Northern mossback tortoise

Northern mossback tortoise is a species of a very large tortoise from the family of shelled dragons, and the largest member of the family, with adults weighing up to 400kg. With a lifespan of over 100 years in the wild, it is one of the longest-living tortoises on the planet.
Native to the grassy plains north of /uuu/ (now part of /nasa/ territory) Northern mossback tortoise is uniquely adapted to cold environment, and the territory's most prominent herbivorous reptile.

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Description
The tortoises can grow up to 1.2m in length and weigh as much as 400kg. They are covered with a strong grey or brown coloured shell, with the individual plates fused with ribs, forming the integral part of the skeletal structure. Their shells are covered by different species of moss and small plants, with some members acting as hosts to Weeping Marley, a symbiotic species of foul smelling shrub. They can walk at a speed of 0.7km/h, with short bursts of up to 5km/h when in distress. They possess a strong beak used to crush the vegetation as well as long claws on front legs, which they use for shallow digging, exposing the roots of certain plants.

As an ectothermic (cold-blooded) animal, they use Chuubanite from their diet as a heating source to keep their body temperature at 32°C-36°C. They initiate the chemical reaction in a special organ located between the lungs and stomach, a remnant of their drake ancestors. This "heat sac" is encased in a thick web of blood vessels, which warms the blood flowing through them, as well as directly connected to the mouth. In cases of emergency, as when preyed upon by Coated Drakes, they have been observed to eject a mixture of this liquid and their saliva. Said liquid can reach temperatures of up to 130°C, inflicting heavy burns on any part of the body it lands on.

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Evolution
Northern mossback tortoise is closely related to /uuu/ native Mossback tortoise, driven north some 5 million years ago during a relatively warm period in planet's history. Both species are the last surviving members of an order of herbivorous drakes, the common ancestor of which arrived in /uuu/ some 12 million years ago.

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Routine
As a constant supply of Chuubanite is needed to keep up their body temperature, they spend 9-11 hours a day foraging for food. They travel constantly between grazing areas, with no permanent resting area observed. They travel in groups of up to 30 individuals, with adult males on the outside of the group, while smaller females and juveniles are safe in the middle. The oldest and biggest male usually leads the group. The groups spend the summers in the northern regions, moving south towards the pine forests as winter approaches. Each group has a well defined route they take each year, that is passed on from generation to generation.

They have been observed using their strong front legs to throw dirt and mud on their shell, as well as laying in mud puddles. This is believed to be a behavior to protect against parasites. During night they form a circural depression in the ground, with the entire group laying in a close formation, or shelter in smaller caves.

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Diet

The tortoises are herbivores that consume a diet of grasses, leaves, berries and roots. Juveniles consume up to 18% of their body weight in dry matter in a day, with adults consuming up to 12%. They recieve most of their water from the dew, with occasional supplements from ponds and bogs. Without one around, however, they can survive up to 6 months just from the dew, and up to a year without any food or water, due to their slow metabolism.

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Mating

Every five winters, groups of tortoises gather at the southern pine forests, forming a large herd of hundreds, if not thousands, of individuals. There, mature males will fight to establish dominance and secure females, forming large piles, that from a distance look like the ground itself is moving. As the few weeks of mating pass, the groups will find each other again by their smell, and once reunited, females will begin laying eggs in their area.

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Egg laying

Digging out a shallow hole in the ground with her front legs, the female will then lay between 15 and 20 eggs inside. Coveing the hole with dirt and her body, she will then stay still for 170-200 days, burning through her Chuubanite reserves she was stockpiling for months before. At this time, the female's body temperature rises up to 42°C in order to warm the eggs under her. By regulating this temperature, the female can influence the gender of the hatchlings, with more males emerging from warmer nests, and more females from colder nests.

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Life cycle

As the hatchling break out, the entire group will start feeding them partially digested food, which will serve as a source of nutrients and Chuubanite for the first few weeks of their life. At this stage, the individual hatchling weighs no more than 100g. After 10-12 weeks, the new batch of tortoises will emerge from the nest and embark on a journey back to the north plains, where they will spend most of their lives. By now they can eat their own food and process Chuubanite. The journey back is slower, as the hatchlings will travel on their mother's shell. Even so, due to predators and accidents, almost 80% of hatchling never make it to the grazing grounds.

Those that do, however, will now start consuming vegetation at an increased rate, in just a few years reaching almost 150kg. Now in their juvenile state, only the biggest predators will be able to take them down. It will take another 10-15 years before they reach full maturity and size, some weighing in at almost 400kg. They will then protect their group until their death. If no predator ends them sooner, they can live for another 70-80 years. Most, however, will never reach that stage. It is recorded that group of Mossbacks can sense when one of the members is nearing it's end, and will huddle together for days and weeks before it happens, with the old Mossback dying silently in the middle of their group.

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