Amphibia and reptilia - class-X

Ophisaurus ,occurs in southern Europe, is a limbless lizard 

Anapsida has a solid roof due to the absence of any temporal vacuities on skull.

Ophisaurus, commonly known as the glass lizard, is a genus of reptiles that look like snakes but are actually legless lizards.

Crocodiles, alligators, and tortoises are all members of the class Reptilia.

Living fossil lizard of new zeal and sphenodon belongs to Rhyncocephalia. The single species of Tuatara is the only surmising member of its order, which flourished around 200 million years ago.

Cotylosauria, often called stem reptiles, are the most primitive reptiles and are characterized by an anapsid skull, meaning they lack temporal fossae. Chelonia (turtles) also have anapsid skulls, but Cotylosauria is the broader ancestral group typically associated with this definition in evolutionary biology contexts.

Dinosaurs are divided into two orders based on their pelvic structure: Saurischia (lizard-hipped) and Ornithischia (bird-hipped). Saurischia includes both theropods and sauropods.

• The anterior middle portion of vertebrae is known as centrum and a posterior vertebral arch known as the neural arch. 
• The procoelous vertebra is convex at the anterior side while convex at the posterior side. 
• Ophidia is a suborder that includes snakes and reptiles and has procoelous vertebrae.
• So option A is the correct answer

The living amphibians are divided into three subclasses:

The options are all genus of different species of toad.

The order Anura includes the amphibians like the frogs and toad. The basic characteristics of Anura species are 

Salientia is a Latin word which means 'to jump'. So, it is justified calling Anura as Salientia as frogs and toads have larger hindlimbs and forelimbs which helps them to leap. So, the correct answer is 'Anura'.

The characteristics of salamanders are as followed:

Tortoises are considered as reptiles and not amphibians because of the following characteristics:

Chameleons are squamate reptiles belonging to the family Chamaeleonidae. They are cold-blooded vertebrates covered in scales, which places them firmly in the class Reptilia.

Tyrannosaurus is a well-known large extinct carnivorous dinosaur characterized by huge, dagger-like teeth and immense height and size.

Limbless amphibian belongs to order Gymnophiona and family Ichthyophiidae. So, the correct answer is (A).

(A) Testudo - Tortoise

Pterosaurs were a group of flying reptiles that lived during the Mesozoic Era. They were the first vertebrates to evolve powered flight.

Ichthyosaurus are the ancient animals. These are marine reptiles. This is a genus of ichthyosaurs from the late triassic and early jurassic period. They are the best known ichthyosaur genera, with the Order Ichthyosauria. Ichthyosaurus was the first complete fossil to be discovered in the early 19th century. The fossil was found in England. Plesiosaurus was a genus of large marine sauropterygian reptile. They lived during the early part of the Jurassic Period. They are known by skeletons as fossils from England.

Given here are the animals and the class where they belong.

Tortoises are considered as reptiles and not amphibians because of the following characteristics:

• Ichthyophis is a genus of caecilians (a group of limbless, serpentine amphibians).
  
• They are found in moisturized or wet tropical habitats.
  
• So, the correct answer is 'It is a limbless amphibian, who lives in water'.

Anapsid is a subclass of reptiles. An anapsid is an amniote whose skull does not have openings near the temples. The skull of anapsid are made by solid roof. It includes turtles and extinct Permian forms. 

Turtles are characterized by a special bony or cartilaginous shell developed from their ribs and acting as a shield. Before the turtle lay their eggs, nearly all turtles prepare a nest on land. During the last weeks of gestation, the pregnant female spends less time in the water and more time on land, smelling and scratching at the ground in search of the perfect place to lay her eggs.

Among living reptiles, the saltwater crocodile is recognized as the largest reptile in the world by weight and size.