Fossils in life position (Part 1)

One reader of this blog asked how our beliefs might have changed or developed in the twelve years since our book was published. One answer is that if we were writing the book today, Dr. Stephen Godfrey would include additional material about fossils found in life position, which he feels provide a compelling counter-example to the claims of creationist flood geology. In this series of posts, he explains this phenomenon.

As Curator of Paleontology at the Calvert Marine Museum, I collect fossils in all kinds of settings. I see how and where they are preserved. I find that, remarkably, as I shall explain, they inform not only our understanding of nature, but also of the Bible, to the extent to which these understandings intersect.

A fossil is said to be in “life position” if it is found in sedimentary rocks in the same spatial orientation and geographic and vertical position within the strata as where it lived and died. The most obvious fossils preserved in life position are those from “sessile” organisms, that is, ones that could not move from where they were living because they were anchored in one spot. A few examples of such organisms include trees, oysters growing in an oyster reef, barnacles, stromatolites, sea lilies, and coral reefs. In addition to strictly sessile organisms found in life position, other kinds of organisms such as burrowing clams and brachiopods can also be found in life position, buried where they lived their life as filter-feeders.

Becoming aware that certain kinds of fossils are often preserved in a life position had a profound impact on my understanding that the sediments in which they are buried could not have been deposited during Noah’s Flood (described by young-Earth creationism as a global catastrophe). Recognizing this phenomenon is also one of the easiest ways to know that the Earth is much older than young-Earth creationists believe. It is also one of the fundamental characteristics of the fossil record.

To be clear, there are many more examples of fossils, like sharks’ teeth, that are not found in life position. There are no permanently sessile sharks. Throughout their life, sharks move about, shedding teeth periodically. When a shark tooth is found in sedimentary rock, we rightly conclude that that tooth did not form and exist onlyright where it was found; rather, it came to rest there and was buried after it fell from a shark’s mouth (or the shark died and was buried in the vicinity of where the tooth was recovered).

However, there are other large categories of fossils preserved right where they were made by the living animal. These include fossilized footprints and burrows, which could not have been moved by Flood waters to their final resting place. Prehistoric burrows into sediments are also preserved right where they were made and did not settle out of Flood waters. Both of these kinds of fossil types are found at countless levels within the global record of sedimentary rocks.

There are many examples of burrows and fossils preserved in life position along Calvert Cliffs. There are literally trillions preserved in the geologic formations that make up the naturally eroding sea cliffs along the Chesapeake Bay.

A view of Calvert Cliffs just south of Bay Front Park, Calvert County, Maryland, U.S.A. Notice the person in the lower right-hand side of this photo standing at the base of the cliff. Immediately above the clay sediments on which this person is standing is a fossilized oyster reef, which is shown in greater detail in the two pictures below. (Photo by S. Godfrey.)

As impressive as these sea cliffs are, they represent only the top 3.5% (about 80 feet) of a much thicker (2700-foot) pile of sediments hidden underground. What’s even more impressive is that this depth of sediment is only the narrow end of a vast wedge of sediment that thickens increasingly to the east, out under the waters of the Atlantic Ocean to the continental slope, where the pile is 10-14 km thick! These sediments, consisting of a mixture of sand and clay, eroded from the Piedmont and Appalachian mountains. The fossils found along Calvert Cliffs include the remains of over 600 different kinds of mostly marine organisms; these include a great variety of seashells (clams, oysters, and snails), sharks’ teeth, and whale and dolphin bones.

Fossil seashells, some forming thick layers, occur throughout most of the sediments that comprise Calvert Cliffs. At the northern end of Calvert Cliffs is a layer of heavy-shelled extinct oysters. In the next picture, notice the prominent layer of oyster shells at the base of the cliff, to which the individual in the distance is pointing. These oysters are among the most obvious and easily accessible examples of fossils preserved in life position along Calvert Cliffs (although there are many others). These shells are from an extinct kind of oyster, Pycnodonte percrassa.

A view along the oyster reef at the base of the cliff seen in the picture above. At this spot the Pycnodonte oyster reef formed on a heavily burrowed blue marl (clay layer).
Close-up view of the heavy Pycnodonte oyster shells. Fingers for scale.

In my next post, I’ll explain what we can conclude about the formation of these fossils from their occurrence in life position.

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