Tuatara

The tuatara is the only representative of the order of beak-headed reptiles. It lives only on the small islands of New Zealand, is endemic to the archipelago. Outwardly, it looks like rather large lizards and leads a lifestyle similar to them. It feeds on eggs, chicks, insects, worms, and other invertebrates. Although it lives only on a few small islands, it is not endangered.

There is no consensus among scientists about the exact classification of tuatara. Usually, a single modern species of Sphenodon punctatus is distinguished with two to three subspecies. Less commonly, another species stands out, Sphenodon guntheri. Recent genetic studies support the traditional view. The closest modern relatives of the tuatara are lizards and snakes from the numerous scaly order.

The tuatara belong to the wedge-toothed family, known since the time of the first dinosaurs. In the Mesozoic, the order of beakheads consisted of dozens of species. Even 60–70 million years ago, a very large variety of wedge-toothed existed on the planet. Today, only the tuatara remains, and externally and morphologically, it has changed very little since the Mesozoic. In fact, this animal is a relic of the era of giant dinosaurs.

Hatterias look like large iguanas. Body length – 50-75 cm. A crest of triangular plates with spikes runs along the back. Body color varies from reddish-brown to greenish-olive, may be gray or brown with small spots on the back and neck. An important characteristic feature of the tuatara is the mobility of the upper jaw relative to the skull in young specimens. They adopted this feature from lobe-finned fish.

Another characteristic feature of the wedge-toothed is the presence of a “third eye”. This parietal notch is expressed only in young animals and overgrows with age. Tuataria do not have an eardrum. There is also no penis. The skeleton of the skeleton is massive, powerful limbs have five fingers with webs and claws. The tail is almost equal in length to the rest of the body, laterally compressed. The body is squat, shortened. Males are larger than females.

Tuatara lives only in New Zealand. Before the appearance of man, it inhabited both large islands of the archipelago, North and South. Hunting by the Maori, extermination by dogs, rats and pigs led to a rapid decline in the tuatara population in most of its natural range. This process accelerated even more after the start of European colonization. In the 19th century, the tuatara completely disappeared from the North and South Islands.

Today, the tuatara inhabits about 30 small islands in the northeast of the archipelago and in the Cook Strait. Lives in small shelters, crevices, holes. She can dig them herself or use ready-made ones. Ethologists note an interesting feature of the tuatara living in the Cook Strait. They often occupy the same burrows with gray petrels. Birds sleep at night and hunt during the day. Tuataria are awake at night.

Hatterias are characterized by a slow metabolism, so they do not require large amounts of food. This contributed to the survival of the Tuatara for tens of millions of years. The usual diet is similar to many medium-sized lizards and consists of insects, spiders, worms, snails, other invertebrates, bird eggs. Tuataria also feed on chicks and small birds. They go hunting at night, sleep during the day.

Nocturnal life is associated with unusual features for reptiles: tuatara are most active at low temperatures in the range of +6 – +8 ° С. The slowness of vital processes is also manifested in rare breathing. The interval between breaths is about 7 seconds. Sometimes breathing slows down so much that the animal can take only one breath per hour. In winter, tuatars hibernate (March-August).

Tuatara love water and are good swimmers. Another interesting feature of them is the presence of a voice, which is not typical for reptiles. At night, tuatars make sharp sounds. The slow development of the tuatara organism is also manifested in a very long growing up. Young individuals reach sexual maturity only by 15-20 years. But life expectancy reaches 100 years or more, according to some (unconfirmed) estimates – up to 200 years.

The tuatara is characterized by a very low reproduction rate. Adults mate only once every 4 years. Eggs are laid in spring, 8–9 months after fertilization. The clutch consists of 8-15 eggs. The incubation period also differs in duration – 12-15 months. The term for the appearance of offspring reaches two years after mating. Such slow breeding of hatterias makes them very vulnerable.

Recent studies of the tuatara have shown very interesting features of the beakheads, which shed light on the development of all amniotes (including birds and mammals). It turned out that tuatara embryos develop a penis. However, then its development stops and it is reabsorbed. This means that the penis as a separate organ appeared in the distant ancestors of reptiles (the first amniotes) hundreds of millions of years ago.

The tuatara survived in New Zealand because they had practically no natural enemies. The situation changed dramatically after the appearance of people (Maori tribes). The main enemies of the Tuatars for several centuries were people, dogs, rats, and pigs. Today, tuatara live only in a protected area, where nothing threatens them. In protected conditions, they have practically no natural enemies.

The tuatara are unique animals. They belong to a group of reptiles that originated about 250 million years ago. Moreover, over the past 200 million years, the tuatars have not changed much. They are distinguished by very rare and often truly unique features. Due to human activities, the tuatars were brought to the brink of extinction. Fortunately, they were saved and today the species is not threatened with extinction.

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