Traits:
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Cells have DNA
Cells have a nucleus in them
Cells have mitochondria
Multicellular
Cells are held together with collagen.
Sexual reproduction
 Early embryo forms as a hollow ball of cells called a blastula
 This blastula opens into a tube “tail end first”
 Has a head and is bilaterally symmetrical (you can draw one line down the middle)
 Cells organize themselves into true tissues (muscle, nerves)
 Cells organize themselves into true organs (heart, liver, stomach)
 Has a hollow space between the gut and outer body wall where organs are (this space is
called a coelem—pronounced “see-lome”
 Segmented body
 Internal bony skeleton
 Backbone, Spinal chord and braincase
 Had jaws
 Had lungs
 Had paired appendages
 Had four legs
 Amniotic egg (able to lay its eggs out of water)
 Two openings in the roof of the mouth (“palatal openings”)
 Two openings in the side of the skull at the temple (“diapsid openings”)
 Opening in the skull in front of eye socket (“antorbital fenestra”)
 Has a hole in the hip socket allowing it to stand upright
 Has grasping hands
 Narrowing of the middle ear bone—only one middle ear bone (“slender stapes”)
A notch in the two bone just behind the eye opening (“notch in postorbital”)
Simple hinge-like ankle (requiring a more erect posture—no sprawling walk)
A2.14 Plateosaurus trossigensis (broad reptile)
 Long neck bones
Plateosaurus was a large, early herbivore that was about 27.5 feet (8 m) long and weighed about 1,500 pounds (700 kg). It had a long
neck, very long tail, a small head with a long snout, and large, five-fingered hands with a large thumb claw (and smaller claws on the other
fingers). Plateosaurus may have been able to use its hand for grasping in addition to walking. Its back legs were larger than its front legs.
It was a very common dinosaur in Europe during the late Triassic period.
Plateosaurus lived about 222-219 million years ago, during the late Triassic period.
Plateosaurus lived in a dry, almost desert-like environment in what is now Europe.
Plateosaurus may have congregated in herds, and may have migrated seasonally across the arid (dry) European landscape during the
late Triassic period.
Plateosaurus was one of the first tall, long-necked herbivores (plant eaters). It was probably able to rear up on its back legs in order to
graze on tall vegetation, like conifers and cycads. Its sharp teeth let it tear these tough leaves from the plants. It may have swallowed
pebbles and small stones to help in the digestion of the tough leaves and other plant material that it ate. These gizzard stones (gastroliths)
would help grind up the food in the stomach.
Plateosaurus was a sauropodomorpha, whose intelligence (as measured by its relative brain to body weight, or EQ) was the lowest among the dinosaurs.
Plateosaurus had short claws on its front and rear limbs, and weak, leaf-shaped teeth. These paltry defenses were probably not very effective against large
predators, which had bigger claws, sharper teeth, and were stronger overall. Its best defense was to run away.
Plateosaurus walked on four muscular legs, but may have been able to rear up on its back legs to eat tall vegetation.
Plateosaurus is one of the most common dinosaur fossils found in Europe; it has been found in over 50 European locations. It was first described (and named) by the
German paleontologist Hermann von Meyer in 1837.
http://www.enchantedlearning.com/subjects/dinosaurs/dinos/Plateosaurus.shtml 3/16/08