Walking with the Dinosaurs Lab - Part 3

Note: Remember you are responsible for graphs, charts and other items that form part of the overall summary of this topic.

Upon completion, the Walking with the Dinosaurs Lab activity will introduce you to the life of a paleontologist from the planning of an expedition, to the actual “dig” of a dinosaur skeleton and finally to the building of a dinosaur showcase.  Be sure to familiarize yourself with the Paleontological Studies notes; geologic timeline and extinction theory notes as you complete this lab.  You may also wish to visit the Walking With Dinosaurs website.  Be sure when completing the lab report, that you follow the given format.

Vocabulary

• bipedal – walking on two (2) legs
• carnivore – meat-eating animal
• herbivore – plant-eating animal
• invertebrate – an animal that has no backbone; vast majority of animals are invertebrates
• mammals – animals with backbones that have hair; give live birth and feed their young milk
• Ornithischians – “bird-hipped” dinosaurs with a hip structure in which the two lower bones on each side lie parallel; all Ornithischians were plant eaters
• Quadrapedal – walking on four legs
• reptiles – animals with backbones that are “cold-blooded”; have scaly skin and lay leathery eggs
• Saurischians – “lizard-hipped” dinosaurs with a hip structure in which the two lower bones on each side point in opposite directions
• Sauropods – large quadrapedal, saurischian, plant-eating dinosaurs, with very long necks and tails
• Therapods – carnivorous, bipedal dinosaurs
• vertebrae – bones that form the backbone
• vertebrate – an animal with a backbone

Laboratory Activity – Digging for Dinosaurs

Dinosaur bones are extremely fragile when first discovered in the field.  They almost always require excavation and a protective covering, called a jacket, before they can be moved safely.  The basic tools and material needed to collect a bone include:

• excavation tools (marker; brush; awl; hammer; chisel)
• jacket material (plaster; burlap; separator material (paper); water)

The jacket looks like the white plaster casts doctors make for broken human bones.  The plaster comes as a powder and is mixed with water.  The plaster is made stronger by dipping burlap in it and then wrapping the plaster/burlap combination around the bone.  The plaster and burlap, however, cannot be placed directly on the bone, as it would be very difficult to remove the jacket later.  A separator, (paper), is used to cover the bone before the plaster-dipped burlap is applied.  Once the plaster dries, the jacket can be labeled with a permanent marker.  It is very important to label the jacket and record its contents in a field book, because the bone can no longer be seen.

If the bones were completely exposed in the field, lying on the surface, it would be easy to make a complete jacket all at once.  However, most bones are buried and so the jacket must be made in two (2) stages.  First, the bones are cleaned on the top and sides.  The top half of the jacket is then completed.  The bone is now strong enough to turn over and it rests on the newly made jacket, with its bottom surface facing upward.  The second jacket is then completed over the bottom surface of the bone.

Directions

Below are the actions necessary for excavating and jacketing a dinosaur bone.  Number them in the correct order.

        __________ Clean and outline bones in place in the ground

        __________ Label jacket

        __________ Clean bottom surface of rock

        __________ Let plaster jacket dry

        __________ Add separator and plaster-dipped burlap to bottom of bone

        __________ Add separator and plaster-dipped burlap to top and sides of bone

        __________ Mix plaster with water and cut burlap strips

        __________ Flip half-jacket

<  Walking with the Dinosaurs Lab - Part 3  >