Category Zoology

        Some snakes swim in the sand. The Australian Sandfish, the nearly legless Neoseps of Central Florida, several other lizards and some snakes are known for swimming in the sand. They go underground by wriggling in through the loose soil or sand. The sand viper of the African desert swims into the sand and sticks the black tip of its tail out to attract prey. Sand swimmers are mainly desert animals.

Monitors, some other lizards and some tortoises live in permanent burrows. The burrows serve to beat the heat and the cold and for hiding from enemies. These reptiles come out of their burrows to eat. Another group of reptiles spent their entire lives under the ground. Blind legless lizards fall into this group. They tunnel great distances in search of worms and insects. These strange creatures have lived in the soil, since the days of the dinosaurs. 

Early reptiles like the Dimetrodon were meat eaters. Many ate insects. Insects are small packages of energy, and for many reptiles, it is still the basic food. Most young reptiles start out as insect eaters. The young need plenty of energy for growing up, and the insects provide just that. Older lizards continue to eat insects. However, older snakes

 Synapsids are reptiles that look like mammals. In fact, mammals, animals which give milk to their young, arose from reptiles. Synapsids have a single opening on the side of the skull, behind the eye socket. Primitive synapsids are called pelicosaurs. More advanced mammal like ones are known as therapsids. Several sub groups of pelicosaurs exist. Some ate fish. Dimetrodon was a pelicosaur that preyed on other animals. It reached a length of about three metres. Edaphosaurus was a ‘vegetarian’ pelicosaur. It had strange long spines on its back. This could have supported a large ‘sail’ rich in blood vessels. The edaphosaurus turned the sail towards the sun to warm up in the cold, and away from the sun to keep cool.

Pelicosaurs were replaced by therapsids 299 to 251 million years ago in the Permian period. Some therapsids ate plants, while others preyed on animals. Therapsids in turn, gave rise to the mammals, 250 to 200 million years ago in the Triassic Age. Like mammals, some therapsids had different types of teeth, and limbs pulled beneath the body, lifting it off the ground. However, we are yet to find out exactly when the reptiles became mammals. 

Once upon a time, reptiles were the kings of the Earth. They were the most dominant animals. However, thousands of reptiles became extinct, or died out completely. Euryapsida is a subclass of extinct reptiles. These reptiles had a single opening on the upper part of the skull, behind the eye socket. Eurapsids are further divided into four orders or groups. The Araeocelidia had long necks, and they lived on the land. Sauropterygians had long necks, a small head, and short wide bodies. They swam using flipper like limbs, and ate fish.

 A small group of reptiles ate snails and other molluscs. They were heavy bodied with long tails, and had broad flat teeth for crushing shells. This order is known as Placodontia. Ichthyosaurs of the final order were fish eaters. They had paddle like limbs, a fin on the back, and a fish like tail. Scientists have found an ichthyosaur fossil containing a baby ichthyosaur. So, we know that ichthyosaurs gave birth to young ones. 

The archaeopteryx was part reptile, and part bird. It is a wonderful example of an in-between creature. Several fossils of this reptile-bird have been found in fine grained stone. The skeleton looks like that of a dinosaur, but it shows the presence of feathers. Feathers evolved from the scales of reptiles, and are the most important feature of birds. The archaeopteryx had a toothed jaw, a long tail, and a weak breast bone. Unlike the bones of birds, all the bones of archaeopteryx were solid. The feathers of the archaeopteryx tell us that the crocodile is related to the cuckoo.

Pterosaurs were flying reptiles. About 150 million years ago, this group of reptiles took to the air. Pterosaurs were light bodied creatures with leathery membranes stretched between their arms and forefingers to form wings. The first pterodactyls may have been gliders. Later, they may have developed the ability to fly by flapping their wings up and down. Some even fed on the wing. They plucked fish out of the sea in the manner of modern sea birds. Pteranodon was the largest of them. It had a wingspan of six metres. Pterosaurs are also known as pterodactyls.