Marsupial mammals presentation. Presentation on biology "class marsupials"
Appearance and distribution
- Giant kangaroo (Macropus giganteus)
- Based paleontological studies, marsupials were very common in Mesozoic, but subsequently them, like cloacal, supplanted placental from most continents. The time of appearance of marsupials, according to some estimates, is ~ 186-193 million years ago ( Jurassic period).The oldest fossil remains of marsupials are considered to be those found in sediments Cretaceous period provinces Liaoning, in northeast China, remains of a mammal Sinodelphys szalayi 125 million years old.
- Most marsupials South America became extinct after the emergence of a natural bridge between the South and North America, along which new species began to penetrate from north to south (“ great inter-american exchange"). Only opossums were able to withstand the competition and even spread to the north.
- Unlike South America Australian The world of marsupials, as a result of geographical isolation, has survived to this day, but after the appearance person 45,000 years ago and here it underwent significant changes. According to a widely accepted hypothesis, all species of large marsupials were extirpated by settlers soon after they settled in Australia. There are, however, studies that claim that large marsupials coexisted with humans until 15,000 years ago and became extinct as a result of the cold and droughts of the latter ice age. According to this hypothesis, the reason for their extinction was not humans, but their insufficient adaptive ability. The influence of man, as well as the species he brought, however, cannot be denied.
General information
- Sugar Flying possum has a flight membrane
- Marsupials occupy various ecological niches; there are species that lead an underground lifestyle ( marsupial mole), some animals, such as various opossums And koalas They climb well; there are also representatives that lead a semi-aquatic lifestyle ( water possum). Among marsupials there are insectivores , predatory And herbivores kinds. Depending on their lifestyle, animals have various adaptations to a specific habitat: a prehensile tail for climbing ( Virginia opossum), powerful claws for digging ( marsupial mole) etc. Also, their embryonic period is very short. The cubs are born small and poorly developed. Additional development occurs in the mother's pouch. The cub grabs the mother's nipple and hangs on it. By contracting special muscles, the mother periodically injects milk into the baby's mouth. The cubs are fed milk for about 2 months. And they stay in the bag for 9-10 months
Structure
- Body sizes vary greatly: from 10 cm ( marsupial mice) up to 3 m ( big red kangaroo). Body temperature is lower than that of most mammals: 34-36 degrees.
- One of the features of the skeletal structure of marsupials is the presence marsupial bones- special bones pelvis. They also have a different structure from other mammals lower jaw, the rear ends of which are bent inward. Based on the structure of the dental system, marsupials can be divided into two groups: two-incisor and multi-incisor. Quantity incisors largely depends on the animal’s lifestyle. For example, in primitive insectivorous and carnivorous forms the number of incisors is especially large - on each half of the jaw they have five at the top and four at the bottom. Herbivorous animals do not have more than one incisor on each side of the lower jaw.
- Some species may lack a bursa ( marsupial anteater); can be expressed only by a small fold limiting the milky field. In some marsupials, the pouch can open backwards ( koala)
- It’s a different matter with kangaroos, which jump on their hind legs, using their tail to maintain balance at high speed, or on all four limbs, and then the tail serves as an additional point of support. In open spaces, large kangaroos can move very quickly: their speed reaches 65 km/h, and the length of their jumps is 7.5 m or more.
The sugar glider has a body length of 27.5 to 40 cm, with a bushy tail accounting for 15-20 cm of this length. In appearance and size, the sugar glider is similar to our common squirrel, although thanks to the flight membrane, it seems unusually wide. There is sexual dimorphism in size: males are larger than females. The weight of adult males ranges from 115 to 160 g, while the weight of females varies from 100 to 135 g. The head of the flying possum is relatively short and flat with a somewhat pointed muzzle, the neck is short and rather thick. The legs are small, the feet are five-toed.
The Virginia opossum, when threatened, first hisses and then secretes a foul-smelling liquid. But if these tricks do not scare off the attacker, the opossum falls into a kind of coma. He lies motionless, his tongue hanging out, his limbs become stiff and lose visible sensitivity, his breathing and heartbeat slow down so that they are almost unnoticeable. This happens in moments of danger, but even under normal conditions, the metabolism of opossums and other marsupials is less intense than that of placental mammals, the body temperature is lower, and the heart beats less often.
Wombats and moles
Wombats and marsupial moles dig holes with powerful front paws with spade-shaped claws. Tearing up the ground, the mole covers the passage behind itself with its hind limbs. Sometimes it travels across the surface of the earth for short distances. The stocky, badger-sized wombat digs tunnels up to 30 m long.
Marsupial anteater
- The marsupial anteater feeds mainly on ants and termites, opening their homes with its front paws with powerful claws and sticking its long snout with a sticky tongue inside.
- The gigantic marsupial marten with its long body and short tenacious paws deftly climbs trees, but sometimes descends to the ground. It feeds on small animals and eggs, and hunts mainly at night.
- Marsupial mice, or mousebirds, feed on insects and other small animals. Thanks to their flattened heads, they are able to climb into narrow crevices.
Disappeared in 1934
- Tasmanian wolf, the largest marsupial predator. In pursuit of prey, including kangaroos, he gained the upper hand not through speed, but through endurance.
Students of grade 7 "B"
Gymnasium No. 2
Swede Svetlana and Globa Olga
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general characteristics
There are about 250 species. They live in Australia, New Guinea, and several species in America. The name was given for the presence of a special fold of skin on the belly in the form of a pocket, or bag, where newborns are placed.
Cubs are born helpless, small, underdeveloped. Their further development occurs in the bag.
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Kangaroo
Peculiarities
The presence of marsupial bones (special pelvic bones that are developed in both females and males). Body temperature is 34-36° C. Kangaroos give birth to live young and feed them with milk. Kangaroos have a pouch for carrying their young; it opens towards the head, like an apron pocket.
The special structure of the lower jaw, the lower ends of which are curved inward. Their fangs are absent or underdeveloped, and their molars have blunted tubercles.
Kangaroos are born just a few weeks after conception, while the mother kangaroo sits in a certain position with her tail between her legs, and the baby (at this moment smaller than her little finger) crawls into her pouch, finds a nipple there and sucks on it, feeding on milk.
The immune system of a newborn kangaroo is not formed, so mother kangaroo milk has a strong antibacterial effect.
Contrary to popular belief, male kangaroos do not have a pouch, but only females do.
It is much easier for kangaroos to move around during their long hops than to walk or hop little by little!
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Opossums
The dimensions of opossums are small: body length 7-50 cm, tail 4-55 cm. The muzzle is elongated and pointed. The tail is entirely or only at the end bare, prehensile, sometimes thickened at the base with fat deposits. The body is covered with short, thick fur, the color of which varies from gray and yellowish-brown to black. The structure of the dental system, limbs, and bag indicates the primitiveness of opossums. Their limbs are shortened, five-fingered; the big toe of the hind limb is opposed to the other toes and lacks a claw. The hind legs are usually more developed than the front legs. The dental formula is archaic: a full row of incisors (5 on the upper jaw and 4 on the lower jaw), well-developed canines and sharply tuberculated molars. All opossums have 50 teeth. Opossums are inhabitants of forests, steppes and semi-deserts; found both on plains and in mountains up to 4000 m above sea level. Most lead a terrestrial or arboreal lifestyle; the water possum is semi-aquatic. Active at dusk and at night. Omnivores or insectivores. Outside the mating season they lead a solitary lifestyle.
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Koalas, or marsupial bears
The koala is a medium-sized animal with a dense build: its body length is 60-82 cm; weight from 5 to 16 kg. The tail is very short and invisible from the outside. The head is large and wide, with a flattened “face”. The ears are large, rounded, covered with thick fur. The eyes are small. The bridge of the nose is hairless and black. There are cheek pouches. The koala's limbs are adapted for climbing - the thumb and forefinger of the forelimbs and limbs are opposed to the rest, which allows the animal to grasp tree branches. The claws are strong and sharp, capable of supporting the weight of the animal. There is no claw on the big toe of the hind limbs. Koalas inhabit eucalyptus forests, spending almost their entire lives in the crowns of these trees. During the day, the koala sleeps (18-22 hours a day), sitting on a branch or in the forks of branches; At night it climbs trees, looking for food. The koala's slowness is associated with its feeding habits. It has adapted to feed almost exclusively on eucalyptus shoots and leaves, which are fibrous and contain little protein, but a lot of phenolic and terpene compounds that are poisonous to most animals. To avoid poisoning, koalas choose to eat only those types of eucalyptus trees that contain fewer phenolic compounds.
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Carnivorous Marsupials
Predatory marsupials (lat. Dayuromorphia) - a detachment of Australian marsupials (Metatheria). Most meat-eating marsupials belong to this order. All of them are agile and skilled hunters, feeding on insects or vertebrates depending on their size. Some species feed on carrion. European settlers named many species after the familiar planar predators living in Europe, for example, the marsupial wolf or the marsupial marten.
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Marsupial anteaters
Marsupial anteater, nambat, anteater (Myrmecobius fasciatus) is a mammal of the family of marsupial anteaters; the only representative of the family of the same name. The dimensions of this marsupial are small: body length 17-27 cm, tail - 13-17 cm. The weight of an adult animal ranges from 280 to 550 g; males are larger than females. The head of the marsupial anteater is flattened, the muzzle is elongated and pointed, and the mouth is small. The teeth of the marsupial anteater are very small, weak and often asymmetrical: the molars on the right and left can have different lengths and widths. In total, the nambat has 50-52 teeth. The hair of the nambat is thick and hard. The numbat is one of the most beautiful marsupials in Australia: it is grayish-brown or reddish in color. The fur on the back and upper thighs is covered with 6-12 white or cream stripes. The eastern nambats have a more uniform coloration than the western ones. A black longitudinal stripe is visible on the muzzle. The belly and limbs are yellow-white, buffy.
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Marsupial martens
Marsupial martens, or marsupial cats (Dasyurus) are a genus of mammals in the family of predatory marsupials. The name was given due to some resemblance to real martens and cats. Also called "quolls". Body length 25-75 cm, tail 20-60 cm; weight varies from 900 g (Dasyurus hallucatus) to 4-7 kg (Dasyurus maculatus). Females are smaller. The body hair is usually short, dense and soft; the tail is covered with longer hair. The ears are relatively small. The color on the back and sides is from gray-yellow to black with numerous white spots; on the belly - white, gray or yellow. Females have 6-8 nipples. The brood pouch develops only during the breeding season and opens back towards the tail; the rest of the time it is represented by folds of skin that limit the milky field in front and on the sides. Well developed canines and molars.
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Marsupial moles
Marsupial moles are so different from other marsupials that they are classified as a separate family. They have a strong, ridged body ending in a small (12-26 mm) conical tail. The body length is only 15-18 cm, and the weight is 40-70 g. The neck is short; five cervical vertebrae are fused, increasing the rigidity of the neck. The tail is hard to the touch, with ring scales and a keratinized tip. Short, five-toed paws are well suited for digging. The claws are unevenly developed. The third and fourth fingers of the forelimbs are armed with large triangular claws; with their help the mole digs the ground. The claws on the hind feet are flattened, and the foot is adapted for throwing away dug sand. The hair of marsupial moles is thick, soft and beautiful. Its color varies from white to pinkish-brown and golden. Its reddish tint is given by iron, which is rich in the red sand of the Australian deserts.
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Contents.1.Introduction(3).
2.Kangaroo(4.5).
3.Possum(6,7).
4. Koalas, or marsupial bears (8,9).
5. Predatory marsupials.
6.
7.
8.
9.
10.
Introduction.
Marsupials (lat. Metatheria, Marsupialia) - an infraclass of mammals, united togetherwith placental ones in the subclass. Differ from
placental for a number of characteristics, in particular the fact that
are born underdeveloped and then grow into
mother's bag. At the moment there are about
250 species of marsupials.
Kangaroo.
Kangaroos have powerful hind legsmassive tail, narrow shoulders,
small, similar to
human hands front
paws that kangaroos use
dig up tubers and roots. IN
in case of danger kangaroo
transfers the entire weight of the body to
tail, and then both hind legs,
freed, alone
applied from top to bottom
terrible wounds to the enemy.
Pushing off with powerful rear
kicking, they rush in leaps to
12 m long and up to 3 m high.
Body weight is up to 80 kg.
Opossums.
Opossums (Didelphidae) -mammal family
infraclass marsupials. It
includes the most ancient and least
specialized marsupials,
which appeared at the end of the Cretaceous
period and since then almost no
have changed. All living people
representatives of the possum family
inhabit the new world, although
fossil forms are known from
Tertiary deposits of Europe.
Most marsupials of the South
Americas are extinct
after the emergence of natural
bridge between North and South
America, along which from north to south
New species began to penetrate. Only
the opossums were able to carry it out
competition and even
spread north.
Koalas, or marsupial bears.
Koala (eng. Koala, lat. Phascolarctoscinereus) - moving along
herbivorous marsupial to trees,
living in Australia. The only one
a member of the Phascolarctidae family.
The koala lives in coastal areas on
eastern and southern Australia, in the territory
from Adelaide to the south
Cape York Peninsula, as well as
Kangaroo Island, where they were introduced in
beginning of the 20th century. They also
common in regions with sufficient
amount of moisture to support
forests suitable for koalas. Koalas
South Australia were in
largely destroyed in
during the first half of the 20th century, but with
with the help of individuals from Victoria,
koala population in South Australia
restored. This animal does not live
in Tasmania and Western Australia
Marsupial anteater.
The dimensions of this marsupial are small:body length 17-27 cm, tail - 13-
17 cm. Weight of an adult animal
is 280-550 g; males
larger than females. The head of a marsupial
anteater flattened, muzzle
elongated and pointed, mouth
small. Worm-shaped tongue
can protrude from the mouth almost
10 cm. Large eyes, ears
pointed. The tail is long,
fluffy, like a squirrel, not
prehensile. Usually nambat
holds it horizontally, slightly
tip bent upward. Paws
quite short, wide
stationed, armed with strong
claws. Forelegs with 5
fingers, back - with 4.
The nambat's hair is thick and
hard. Nambat is one of the most
beautiful marsupials of Australia: he
colored grayish brown or
reddish color. Fur on the back and
upper thighs covered 6-12
white or cream stripes. U
eastern nambats are single-colored,
than the Western ones. Black is visible on the muzzle
longitudinal stripe. Belly and limbs
yellow-white, ocher.
The teeth of the marsupial anteater are very small,
weak and often asymmetrical: molars
right and left may have different lengths and
width. In total, the nambat has 50-52 teeth. Solid
the palate extends much further than
most mammals, which is typical for
other "long-tongued" animals
(pangolins, armadillos). Females have 4
pacifier. The brood pouch is absent; there is only
a milky field bordered by curly wool.
Predatory marsupials.
Predatory marsupials - squad squadAustralian marsupials.
Most marsupials feed
meat belong to this order.
Many species are European
the settlers christened them
familiar placental predators,
living in Europe, for example
marsupial wolf or marsupial
marten. Of course no relation
between these species there are no
there are no European namesakes,
and external similarity is based on
convergent evolution.
General characteristics There are about 250 species. They live in Australia, New Guinea, and several species in America. The name was given for the presence of a special fold of skin on the belly in the form of a pocket, or bag, where newborns are placed. Cubs are born helpless, small, underdeveloped. Their further development occurs in the bag.
Kangaroo Features The presence of marsupial bones (special pelvic bones that are developed in both females and males). Body temperature is 3436° C. Kangaroos give birth to live young and feed them with milk. Kangaroos have a pouch for carrying their young; it opens towards the head, like an apron pocket. The special structure of the lower jaw, the lower ends of which are curved inward. Their fangs are absent or underdeveloped, and their molars have blunted tubercles. Kangaroos are born just a few weeks after conception, while the mother kangaroo sits in a certain position with her tail between her legs, and the baby (at this moment smaller than her little finger) crawls into her pouch, finds a nipple there and sucks on it, feeding on milk. The immune system of a newborn kangaroo is not formed, so mother kangaroo milk has a strong antibacterial effect. Contrary to popular belief, male kangaroos do not have a pouch, but only females do. It is much easier for kangaroos to move around during their long hops than to walk or hop little by little!
Opossums The dimensions of opossums are small: body length 750 cm, tail 4-55 cm. The muzzle is elongated and pointed. The tail is entirely or only at the end bare, prehensile, sometimes thickened at the base with fat deposits. The body is covered with short, thick fur, the color of which varies from gray and yellowish-brown to black. The structure of the dental system, limbs, and bag indicates the primitiveness of opossums. Their limbs are shortened, five-fingered; the big toe of the hind limb is opposed to the other toes and lacks a claw. The hind legs are usually more developed than the front legs. The dental formula is archaic: a full row of incisors (5 on the upper jaw and 4 on the lower jaw), well-developed canines and sharply tuberculated molars. All opossums have 50 teeth. Opossums are inhabitants of forests, steppes and semi-deserts; found both on plains and in mountains up to 4000 m above sea level. Most lead a terrestrial or arboreal lifestyle; the aquatic possum is semi-aquatic. Active at dusk and at night. Omnivores or insectivores. Outside the mating season they lead a solitary lifestyle.
Koalas, or Marsupial Bears The koala is a medium-sized animal with a dense build: its body length is 6082 cm; weight from 5 to 16 kg. The tail is very short and invisible from the outside. The head is large and wide, with a flattened “face”. The ears are large, rounded, covered with thick fur. The eyes are small. The bridge of the nose is hairless and black. There are cheek pouches. The limbs of the koala are adapted for climbing; the thumb and index fingers of the forelimbs and limbs are opposed to the rest, which allows the animal to grasp tree branches. The claws are strong and sharp, capable of supporting the weight of the animal. There is no claw on the big toe of the hind limbs. Koalas inhabit eucalyptus forests, spending almost their entire lives in the crowns of these trees. During the day, the koala sleeps (1822 hours a day), sitting on a branch or in the forks of branches; At night it climbs trees, looking for food. The koala's slowness is associated with its feeding habits. It has adapted to feed almost exclusively on eucalyptus shoots and leaves, which are fibrous and contain little protein, but a lot of phenolic and terpene compounds that are poisonous to most animals. To avoid poisoning, koalas choose to eat only those types of eucalyptus trees that contain fewer phenolic compounds.
Predatory Marsupials Predatory marsupials (lat. Dayuromorphia) are a detachment of Australian marsupials (Metatheria). Most meat-eating marsupials belong to this order. All of them are agile and skilled hunters, feeding on insects or vertebrates depending on their size. Some species feed on carrion. European settlers named many species after the familiar planar predators living in Europe, for example, the marsupial wolf or the marsupial marten.
Marsupial anteaters Marsupial anteater, nambat, anteater (Myrmecobius fasciatus) is a mammal of the family of marsupial anteaters; the only representative of the family of the same name. The dimensions of this marsupial are small: body length cm, tail 1317 cm. The weight of an adult animal ranges from 280 to 550 g; males are larger than females. The head of the marsupial anteater is flattened, the muzzle is elongated and pointed, and the mouth is small. The teeth of the marsupial anteater are very small, weak and often asymmetrical: the molars on the right and left can have different lengths and widths. In total, the nambat has 5052 teeth. The hair of the nambat is thick and hard. The numbat is one of the most beautiful marsupials in Australia: it is colored grayish-brown or reddish. The fur on the back and upper thighs is covered with 612 white or cream stripes. The eastern nambats have a more uniform coloration than the western ones. A black longitudinal stripe is visible on the muzzle. The belly and limbs are yellow-white, buffy.
Marsupial martens Marsupial martens, or marsupial cats (Dasyurus) are a genus of mammals of the family of predatory marsupials. The name was given due to some resemblance to real martens and cats. Also called "quolls". Body length 2575 cm, tail 2060 cm; weight varies from 900 g (Dasyurus hallucatus) to 47 kg (Dasyurus maculatus). Females are smaller. The body hair is usually short, dense and soft; the tail is covered with longer hair. The ears are relatively small. The color on the back and sides is from gray-yellow to black with numerous white spots; on the belly white, gray or yellow. Females have 68 nipples. The brood pouch develops only during the breeding season and opens back towards the tail; the rest of the time it is represented by folds of skin that limit the milky field in front and on the sides. Well developed canines and molars.
Marsupial moles Marsupial moles are so different from other marsupials that they are separated into a separate family. They have a strong, ridged body ending in a small (1226 mm) conical tail. The body length is only 1518 cm, and the weight is 4070 g. The neck is short; five cervical vertebrae are fused, increasing the rigidity of the neck. The tail is hard to the touch, with ring scales and a keratinized tip. Short, five-toed paws are well suited for digging. The claws are unevenly developed. The third and fourth fingers of the forelimbs are armed with large triangular claws; with their help the mole digs the ground. The claws on the hind feet are flattened, and the foot is adapted for throwing away dug sand. The hair of marsupial moles is thick, soft and beautiful. Its color varies from white to pinkish-brown and golden. Its reddish tint is given by iron, which is rich in the red sand of the Australian deserts.
Description of the presentation by individual slides:
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Opossum The common opossum is the only marsupial in North America, but it also lives in South America. In fact, the homeland of the common opossum, like all marsupials of the New World, is South America. But in the past millennia, opossums rushed to attack the North American continent, and their campaign continues: in recent years, opossums have been spreading further and further north across the United States. Sparse forests and bushes, even around farms and among fields, suit them well.
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Possums' home and food During the day, they sleep somewhere in a hollow, on a branch or among stones. They carry leaves and grass for nesting, picking them up with a flexible, bare tail. When the evening dawn fades, possums go out to hunt. The animals are not capricious: they eat everything they can find - wild grapes, plums, juicy leaves, and corn in the fields. On the way, a beetle will be caught and eaten, a lizard will be caught, or a mouse will be caught and put into the stomach. Crayfish and crabs are a delicacy for opossums. Bird eggs are also very fond of them and are not too lazy to climb high for them (although in general they are quite lazy). If the branch on which the nest is built is too thin and it is impossible to get to it, the opossum manages to rob the bird. It will crawl along the branch that grows above the nest, cling to its tail, hang upside down and steal eggs from the nest with its front paws.
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Thief's Paws And the possum's paws are almost like hands: with five dexterous long fingers. The front and rear are equally grippy. The big toe on the hind legs (it has no claw) is contrasted, as on our palm, with all the others.
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After lunch Having eaten a hearty meal (opossums are very gluttonous), the possums love to cling to a branch with their back leg and tail (or one tail), hang upside down and sway, blissfully digesting lunch.
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Pretender In America they say “play possum,” that is, pretend. The possum is a great master at such things. An actor, of which there are few. When he feels that he is in a bad situation, a strong enemy is ready to grab him (or has already grabbed him), and there is nowhere to run, he pretends to be dead. He even falls from a tree like a corpse and lies as if dead, his glassy eyes rolled back and his paws spread out as if numb. Or he’ll stick out his tongue. It lies for a long time - as long as it takes to deceive a person or a predator who does not eat dead meat. The “dead man” can be kicked away or grabbed by the tail and thrown away, he will not give himself away “even by the trembling of his eyelids.” As soon as the potential death on two or four legs is removed, the opossum will immediately jump up and quickly run into the bushes.
