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Description

An entry for the Spec Evo community challenge/contest of Hyrotrioskjan/Joschua Knüppe 's #AtlantisBestiary3 project !

My 5th one !

For this entry, I choose to made another native species that descend from the surviving species from Phase 2.

This time, a species of land/terrestrial tortoise, who descend from the Miocene Eastern grass-tortoise (see « Atlantis Phase 2 » Post, 1st April 2023, second box picture from the top of the chart. Link : www.deviantart.com/hyrotrioskj…).

I decide to use this Miocene species of chelonian of Atlantis as ancestor, since the Atlantis giant tortoise and the Volcano tortoise died out since Phase 2.

The fourth land tortoise that exist is the Hephaestochelys platystega, which I will likely use as an ancestor of another species of tortoise a close coming future.

All the others remaining species of chelonian present at this time were semi-aquatic species.

I choose to do a chelonian, a land one, because tortoise, both small and giant ones, are perfect candidates for every kind of spec evo setting !

Already in real-life, they are really more fascinating and marvelous animals more thank we already realise and see.

Already, think that not many people in general know about giant tortoises, and something that only recently was put forward and realised by scientists (a good decade but still recent at ours scale), is that big tortoises similar in size to the Aldabra giant tortoise (Aldabrachelys gigantea) and the highly famous differents Galapagos species (Chelonoidis sp.), see even bigger, can live perfectly whithoit problems on continental mainland, in the middle of all others mainland animals including big predators.

Their famous greats size not being a result of « Insular Gigantism » process, like it was once thought to be.

Not long time ago, during all the Pleistocene, several taxas of giant tortoise roamed continental North and Central America (Hesperotestudo), Europe (Titanochelon) and Asia (Megalochelys, including M. atlas, none other than THE largest land tortoise ever know to this day), some big species in Africa and some big sized Chelonoidis species in South America.

These species were already giant since a long time before arriving and establishing themselves on islands even very far away from mainland masses. They come to these islands by themselves by the sea, by swimming, since tortoises have a surprisingly high and good boyancy when their are on waters, even open ones. Even despite their big weight, who can reach 1 ton in some cases.

They also swim pretty fast.

They all died out almost att he same time during the Middle Pleistocene, which coincides with the arrival of Homo erectus, even if today their extinction is mostly due to climatic change rather than overhunting from this human species (evidences of exploitation by H. erectus exist).

On mainland, the genus Hesperotestudo survived on North America until the end of the Pleistocene.

Every giant tortoises groups, including the ones extants today, are unrelated, and became independently giants by themselves, being polyphyletic as a « group ».

With, as example, the Aldabra species (Aldabrachelys) being related to Malagasy tortoises (Asterochelys genus), while the Galapagos giant tortoises are related to South American mainland tortoises, particularly the Chaco tortoise (Chelonoidis chiliensis).

Tortoises as a whole, whatevers small, medium or giants are among the animals groups that managed to be the most successull and to have remained on a high level of success their very beginning.

Accumulating almost all the greatest abilities possible !

Here :

- Being complete omnivorous and opportunistic animals about the diet aspect, being mainly herbivorous but eating whatevers they can eat if the occasion occured.

- Can subtain long without who and on few reserves during a long time thank to their low and slow metabolism and the fact they don’t made physical efforts most of the time (keeping precious energies).

- Live very, verrrrry old (even the smallest species), and laying tons of eggs per clutches, each years. Allowing a great legacy of offsprings among which at least many will reach adulthood.

- Are able to resist low temperatures and a certain cold level, allowing them to live in almost all kind of habitats, from humid warm to dry cold biomes.

So, I decide to do a giant tortoise to honor these fantastic animals that fight whithout too many efforts the ages and evolution itself, since tortoises as a group/family (the whole Testudinidae inside the Cryptodira suborder) exist since the Eocene and managed to live in great diversity to our days.

The results are the following species :

* The Atlantean rock tortoise (Magnochelys pratum) ;

A large land giant tortoise that inhabit the island of Atlantis, who descend from the Miocene Eastern grass-tortoise who lived at least there almost 6 mya years ago and a little before.

Her size on average is around 90 cm (3 ft) at the front tip of his shell (where where the two front legs and the head/neck come from), reaching human’spelvis, and 1 m (100 cm) at the very top of the shell.

Which is bigger than the two extant giant tortoises species alive today, the Seychelles/Aldabra and Galapagos species.

Since her ancestor was a way smaller species (being smaller than the stork-like bird Ciconognathus litorus, with which it shared most of it distribution, itself the size of a normal White stork), the case of the Atlantean rock tortoise represent, at the opposite of all giant tortoise living on islands, a true case of insular gigantism.

This large species of land tortoise inhabit the vast grasslands of Atlantis, by far the main biome which composed the landmass at the Holocene era. It pass most of it live in grasslands (80%), but occasionaly occur in bushlands and open-woodland areas as well (20%).

His lifestyle is highly similar and in fact pretty generic to any others giant tortoises.

Same as for his overall shape and behaviors.

Only the size id the main notable difference, being easily twice the size on averageof the latters, and can easily even get a little more larger at old age.

While primarily herbivorous, eating mainly grass and leaves on occassion from low branches of any kind of trees if available, it will eat anything who pass in front of her : any kind of plant matters, carrions, and will even actively hunt smalls animals (juveniles or weaken specimens), especially birds during breeding seasons (althought, on very, very rare occasions).

This species lay eggs near or on beaches, were his ancestor mainly lived during the Miocene.

Youngs will remain in this biome until they reach a sufficient size and migrate into the interior of the island.

The great expansion of the Eastern side of the island and the grassland biome after the Miocene and especially with the Younger Dryas have played a great role in the evolution of this species, since his ancestor was a grass-eater animal living in this specific region.

The higher level of food (grass) and (open)space is why it became larger and taller overtime.

Like every giant tortoise, they can subsist during months, see a years, whithout eating or drinking and on few reserves, live very long (150-200 years, see a little more).

It a very good swimmer and have a very high boyancy despite their weight and can do island hopping.

It an important megafauna herbivore in it environnment, and numerous animals use it as a perch/platform, for numrous use (to rest, to watch the surroundings), mistaken it for a rock or a mound of earth (hence it name).

The coloration of the species play a role in this confusion, but give numerous reciprocal beneficials benefits to both species.

Juveniles, them, have a greyish coloration to made them blend and pass as rocks on the beaches and rock-gardens areas.

Description

An entry for the Spec Evo community challenge/contest of Hyrotrioskjan/Joschua Knüppe 's #AtlantisBestiary3 project !

My 5th one !

For this entry, I choose to made another native species that descend from the surviving species from Phase 2.

This time, a species of land/terrestrial tortoise, who descend from the Miocene Eastern grass-tortoise (see « Atlantis Phase 2 » Post, 1st April 2023, second box picture from the top of the chart. Link : www.deviantart.com/hyrotrioskj…).

I decide to use this Miocene species of chelonian of Atlantis as ancestor, since the Atlantis giant tortoise and the Volcano tortoise died out since Phase 2.

The fourth land tortoise that exist is the Hephaestochelys platystega, which I will likely use as an ancestor of another species of tortoise a close coming future.

All the others remaining species of chelonian present at this time were semi-aquatic species.

I choose to do a chelonian, a land one, because tortoise, both small and giant ones, are perfect candidates for every kind of spec evo setting !

Already in real-life, they are really more fascinating and marvelous animals more thank we already realise and see.

Already, think that not many people in general know about giant tortoises, and something that only recently was put forward and realised by scientists (a good decade but still recent at ours scale), is that big tortoises similar in size to the Aldabra giant tortoise (Aldabrachelys gigantea) and the highly famous differents Galapagos species (Chelonoidis sp.), see even bigger, can live perfectly whithoit problems on continental mainland, in the middle of all others mainland animals including big predators.

Their famous greats size not being a result of « Insular Gigantism » process, like it was once thought to be.

Not long time ago, during all the Pleistocene, several taxas of giant tortoise roamed continental North and Central America (Hesperotestudo), Europe (Titanochelon) and Asia (Megalochelys, including M. atlas, none other than THE largest land tortoise ever know to this day), some big species in Africa and some big sized Chelonoidis species in South America.

These species were already giant since a long time before arriving and establishing themselves on islands even very far away from mainland masses. They come to these islands by themselves by the sea, by swimming, since tortoises have a surprisingly high and good boyancy when their are on waters, even open ones. Even despite their big weight, who can reach 1 ton in some cases.

They also swim pretty fast.

They all died out almost att he same time during the Middle Pleistocene, which coincides with the arrival of Homo erectus, even if today their extinction is mostly due to climatic change rather than overhunting from this human species (evidences of exploitation by H. erectus exist).

On mainland, the genus Hesperotestudo survived on North America until the end of the Pleistocene.

Every giant tortoises groups, including the ones extants today, are unrelated, and became independently giants by themselves, being polyphyletic as a « group ».

With, as example, the Aldabra species (Aldabrachelys) being related to Malagasy tortoises (Asterochelys genus), while the Galapagos giant tortoises are related to South American mainland tortoises, particularly the Chaco tortoise (Chelonoidis chiliensis).

Tortoises as a whole, whatevers small, medium or giants are among the animals groups that managed to be the most successull and to have remained on a high level of success their very beginning.

Accumulating almost all the greatest abilities possible !

Here :

- Being complete omnivorous and opportunistic animals about the diet aspect, being mainly herbivorous but eating whatevers they can eat if the occasion occured.

- Can subtain long without who and on few reserves during a long time thank to their low and slow metabolism and the fact they don’t made physical efforts most of the time (keeping precious energies).

- Live very, verrrrry old (even the smallest species), and laying tons of eggs per clutches, each years. Allowing a great legacy of offsprings among which at least many will reach adulthood.

- Are able to resist low temperatures and a certain cold level, allowing them to live in almost all kind of habitats, from humid warm to dry cold biomes.

So, I decide to do a giant tortoise to honor these fantastic animals that fight whithout too many efforts the ages and evolution itself, since tortoises as a group/family (the whole Testudinidae inside the Cryptodira suborder) exist since the Eocene and managed to live in great diversity to our days.

The results are the following species :

* The Atlantean rock tortoise (Magnochelys pratum) ;

A large land giant tortoise that inhabit the island of Atlantis, who descend from the Miocene Eastern grass-tortoise who lived at least there almost 6 mya years ago and a little before.

Her size on average is around 90 cm (3 ft) at the front tip of his shell (where where the two front legs and the head/neck come from), reaching human’spelvis, and 1 m (100 cm) at the very top of the shell.

Which is bigger than the two extant giant tortoises species alive today, the Seychelles/Aldabra and Galapagos species.

Since her ancestor was a way smaller species (being smaller than the stork-like bird Ciconognathus litorus, with which it shared most of it distribution, itself the size of a normal White stork), the case of the Atlantean rock tortoise represent, at the opposite of all giant tortoise living on islands, a true case of insular gigantism.

This large species of land tortoise inhabit the vast grasslands of Atlantis, by far the main biome which composed the landmass at the Holocene era. It pass most of it live in grasslands (80%), but occasionaly occur in bushlands and open-woodland areas as well (20%).

His lifestyle is highly similar and in fact pretty generic to any others giant tortoises.

Same as for his overall shape and behaviors.

Only the size id the main notable difference, being easily twice the size on averageof the latters, and can easily even get a little more larger at old age.

While primarily herbivorous, eating mainly grass and leaves on occassion from low branches of any kind of trees if available, it will eat anything who pass in front of her : any kind of plant matters, carrions, and will even actively hunt smalls animals (juveniles or weaken specimens), especially birds during breeding seasons (althought, on very, very rare occasions).

This species lay eggs near or on beaches, were his ancestor mainly lived during the Miocene.

Youngs will remain in this biome until they reach a sufficient size and migrate into the interior of the island.

The great expansion of the Eastern side of the island and the grassland biome after the Miocene and especially with the Younger Dryas have played a great role in the evolution of this species, since his ancestor was a grass-eater animal living in this specific region.

The higher level of food (grass) and (open)space is why it became larger and taller overtime.

Like every giant tortoise, they can subsist during months, see a years, whithout eating or drinking and on few reserves, live very long (150-200 years, see a little more).

It a very good swimmer and have a very high boyancy despite their weight and can do island hopping.

It an important megafauna herbivore in it environnment, and numerous animals use it as a perch/platform, for numrous use (to rest, to watch the surroundings), mistaken it for a rock or a mound of earth (hence it name).

The coloration of the species play a role in this confusion, but give numerous reciprocal beneficials benefits to both species.

Juveniles, them, have a greyish coloration to made them blend and pass as rocks on the beaches and rock-gardens areas.