In this article we will discuss about Reptiles:- 1. Definition and Origin of Reptiles 2. History of Reptiles 3. Characteristic Features 4. The first reptiles arose from ancient labyrinthodont amphibians during upper Carboniferous period, about million years ago and have adapted to terrestrial life. Living orders can be traced back to the Triassic. More primitive forms still unquestionably reptiles are known from as early as the base of the Pennsylvanian.
Reptile - Wikipedia
Reptile egg fossils are the fossilized remains of eggs laid by reptiles. The fossil record of reptile eggs goes back at least as far as the Early Permian. However, since the earliest reptile eggs probably had soft shells with little preservation potential , reptilian eggs may go back significantly farther than their fossil record. Many ancient reptile groups are known from egg fossils including crocodilians , dinosaurs , and turtles.
Western Brown Snakes
A myriad of extant and extinct vertebrates produce eggs. Eggs and eggshells provide a useful substrate for reconstructing environment, ecology and biology over a range of time scales from deep time to the present. In this review, methods for analysing and understanding records of diet, climate, environment and biology preserved in eggshells are presented.
For many years it was suspected that the widespread Western Brown Snake Pseudonaja nuchalis was in fact a composite species, however efforts to split nuchalis were largely defeated by the extreme level of colour and pattern variation encountered both within and between populations. Ontogenetic colour changes, suggestions of intergrades, and possible hybridisation with other Pseudonaja species added to the confusion. Despite the enormous challenge researchers were able to narrow down a number of basic colour morphs, and recent genetic studies have now built upon earlier findings to confirm the existence of at least three species within the nuchalis -complex.