculata in Australasia. There are over 330 species divided into 19-21 families, such as:
| Family | Genera |
|---|---|
| Didelphidae | Caluromys, Chironectes, Didelphis, Glironia, Gracilinanus, and others |
| Potoroidae | Aepyprymnus, Bettongia, Caloprymnus, Potorous |
| Macropodidae | Dendrolagus, Dorcopsulus, Lagorchestes, Macropus, Onychogalea, Petrogale, Wallabia |
So squirrels and marsupials are not at all closely related taxonomically.
Reproduction
The main difference in reproduction is that marsupials give birth to highly altricial young that complete development nursing in the mother’s pouch, whereas squirrels give birth to relatively mature young.
– Marsupial babies are born at a very early stage of development after a short gestation period (12-43 days depending on species). They are unable to survive independently and must crawl into the mother’s pouch to nurse and continue developing.
– Squirrels have a longer gestation period of 30-60 days. The young are relatively mature at birth, with fur and eyes open. They are able to survive outside the mother’s body but are not fully weaned for 2-3 months.
Physical Features
Squirrels and marsupials also differ significantly in their physical features:
| Feature | Squirrels | Marsupials |
|---|---|---|
| Body Plan | Long bushy tail, elongated hind legs, compact body | Varied, but very few have bushy tails. Many hopping marsupials have enlarged hind legs. |
| Teeth | One pair of chisel-like incisors that grow continuously. Flat premolars and molars. | Varied teeth specialized for different diets. Many have two pairs of incisors and several pairs of molars/premolars. |
| Pouch | No pouch | Females have a marsupium or pouch to support underdeveloped young. |
| Limbs | Claws for gripping. Five digits on front feet, four on hind. | First digit on hind foot is often opposable. Some species have syndactyly. |
Habitat and Behavior
Squirrels and marsupials also differ in terms of their habitat, diet, and behavior:
– Squirrels live in wooded areas worldwide and eat nuts, seeds, flowers, and sometimes insects. They are diurnal and live in nests or tree hollows.
– Marsupials occupy diverse habitats in Australasia and the Americas. Diets vary widely by species. Some are nocturnal while others are active in daytime. Shelter includes burrows, tree hollows, and nests.
– Squirrels demonstrate great agility leaping through trees. Some marsupials hop or jump though most walk/run along the ground.
– Squirrels hoard food in caches. Very few marsupials exhibit food caching.
So in habitat, diet, activity patterns, and behavior, squirrels and marsupials show considerable differences.
Geographic Distribution
Squirrels and marsupials inhabit very different parts of the world:
– Squirrels are found throughout Eurasia and the Americas in wooded and forested environments. They are absent in Australasia.
– Marsupials are native to South America, Central America, and Australasia. Very few marsupial species reached North America, and no marsupials live naturally in Europe or Asia.
Australia in particular is known for its abundance of marsupial species. Over 300 species of marsupials occur in Australasia compared to only one native marsupial in South America and around 100 in Central/North America. Squirrels do not inhabit Australia at all.
So squirrels have a primarily Northern Hemisphere distribution, while marsupials are concentrated in Australia and South/Central America. Their ranges do not overlap significantly.
Major Groups
Some of the most common types of squirrels include:
– Tree squirrels: Small to medium-sized with bushy tails adapted for climbing, like gray squirrels and fox squirrels
– Ground squirrels: Live mostly on the ground rather than trees, like chipmunks and prairie dogs
– Flying squirrels: Capable of gliding flight using patagia extending between limbs
Some of the major groups of marsupials include:
– Opossums: Around 100 species in the Americas, including the Virginia opossum
– Shrew opossums: Very small marsupials in the Americas and Australasia
– Paucituberculata: Includes shrew opossums; 6 species in South America
– Dasyuromorphia: Carnivorous marsupials like quolls, dunnarts, the Tasmanian devil
– Diprotodontia: Largest order with kangaroos, wallabies, possums, koala, wombats
Conclusion
In summary, squirrels and marsupials are completely unrelated groups of mammals belonging to different taxonomic orders. They differ substantially in their reproductive biology, physical characteristics, habitat and behavior, and geographic distribution. No species is classified as both a squirrel and a marsupial. While both groups contain small, furry mammals adapted to climbing, their evolutionary histories and biological attributes are very distinct. Taxonomically, reproductively, morphologically, ecologically, and geographically it is clear that squirrels are not marsupials.
