As far as I know a term "subfossil" is usually preferable for such bones and plant remains

I would argue that an organic remain qualifies as a fossil if it shows some level of diagenetic alteration (i.e., that some of its constituants have been replaced by those from the embedding sediment)

In my opinion, the only non-subjective criteria to identify what is fossil and what is not is whether or not it has been naturally buried. The problem with subfossil is that it's an arbitray cutoff - anything from the Pleistocene is a fossil, while something from the earliest Holocene is somehow magically a subfossil. Diagenesis also doesn't work, as a lot of Pleistocene fossils have not really undergone much diagenetic alteration. This means many specimens from the Pleistocene would not count as fossils - which, from a standpoint of consistency is fine, but unconventional due to the perception of certain Pleistocene material as non-fossilized and impractical on the grounds that some sort of time-intensive test for diagenetic alteration is needed to even tell you if you have a fossil.

Ironically, identifying a golden retriever who went missing on a camping trip and whose skeleton was naturally buried in a river bank last August as a fossil seems just as unconventional (even though from a taphonomist's perspective, what I think to be most correct), so perhaps the fossil/subfossil convention for Pre-Holocene/Holocene remains is perhaps the best (and most widespread in use).

Agree with many opinions expressed above.

The problem arises time to time due to confusion of the term itself and the process. The widely accepted definition for "Fossil" vs. "Subfossil"  is based on the geological time boundary (10,000 yr B.P.), and is not directly related to the term "fossilization" . Some consider the term "subfossil" as a subcategory of "fossil", which I think is not incorrect. The "fossilization process" and definition "fossilized" is about if the tissues were geochemically altered or not), because this process can be quick or long, ignoring the geological boundary.  Mammoth bones and carcasses of Pleistocene age found in the permafrost, which we consider "fossils", are not geochemically altered (= fossilized), preserving wonderfully their tissues (soft and hard). The same is known for T. rex bones of million years old, reserving protein molecules (still being debated, but it is beyond the point). Bones from the Mammoth Site of Hot Springs in South Dakota, majority of which come from Columbian mammoth about 26,000 years old, are also not altered . Contrarily to the frequently found not-altered Pleistocene-age tissues, some Holocene bones found in caves with right conditions are discovered being completely recrystallized (original tissue structure is lost).

Fossils are witnesses of past life, i.e. they were all produced by a single natural process: biological evolution. Putting an age limit for fossil/sub-fossil is an arbitrary convention, and I don't think studying fossils is a fundamentally different thing from studying subfossils. Restricting the name "fossil" just for some type of preservation seems also arbitrary, the main thing being that these objects were preserved until now, whatever their age and the involved mechanisms of preservation.

So, I would be in favour of calling call "fossil" every bone, imprint, mould, mummified / frozen body, etc. of past living organisms, to the exclusion of those which belonged to still existing populations (of course, the bones of our dead relatives should certainly not be seen as fossils, but the bones of people not attributable to existing population could be called fossils). This view will be seen by many as a bit extreme, but it may as well be seen somewhat less arbitrary than age- or preservation-based ones.

The term "fossil" should be taken as a neutral expression

for any remains of plants or animals of past times that have

been discovered in natural sediments by digging

(Latin fossilis = dug out or dug up).

The term "subfossil" makes no sense, if you had to dig to

discover the object. The term "subrecent" is more correct.

A time boundary of 10,000 yr B.P. makes no sense, too.

An 11,000 year old object would be regarded as a fossil.

A 9,000 year old object not?

I think, that reference of object to fossil or subfossil is rather symbolically, as there is no precise border in criteria of estimations. I agree with reasons above about natural burial and a mineralization. I shall note also, that the age border is symbolically too. Nobody has written on fossil, what age it has. The age is estimated during studying the fossil and conditions of its burial place.

remains of organism older than 10000 years i.e. prior to beginning of Holocene is classified as FOSSIL

Agree - it is an arbitrary distinction whether something is fossil / subfossil, and alteration is definitely not a valid criteria.  I have collected unaltered Cretaceous clams and snails from fine-grained sediments that rapidly covered/sealed the specimens.  I've always liked my first paleo professor's definition - if it no longer smells, then it's a fossil!

Just a side comment: in (Neo)Ichnology, wen we are able to identify an ichnotaxon (let's say Skolithos) registered in a modern environment, we call this following the formula "incipient" + "the name of the ichnotaxon" (in our case, "incipient Skolithos"). There is no need that burial has even started.

Cheers.

As Lynn, I support the traditional definition, "Fossils are the preserved remains or traces of life from the past. Any preserved evidence of past life"

A fossil is simply, as stated by others here, "ANY evidence of past life", period. Any other definition is overly complicated. Sometimes a single term is not sufficient to describe, in detail, what the complete nature of a specimen is. In my opinion, this is the purpose of additional descriptors (e.g., Recent, Ma, not mineralized, archaeological, etc...).

Thanks to all for very fruitful discussion. Can there be a consensus now! But before reaching to any conclusion just ponder over the following points:

1. At beaches, one finds shells of the most recent animals, they are past life and can be dug out from the waves-brought-sands. Can we call these shells as fossils?

2. There is tradition for burying pet animals and even humans. The chemicals spread on them cause induced diagenesis and will soon get decapitated. Such remains can accidentally be dug our or may be knowingly (in some special situations, if one argues them as fossils then complications will arise. In such cases we can of course follow Kenneth's views but then we have to arrive at universal definition)  

3 Please also see the explanation given with the question.

@Kenneth. Thanks. Probably one more rider can make it complete...Excluding "Living fossils" (e.g., sequoia)????!!!! 

Kenneth....Could you please recommend these words to geological forums, say Palaeontological Society, for universal acceptance. (So many times different connotations cause confusion to our young budding geologists/scientists......I wish many bottle necks in geology may get removed this way). THANKS.  

In palaeontology books the fossils are considered the 'petrified' remains of the past life. That means for a a fossil mineralization is a must without which it would remain a fossilized bone. Holocene bones are generally non-mineralized and therefore non-fossilized, and are usually referred to as skeletal remains.

"Living fossil" is referred to those extant species which remained unchanged all through a long geological time scale or are like their ancestors found in fossil record.

A plant or an animal or a part of them become fossils when they undergo the fossilization processes: transformation of mineralized and organic part and so on...

All organic material before transformation are not fossilized. Those part may be considered subfossils, but it is an arbitrary definition.

In my opinion

I had emphasized the typical /common true fossils are of the bones and dentition, which become fossils after mineralization which usually takes over 10kyr.. But the exact age depends on the environment and basin of deposition and taphonomic conditions which delay or speed up the mineralization process Some had argued and considered all past bones as fossils irrespective of the fact they are mineralized or not, to which I do not subscribe.

Regarding the moulds, impressions, and the like, they are pseudo-fossils and not true fossils.

I also do not diverge from the what RWB has said on Aug 7 in as much as the conventional definition is concerned. It becomes meaningless if we consider every bone or the impressions buried a month or year ago as fossils.

Please read complete discussion before you post your answer....Anek... there are some animals of Pleistocene age which have remained unchanged because of their preservation in ice...They are fossils by any definition.

I know the original question was about bones, imprints or mould.... but a definition of what a fossil is has to englobe a lot of different preservation types and timespans.... I think we face the same problem as neontologist face when trying to use a universal definition of what a "species" is..... there is simply no clear cut line that satisfies all cases. For example... if we go for a fossil definition with a time bias of +10kyears.... what do we do with.... for example.... ostracod shells that are recovered from lake botom cores, thar are 8kyears old and represent different taxa that the one present today?? or how about pollen?... the sporopollenine is preserved as mummification.... is a 10001 years old polen a fossil but a 9999 years old one not?...... If we are going to use an arbitrary criteria it should be as inclussive as possible.... and not be centered on a paleovertebradologist or paleobotanist point of view........ either that or start using different definitions of "fossil" depending on what criteria you want to follow

I think burial by naturall processes should be a cut line in any definition.... but that would leave out zooarqueological remains that could be interpreted as fossils too.... again..... not a clean cut line

As has been stated by many people already, the generally accepted definition of a fossil is anything >10 ka is considered a fossil, while anything less than that is not. This is an arbitrary definition, but it is worth pointing out that just about everyone so far is immediately aware of this definition, even if they disagreed with it.

I agree that diagenesis is a poor criterion for determining whether an organism is a fossil or not. There are places in Florida where the water is so mineralized that a bone is completely diagenetically altered to the point it is indistinguishable from Pleistocene remains in less than a few centuries. On the other hand, there are many cases of specimens millions of years old that still contain some of the original chemical traces of the organisms that produced them. Fossilization in vertebrates typically occurs when the organic parts of a specimen are replaced by minerals, but the mineralized portions (enamel, hydroxylapatite in bone) often remain intact. Isotope studies have been performed on specimens as old as (to my knowledge) dinosaur teeth from the late Jurassic and early Cretaceous. This would not be possible if the teeth had been completely replaced with minerals or the original material had been diagenetically altered.

At the same time, applying the term “fossil” to everything that comes out of the ground is equally unhelpful. As others have pointed out, this would make a pet dog buried less than a few years ago a fossil. I would go even further than that. If I bury an opossum carcass for six months to deflesh it for study, does that make this opossum a fossil? Even if I have a second carcass of an opossum which I let decompose subaerially, is one a fossil and the other not because they are the same age? If I bury an opossum for thirty minutes to deflesh but then dig it up because I have changed my mind and want to macerate it instead, does that make it a fossil? Does a specimen that has been found in a cave, clearly not buried yet still pertaining to an animal more than 12,000 years old (case in point, the numerous caves that have preserved extinct Pleistocene sloth dung) count as fossils?

Restricting this definition to “natural” burial is also full of problems. Humans have been burying thing in the ground for as long as there have been people capable of coming up with the concept. There are purported Neanderthal burials that are 60-100 ka old (or, if you do not accept these individuals as having been intentionally buried, there are Homo sapiens burials that are of similar age from the Middle East). Do these individuals not count as fossils despite other human (or animal) remains of the same age being considered fossils? Do bones in human middens count as fossils? Do forgotten food caches not count as fossils? And, of course, there is the issue of recognizing whether remains were accidentally buried or if they were intentionally buried and any evidence of them being intentionally buried is lost.

The same is true of excluding the remains of species that belong to extant populations. First, does this mean that the remains of a raccoon or pronghorn found in-situ alongside the remains of a 20,000 year old Columbian mammoth at a site like the La Brea tar pits, even though they both are the same age? Based on the number of individual ancestors any organism has had throughout history and the sheer number of pre-Holocene remains that have been discovered, the probability that at least one specimen that has been collected pertains to an organism that is directly ancestral to some organism living today is effectively 1. Directly proving this is another matter and is essentially impossible with modern methods, which is why most systematics no longer focuses on ancestor-descendant relationships. Many remains of Pleistocene organisms probably belong to living populations. Genetic analysis of ancient humans and domestic animals has often placed them within the group formed by living individuals, and it’s likely that studies of remains of wild species would do the same, it’s just that the interest in doing the paleogenomic studies isn’t as great

.

Claiming that applying “fossil” to anything dug out of the group most closely follows the original spirit of the term also does not work. The term “fossilis” was originally applied to anything interesting that came out of the ground, not only the remains of ancient organisms but also pseudofossils, mineral clusters, etc. The word fossil has evolved to mean something very specific today, namely the preserved remains of ancient organisms from long ago. Almost everyone would agree that the 68 Ma old remains of a Tyrannosaurus rex are fossils. Almost everyone would agree that the remains of a stray cat that died last year are not. Where the controversy lies is something like the 6800 year old remains of a moa.

I think it is a matter of all models being wrong but some models being useful.

Organisms preservaed in ice or amber or resin may not be called fossils as they received no diagenetic change or mineralization. We may emphasize natural burial and mineralization or diagenetic alteration as essential requirement for reconizing a fossil: 10 ka mark could be flexible

Just wanted to update my answer - I mentioned earlier that the "un-altered" (fossil) mammoths' bones at The Mammoth Site (Hot Springs, SD, USA) were 26,000 years old. We performed the OSL analyses of 7 bones revealing much older date - between 130-200,000 years old! (The publication will be out this spring/summer). According to Mr. Anek R. Sankhyan (see above), The Mammoth Site bones cannot be called fossils (no diagenetic change). Again, I want to emphasize that "fossil" and fossilization" are semantically different (please see above my initial comments).

Such bones could be of any antiquities, but why to call these fossils if we call petrified remains as fossils. If we call every thing of the past as fossils then the definition if 'fossil' becomes meaningless. We need to agree on some parameters to redefine a fossil or consider the tradtional definition.

Anek R Sankhyan, there are unaltered dinosaur and fish teeth of Jurassic and Cretaceous age. They are fossils by any definition. What would you like them to call, fossil or not? Please read Kenneth M Towe's answers.