👉 Plectroglyphidodon is a type of dinosaur that lived in the Late Cretaceous period, approximately 69 million years ago, during the Triassic Period. It was part of the group known as the Plesiosauridae and was distinguished from other dinosaurs by its distinctive pectoral girdle with two large holes on each side, which are called "plectories." This type of dinosaur is characterized by its long neck, large jaw, and powerful jaws that