19 facts about Hawksbill sea turtle
Hawksbills are one of the smallest sea turtles. Their distinguished shells make being considered the most beautiful sea turtles. They are listed as Cr ...
The first turtles appeared on Earth at the end of the Permian about 240 million years ago. Although the first ones had neither plastron nor carapace, the seeds of these elements were already developed. Over the years, turtles increasingly resembled the present forms, although the ancestors of the species living today did not appear until the early Cretaceous, about 140 million years ago. Turtles are considered living fossils because their body structure has not changed significantly for millions of years.
They inhabit all continents and oceans except Antarctica in circumpolar waters.
They inhabit both land and fresh and salt waters.
They are small turtles that live in aquatic environments. In Central Europe, they rarely reach a body length of more than 25 cm. In other ecosystems (they live from northern Africa to central Asia) they can reach much larger sizes, even above 40 cm in length.
Most terrestrial turtles are herbivores and aquatic turtles are carnivores, this is determined by their speed of movement.
Very often the diet changes with growth, in many species young individuals are more carnivorous and as they grow up they change their preference for plant foods.
They have short, columnar legs that resemble the feet of an elephant.
They are helped by their streamlined body and paddle-like front limbs. The hind ones, on the other hand, perform more of a steering function than a propulsion function. Soft-shelled turtles and sea turtles are the best adapted to swimming.
Their eye has rods adapted to both low-light conditions and cones that allow them to see in the full-color spectrum. There is a hypothesis, though as yet unconfirmed, that turtles have a fourth type of cones sensitive to ultraviolet radiation.
They are most sensitive to sounds in the range of about 100Hz, and cannot hear sounds above 500 Hz.
They most often make sounds during courtship and mating however, some species also make sounds to stay "in touch" during migration.
It has not been well understood so far and is most likely used by these reptiles for navigation.
Instead, the insides of their mouths are overgrown with sharp horn-like protuberances used to cut, hold and grind food. Some extinct species had teeth but became extinct about 160 million years ago. A recently discovered representative of turtles equipped with teeth is Sichuanchelys palatodentata.
Marine species are forced to emerge from time to time to get fresh air. The frequency with which they do this depends on the species, some surface every few minutes while others can remain submerged for up to an hour.
The armor consists of a convex carapace located on top and a flat plastron that covers the animal from below.
On the outside, the carapace is covered with scales, which are keratinized plates made of keratin. These plates protect the shell from scratches and bruises.
It is formed by exactly nine bones, of which the two anterior bones are precisely the transformed clavicles.
Representatives of this species reach a body length of 220 cm and a maximum weight of 700 kg. The record holder measured about 270 cm. They are aquatic turtles that live in the oceans. They are also among the deepest diving marine animals, being found at depths of 1280 meters above sea level.
The body length of this marine giant was as long as 4.5 m and its weight was about 2.2 t. It lived at the end of the Cretaceous about 75 to 65 million years ago. It is possible that this turtle survived the extinction of the dinosaurs and its extinction was linked to the appearance of new species of marine animals and mammals feeding on its eggs.
The species of this land tortoise is found in southwestern Africa. Females are larger than males, the length of their carapace does not exceed 10 cm.
Representatives of sea turtles can make migrations of thousands of kilometers, land turtles much shorter. Young sea turtles, after hatching on the beach, migrate to the oceans, where they travel thousands of kilometers. During their migrations, they grow and reach sexual maturity to return years later to the vicinity of their birthplace to copulate. Land ones usually do not travel further than 30 kilometers to their breeding sites.
Usually, during mating season, males fight with each other with aggression being more common among terrestrial species.
In a study conducted on representatives of the Pseudemys nelsoni species, it was proven that they are capable of learning new skills and their long-term memory is at least 7.5 months. Other studies indicate again the recall of instrumentally conditioned information even after 9 years.
Terrestrial turtles copulate on land while marine turtles copulate in the water and only the fertilized female travels to land to lay eggs. Eggs are laid on land because the heated ground allows the young to develop, which would be impossible in the cool marine waters. Another reason for laying eggs on land is that during development turtle embryos breathe atmospheric air, which enters the eggs through a special membrane in the shell.
The mission began at 21:42 UTC on September 14. The step-turtles stayed aboard the ship for 6 days, 18 hours, and 24 minutes. Although the trip was certainly traumatic for them, they returned to Earth in good condition, only slightly starved and with a slight reduction in muscle mass (they lost about 10 percent of their body weight). After landing, they received a nutritious diet and quickly returned to normal.
The record holders are elephant tortoises, which live more than 100 years, and among them is a tortoise named Harriet, who lived at least 175 years. The longevity of turtles is related to their size, larger turtles tend to live longer. This does not change the fact that even the small species, eagerly kept in homes, reach an impressive lifespan of 30 to 40 years.
The last extinct species is Chelonoidis abingdonii, whose last representative died on June 24, 2012. He was kept in a breeding center, where attempts were made to get him to mate with females of other species, but George, as that was his name, was not interested. The Guinness Book of Records describes him as the most solitary animal.
At present, there are only three representatives of this species on Earth one male and two individuals, the sex of which has not yet been verified.
