Dinosaur Evolution -- May 14, 2019

Classical taxonomy:

• Class: Reptilia
• Subclass: Archosauria
• Orders:
• Order: Saurischia (never completely died out; lived on as sparrows)
• Suborders:
• Theropoda
• Saurpodomorpha
• Order: Ornithischia (completely died out)
• Suborders:
• Ornithopoda
• Stegosauria
• Ankylosauria
• Certopsia

Subclass:
Subclass: 
No dinosaurs "lived" in water. They may have waded into the water, lived near water, but did not live in water. Nor did they fly. 

Theropods: first to appear; only dinosaurs that are carnivores are theropods; all other dinosaurs are herbivores

It appears interesting that the "giant" dinosaurs were all in the "Saurishia" order.

We'll come back to examples and comments on the suborders of Ornithischia later.

From this site: four order and three subclasses:

• Subclass Lepidosauria
• Rhynchocephalia (tuataras)
• Squamata (lizards, snakes, amphisbaenas)
• Suborder Sauria (lizards)
• Suborder Serpentes (snakes)
• Suborder Amphisbaenia (amphisbaenas)
• Subclass Anapsida
• Testudines or Chelonia (turtles, tortoises, terrapins)
• Subclass Archosauria
• Crocodylia (crocodiles, alligators, caimans, gavials, false gavials)

Many different clade diagrams/theories.