Instruments Used In The Laboratory

Item

Purpose

Computer tomography (CT)

Electronic caliper Video camera

Mass spectrometer

Scanning internal structure of fossil specimens (especially skulls and eggs), and constructing three-dimensional images of structure with computer.

Measuring fossil specimens electronically, and transmitting information to a computer. Capturing images of unmagnified or magnified fossils and transmitting digitized images to computer for analysis. Measuring atomic masses of elements and determining abundance of isotopes for radiometric age dating of rocks associated with dinosaur fossils or stable isotope analysis of bones and eggshells.

and decreasing equipment costs, these methods will no doubt be used even more in the future. Nor is the equipment used in paleontological research limited to field-work tools, because the study of fossils is sometimes best done by examination of specimens in museum or university collections. Likewise, a laboratory setting, possibly using the latest technological wonders accessible to a paleontologist's budget, can be used to study the specimens gathered through present-day fieldwork or uncovered in the inner bowels of a museum.

Nevertheless, fieldwork is still where many paleontologists start their investigations. It is also a less expensive method of original research for paleontologists who are not associated with institutions that have a support staff, numerous catalogued specimens in storage, and expensive equipment. The potential for making discoveries with only a minimal investment in equipment is a very distinctive feature of paleontology relative to the other sciences (Chapters 2 and 3). With this perspective, the most basic items that a geologist, paleontologist, or other interested naturalist should always take into the field are a notebook and pencils or pens to record their observations. Personal digital assistants (PDAs) are now being used more for recording data, but currently have the distinct disadvantage of limited battery life; notebooks only run out of useable pages. Secondary items for geologic investigations include a hand lens, a measuring device, a compass, maps, a camera, and a rock hammer. Optional items are sample bags with labels for recording information about collected specimens, and a small bottle of dilute acid for testing the presence of calcite or aragonite (CaCO3) in a rock. A first-aid kit, water bottles and broad-brimmed hats are also recommended to treat minor injuries, prevent dehydration, and sunburn, respectively. Many areas containing well-exposed, fossil-bearing rocks are in deserts (see Fig. 1.4).

Maps are important for documenting the exact locations of fossils, besides being used for navigating in a fossil-bearing area and understanding the geologic context of fossils. Topographic and geologic maps are the two types most commonly used for these purposes. Topographic maps show the differences in elevation in a specific area as well as the area's surface features, such as forested areas, roads, and cities. Differences in elevation are represented by contour lines, lines

Among the most important items that an informed fossil prospector should take into the field are maps.

of equal elevation that follow the contours of the land surface. The spacing of contour lines gives a good indication of the relative steepness of the terrain in the field area, knowledge that is useful for traversing a hilly area or avoiding steep cliffs. A wilderness excursion should never be attempted without first investigating the availability of topographic maps for the intended region.

Geologic maps typically have contour lines too, but their main value lies in how they show the outcrop patterns of rock units on the land surface. Contour lines in combination with the geology help to illustrate how the topography of an area may relate to weathering patterns of the rocks (Fig. 4.1). Perhaps most importantly,

FIGURE 4.1 Section of a geologic map, which also has contour lines of a topographic map. The contour lines show elevation changes in a landscape, and closely spaced lines indicate relatively steeper elevation changes than widely spaced lines. Rock formations are mapped on the basis of their outcrop patterns, and letter symbols on the map correspond to the age and name of the formation (i.e., Jm is the Morrison Formation, which is Jurassic). US Geological Survey Map GQ 57, 1955.

FIGURE 4.1 Section of a geologic map, which also has contour lines of a topographic map. The contour lines show elevation changes in a landscape, and closely spaced lines indicate relatively steeper elevation changes than widely spaced lines. Rock formations are mapped on the basis of their outcrop patterns, and letter symbols on the map correspond to the age and name of the formation (i.e., Jm is the Morrison Formation, which is Jurassic). US Geological Survey Map GQ 57, 1955.

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Responses

  • Steven
    Which instrument is used to show the bones of fossi?
    2 years ago

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