Index, noun; a pointer, indicator, a thing that points out. (Webster’s Dictionary)
Evolutionary paleontologists use ‘index fossils’ to assign an age to a layer of sedimentary rock and its associated fossils.
Evolutionary theory assumes that a particular creature evolved from its ancestors, lived successfully for a period, then became extinct as its descendants evolved better ways of surviving. In other words, that creature had a defined ‘evolutionary life-span’. We may be told, “It thrived in the Devonian period”. For example, we all ‘know’ that the dinosaurs ‘evolved’ about 230 million years ago, and died out 65 million years ago, don’t we?
Or do we? To ‘know’ that, people need to make two assumptions.
One is that fossils and rocks can be accurately assigned an ‘age’ directly, through various scientific techniques. However, no matter how accurate the measurements of chemicals in the rocks are, there is no way of calibrating a dating technique for supposedly pre-historic events.1 In spite of paleontologists trying to make sense of these scientific measures, the ‘dates’ they assign to rocks are actually constrained by the fossils found in them.
For example, if dinosaur fossils are found in a rock layer, the rocks are assumed to be at least 65 million years old. So if a radiometric dating result indicates an age of 40 million years, it is interpreted as representing, not the age of the rock, but a later geological process, such as disturbance, reworking or contamination. The fossils always trump the supposedly objective radiometric dating!2
The second assumption has two complementary parts. First, in the strata above and below (“after and before”) the range where fossils of a particular creature are known, it is assumed it didn’t exist at that time. Evolutionists would say either that it hadn’t evolved yet, or that it had become extinct. Second and conversely, if a particular fossil is frequently found in rocks of a particular ‘age’ then we can say that that creature is an indicator fossil for rocks of that age—an ‘index fossil’. In other words, rocks that contain fossils of that creature must be of that ‘age’, and so must any associated fossils.
Graptolites, fossils of colonial marine creatures, are widely used as index fossils.
But can we be sure that, if a creature does not appear in the fossil record of a particular age range of rocks, it did not exist then? No, we can’t.
Consider the many so-called ‘living fossils’—creatures whose fossils are not found in any rocks younger than a certain age, but discovered alive today. One famous example is the coelacanth, a fish regarded as becoming extinct supposedly 65 million years ago because it was missing from the fossil record since then. Yet, in 1938, it was discovered to be still alive. Similarly, the recent discoveries in the last two decades of dinosaur bones that contained tissue that was still flexible, as well as blood cells, challenges the idea that dinosaurs disappeared from the earth 65 million years ago.3
These examples show the futility of this assumption. The fact that an organism is not found in the fossil record does not mean it was not alive somewhere on the earth. For example, ‘ancient’ and ‘primitive’ organisms (crinoids, mosses, stromatolites, etc.) have flourished from very early in the fossil record and continue in our present world, but they don’t appear in all levels of the geologic column. Evolutionists themselves recognize this with their adage, “Absence of evidence is not evidence of absence.” But it’s certainly no evidence of presence!
Left: Part of the dinosaur ‘evolutionary tree’ (the sauropods).8
Right: The ‘tree’ disappears when areas are removed for which there is no fossil evidence
Ranges keep growing
This should alert us to the fact that we cannot assume that the dates assigned to an ‘index fossil’ are real limits on its period of existence. ‘Out-of-place’ (or ‘offset’) fossils are not uncommon,4 such as fossil fish being found in China millions of years older than previously thought.5 Such discoveries are not reported to be ‘out of place’ but are catered for by increasing the fossil range of the organism. Consequently, the ‘evolutionary life-span’ allotted by evolutionists for many index fossils has continually been increasing, as examples are found in rocks of different assigned ‘ages’.6
Another factor that challenges the million-year ages produced by these dating methods is the absence of evolutionary change in many organisms over these vast periods, a phenomenon that is even given a name—stasis. How is it that crinoids and the coelacanth have not evolved in those millions of years? Change would show the passage of time. Lack of change throws doubt on the idea of millions of years and that evolution happens at all.
When they are interpreting the fossils, evolutionary geologists assume that animals evolved over millions of years, and that fossils buried together, (that is, in the same layer of rock) lived together at the same time. They assume that layers in different parts of the world containing the same fossils are the same age. This is the whole idea behind using index fossils to relate rocks around the world. But suppose there was a world-wide flood. Then the vast majority of fossils would all have been buried during that Flood year. Different layers would contain fossils transported from different ecosystems rather than different evolutionary time periods, completely destroying the idea that index fossils represent different evolutionary ‘ages’. With the global Flood we would expect particular fossils to sometimes be present and sometimes absent from layers of the same ‘age’ in different parts of the world, as well as ‘index fossils’ to be found in rocks of supposedly ‘wrong’ age.
Ammonites, picture an octopus with a shell, are well known as index fossils
A typical diagram of an ‘evolutionary tree’ has the creature assigned to an ‘evolutionary life-span’ (see above). The vertical line shows the point at which it ‘appears’, and continues, either to the present, or to a point where it stops abruptly, indicating the point where evolutionists believe the creature became extinct. But, as we have seen, it may not be extinct but still alive somewhere on the earth today. It’s just missing from parts of the fossil record. More importantly, it’s possible that the creature existed before it first appeared as a fossil. In fact, its ‘kind’ was alive on the earth from creation up to its first ‘appearance’ as a fossil. It would then ‘appear’ in the fossil record fully formed, without ‘evolutionary ancestors’, just as the Bible predicts, and just as we actually find in the rocks.7
No such thing
What can we deduce from all this? Basically, that index fossils are no such thing. They are not indicators of an evolutionary progression, and they cannot be relied on without question as indicators of the age of any particular rock layer. If they ‘indicate’ anything at all, it is that God created the different kinds of animals and plants fully formed, and buried them in His judgment on the world in the biblical Flood about 4,500 years ago.
References and notes
- See Walker, T., The fatal flaw in radioactive dating, Creation 32(1):20–21, 2010. Return to text.
- See an account of the long argument over the dating of the famous fossil KNM-ER 1470 in Sarfati, J., The Greatest Hoax on Earth?: Refuting Dawkins on Evolution, Creation Book Publishers, pp. 194–195, 2010. Return to text.
- Doyle, S., The real Jurassic Park, Creation 30(3):12–15, 2008; creation.com/real-jurassic-park. Return to text.
- Oard, M., Are fossils ever found in the wrong place, Creation 32(3):14–15, 2010, creation.com/fossils-wrong-place. Return to text.
- Walker, T., Slow fish in China, Creation 22(3):38–39, 2000, creation.com/slow-fish-in-china. Return to text.
- Woodmorappe, J., The fossil record: Becoming more random all the time, Journal of Creation 14(1):110–116, 2000; creation.com/fossil-random. Return to text.
- See also Morris, J.D. and Sherwin, F.J., The Fossil Record, Institute for Creation Research, Dallas, TX, 2010; Sarfati, J., Greatest Hoax on Earth? chs. 8 and 9, Creation Book Publishers, 2010. Return to text.
- By world dinosaur expert, Paul Sereno, The evolution of dinosaurs, Science 284: 2137–2147, 1999. Return to text.
The index fossils have long been used to guide geologists in the search for oil deposits. Their sequences are well understood. That they are used to reliably find oil is evidence of their utility.
Yes, they can be useful on a regional basis, and this can be explained in terms of deposition during the global Flood. But as discussed in the article, "They are not indicators of an evolutionary progression, and they cannot be relied on without question as indicators of the age of any particular rock layer."