The Epoch of Reptilian Dominance: From Amphibian Ancestors to Pterosaur Flight

Around 320 million years in the past, the first reptiles emerged, originating from amphibian ancestors. They possessed lungs, more robust legs, and laid hard-shelled eggs that were better suited for land survival compared to the water-bound eggs of amphibians. The reign of reptiles reached its zenith during the Mesozoic era, which spanned from 250 to 265 million years ago, aptly named the Age of Reptiles. During this era, reptiles were the most abundant and dominant vertebrates. However, following this period of supremacy, only a handful of reptile groups persisted, including sea turtles, crocodiles, snakes, and lizards, with lizards constituting over 95 percent of the surviving reptiles.

Reptiles are categorized as amniotes, a group of tetrapods that lay eggs on land (excluding birds and mammals). They are characterized by their scaly or bony exterior coverings and are ectothermic, relying on external sources for body heat regulation. The earliest known reptilian fossils, dating back 315 million years, were discovered in Nova Scotia. They consist of a series of footprints left by a lizard-like creature, measuring approximately 8 to 12 inches (20 to 30 centimeters) in length.

Among the earliest divisions of reptiles were the diapsids, identifiable by a pair of openings on each side of their skulls. Diapsids eventually gave rise to two major branches: the lepidosaurs and the archosaurs (with "saur" meaning lizard).

Lepidosaurs encompassed lizards, snakes, and tuataras. The tuatara, a lizard species that can grow up to about 39 inches (1 meter) in length, once inhabited various regions across the world but now primarily resides on the coastal islands of New Zealand. One of the most remarkable lepidosaurs was the mosasaur, an extinct marine reptile resembling a monitor lizard, which could reach an impressive length of 57 feet (17.5 meters). It was known for its speed, agility, and its reign as the dominant marine predator for nearly 20 million years.

Within the archosaur category, two prominent groups were the pterosaurs and dinosaurs. Pterosaurs, previously referred to as pterodactyls, were the earliest vertebrates to achieve powered flight. They held the title of the largest flying creatures in history, boasting wingspans of up to 40 feet (12 meters). Even the smallest among the approximately 120 pterosaur species was larger than a sparrow. Their skeletal structure resembled that of birds, featuring hollow bones, and their exceptionally long fourth digit supported wings distinct from those of bats and birds. Pterosaurs first emerged about 215 million years ago and thrived for a staggering 150 million years before eventually becoming extinct.

The green tree python inhabits regions including New Guinea, Indonesia, and the northern Australian Cape York Peninsula. With the capacity to exceed 6 feet (180 cm) in length, this python is known for its unique coiled stance, often found wrapping around tree branches.