The earliest known dinosaur is Nyasasaurus parringtoni, which lived during the Middle Triassic period, around 243 million years ago. Discovered in Tanzania, Nyasasaurus represents a key transitional form, showcasing features that are both dinosaurian and pre-dinosaurian, highlighting the evolutionary path leading to more well-known dinosaurs of the Late Triassic and beyond. This discovery pushes back the origin of dinosaurs by approximately 10 to 15 million years earlier than previously thought, providing crucial insights into the early evolution of these remarkable creatures.

• Kingdom: Animalia > Phylum: Chordata > Class: Reptilia > Saurischia (or Ornithischia)
  (Clade: Dinosauria)