BACKGROUND:
Children may not realize that the appearance of dinosaurs portrayed in
paintings, sculptures and models are based on information collected by paleontologists. Fossil bones are usually all that paleontologists have to
use in trying to reconstruct a dinosaur’s appearance and behavior. Fossil
bones contain many types of information, including 1) dinosaur size; 2) how
many legs they walked on; 3) what they ate (by teeth and jaw shape); 4) how
they defended themselves (by the presence of defensive body armor or
weaponry); 5) how big their muscles were (by looking at muscle attachment
points on bones); and 6) even how large and where major nerves and blood
vessels were located (by looking at openings in and traces on bones).
After collecting all the available information from a dinosaur skeleton,
paleontologists compare the features of that skeleton with skeletons of
living reptiles, large mammals or any other animal that it resembles. For
instance, the three-horned dinosaur Triceratops is built and armored
much like the modern Rhinoceros. We thus infer that Triceratops,
like Rhinoceros, was a plant-eater that was able to defend itself. By
using this sort of analogy, paleontologists are able to make educated
guesses about the appearance and behavior of dinosaurs, even though
dinosaurs are extinct.
In this lab we ask your students to be paleontologists. They will not
reconstruct animals from skeletal remains, but they will interpret the
shapes and features of model dinosaurs. They will instinctively do this by
comparing dinosaurs with modern animals without realizing it.
PROCEDURE:
- Ask students what a dinosaur looks like. Use the set of
dinosaurs and non dinosaurs (Past Life 1A) and see if the students can
determine characteristics. Remember dinosaurs were land animals. Ask the students which of the non-dinosaurs were land-living,
which were swimmers, and which were fliers, based on their body shapes.
You may want to use the dinosaur placemats to determine the characteristics
of a dinosaurs. They they could swim or fly they were probably not
dinosaurs, however some of the Mesozoic reptiles and mammals are
difficult to determine.
- Discuss with students that the "Present is Key to the
Past." This statement helps paleontologists to determine how
an extinct animal may have lived. For example, if an extinct
animal had sharp teeth, it probably was a meat eater.
- Instruct students to look at the Carnegie dinosaur models or other
similar models included those in the Past Life 1A kit. They should work as a
group to decide which dinosaurs fit into categories listed below. NOTE:
some dinosaurs belong in more than one group. They should also name as
many living animals as they can think of that also would fit into each
category. You may also use the dinosaurs on the placemat and
group them also.
- Fast-moving: dinosaurs (Velociraptor, Tyrannosaurus)
Living animals: cheetahs, ostriches, gazelles, horses, etc.
- Slow-moving: dinosaurs (Brachiosaurus, Apatosaurus,
Euoplocephalus) Living animals: elephants, hippopotamuses,
turtles, etc.
- Animals that ate leaves off tall trees: dinosaurs: (Brachiosaurus
and Apatosaurus). Living animals: giraffe
- Animals that had heavy armor for defense from meat eaters:
dinosaurs (Stegosaurus, Triceratops, Euoplocephalus). Living
animals: rhinos, crocodiles, armadillos, porcupines, hedgehogs,
turtles, etc.
- Animals that killed prey with their claws: dinosaurs: (Velociraptor).
Living animals: cats (including lions), birds of prey, badgers.
- Animals that had fancy decorations to attract mates:
dinosaurs: (Parasaurolophus, Pachycephalosaurus). Living
animals: deer, moose, peacocks (and many other types of birds), etc.
- Animals that defended themselves with their hands:
dinosaurs: (Maiasaura and Parasauralophus). Living animals:
rabbits, etc.
- Animals that defended themselves with their heads:
dinosaurs: (Triceratops, Pachycephalosaurus, maybe Parasaurolophus).
Living animals: rhinos, horned gazelles, deer, etc.
- Animals that defended themselves with their tails:
dinosaurs:(Stegosaurus, Euoplocephalus, Apatosaurus and
Brachiosaurus). Living animals: scorpions, kangaroos, etc.
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