How rare are dinosaur fossils really? (dinosaurs/volume)

[Flx]

Hi

I have a somewhat weird question you can probably help me with:

 

I was currently discussing with some other fossil enthusiasts about how rare dinosaur fossils really are. Obviously, there are areas where no dinosaurs are found and then there are places where dinosaur fossils have been piled up and preserved in large numbers. My friends claim was that dino fossils are not rare at all but are very labourous to collect (and therefore rare).

 

-> I am trying to get an idea about the number of dinosaur fossils per area or even better per volume.

 

For example, If I look at a certain area (for example 1 km2) of a fossil rich formation such as Hell Creek or Morisson and then:

- I carefully look at the whole surface, what can I expect to find?

- If I would vertically dig through 1m of matrix on the whole area, how many bones or teeth would I find?

- If I would vertically dig through 1m of matrix on the whole area, how many museum quality skeletons (eg 30%+ complete) would I find?

 

I am aware that the example above is not practical to do experimentally. However, I am trying to get an order of magnitude (is it more like 0.001 dino or 100 dinos for the given volume). Is there any scientific data available about dino/volume? 

 

 

 

[Fossildude19]

I don't think this can be answered easily, as it would depend on the exact area chosen.

You may happen to dig down into a death assemblage that happened due to flooding, and find lots of dino fossils.

Conversely, you could pick an area that is absolutely devoid of fossils.

 

Generally speaking, I think they are fairly rare.

 

[Misha]

I am not an expert on this topic and don't even know if this is something that could be answered, but I would like to add a few things to consider:

What do you count as an individual fossil? Because this could significantly influence results, are you asking about every individual fragment? ones above a certain size? complete bones and teeth? do fragments of the same bone or from the same individual count as one fossil?

Also consider that different layers within a single formation can have different amounts of fossils and different percentages of partial and complete specimens as this can depend on a huge number of factors, so even sampling one part of a "fossil rich formation" as you suggest may not give you a great picture of their relative abundance. 

To me this seems like something that just could not be answered as it is not only different by each formation but even within the formation itself depending on where you look.

[FranzBernhard]

What a nice question, one of the nicest ever seen here on TFF! Because I like this kind of number playing. Maybe @Top Trilo has  an answer ?

 

I like fossil mass occurrences, so I made a contest about this about a year ago:

40th Rolling Contest - Macro Fossil Mass Occurrences - Contests - The Fossil Forum

Its about oysters, ammonites and mud snails, though .

 

Eagerly waiting for all the proposals, fantastic topic!

 

Franz Bernhard

[Troodon]

Well I think all dinosaur material is rare because its not everywhere and you have to search to find localities where deposits exist.  When you find these deposits its not a trival task to extract specimens.   You have to work hard at it.  Articulated material is even rarer, even in the Hell Creek/Lance deposits.  You just don't go out and find a skeleton.   Even in channel deposits you can have good days or bad days depending on if you hit a pocket.  We then have numerous hadrosaurs bonebeds but thats a different kind of collecting.

 

Walter Stein did a census of  material found in the HC/L formations by private individuals and institutions and its attached.  Its not complete but gives one an idea of the distribution between theropods and herbivores finds and the number of associated skeletons found.    Considering the scores of years we've been collecting in these rich deposits the numbers are not over the top.

 

HC census.pdf

[jpc]

Are dinosaur fossils rare... no.  And I say this as a seasoned collector for both my own fun and for the Tate Museum where I work as The Field Guy.

Are complete dinosaur skeletons rare?  Very.  

Are 30% complete skeletons rare?  yes. 

 

My experience is primarily in the Lance, the Morrison, the Hell Creek of Montana and North Dakota, but also the Djadochta Fm in Mongolia, the Tiouraren Fm of Niger, the Galula Fm of Tanzania and the Prince Creek Fm of Alaska.  Dinosaur fossils are differently abundant in different formations.  The Galula Fm, for example is a lot less fossiliferous than the Lance.  So in the Galula, I would say dinosaur fossils are indeed uncommon, if not rare.    

 

If I were to take someone out into the Lance Fm for a day.  They will find dinosaur fossils.  To me that is not a rarity.  They will probably not find any T rex or probably not any complete bones just walking around, but if I put them in an established bone bed, they will have a better chance of finding a complete bone or even a rex tooth. 

 

This is an interesting question, that as others have said cannot be answered with a simple "rare" or "not rare"... too many variables.      

[doushantuo]

Cite this article: Starrfelt J, Liow LH. 2016 How many dinosaur species were there? Fossil bias and true richness estimated using a Poisson sampling model. Phil. Trans. R. Soc. B 371: 20150219. http://dx.doi.org/10.1098/rstb.2015.0219

rstb.2015.0219.pdf

[doushantuo]

Proc. R. Soc. B (2011) 278, 1165–1170 doi:10.1098/rspb.2010.1754 Published online 29 September 2010

Sea level, dinosaur diversity and sampling biases: investigating the ‘common cause’ hypothesis in the terrestrial realm

Richard J. Butler, Roger B. J. Benson, Matthew T. Carrano , Philip D. Mannion and Paul Upchurch

rspb20101754 (1).pdf

[doushantuo]

Cite this article: Brown CM, Campione NE,Giacomini HC, O’Brien LJ, Vavrek MJ, Evans DC.2013 Ecological modelling, size distributions
and taphonomic size bias in dinosaur faunas:
a comment on Codron et al. (2012). Biol Lett
9: 20120582.
http://dx.doi.org/10.1098/rsbl.2012.0582

discodrrsbl.2012jhg.0582 (1).pdf

[doushantuo]

PALAIOS, 2012, v. 27, p. 220–234
DOI: 10.2110/palo.2011.p11-096r
DO TERRESTRIAL VERTEBRATE FOSSIL ASSEMBLAGES SHOW CONSISTENT TAPHONOMIC PATTERNS?
JASON RICHARD MOORE

Moore2012Doterrestrialvertebratefossilassemblagesshowconsistenttaphonomicpatterns.pdf

Edited March 18, 2022 by doushantuo

[doushantuo]

The dinosaur fossil record is, of course, a chimaera, composed of unequal parts of (at least) public interest/funding/museology.manpower (-budget), instrumentation, orginal abundance and diversity (speciation), vicariance, biogeography, geodynamic factors at ALL scales

biostratinomy scientific rigor in clade attributions, detailed codification,tabulation,the use of digital and analog repositories.

 

edit: spelling

 

 

 

 

et VERY MANY cetera

[doushantuo]

A dromaeosaur from the Maastrichtian of James Ross Island and the LateCretaceous Antarctic dinosaur fauna
Judd A. Case, James E. Martin, and Marcelo Reguero

an example of a(for obvious logistic reasons) (as yet)inadequately sampled region:

2007-CaseetalUSGeolSurv.pdf

Edited March 18, 2022 by doushantuo

[doushantuo]

Paleobiology, 36(1), 2010, pp. 61–79

The geological completeness of paleontological sampling in North America

Shanan E. Peters and Noel A. Heim

 

Personal opinion: I think this is reasonably germane to the issue at hand

PetersHeim2010.pdf

Edited March 18, 2022 by doushantuo

[doushantuo]

Ditto for:

Recurrent hierarchical patterns and the fractal distribution of fossil localities
Roy E. Plotnick

GEOLOGY, April 2017; v. 45; no. 4; p. 295–298

295.pdf

[Flx]

@Fossildude19 Yes, one of the biggest problems for a good estimation is that the fossils are distributed extremely uneven. I am still hoping to get an average value somehow though.

 

@Misha I agree. I single bone could be broken up into hundreds of fragments. I tried to deal with that issue by asking what to expect when looking at a certain area (eg 1km2) in the correct formation. Also, I added the question for a 30% complete skeleton as an example for an exceptionally good find. 

 

@FranzBernhard Thank you. I am happy to see that other people are interested in this kind of questions and number playing. 

In the past, I estimated things like how many trees exist on earth or how many fish swim in the oceans which worked quite well (the difference to the concensus by other scientists was about a factor of 10 only). I am hoping to do something similar for dinosaur fossils, but I am lacking good data to start with.

 

@Troodon Thank you for the publication. This looks interesting. I will read it in detail.

 

@jpc Thank you for sharing your experience with dino fossil collecting.

I have one follow-up question: You mentioned that you will find something within 1 day when going to Lance Fm. Is this the case for a random area in Lance formation or only for areas of which you know that dino fossils have been found before?

 

@doushantuo Thank you for digging out the publications. This will give me something to read and hopefully give me a good starting point for my estimation.

[doushantuo]

No trouble at all.

Please keep all of us informed,because I really think the whole exercise is very worthwhile.

I might be back here in this thread for spitballing purposes

 

[jpc]

6 hours ago, Flx said:

 

 

@jpc Thank you for sharing your experience with dino fossil collecting.

I have one follow-up question: You mentioned that you will find something within 1 day when going to Lance Fm. Is this the case for a random area in Lance formation or only for areas of which you know that dino fossils have been found before?

 

 

Yes, the Lance has bones and bone pieces anywhere you go.  All of the places I have explored in the Lance, I have found bones within an hour.   These are often either smaller bones, or pieces of larger bones on the surface.  It can be much more difficult to find out where that broken piece of bones actually came from.  The Morrison is more random.  There are places in the Morrison that are devoid of bones, but most of it is pretty rich as well.   

[Troodon]

I've have had mixed results prospecting in HC deposits.   There are some areas were you would be fortunate to find anything while other areas you will find scattered bones and microsites.  Just takes lots of walking and being in the right place and lucky.

[Flx]

I am currently thinking about the following approach (for the upper limit only):

 

Assumption 1: A good Morrison fm. dinosaur skeleton found by a commercial fossil collector will sell for about 800kUSD. source: https://en.wikipedia.org/wiki/List_of_dinosaur_specimens_sold_at_auction

Assumtion 2: Costs for land lease, collecting, transportation, preparation is 50% of the costs (400kUSD). This means that there is 400kUSD is left for finding the animal and all the other costs.

Assumtion 3; If (!) it would be commercially attractive to brute force dig through Morrison fm matrix, it would be done.

Assumtion 4: A medium sized excavator can process a volume of about 250m3/day (soft mudstone matrix). Let's take one person who operates the excavator and a 2nd person continously checking the processed matrix for bones. This high speed method of going through matrix will damage fossils of course (e.g. a 60% complete skeleton would probably be a 40% complete skeleton when it is found but let's ignore that for now). The costs for that procedure would be around 1000 USD/day (salaries and rent for excavator).

 

-> If your budget is 400kUSD, you could process matrix for 400 days. This correponds to 100'000m3 of matrix.

-> There is less than 1 good dinosaur skeleton per 100'000m3 (imagine a trench which is 100m wide, 1000m long, 1m deep). 

 

Please let me know what you think. 

 

 

 

 

 

[FranzBernhard]

2 hours ago, Flx said:

Please let me know what you think. 

Very creative approach, I like it! Thanks for presenting it.

Franz Bernhard

[jpc]

4 hours ago, Flx said:

I am currently thinking about the following approach (for the upper limit only):

 

Assumption 1: A good Morrison fm. dinosaur skeleton found by a commercial fossil collector will sell for about 800kUSD. source: https://en.wikipedia.org/wiki/List_of_dinosaur_specimens_sold_at_auction

Assumtion 2: Costs for land lease, collecting, transportation, preparation is 50% of the costs (400kUSD). This means that there is 400kUSD is left for finding the animal and all the other costs.

Assumtion 3; If (!) it would be commercially attractive to brute force dig through Morrison fm matrix, it would be done.

Assumtion 4: A medium sized excavator can process a volume of about 250m3/day (soft mudstone matrix). Let's take one person who operates the excavator and a 2nd person continously checking the processed matrix for bones. This high speed method of going through matrix will damage fossils of course (e.g. a 60% complete skeleton would probably be a 40% complete skeleton when it is found but let's ignore that for now). The costs for that procedure would be around 1000 USD/day (salaries and rent for excavator).

 

-> If your budget is 400kUSD, you could process matrix for 400 days. This correponds to 100'000m3 of matrix.

-> There is less than 1 good dinosaur skeleton per 100'000m3 (imagine a trench which is 100m wide, 1000m long, 1m deep). 

 

Please let me know what you think. 

 

 

 

 

 

This sort of thing is done all the time out here.  When pipelines are put in.  A back hoe (it is actually a trench-digger) digs a trench hundreds of miles long, maybe 25 feet (5 meters) deep and about 12 feet (4 meters) wide.  One could, for a lot less than 400K contact these outfits and see if you could tag along as they dig through Morrison Fm.  Better yet, if these pipeline projects are federally funded, they must do a paleo survey before digging, and if they actually do go through Morrison or other "highly fossiliferous" formations, they have to have a paleo person watching.  About 15 years ago, I got to work on a sauropod that was found by one of these machines.  I imagine the data is already out there with the paleo mitigation companies.  PM me if you want to actually get in touch with any of these people.     

[Flx]

@jpc This is super exciting! I was not aware that there are actual projects for which large amounts of matrix is excavated and a paleo person is watching the process.

If there is data available about how many miles of pipelines are built (and watched by a paleo person) and how many fossils have been found during that process, that could probably give a pretty good estimate about the rarity of fossils in that formation.

 

If you have contacts that you could ask for specific numbers or alternatively forward a contact to me that would be great!

[Flx]

There is data available about the area and the thickness of the Morisson formation (and thus the volume). This means if we can get a "dinosaur density" from the pipeline projects we can also estimate the total number of dinosaur skeletons still burried in the ground. 

 

Has someone ever seen a number for the surface area of Morrison fm.  that is exposed? If not I can try to get an estimate from geological maps.

I think most fossils are not very accessible.

 

 

[Phos_01]

1 hour ago, jpc said:

This sort of thing is done all the time out here.  When pipelines are put in.  A back hoe (it is actually a trench-digger) digs a trench hundreds of miles long, maybe 25 feet (5 meters) deep and about 12 feet (4 meters) wide.  One could, for a lot less than 400K contact these outfits and see if you could tag along as they dig through Morrison Fm.  Better yet, if these pipeline projects are federally funded, they must do a paleo survey before digging, and if they actually do go through Morrison or other "highly fossiliferous" formations, they have to have a paleo person watching.  About 15 years ago, I got to work on a sauropod that was found by one of these machines.  I imagine the data is already out there with the paleo mitigation companies.  PM me if you want to actually get in touch with any of these people.     

Imagine they dig to make a pipeline and destroy a 70 million old Dinosaur Fossil while making the trench. That would be horrible, 

Perhaps im a little crazy but each time I see a huge construction with digging, I think about dinosaurs, and I think 'if they would stumble on something, would they tell? Or just continue business' 

 

Maybe im a little crazy 

[Crusty_Crab]

There are 2 major regulations in the US I am aware of regarding paleontological resources and developments: 

 

1. The National Environmental Policy Act or NEPA. This directs federal agencies to consider the environmental impacts to any projects they approve, fund or take place on their lands. One of the environmental impacts they must consider includes paleontological resources. Note that NEPA only considers the federal agency to consider impacts, it has no requirements to mitigate or deny projects. For example, someone may propose to build a dam on Bureau of Land Management administered property. The BLM, as the lead agency, would do a NEPA review. That review may show that the dam will wipe out some dinosaur bone beds. The BLM is only required to consider that impact. They are not obligated to enact mitigation measures such as employing a paleontological monitor or to remove the bone beds prior to construction of the dam. In practice though, federal agencies are likely to go beyond what NEPA requires. @jpc mentioned federally funded projects with a paleo monitor. The permittee may choose to employ a monitor as part of their NEPA compliance, but there is nothing inherent in the NEPA regulations that requires them to do so. This apparently did not sit well with some lawmakers regarding BLM land, which encompasses a wide swath of property across the US. The Paleontological Resources Preservation Act (PRPA) aimed to address some of those shortcomings on BLM land ONLY. https://www.blm.gov/paleontology NEPA and the PRPA does NOT apply to private property with no federal involvement, where many significant finds have been found in the past. 

 

2. In California, any state or local agency permitted, state funded or project on state lands must comply with the California Environmental Quality Act (CEQA). Unlike NEPA, CEQA compels the responsible agency to take action if there is an environmental impact, which includes impacts to paleontological resources. In this case, CEQA would require mitigation measures, such as employment of a paleontological monitor to make sure any fossils are protected and preserved while they are doing excavations. Recovered fossils are typically deposited in local qualified museums. CEQA is much more expansive than federal regulations. Some states have followed California's lead and enacted their own regulations with varying requirements:

https://ceq.doe.gov/laws-regulations/states.html Note that Wyoming, where many significant dinosaur finds have been discovered, has no CEQA equivalent regulations. 

 

None of these regulations would prevent a private property owner from removing (or destroying) fossils on their own property independent of any state or federally funded, or permitted actions. My point is that the regulations are patchwork, and generally, individual property owners rights would appear to supersede the public's interest in preserving paleontological resources.

 

Disclaimer: I am not an attorney, but I do have a lot of experience working in this area.