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| Fossils are the remains or evidence, of organisms or organic material, that have been preserved. Fossils are also are a representation of impressions created by the organisms or organic material. The word fossil comes from the Latin word “fossilis”, which means “dug up”. This definition was first applied to anything unusual dug up from the earth but now it refers specifically to the remains or impressions of organisms or organic material. | |
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A most famous historian, and also a geographer of the ancient times, was Herodotus of Halicarnassus (ca 480 - 420). He started a long journey in 445 BC and traveled along a number of different lands and cultures, from Egypt through to Syria and Babylon, Colchis, Paeonian and Macedonia. He also stayed in the Greek city of Athens for a long time |
| Of his books, one book was totally dedicated to the people, culture and land of Egypt. In 450 BC, Herodotus noticed fossils in the Egyptian desert, and he correctly concluded that the Mediterranean Sea had once been in the area. |
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Aristotle ( 384 - 322 BC), was born in Stagira, a Greek colonial village on the Aegean Sea near the Macedonian border. In 367 BC, Aristotle entered the Academy at Athens, and he was both a student and friend of Plato between 367 BC and 347 BC. Aristotle stated that fossils were organic in origin, but that they were embedded in the rocks as a result of mysterious forces at work within the earth. |
| People have been finding fossils ever since there were people to look for them. Gaius Plinius Secundus, known as Pliny the Elder, served both as a cavalry officer in Germania and as procurator. He combined with this public service, a deep interest in science. Pliny (23-79 AD) spoke of "tongue stones," which were later demonstrated to be fossilized shark teeth. His only extant writing, The Natural History, divided into 37 books, was completed in 77 AD. Some people thought that the fossils were created when lightning struck rocks, causing them to become molten and formed into new shapes. Others relied on the Neo-Platonic view. This meant that each creature on the land had its counterpart in the sea, the merman for the man, the narwhal for the unicorn. With such a principle of order, it surely caused each terrestrial and marine creature to also have its counterpart in stones underneath the ground. Still others thought that there was a latent plastick virtue in stones, which caused them to spontaneously form themselves into the shapes of plants and animals. | |
| During the “Dark Ages” fossils were explained as either freaks of nature or the devices of the devil. The latter theory prevented fossil research during this period of time for fear of the consequences from the religious authorities. It was not until the fifteenth century that the true origin of fossils was generally accepted. It was then that fossils were considered to be the organic remains of previous life forms. |
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Leonardo da Vinci (1452 - 1519) was an artist, and the creator of such masterpieces as the Mona Lisa and The Last Supper, yet Leonardo was far more than a great artist. He was also an inventor and visionary, with one of the best scientific minds of his time. His research into the fields of anatomy, architecture, astronomy, civil engineering, geography, geology, zoology and paleontology are often overlooked. Several hypotheses of how shells and other living creatures were found in rocks on the tops of mountains during Leonardo's time included the belief by some that the shells had been carried there by the Biblical Flood. Leonardo had a different hypothesis. He thought that fossils were once living organisms that had been buried at a time before the mountains were raised, "it must be presumed that in those places there were sea coasts, where all the shells were thrown up, broken, and divided." |
| By the seventeenth century, some naturalists were beginning to believe that life on Earth had been around a very long time, and that fossils were the preserved remains of that life. This idea was not entirely new, but its acceptance was. |
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By the beginning of the nineteenth century, Baron Georges Cuvier
(1769 - 1832) proved on the basis of fossils, that some species had
become extinct. Georges Cuvier was born on August 23, 1769, at Montbéliard,
a French-speaking community in the Jura Mountains . He helped to
create vertebrate paleontology as a scientific discipline and created the
comparative method of organismal biology. He wrote in his Discourse
on the Revolutions of the Surface of the Globe, "Why has not anyone seen
that fossils alone gave birth to a theory about the formation of the earth,
that without them, no one would have ever dreamed that there were successive
epochs in the formation of the globe." This idea was soon changed
into believing that most species had become extinct.
Fossil records demonstrated that creatures have been living, and dying, for much longer than had been imagined. This idea was, and is, disturbing to the religious beliefs of some. |
| This conflict moved Alfred, Lord Tennyson (1809-1892) to write on
the subject in his poem In Memoriam:
Are God and Nature then at strife, ...
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There are several forms of fossils that can be found, with molds and casts being among the most common. After an organism is covered with sediment, the entire organism usually dissolves or decays away, leaving its impression as a mold. This type of fossil impression is called an exterior mold. If the sediment then fills in the impression of the exterior mold void created by the decomposition of the organism, the type of fossil that is formed is called a cast fossil. Another type of fossil mold is called an interior mold. This is created when a creature such as a clam dies, and sediment fills in the interior of the clam shell, after the creature inside dissolves or decays. As the clam shell dissolves, what is left is the fossil impression the sediment made of the interior of the clam’s shell. This type of interior mold, when made from the interior of a gastropod, is called a steinkerns. Also remember that parts of an organism can make an exterior mold, such as a leaf from a tree, or a feather from a bird. To see some specific examples of casts and molds, just click on the image below. |
| Another type of fossil that is common to find is one created by mineralization or petrifaction. We all have heard of petrified wood or a petrified forest. This type of fossilizing occurs when water containing minerals seep into an organic object or organism through the porous areas, where the water then deposits the minerals in the porous areas. As the remainder of the organic object or organism dissolves or decays away, new mineral-laden water seeps into these areas, and the minerals are again deposited. In time, the entire organic object or organism may be replaced by minerals, and it appears to have been turned to stone. To see examples of this type of fossilization, and our examples of petrified wood, click on the image. |
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Another type of fossilization in called carbonization. This occurs more commonly in plants, as they contain a large amount of dark carbon. As the organic object or organism dissolves or decays, an impression is left in the rock, and only the more stable carbon remains. This carbon is called a carbon film and this process is also called distillation. This type of fossilization can be found in what are more commonly known as ironstones. These ironstones have an appearance of being just a stone and are found where a shallow body of water had been millions of years ago. Ironstone will usually cleave evenly when struck correctly, exposing the fossil contained within. To see examples of this type of fossilization, and what we have found, click on the image. |
| Trace fossils include casts and molds previously mentioned. Also remember that the impression that organisms make, such as foot prints, are a type of trace fossil. Tunnels and burrows are also examples of trace fossils, as are coprolites. To learn more about coprolites, click on the image. |
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Be sure to return to the main Paleontology page, and check our Collections pages, to see what fossils we have found. To learn more about other trace fossils, and to see our examples of trace fossils, just click on the image. |
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