Prehistoric Biology Atlas 142 - Heterocerodosaurus (non-dinosaur)

Branch analysis showed that amniotic animals can be divided into three categories: the two-hole and non-porous types that make up true reptiles, and one lower hole type. In the late Permian period, about 250 million years ago, the two-porous reptiles differentiated into two classes, which later became extremely important. Dinosaurs, crocodiles, and birds were derived from the main dragon type, while the lepidoptera gave rise to snakes and lizards.

The main dragon type consisted of beaked dragons, protosthes, and main dragons, with protosaurus rising in the middle of the Permian, the main dragons rising at the end of the Permian, and the others rising in the Triassic.

Most of the main dragon-type lower order adapted to terrestrial life. Their long legs lie more directly under the body than other reptiles, making their bodies more stable and moving more quickly. Associated with the evolution of the legs are the improvement of the foot, especially the joint structure of the ankle joint and the change in the flexibility of the first toe (the big thumb), which greatly improves their ability to move.

The protosaurus suborder includes carnivorous protosaurus (the earliest known animals of the lower order), such as the prototylans of the late Permian and the late Triassic plant-beaked dragons represented by heteropendontosaurs.

The most important species in the lower order of the main dragon type is the main dragon, whose evolution in the Triassic period is about to change the history of terrestrial animals for nearly 200 million years. The main plesiosaurs spawned dinosaurs , crocodiles , pterosaurs , and birds.

Name: Heterodenophoraurus (early taprozoosaurs)

Age: Late Triassic

Location: Asia (India) and Europe (Scotland)

Size: Length 1.3 meters

Diplodocus belonged to the reptile order " Beaked " , especially in South America and Africa. They were bulky plant-eaters that flourished during the mid-Triassic to the Twilight Period and were the most numerous reptiles of the time.

Heterodontosaurus and its close relatives survived briefly but were extremely successful, and their success stemmed from their teeth. It has a wide tooth plate on each side of the upper jaw, and there are several rows of teeth on the tooth plate, and a groove in the middle, when the jaw is closed, the two rows of teeth of the lower jaw bite exactly with these grooves, which in turn produces a huge cutting force, which is very much in line with its habit of eating and planting.

The beaked plesiosaurs may have fed on seed ferns, which were found throughout the Triassic but were replaced and extinct by conifers during the Triassic. The beaked dragon was also extinct at the end of the Triassic period, and its plant-eating niche was replaced by the newly evolved plant-eating dinosaurs, and the "main dragon age" began.