A fossil is a fossil is a fossil. Right?
by Cecil Allen
The recent findings of bio-molecules, soft-tissue blood vessels and blood cells
in 65-million-year-old Tyrannosaurus rex fossil bones1 have caused geologists to re-evaluate the process
of the preservation of fossils. After all, everyone knows that a fossil is an impression,
cast, outline, or track of any animal or plant that is preserved in rock after the
original organic material is transformed or removed.2 So, how can blood vessels and bio-molecules be found
in fossils that are rock? Answer: a fossil does not need to be turned to stone to
be a fossil.
Figure 1. MOR555 (AKA Wankel T-rex) on display at the Museum of the Rockies, Montana,
USA. All bones are in excellent preservation but show little sign of petrification.
They are pure bone thought to be 65 million years old.
Figure 2. The right foot of MOR555 on display at the Museum of the Rockies, Montana,
USA. In the background is the display of the rest of Wankel T-rex.
The definition of fossil by the American Geological Institute begins, ‘The
remains or traces of animals or plants which have been preserved by natural causes
in the Earth’s crust.’3
There is nothing in this definition that requires transformation into rock. All
that is important is that the fossil has been preserved. And preservation is a qualitative
term that does not describe how the fossil was preserved. This is illustrated by
Schweitzer in describing the fossil specimen MOR 555 [AKA, ‘Wankel T-rex’]:
‘An exceptionally well preserved specimen of the tyrannosaurid dinosaur Tyrannosaurus
rex shows little evidence of permineralization or other diagenetic effects.’
She further states, ‘Most fossils show signs of sediment infilling or secondary
mineral deposition, but certain specimens can show little evidence of diagenetic
change.’4
In other words, MOR 555 is a well preserved fossil with almost no mineral petrification,
i.e. it is nearly pure bone (see figure 1)! This ‘65 million year old’
fossil is almost exactly the same today as it was when it was buried. So, if a fossil
like MOR 555 can be a fossil without being turned to rock, then what makes a fossil
a fossil?
We need to read the rest of the definition of fossil by the American Geological
Institute. ‘The remains or traces of animals or plants which have been preserved
by natural causes in the Earth’s crust exclusive of organisms which have been
buried since the beginning of historic time.’3 It
is more clearly stated as, ‘A remnant or trace of an organism of a past geologic
age, such as a skeleton or leaf imprint, embedded and preserved in the
earth’s crust.’5
So, according to this definition, a true fossil is something that has been preserved
in some way or other from some ‘past geologic age before the beginning of
historic time.’ It doesn’t matter if the material has or has not been
turned to stone, i.e. petrified, but just that it was buried before the historic
records of man!
Has this added caveat of deep time always been a part of the definition of fossil?
Let’s begin with a history of the use of the word fossil as paraphrased from
Challinor’s A Dictionary of Geology:
It doesn’t matter if the material has or has not been turned to stone, i.e.
petrified, but just that it was buried before the historic records of man!
The term ‘fossil’ (L. fossilis, dug up) was, as the word suggests,
originally given to anything extracted from the earth or the rocks. It included
minerals, all kinds of stony objects, and pieces of the rock itself, as well as
the remains of organisms. ‘Fossilia’ in the wide sense and not, in fact,
including organic remains, was used by Agricola in 1546. Gesner’s illustrated
work on fossils included organic remains (1565). In Britain organic fossils were
called ‘petrified shells’ (1665), ‘formed stones’ (1677),
‘fossil‑shells’ (1695), ‘figured stones’ (1699), ‘marine
fossils’, ‘fossil fish teeth’ (1721), ‘native’ (minerals,
&c.) and ‘extraneous’ (fossil shells, &c.) (1728). Owing, no
doubt, to these various confusing usages, the term ‘fossil’ dropped
out for a time, ‘petrification’ largely taking its place. The always
appropriate ‘organic remains’ then became popular (1804/11), and was
being used much later (1849 and following years). Meanwhile ‘fossil’
was again coming into use, but now for organic remains only, though usually with,
or as, a qualifying adjective (1816, 1822). Already, however, the word by itself
was beginning to be used. Parkinson (1804) remarks that ‘in the common language
of those most conversant with these substances’ their nature ‘is conveyed
by the substantive (“fossil”) alone’. Lamarck in France seems
to have been the first definitely to restrict the term (1801, 1802). The substantive
‘fossil’, alone and exclusively for organic remains, became thoroughly
established some twenty years later (1822).6
Figure 3. The femur of MOR1125 (AKA B-rex), the first dinosaur fossil from which
soft tissue was extracted. B-rex is also the first fossil dinosaur to be identified as
female.
Photo by M. H. Schweitzer
Figure 4. Well preserved soft tissue that is still elastic within a recently discovered Tyrannosaurus rex skeleton. For an animal that is claimed to have died at least
65 million years ago, the existence of soft tissue in its remains is astounding.
Up through 1948, fossils were defined as the remains of animals and plants or direct
evidence of their presence preserved in the rocks of the earth. Yet, even then,
the caveat of age is hinted at. While fossils were ‘evidences of animal or
plant life in the rocks, such as petrified shells, skeletons, leaf and fern imprints,
animals footprints and the like. It is chiefly by the aid of fossils that the age
of the rock is determined.’7
As is typical of much of the debate about evolution and creation, the definition
of fossil is not just descriptive but also interpretive since it includes the evolutionary
interpretation of long ages. Therefore, in the evolutionists’ minds, every
time creationists use the word fossil, they unwittingly concede the validity
of the evolutionary paradigm. Furthermore, since creationists believe that most
everything typically called a fossil was actually buried during Noah’s Flood,
which occurred within historic time, then, from the creationists’ viewpoint,
there is no such thing as a fossil, by that definition!
So what are creationists to do with the word fossil? It seems there are
two choices. Either creationists can redefine fossil to fit the creationary
viewpoint every time we use it, or invent a new word. A redefinition of fossil
could be as simple as using just the first part of the American Geological Institute’s
definition: The remains or traces of animals or plants which have been preserved
by natural causes in the earth’s crust. The inconvenient part would be the
need to state that redefinition in each creationary paper where fossil
is used. The Latin clades fossio, meaning ‘catastrophic buried fossil’,
has been suggested8 as a
possible replacement. But anything new that is not as simple as the original may
not catch on. In any case, the important thing to remember is a fossil may or may
not be petrified. But we do not accept the evolutionary definition that a fossil
is a biological remnant of a past geologic age before the history of mankind.
Further reading
Recommended Resources
References
- Schweitzer, M.H. et al., Soft-tissue vessels
and cellular preservation in Tyrannosaurus rex, Science 307:1952–1955,
2005. Return to Text.
- Dictionary of geologic terms, 18 January 2006. Return to Text.
- Dictionary of Geological Terms, 2nd ed.,
American Geological Institute, 1960. Return to Text.
- Schweitzer, M.H. et al., Preservation of
biomolecules in cancellous bone of Tyrannosaurus rex,J. Vertebrate Paleontology
17(2):349, 1997. Return to Text.
- The American Heritage Dictionary of the English Language,
4th ed., Houghton Mifflin Company, 2000. Return to Text.
- Challinor, J., A Dictionary of Geology, 5th
ed., University of Wales Press, 1978. Return to Text.
- Rice, C.M., Dictionary of Geologic Terms, Edwards
Brothers, Inc, Ann Arbor, MI, 1948. Return to Text.
- Beverly Oard, personal communication. Return
to Text.
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