Paleontology is a field that tries to answer questions about the past. Its goal is to reconstruct the evolution of life on Earth, and its methods are not unlike those used in other fields of science. Paleontologists use fossil records to understand how ancient organisms evolved into new forms over time.
They accomplish this by studying fossils preserved in rock strata, which can tell us about changes across species over millions of years. The reason paleontology differs from other sciences like astronomy and chemistry is that it studies historical processes—it looks at what happened in the past rather than what happens now or might happen in the future. It's also different from archaeology because it doesn't usually focus on humans but rather animals (and plants).
The fossil record is your data. It's what you're studying and it's the reason that you're interested in paleontology. You're using scientific methods to get answers from that data.
The scientific method is a series of steps:
- Data is collected (e.g., fossils)
- Data is analyzed (e.g., using morphometrics)
- Results are published (e.g., peer reviewed articles)
Once we locate fossils, we prepare them in the lab. The process starts with removing sedimentary rock from around the fossil. The goal is to reveal as much of the fossil as possible without damaging it, because once you break up a fossil, it's lost forever.
After removing all of the surrounding sedimentary rock, we often need to expose different parts of the specimen by chiseling away chunks of surrounding rock and clay. Then we use compounds like sodium carbonate (Na2CO3) or potassium feldspar (KAlSi3O8) that dissolve easily in water but not in oil-based solvents such as acetone or xylene so that they can act like glue when they're applied directly onto exposed surfaces. Some fossils are still buried in rock.
This can be a challenge for paleontologists, but it's not impossible to crack open the rock and reveal what's inside. After all, we've been doing this for hundreds of years!
There are two main ways that paleontologists remove fossilized bones from their rocky tombs: chiseling and hammering. Chisels are used for very small rocks; hammers work better on larger pieces of stone. A hammer has two sides: one side has a blunt edge and one has a sharper edge. The blunt side is used to break off large pieces while the sharp side helps break apart smaller rocks into smaller pieces so they can be removed easier by hand or with another tool such as chisel or toothbrush. Once we clean a fossil, we usually want to make a cast of it. The process is called “casting” or “master molding” and involves making a mold around the fossil using some sort of material (often plaster). Usually this is done with something called alginate, which is like rubber that has been dissolved in hot water and then poured into the desired shape as soon as it cools.
Once you have your master mold made, you fill it with more liquid plaster (also known as investment) and let that dry. When it's fully dry, you use an air gun to blow off any excess material on top of the cast. You then take away all of the supports holding up your original fossil so that they don't show up in your final product—for example, if there were some kind of structure around where your dinosaur stood or sat while alive then those things will probably show up when casting because they were attached!
The final result after removing all support structures should be something like what's pictured below:
Analyzing a fossil can involve many different approaches and techniques.
- Shape analysis is a simple technique that can be used to compare the shapes of different fossils. It involves measuring and recording the lengths, widths, and angles of certain landmarks on an object. The locations of these landmarks are usually determined by reference to anatomical features such as the mid-line (center line) of bones or other structures like teeth.
- Landmarking is another approach that uses points on a fossil to define specific measurements. With this method, you can determine how far apart two parts of your specimen are from each other by measuring the distances between pairs of landmarks and then multiplying them together so they're all converted into consistent units (for example centimeters).
- Statistical shape analysis is used when there are many different variables being considered at once—in other words it's a way of analyzing data with multiple dimensions (e.g., length, width). This method involves calculating distances between points on an object and applying those distances to create points in three dimensional space using mathematical formulas like linear regression analysis
One way paleontologists analyze fossils is by measuring their shapes. Shape is a function of both size and shape, so if you want to measure the shape of a fossil it’s not enough just to take its measurements in two dimensions; instead, you need landmarks on the fossil that are meaningful for how it was used by its owner (usually an animal). Landmarks can be anything distinctive in appearance—such as holes or bumps—or even areas where there are distinct textures.
For example: If you were analyzing a trilobite, which has many eyes along the edges of its body, then early in your research process you would mark these eyes with a pencil so that when you later measured them with calipers they will come out as part of your final dataset.
Shape is complicated, and we can't always just look at an animal and know exactly how its body will change. That's where computers come in! They can help us measure shape by doing many different kinds of calculations.
The most common type of computer program used to measure shape is called a "morphometric" program, or "mophometrics". Mophometrics are mathematical algorithms that tell you things like how long something is or how tall it is (or maybe even whether it has back legs).
Morphometrics is the use of morphological measurements to characterize living and extinct organisms. Although it has been most commonly used in biology, paleontologists are increasingly utilizing this technique to quantify shape variation among fossil specimens and compare them with extant species. The main advantage of morphometric analyses over traditional taxonomic methods is that they can be performed independently of any comparative data on living species, which can often be difficult or impossible to obtain for many fossil species. The process typically involves taking multiple measurements from each fossil specimen and then using statistical analyses to compare those measurements with those taken from other fossils (or even modern animals).
The most common way that paleontologists measure shape variation is by using bilateral landmarks—these are small points on an object where two lines cross at 90° angles. This works well because most vertebrates have bilateral symmetry (meaning they're symmetric along their long axis), so it's easy to identify these landmarks without having to measure every point on a specimen individually (which would take forever). Typically, there are 19-36 landmarks used for each measurement. For example, if you were measuring the shape of the skull of a whale, you would mark the tip of its snout and then use that point as a landmark for all other measurements. Landmarks should be evenly spaced around the measurement area so that they can be easily identified and measured in an accurate way. They should also be easy to locate so they can be found again if needed—this is particularly important if only some measurements will be taken from one specimen due to limited availability of bones or fossils at certain museums or locations with collections stored away from public view.
First, you have to decide what's important to measure on your fossil. Landmarks can be anything, but usually they're anatomical features like snouts or eye sockets. The main thing is that they should be easy for someone else who doesn't know your specific fossil to find and count on their own.
Because different species have different body shapes, the number of landmarks will vary depending on what you're measuring. If you're trying to compare two different dinosaurs in length, then it probably makes sense to use more than one landmark (two snout tips might not be enough). But if all you want is an estimate of how big an organism was overall then one set of eye sockets may be enough!
To ensure consistency across specimens studied by other researchers later on down the line though; I would recommend using four landmarks at most: two midline skull points (one above each eye), one center point between these two skull points (to mark where halfway up the head would sit) and lastly one end point marking where distance from tip-to-tip ends at this center point (not counting any nose!).
Then you choose where on the fossil those important parts are and mark them with landmarks. After you've chosen your landmarks, you use software to map each landmark onto a new place on the fossil like localizing them into a coordinate system. Once all of your landmarks are localized, you can start asking questions about your data!
Once you've chosen your landmarks, you use software to map each landmark onto a new place on the fossil like localizing them into a coordinate system. Once all of your landmarks are localized, you can start asking questions about your data!
This is where things get fun! You can do things like:
- Make an outline of the fossil. The outlines of fossils are called "coefficients" and they're super important in certain types of studies (like morphometrics). If you have lots and lots of fossils in one place (like a bone bed), then this will be easy for you since their shapes are already pretty obvious. But sometimes fossils aren't so easy to see because they're covered with rock or sandstone or whatever else makes up most rocks on earth today. So if this happens to be true for whatever fossil(s) you've chosen to study, don't worry too much about making an outline just yet—just worry about marking out as many landmarks as possible first before committing yourself too heavily into anything more time consuming than necessary!
The next time you see a fossil, take a moment to think about how much work went into its discovery. To make these specimens available to us, paleontologists must spend years searching for them and collecting data on their shape. Once they're in the lab, though, we still have much work ahead of us before we can understand what happened millions of years ago!