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To identify a fossil is to figure out what kind of fossil you are dealing with, as well as finding out which taxonomical name the fossil has been given within scientific nomenclature. Correctly identifying a fossil is often much more of a challenge than one would think at first glance. The ability to correctly identify fossils is the result of a lifelong learning process. We can make a rough mental excercise to determine some categories, who can turn out to be very useful during the learning process.

Regardless of whether you’re young or old, as soon as you’ve picked up paleontology as a hobby, a truck load of information will come your way. Geological strata, continental drift, Sediments, and evolution. Strange forms of extinct creatures who lived millions of years ago, mineralization forms, deformations by diagenesis, pseudo-fossils, and the list goes on… The difficult vocabulary and theory is building up. With some general knowledge you find yourself going out on your first fieldtrip with a geological association, finding your first fossil. Immediately the first big question arises:

"What have I found?"

There are loads of different possible answers to this question, and most of them are wrong. But even among the wrong answers, there’s a lot of variation. Let’s consider the following example:

You’ve found this fossil somewhere in the pit of a construction side. It is beautifully preserved, and it has some really nice and interesting features. You think you see some enamel, and that seems to be correct, you’ve found a tooth. If you would show your fossil to someone more knowledgable, a correct answer can be anything between 'Shark tooth' or 'Galeocerdo aduncus AGASSIZ 1843' sometimes even down to the level of a subspecies or the position of the teeth inside the sharks’ jaw. In both cases, the fossil has been identified. In the last case however, the identification is a lot more accurate.

Bearing this example in mind, we’d like to focus a bit on the level of identification. The word 'level' in this case, refers to the level of accuracy one uses to assign the specific fossil to a certain location within the taxonomical tree of life. Often, a fossil is identified upon the level of the species. But this is not always possible. For example when the diagnostic features of the fossil (these are the morphological features that distinguish one species from another) are not preserved. I may well be possible, for example, two closely related mammals have nearly identical femurs, but distinct molars. One can find such a femur in a certain geological formation where the occurrence of two species of this mammal were found in the past. The diagnostic feature of this mammal however, lies not within the femur, but in the teeth. At that moment in time you cannot identify your fossil femur to the level of the species, but only to the level of the genus

The www.fossiel.net website offers a variety of practical tools, who can be very useful when starting a fossil identification. The main tool is our ID-system, which is a pictorial database that can be explored starting from taxonomy, age or location. This  database is continuously updated and reviewed by the community behind Fossiel.net.

If you should find yourself stuck with the online identification system, Please feel free to upload a picture of the fossil on the forum. In case of extraordinary finds, you could consider getting in touch with a professional at your nearest institute or through your local association.


1. 'Recreational' identification

Fossil identification often starts out as a game. Because the amount of scientific information can be overwhelming, but at the same time difficult to access, there exists a large market of identification books & guides who focus on the starting amateur paleontologist. These beginners' guides provide an overview of the most common fossils and taxonomical groups. Mostly plant fossils, ammonites, belemnites, trilobites, crinoids, graptolites etc..., from all around the world, or from specific locations.  

Even though these guides do not provide a good reference to identify your local fossils, We suggest the starting amateur to purchase such a book anyhow. In a way, it will help one to start identifying fossils in a serious way. In a primary stage, it will be an exercise in comparing pictures, and finding out to what picture in the book most closely resembles your local fossil. On the other side, it teaches a beginning amateur palaeontologist to look and learn the anatomy of a wide range of fossils from different geological periods and taxonomical groups. This knowledge will come in very handy once you find yourself out in the field. Henceforth, a small piece of shell with  a nod, can now be identified as a part of a regular sea-urchin with interambulacrale nodule, where in the past you just would’ve walked by.


Limiting yourself to the comparison of pictures to identity a fossil, is very tricky. The teeth above are definitely not G. cuvier.

When you come across a picture of a fossil inside a identification guide, that resembles your fossil a lot, It’s tempting to copy-paste the taxonomical name and include the fossil into your collection under that name. Chances are very high, however, that the identification is wrong. It is therefore of the utmost importance to accompany your identification of the exact location (as accurate as possible) where the fossil was found. This information will help you later on. When you’ll perform a genuine identification.

This kind of comparison however, can form a first step towards a more solid identification. In the first example, we understood that the tooth we found, is likely to be a shark tooth, possibly Galeocerdo sp. Or a genus that looks much alike. With this knowledge  we can continue our search more accurately.


2. 'Basic' identification

In order to perform a good identification of a fossil, we’ll try a different approach. We will no longer start our identification by comparing pictures, but we’ll build up our identification, starting from a geological and biological point of view:

1) The stratigraphical origin of the fossil: At which locality was the fossil found, and from which geological layer (as accurate as possible)?

2) The taxonomical classification: based upon the morphological features, in which group can we place the fossil (as accurately as possible)

Based upon the answers to these questions, we search for any kind of accessible and specialized literature that covers the stratigraphic and taxonomic range we're interested in. One can also seek advice from a professional, or specialist.

Some scientific syntheses provide a very good overview of a specific taxonomical group.


3. 'Advanced' identification

In order to find out the exact scientific name, It is necessary to consult the most recent and up-to-date specialized scientific literature. This often poses practical problems, because this kind of literature is not always accessible to the masses, and is often very expensive as well. On top of that, the knowledge about a specific group or species is mostly scattered over loads of different articles from all kinds of scientific journals. More information about how to deal with, and how to find scientific literature, can be found in the info page ‘Literature’. Sometimes a membership to a scientific library can be a solution, but make sure that the library has a subscription to the journals and reviews you’re interested in. Most of the time, natural history museums have a full membership to the most common paleontological and geological periodicals. Many also allow (digital) copies to be taken in their libraries. Online you can also find a vast variety of databases which allow you to search for scientific articles. Sometimes a membership or association with a scientific institute is requested. (example: ISI Web or Knowledge). Such databases are often difficult to access. Others (for example, ScienceDirect) allow specific searches to be performed on their database. For most articles there is a resume or abstract available that can be accessed. One of the most accessible and powerful search engines for scientific publications is Google Scholar.

For the identification of our fossil, we need the original article(s) where a species is described. In this/these article(s) the holotype(s) and sometimes paratypes of this very species are described. Often you will find an extensive listing of all morphologic features of the species as well. Apart from that 'key' article, all other articles covering this species are of interest, in particular those more recent than the original publication. Also relevant are articles covering closely related species, because they are often compared to the species we are looking for. At this point, we don’t know yet what species we’re looking for, we need to cross-compare all related articles. Our knowledge concerning the geological formation, and the exact location where the fossil was found, as well as a vague idea to which taxonomical group this fossil belongs, allows us to really focus on the information presented within the articles.

As a result of this comparison, we obtain insights in the different diagnostic features of all species within the taxonomical group, our fossil is part of. Once acquainted with these diagnostic features, we can apply them to our fossil. This level of identification however can force an amateur paleontologist to concentrate his specimen collection and research upon a specific taxonomical group, or geological period.


4. 'Professional' identification

In the worst case scenario even advanced identification does not comply to identify our specimen. The fossil you’ve found differs fundamentally from every know species within the relevant taxonomical group and time period. Maybe you have found a new species, a yet unknown morphological variety, or a pathological deformation?

Right now we have reached the point where the only way to introduce the fossil into the paleontological knowledge base, can only be accomplished by using extensive comparisons, statistical analysis, and advanced research methods. An example of this might be morphometric analysis, where a number of morphological parameters are measured, from a large amount of individual fossils, in order to find out if they belong to a similar species, or if they can be divided into different groups. An example of such a morphological parameter might be the relative distance between the eyes (in relation to the total width), Or the position of a certain nob in relation to the total length, width, or the length/width ratio of a segment etc… As soon as you have measured a number of these parameters from a sufficient number of individuals, you can fall back on elementary statistics such as PCA (Principal Component Analysis) or CT (Clustering Techniques). These statistics will allow you to divide and cluster your population in a single or several distinct groups. If all data can be classified into one group, then you can assume that you are dealing with only one species. However, when the data can statistically be divided into two or more groups, the variation between the parameters upon which the differentiation is based, can later on be used to define and recognize the diagnostic features between these two or more species.

Do you have additional information for this article? Please contact the Fossiel.net Team.