Turtosaurs

Common name: Turtosaurs

Scientific names: *Turtosaurus armatus* (Armored turtle lizard)

*Chelysaurus bassuspina* (Tortoise lizard with a downward spike)

*Tainiepidesmos gigantospinocephalus* (Banded armor with giant spikes on the head)

Clade: *Saltasauridae*, *Saltasaurinae*, *Turtosaurini*

Ancestor: *Yamanasaurus*

Native environment: *Tainiepidesmos*: Grasslands - Pampas

*Chelysorus*: Savannas and Mixed Forest

*Tortusaurus*: Tropical Rainforest

Location: All across the Neotropical realm and even in the South of the Nearctic realm.

Size: 19m long, 7m tall for *Turtosaurus*

14,5m long, 5m tall for *Chelysaurus*

12m long, 3,5m tall for *Tainiepidesmos*

Environment info: South America has had an interesting history. After it had broken away from the ancestral supercontinent of Pangaea it remained an island continent for most of its life. It connected to the continent of North America in the north, as it is today, only recently, 2,6 million years ago. At the end of the Cretaceous period the hadrosaurs spread over most of the continents and established themselves as the principal large herbivores, replacing the great sauropods. The sauropods still exist, but mostly in places where the hadrosaurs never gained a significant foothold, such as the South American continent. Isolated from the influences of migration from other continents, the sauropods evolved in their own way

Animal description: The titanosaur group - the only surviving clade of sauropods - had begun to develop armor as early as the Late Cretaceous period. They continued to do so in South America and the armor developed into very flamboyant and spectacular forms. The turtosaurs have a solid shield of armor over its back and flanks. The tail and neck are also shielded, the tail by overlapping rings of horn, and the neck by jointed horn sections. The head is covered with a continuous horny shield. The jaws have no teeth, but the mouth edges of the horn shield are sharp and are ideal for cropping grass and cutting branches. The armor of the turtosaur is formed from bone masses that grow in the skin and are covered by a layer of horn. The back armor is a solid mosaic of small skin bones, with much larger bones spread between them. These larger bones provide the bases for a series of conical spikes. Huge hip bones and shoulder bones support the weight. There is no armor on the legs or the underside of the tail. When danger threatens the animal flops down on its belly and presents an impenetrable shield of bone and horn to its enemy. These osteodermic shields protects the turtusaurs of all their former predators, even the powerful bites of the new carnotaurs and tyrannosaurs or the giant teeth of the cutlasstooth can't pass through the thick shells. This protection also allowed the tortusaurs to be protected from the great carnivores of the North continent during the Great American Biotic Interchange and to spread even in some parts of the Nearctic. Some of the tortusaurs, even if already safe from predators still have other ways to defend against the most insisting of them inherited from their less armored ancestors like *Chelysaurus bassuspina* with its spike on the underside of the head, lowering its neck to inflict some damages, or the more basal *Tainiepidesmos gigantospinocephalus* with its two 1,2m long spikes on the sides of the head and its mass at the end of the tail, swang with its still fairly flexible neck and tail. However, some of the most derived species like *Turtosaurus armatus* are big enough to no longer need these spikes.