Tropical “make-believers”
Who are the tenrecs and how they got into the Guinness Book of records.
Tenrecs were first described in the nineteenth century, and they were so unusual that they immediately identified in a separate family terenowych (Tenrecidae). To date, this family includes 34 species, three of which are in Africa, and the remainder in Madagascar. To get from the mainland to the island, the ancestors of the tenrecs (perhaps it was one pregnant female) had to cross a Strait of width 230 miles (at its narrowest point). Apparently, they (or she) drifted on some floating vegetation that washed or blew off the coast of Africa. Researchers estimate, this was from 42 to 25 million years ago.
Once on Madagascar, the ancestors of the tenrecs colonized almost the entire island.
At the moment different types of these animals live on land, in trees, are semi-aquatic or semi-underground way of life.
Along the way, they are similar to hedgehogs, mice, moles, and even otters, though no relation to these animals do not have. In General, the tenrecs are a great example of convergent evolution, which are not related to each other organisms living in the same or similar conditions to be very similar to each other.
In particular a large (Setifer setosus) and small (Echinops telfairi in front of a) tight tenrecs in the process of evolution has got sharp needles and, in case of danger, curl up into a ball, hiding his vulnerable face and belly. But the needles they are constructed differently: the hedgehogs they came from several fused between the hairs and the tenrecs — from one.
Folding into a ball, these mammals use different muscle groups. Rice (Oryzorictes hova) and kretowiny (Oryzorictes talpoides) tenrecs that spend a lot of time under ground, are similar to moles. They have reduced vision and hearing, but they purchased a “plush” coat and large paws which are easy to dig underground tunnels. It should be noted that tenrecs not only “copied” the features of other mammals, they have their own unique characteristics.
So, mountain (Hemicentetes nigriceps), and plains (H. semispinosus) striped tenrecs, whose hair had partially turned into the thorns, using them to communicate with relatives. On their backs grow from 7 to 16 large needles which when struck together emit a vibration. Researchers believe that so tenrecs communicate in family groups and may warn each other of danger. In addition, presumably, striped tenrecs are able to communicate and use echolocation, although this is not definitively proven.
Needle striped tenrecs serve not only for communication but also for protection. With the appearance of a predator (usually a Madagascar mongoose or fossa), tenrecs turn their backs on them and raise the needle back on the “collar”. If a predator not far behind, tenrec, similar to hedgehog, sticks the needle in the paw or nose of the offender. Animals behave not only in case of danger. In the same way females not ready to mate, “discourage” pushy Cavaliers.
By the way, in the field of reproduction of tenrecs can be called Champions. Plain striped tenrecs very quickly “grow up”, so females can breed at the age of 25 days old. For this the animals was listed in the Guinness Book of records. Females of another species, the tailless tenrecs (Tenrec ecaudatus) are very prolific and can bring in one litter of 32 babies, the largest number in mammals.
The ancestors of tenrecs, the remaining “historical homeland” in Africa, evolved and, like a Madagascan family, occupied a free ecological niche.
Now on the continent there are three species of Terekhovich, which both in appearance and in lifestyle resemble otters.
They belong to the subfamily vydrevich shrews (Potamogalinae). Representatives of these species inhabit the shores of the rivers and streams of Equatorial Africa and prey on small fish, crustaceans and amphibians. Like otters, they have a thick coat, badly leaking water, partially fused fingers forming a swimming membrane, and helps to swim a long tail.
For a long time scientists took the insectivorous tenrecs. The structure of the teeth of tenrecs, and insect-eating plutocrats and deleterow very similar, therefore these three groups of mammals are considered close relatives. But it was a little different. Genetic studies conducted in the late 1990-ies, has shown that tenrecs and plutocracy really close relatives; they were related to detachment of afrosoricida. Other relatives Terekhovich not insectivores solenodon and quite unlike them aardvarks, elephant elephant shrews, hyraxes, elephants and sirens. They all occurred about 60 million years ago from a common ancestor that lived in North Africa, and now they belong to the superorder of afrotheria.