to their narrow, pointed beak. 

They also have a distinctive pattern on their shells 

of overlapping scales that form a serrated-look on the edges. (Good description)

The problem they facing is nesting ,they are not having space to nest because the rising  temperature is killing the coral reefs that they rely on for food , and also predoutors eat the turtles eggs so they don't have the chance to reproduce , and another problem is that there is still people are poaching and over- exploitation them for there skin , meat ,shell because it worth lots of money.  Please write in sentences.

Spinal-tailed lizards can tolerate intense temperatures and they use their sharp spines on their their tails to defend themselves from predators. They can also change their colors according to their body temperatures. In the morning when they’re cold, they turn dark grey, it helps absorb the heat, warming the lizards up and then it turns them into a sandy beige color which prevents from overheating and camouflage. 

Sadly, the lizard are under a threat and endangered now because of loss of habitat, unsustainable collection for food and dune bashing and pet trading.