Fossils

A general introduction to the history of fossil studies, religious apprehentions, how the fossil record and the field of paleontology were established.

17th century ammonoid fossils
Figure 1.1 Seventeenth century illustration of ammonoid fossils (Cornua ammonis, or "snake stones") drawn by Robert Hooke, father of microscopy and paleontology in Britain, 1703).

"In the mountains of Parma and Piacenza multitudes of rotten shells and corals are to be seen, still attached to the rocks... And if you were to say that such shells were created, and continued to be created in similar places by the nature of the site and of the heavens, which had some influence there --such an opinion is impossible for the brain capable of thinking, because the years of their growth can be counted on the shells, and both smaller and larger shells may be seen, which could not have grown without food, and could not have fed without motion, but there they could not move.
And if you wish to say that it was the Deluge which carried these shells hundreds of miles from the sea, that cannot have happened, since the Deluge was caused by rain, and rain naturally urges rivers on towards the sea, together with everything carried by them, and does not bear dead objects from sea shores toward the mountains. And if you would say that the waters of the Deluge afterwards rose above the mountains, the movement of the sea against the course of the rivers must have been so slow that it could not have floated up anything heavier than itself."
- Leonardo da Vinci, c. 1500

What is a Fossil?

We have been conditioned to connect fossils to extinct organisms, and difficult to imagine any other explanation. One definition that seems satisfactory, is "any evidence of prehistoric life". We are not only limited to direct evidence, but all indirect evidence. The state of preservation has little to do with determining whether an object is a true fossil. Dinosaur bones are direct evidence, however, many times indirect evidence are considered, such as preserved footprints in mud, fecal material (coprolites) and gastrolliths (pebbles which presumably aided in digestion), worm borings and chemical substances from prehistoric algae and bacteria, such chemicals fossils are products of metabolism and evidence of such nature, are all defined as fossils.

For understanding methods of natural fossilization, visit "How A Living Organism Becomes a Fossil".


The ancient Greeks believed giant mammoth remains to be remains of mythological giants while mystified by seashells found hundreds of feet above sea level. They wondered if the ocean once covered the land, or did these fossils form within rock like crystal. In the sixth century B.C. Xenophanes of Colophon discovered shells in a high cliff on the island of Malta, concluding perhaps the sea once covered land. The oldest known record of such belief, was by Xanthos of Sardis around 500 B.C. who believed fossils were remains from extinct animals entombed in rock. For 2000 years, the belief expressed by Aristotle (384 B.C.) remained influential, suggesting fish fossils were remains of sea animals that had swam into cracks of rocks and stranded.


From latter days of the Roman Empire, people believed in the literal six day creation and the worldwide flood of Genesis, casting confusion on the proper interpretation of fossils and rocks. Most individuals who lived during those times had limited knowledge about what lie at the bottom of the ocean. Many fossils share no resemblance to species familiar to Europeans. The living chambered nautilus was discovered in 1829, - Europeans could scarcely imagine coiled objects known as Cornua ammonis ("Horns of Ammon") (Figure 1.1), "serpent stones" -- and bullet shaped belemnites (Fig. 1.2.), were relatives of squid and octupus.


belemnites
Figure 1.2 Illustration by Conrad Gesner from 1565 of bullet-shaped belemnites and crinoid columnals. These organisms resembled no known species to Renaissance Europe, Gesner included. They were presumed to be a product of falling stars due to the starlike pattern in some of the crinoids.


Even today, people who chance to pick up one, often fail to recognize these cylindrical crinoid columnals as relatives to of the sea urchin. Few people have seen the rare crinoids which still dwell on the ocean floor. Scholars once referred to them as "star stones" (Lapis stellaris or Astroites stellis) believing the star-shaped pattern in the columnal and the radial pattern in fossilized coral to be a product of thunderbolts or falling stars.


The word fossil comes from the latin, fossilis meaning "dug up". Educated men during the Middle Ages and Renaissance began to make speculative interpretations of fossils. At first the word fossil was applied to any formation found in a rock, remains of organisms as well as non-organic crystals and concretions. Some believed those formations resembling living creatures were caused by animals who had been stranded in the rock and turned to stone. Others believed they were grown from seeds or washed in during Noah's flood. Other scholars believed they might be pranks of the Devil, for the purpose of destroying faith, while others presumed supernatural origin, (lusus naturae) or "figured stones" produced by mystical "plastic forces". These assumptions may seem strange today, but during the time they were sensible for people who held the widely shared belief in a literal Genesis and a 6,000 year old earth.


Around 1500, Leonardo da Vinci (1452-1519) acknowledged fossil shells in the Apennine Mountains of northern Italy, located far away from any coastline, represented ancient aquatic life. Unlike his colleagues, da Vinci knew it was unlikely they were washed there during Noah's flood, many of the shells being too fragile for such a journey, and impossible to have washed there by the Flood in forty days. Many of the shells were intact, and in a position which was not dissimilar to extant species living near the seashore, simply, they did not appear to be the product of transported organisms. Some of the shells beds were divided by layers of unfossiliferous strata, it did not appear to be a formation produced by a single devastating flood. Most of da Vinci's ideas remained unpublished, for they would not have been accepted at the time.


In 1565, the Swiss physician Conrad Gesner (1516-1565) authored "On the nature of fossils", De rerum fossilium. It was the first work that illustrated fossils. This, along with brief descriptions by earlier authors could be made more accurate. (Fig. 1.2). Gesner's publication were based on his own fossil collection, and those of colleagues which began the modern tradition of exchange, analysis and comparison. Correct in his comparisons of most fossils with living relatives, but Gesner concluded some items such as the crinoid columnals and belemnites were formed by mineral precipitation. Just as many of his contemporaries, Gesner interpreted from a supernatural perspective, Neoplatonic "ideal forms" and failed to explore the implications that are obvious to most of us today.
Through his publication, four main questions were raised:

  1. Are fossils organic remains?
  2. How did they get into rock?
  3. When did they get there, -when it was formed, or afterward?
  4. How was it the creature became petrified?

Answers to these questions were first offered by Niels Stensen, also known as Nicholaus Steno (1638-1686), a Dane physician. Living near the Apennine Mountains, Steno had the opportunity for a closeup firsthand look at the shells. In 1666, he dissected a large shark caught near Livorno. Upon inspection of the mouth of the shark, he saw that its teeth closely resembled fossils known as "tongue stones", latin glossopetrae which were previously considered petrified snake or dragon tongues. (Fig. 1.3) Steno now realized tongue stones were actually petrified remains of ancient shark teeth, and that fossils were a product of once-living organisms.


tongue stones
Figure 1.3 Illustration by Nicholaus Steno from 1669, showing "tongue stones" and their similarities with modern shark teeth.


Steno published De solido intra solidum naturaliter contento dissertationis prodromus in 1669, "Forerunner to a dissertation on a solid naturally contained within a solid". Steno's publication focused on how solid objects got inside solid objects. Steno theorized the enclosing sandstone must once have been loose sand, which was later petrified into sandstone, an idea which overturned the idea that rocks had been created during the first days of Creation and remained so, as we see them today. Steno's observations extended into further understanding of relative age of geological features, in other words Fossils encased in rock must be older than the rock which formed around them. However, crystals grow within the fabric of the rock, after the rock formed. Steno generalized the principles of superposition, original horizontality and continuity, fundamental principles in historical geology and stratigraphy. Just as the Prodromus was being published, Steno made a conversion to Catholicism forfeiting his interests in science, so the promised disseration never followed. Later, he returned to Denmark, where he lived until his death.


Around the same time of Steno's publication a British scientist, Robert Hooke (1635-1703) was coming to similar conclusions. Hooke was responsible for one of the first microscopes and the first sketches of microscopic organisms, including cellular structure, thus he became known as "the father of Microscopy". In 1665, Hooke made several observations, suggesting fossils might be a useful means to make chronological comparison of age in rocks [similar to coins aiding in accurately dating records in Rome], including the first accurate fossil drawings published posthumously in 1705 (Fig. 1.1). Hooke made the observation that many of the fossils had no living counterparts, therefore he speculated that species may have a fixed "life span". At the time, it was commonly believed the earth and all species had been created a mere 6,000 years before and all species still alive. What Hooke proposed was the first hint at the extinction of species.


Most of the ideas put forth by Steno and Hooke were rejected, until around a century later. Throughout the early 1700's, beliefs about fossils were still influenced heavily by Biblical tradition. In 1726, Swiss naturalist Johann Scheuchzer (1672-1733) described one particularly large fossil, "the bony skeleton of one of those infamous men whose sins brought upon the world the dire misfortune of the Deluge." Scheuchzer named it Homo diluvii testis, or "Man, a witness of the Flood". This early on, comparative anatomy was not advanced enough to make a clear distinction, and the fossil was later discovered to be a giant fossilized salamander. (Fig. 1.4).


Homo Diluvii Testis
Figure 1.4 Homo diluvii testis "Man, a witness of the flood", as Scheuchzer so named the fossil. Donald R. Prothero, "Bringing Fossils to Life", makes the following humorous observation, "Scheuchzer's anatomical skills were not up to his Biblical knowledge, since it is actually the fossil of a giant salamander."


Another sad event involved Dr. Johann Beringer (1667-1740), dean of the Wurzberg, Germany medical school. Fascinated with the "petrifications" that collectors had given to him, he composed a large monograph of the "figured stones". Some bore resemblance with frogs, shells and other natural objects, some with stars and other curious patterns. Colleagues whom Beringer had offended passed off the carved objects, but confessed the hoax too late to stop publication. He was ruined, and died spending his last pfennig attempting to buy back all the copies of the book.


By the mid eighteenth century, naturalistic fossil concepts prevailed. Linnaeus published the Systema Naturae in 1735, which classified all life including fossils, which were treated and named the same as extant species. At the dawn of the nineteeth century, Baron Georges Cuvier (1769-1832) made progress in the area of comparative anatomy, demonstrating how certain features; claws, sharp teeth, hooves and grinding teeth, were correlated. It is to Cuvier we owe the paleontological tradition to predict unknown anatomical structure, based on a comparison with anatomy of close relatives. Cuvier also showed how bones from mastodonts and mammoths were in actuality, an extinct elephant-like species and explorers had discovered no species like them. Cuvier became the founder of comparative anatomy and vertebrate paleontology, bringing the study of fossils away from much of the Biblical superstition previously overshadowing it. Prior to this time extinction was an unacceptable fact for it went against everything believed aobut the creation account in Genesis. For instance, as Donald Prothero states, "If God watched after the little sparrow, surely He would not allow any of his creatures to go extinct."


During the late eighteenth century, William Smith (1769-1839) an engineer from Britain, was surveying for canal excavations and made the observation that fossils reveal a pattern -each formation had different assemblage, as he wrote in 1796, "the wonderful order and regularity with which nature has disposed of these singular productions [fossils] and assigned each to its own class and peculiar Stratum." Smith became an expert at recognizing the fossils in each formation and correctly identifying the layers from which the specimens orginated. Smith used his knowledge of faunal succession in the first geological map, which was published in 1815. At the same time, Cuvier and a colleague Alexandre Brongniart were mapping the Paris Basin's strata. Though independently, these men realized there was a regular fossil succession, differing formation to formation. These discoveries eventually led to modern concepts of biostratigraphy, a means to explain earth's history.


By the time Darwin's On the Origin of Species was published in 1859, the understanding of fossil complexity had became so widely accepted among scholars, few took Noah's flood literally.


REFERENCES
PaleobiologyBringing Fossils to Life, An Introduction to Paleobiology, McGraw Hill Publishers, Donald R. Prothero


PaleobotanyPaleobotany and the Evolution of Plants, by Cambridge University Press; 2 edition, Wilson N. Stewart, Gar W. Rothwell


DinosaursKingfisher Illustrated Dinosaur Encyclopedia, Kingfisher Publishers, David Burnie


FURTHER SUGGESTED READING

Adrienne Mayor's books

1) The First Fossil Hunters (Princeton 2000) explains how ancient Greek and Roman discoveries of mysterious petrifed bones of extinct dinosaurs and mastodons led to myths about griffins, giants, and monsters. Watch for "Ancient Monster Hunters" on the History Channel.
2) Fossil Legends of the First Americans (Princeton 2005) gathers exciting Native American discoveries and myths about fossils, from tiny shells to enormous dinosaur bones, with stories from more than 45 different tribes, beginning with the Aztecs & Incas.


Stephen Meyer's article, "Are Dinosaurs Mentioned in the Bible?"

Edward T. Babinski wrote: "In 1726 [Prof. J.J. Scheuchzer] mistook the skull and vertebral column of a large salamander from the Miocene of Oeningen for the "betrübten Beingerüst eines alten Sünders" (sad bony remains of an old human sinner) and figured the specimen as "Homo diluvii testis" (the man who witnessed the Deluge).


SOURCE: Dirk Albert Hooijer, "Fact and Fiction in Hippopotamology (Sampling the History of Scientific Error)," Osiris, Vol. 10. (1952), pp. 109-116.


Funny comment about the above sentence: Assertion, emphatic and immune to reason, might not be the best foundation for a new critical practice; but we also can’t tell our salamanders from sinners.


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