What Ate What?

[MarcoSr]

I just read a paper on Cretaceous coprolites from Canada, BROUGHTON SIMPSON WHITAKER 1978 Late Cretaceous Coprolites from Western Canada, which complicated identifying spiral valve coprolites as shark. Certain fish like sturgeon (Acipenser), bowfin (Amia) and gar (Lepisosteus) also have spiral valves. However, for my site: sturgeon fossils are extremely rare (I have not found any); Out of the many thousands of fish teeth that I have found, none were gar and I have only found a couple of gar scales; I have found a number of bowfin teeth but very very small in comparison to the many thousands of shark teeth which I have found. Note that the finding of remains of bowfin and gar in early Tertiary shallow water marine environments suggests that these fish in the Early Tertiary may have been more tolerant of salt water than the living species (Kent 1999). The vast number of shark fossils, teeth and vertebrae, compared to the very small number of sturgeon, bowfin, and gar fossils, leads me to the conclusion that most of the spiral valve coprolites from the site are probably shark.

Another interesting aspect from the paper is that originally the thousands of coprolites found at the Canadian site, and they were extremely common, were thought to be just regular concretions. However after in depth study (thin sections) of a sampling because of the suggestive shapes, it was determined that some of the coprolites had a concretion layering around the original, mineral replaced, coprolite or that the entire coprolite had been replaced to form ironstone. I know a lot of concretions can be found in some Cretaceous formations in the US like in NJ. It might be worth the effort to take a closer look at some of these concretions that might have a suggestive coprolite shape.

Marco Sr.

Edited October 16, 2014 by MarcoSr

[fossilized6s]

Thanks Marco for sharing your findings. I've learned something new for the day.

I know most of the coprolite i find in the Mazon creek (Pennsylvanian) are mostly Calcite, wrapped in ironstone and usually are not spiral shaped. But i still believe most are shark copros (Orthacanthus).

It still amazes me to this day how much we can tell and are still being taught by a piece of fossilized poop.

[MarcoSr]

Thanks Marco for sharing your findings. I've learned something new for the day.

I know most of the coprolite i find in the Mazon creek (Pennsylvanian) are mostly Calcite, wrapped in ironstone and usually are not spiral shaped. But i still believe most are shark copros (Orthacanthus).

It still amazes me to this day how much we can tell and are still being taught by a piece of fossilized poop.

Charlie

The more primitive sharks like many lamniformes had/have the spiral valve and the more advanced sharks like many carcharhiniforms had/have a scroll valve (Kent 1994). I'm not sure what type of valve that the Orthacanthus sharks had. Maybe someone reading this post can supply the answer. However even if the Orthacanthus had a spiral valve it would be very easy for that feature to be lost (smoothed/worn away) in the coprolite before fossilization through movement or turbulent water. Can you post any pictures of a Pennsylvanian Orthacanthus coprolite?

Marco Sr.

[RyanNREMTP]

Another possibility is intrauterine cannibalism.

[fossilized6s]

Here are a few examples Marco. These are from pit 11 and is mainly the Essex marine portion of the park. Granted some could be fish, but a few have the "lumpy" look that i see in the spiral shaped coprolites i find while sifting micros.

Sorry for the poor pics.

[MarcoSr]

Here are a few examples Marco. These are from pit 11 and is mainly the Essex marine portion of the park. Granted some could be fish, but a few have the "lumpy" look that i see in the spiral shaped coprolites i find while sifting micros.

Sorry for the poor pics.

IMG_20141016_190810.jpg

IMG_20141016_190914.jpg

IMG_20141016_191015.jpg

IMG_20141016_191124.jpg

Charlie

Thank you for posting. Really interesting. The pictures are really good!!!!

Marco Sr.

[MarcoSr]

Another possibility is intrauterine cannibalism.

Ryan

I was checking on intrauterine cannibalism on the web and came across the link below. I had no idea the variety of shark species that conduct this practice. With man killing 100 million sharks a year worldwide, intrauterine cannibalism hurts the shark populations' ability to sustain their species.

http://www.elasmo-research.org/education/topics/lh_intrauterine_cannibalism.htm

Marco Sr.

[siteseer]

Marco Sr.,

I think that the specimens with vertebrae in them are weathered fossil bird pellets (coughed-up masses of bones, hair, and other hard-to-digest remains). Similar specimens are found in the London Clay which happens to be about the same age as the Nanjemoy. Same group of birds?

Jess

Eric

Thank you for the link. I've been to Oceans of Kansas a hundred times but somehow missed the coprolite page. Seeing all of the bones and vertebrae in those coprolites makes me more confident now that my specimens with all the vertebrae could have passed through a digestive tract. Plus the most interesting aspect of the coprolite page was the marine bird coprolites. So a marine bird could be the "what" that ate the fish. Wow, I wish there was some way to distinguish a marine bird coprolite.

Marco Sr.

[MarcoSr]

Marco Sr.,

I think that the specimens with vertebrae in them are weathered fossil bird pellets (coughed-up masses of bones, hair, and other hard-to-digest remains). Similar specimens are found in the London Clay which happens to be about the same age as the Nanjemoy. Same group of birds?

Jess

Jess

Out of the thousands of coprolites from the site, I only have a small number of specimens like the one in this post. If it was a coprolite, it would have to be heavily weathered because it wouldn't have gotten through a digestive tract/intestines with its current shape. The pristine condition of the vertebrae in the specimens does more suggest gastric residues from a fish/shark/ray or a bird pellet. Can you point me to any bird pellet specimens on the web from the London Clay?

Storrs Olson from the Smithsonian has already studied a number of bird bones from the site and back in March I sent to him another 70+ birds bones. From what I understand there is a lot of similarity with families/genera from the London Clay.

Marco Sr.

[siteseer]

Marco Sr.,

I would try contacting someone at the Medway Mineral and Fossil Society. I'll see if I can contact someone I know there (Dave Rayner and his son have been hunting various London Clay sites for years).

http://www.mfms.org.uk/

Here's a link to a site with a snake skeleton in a nodule:

http://www.sheppeyfossils.com/pages/snake_4.htm

Jess

Jess

Out of the thousands of coprolites from the site, I only have a small number of specimens like the one in this post. If it was a coprolite, it would have to be heavily weathered because it wouldn't have gotten through a digestive tract/intestines with its current shape. The pristine condition of the vertebrae in the specimens does more suggest gastric residues from a fish/shark/ray or a bird pellet. Can you point me to any bird pellet specimens on the web from the London Clay?

Storrs Olson from the Smithsonian has already studied a number of bird bones from the site and back in March I sent to him another 70+ birds bones. From what I understand there is a lot of similarity with families/genera from the London Clay.

Marco Sr.

[RichW9090]

Marco, given the nature of digestive systems and the way they work, I think that the original coprolite pictures show specimens which have been eroded after deposition on the sea floor - that is, the softer ground mass has been eroded away, leaving the bones, which are harder, in high relief. The consistency of shark snarge wouldn't permit them to be excreted with the bones standing out like that.

The erosion could have taken place immediately, when the ground mass was still soft, or after fossilization, when it was lithified, but still less resistant than the bones.

Edited October 20, 2014 by RichW9090

[MarcoSr]

Marco, given the nature of digestive systems and the way they work, I think that the original coprolite pictures show specimens which have been eroded after deposition on the sea floor - that is, the softer ground mass has been eroded away, leaving the bones, which are harder, in high relief. The consistency of shark snarge wouldn't permit them to be excreted with the bones standing out like that.

The erosion could have taken place immediately, when the ground mass was still soft, or after fossilization, when it was lithified, but still less resistant than the bones.

Rich

It definitely makes sense that if the specimen is a coprolite, it had to be eroded after deposition. But I keep going back and forth between coprolite and gastric residue from a fish/shark/ray. I'm not at all familiar with marine birds. Do you know if a marine bird pellet might also make sense?

Marco Sr.

[MarcoSr]

Marco Sr.,

I would try contacting someone at the Medway Mineral and Fossil Society. I'll see if I can contact someone I know there (Dave Rayner and his son have been hunting various London Clay sites for years).

http://www.mfms.org.uk/

Here's a link to a site with a snake skeleton in a nodule:

http://www.sheppeyfossils.com/pages/snake_4.htm

Jess

Jess

Thank you for the links. Those sea snake nodules are truly incredible. A lot of Sheppey specimens are found in nodules. I did wounder if my specimen might be some type of cement stone like those snake nodules from Sheppey. However, nodules like those at Sheppey aren't found at this site. I've made 120+ trips to the site and never found a nodule of any kind, phosphate, calcite or cement stone in the bone bed with a nice specimen in it. There are areas where pyrite is very common and you do find individual teeth, vertebra etc. partially encrusted by pyrite. I would be very interested in what a long time collector of Sheppey might think of my specimen.

Marco Sr..

[squali]

Great post Marco. Typically animals that eat prey whole have one of two mechanisms to protect their digestive tract from damage. Both have been discussed here, regurgitation and aggressive digestion. The condition of the bones leads me to believe the animal regurgitated the indigestible parts. Material that small would of been dissolved in an animal that routinely swallows whole or chunks of prey. Not quite sure how else the finely detailed vertebrae would remain intact.

[MarcoSr]

On 10/20/2014 at 9:11 AM, squali said:

Great post Marco. Typically animals that eat prey whole have one of two mechanisms to protect their digestive tract from damage. Both have been discussed here, regurgitation and aggressive digestion. The condition of the bones leads me to believe the animal regurgitated the indigestible parts. Material that small would of been dissolved in an animal that routinely swallows whole or chunks of prey. Not quite sure how else the finely detailed vertebrae would remain intact.

The coprolites that I think I can identify as shark, either don't show anything on the surface or show very small flecks of bones/scales on the surface. The coprolites that I think are bony fish can either show nothing, fine flecks or some bigger bone fragments but nothing like the pristine vertebrae in my specimen. I'm trying to find a museum person that might be interested in doing some thin sections of some of these specimens and then a paper if the results are interesting. If thin sections don't show much difference inside from the outsides of the coprolites then the specimen from the post and others that I have that are similar have to be something different like a gastric residue. Some of my specimens might be fossilized intestines/contents. But from what I have read recently, typically what is in the intestines doesn't look that different from what is expelled. However thin sections could show evidence of intestine tissue.

Marco Sr.

[squali]

Hmm I think I should of re- reviewed the photographs before responding.

The size of the vertebrae at 1mm could easily pass through either digestive strategy.

Hopefully someone will be able to accept your generous offer to study this unique preservation and the possible findings.

Edited October 20, 2014 by squali

[MarcoSr]

Here are about a third of the coprolites from a single trip to this site. You can see the wide variety of sizes (largest is 37mm) and shapes.

Here are some coprolites which I believe are bony fish (from 24mm to 4mm). You can see flecks of bone/scales in some of them.

A couple of bony fish coprolites with unusual shapes.

Marco Sr.

[PFOOLEY]

This is a very interesting post, Marco. I just wanted to let you know that the New Mexico Museum of Natural History's Bulletin 57 is about vertebrate coprolites. In fact, an illustration on the cover looks very similar to your specimen.

I have never found vertebrae in coprolite, though I have seen crocodile coprolite that was filled with gar scales. Your specimen seems too small to be crocodile.

[MarcoSr]

This is a very interesting post, Marco. I just wanted to let you know that the New Mexico Museum of Natural History's Bulletin 57 is about vertebrate coprolites. In fact, an illustration on the cover looks very similar to your specimen.

I have never found vertebrae in coprolite, though I have seen crocodile coprolite that was filled with gar scales. Your specimen seems too small to be crocodile.

Mike

Thank you for the link. The Bulletin will be very helpful. I have several croc coprolites from the Paleocene of MD. They are indeed very much larger than my specimen.

Marco Sr.

[MarcoSr]

Thanks to Mike’s link to Bulletin 57, I have been able to download 45 papers in the bulletin dealing with coprolites. I had not considered reptiles like turtle or crocodile as a possible source of my specimen because of the specimen’s small size. The below excerpts are from a paper on MDCT scanning of a coprolite (A COPROLITE IN THE MDCT-SCANNER – INTERNAL ARCHITECTURE AND BONE CONTENTS REVEALED JESPER MILÀN, BO W. RASMUSSEN AND NIELS LYNNERUP) with a partially exposed intact vertebra in one end.

With respect to crocodiles: “Crocodylians have a very effective digestive system, with a concentration of hydrochloric acid that exceeds mammalian carnivores by a factor of 50 (Coulson et al., 1989). This completely decalcifies and dissolves all bone before it is evacuated (Fisher, 1981; Coulson et al., 1989; Trutnau and Sommerlad, 2006).”

The presence of well-preserved fish vertebrae would seem to eliminate crocodiles as a source of my specimen.

With respect to turtles: “Examination of the digestive tract of the modern marine turtle Caretta caretta has shown that fish bones are not digested, but can survive throughout the digestive tract and be expelled in the feces (Plotkin et al., 1993). Moreover, gut contents of sea turtles from the Upper Cretaceous of Queensland, Australia, showed high concentrations of bivalve shells, only slightly corroded from gastric acid (Kear, 2006). ……. Other coprolites attributed to turtles are depicted from the Upper Cretaceous of Brazil and they appear as cylindrical, tapering masses (Souto, 2008). Farlow et al. (2010), examined fresh scat from snapping turtles, Chelydra serpentina, and they have preserved abundant prey remains in the form of hair and bones. “

So turtle coprolites could have well preserved fish vertebrae.

Marco Sr.

[siteseer]

Marco Sr.,

My friend sent me comments about your specimen a couple of weeks ago and I'm finally getting around to posting them as follows:

"Having collected from the London Clay sites for about 30 years or more the number of possible coprolite specimens found compared to the number of other fossil types found is very few. If you look on page 41 of our London Clay book you will see three samples shown. Other types that we have found and which we believe to be possible coprolites are small phosphatic nodules containing small grey/black pieces. To my knowledge nobody has ever sliced these nodules and carried out a detailed study of the pieces contained in them.

From other collectors comments about the specimen shown from the Muddy Creek site it appears to me that most specimens from there are not encased in matrix as per the London Clay specimens. Also reading through a copy of the Virginia Division of Mineral Resources Publication 152 it appears that the conditions of the Muddy Creek site compares quite well with the London Clay sites. The specimen shown is very small compared to similar London Clay nodules that we have found. - Muddy Creek 8mm long 1mm diameter vertebra (fish). London Clay 50mm long 10mm vertebra (fish), 50mm long 14mm vertebra (fish), 65mm long 22mm vertebra (fish), 90mm long 20mm oval vertebra (ray).

The London Clay sites over their time period had mostly deep water conditions alternating between deep and shallow seas at the beginning and end of the period. So I feel that any coprolites from most animals, fish, sharks etc. would probably be washed out and dispersed before they could be deposited on the sea bed. From our finds and other collectors finds, animal specimens appear to be the rarest then bird specimens, snake specimens, turtle fish and so on. Bearing in mind that in the London Clay period land was possibly quite a distance from our collecting sites any animal coprolites or bird pellets tend to be rare.

[side note from Jess: I think when he says "animal" in the paragraph above, he means "mammal"]

If you look on page 179 of our London Clay book and refer to specimen 4 we believe this specimen to be stomach contents - of what - we are not sure. Although I have carried out prep work on it I didn't have to do a great deal. Besides the fact that there were "stomach stones" the bone contents were very degraded with the surface appearing to be etched by acid. The pebble on the right of the nodule has a smooth and a rough surface texture (shown by the line around it). The larger cream coloured pebble shown loose on the left of the specimen has a rough surface texture and is also very light in weight suggesting that it might have been worn away by acid seepage.

Considering that if a large animal/fish etc. is killed or dies from some calamity and it's body is deposited on the sea bed then the stomach contents are probably more likely to remain fairly intact. Animals scavenging the dead body would mostly strip the flesh/meat parts of the body and would probably not bother with the stomach contents which had mostly been digested. I have seen coprolite specimens from other sites which have contained fish scales which I am sure would not always be destroyed and would pass through the digestive system.

So after all that Jess, what I am saying is some of the specimens that are found containing bone fragments, or scales and vertebra could well be stomach contents rather than a coprolite. As the specimen is only 8mm long it could be a bird pellet but it could also be stomach contents of a large fish. I'm not sure if the above 'ramblings' help in any way but it's my observation and experience of specimens that we have found from the London Clay."

Jess

Jess

Thank you for the links. Those sea snake nodules are truly incredible. A lot of Sheppey specimens are found in nodules. I did wounder if my specimen might be some type of cement stone like those snake nodules from Sheppey. However, nodules like those at Sheppey aren't found at this site. I've made 120+ trips to the site and never found a nodule of any kind, phosphate, calcite or cement stone in the bone bed with a nice specimen in it. There are areas where pyrite is very common and you do find individual teeth, vertebra etc. partially encrusted by pyrite. I would be very interested in what a long time collector of Sheppey might think of my specimen.

Marco Sr..

Edited January 29, 2015 by siteseer

[MarcoSr]

Marco Sr.,

My friend sent me comments about your specimen a couple of weeks ago and I'm finally getting around to posting them as follows:

"Having collected from the London Clay sites for about 30 years or more the number of possible coprolite specimens found compared to the number of other fossil types found is very few. If you look on page 41 of our London Clay book you will see three samples shown. Other types that we have found and which we believe to be possible coprolites are small phosphatic nodules containing small grey/black pieces. To my knowledge nobody has ever sliced these nodules and carried out a detailed study of the pieces contained in them.

From other collectors comments about the specimen shown from the Muddy Creek site it appears to me that most specimens from there are not encased in matrix as per the London Clay specimens. Also reading through a copy of the Virginia Division of Mineral Resources Publication 152 it appears that the conditions of the Muddy Creek site compares quite well with the London Clay sites. The specimen shown is very small compared to similar London Clay nodules that we have found. - Muddy Creek 8mm long 1mm diameter vertebra (fish). London Clay 50mm long 10mm vertebra (fish), 50mm long 14mm vertebra (fish), 65mm long 22mm vertebra (fish), 90mm long 20mm oval vertebra (ray).

The London Clay sites over their time period had mostly deep water conditions alternating between deep and shallow seas at the beginning and end of the period. So I feel that any coprolites from most animals, fish, sharks etc. would probably be washed out and dispersed before they could be deposited on the sea bed. From our finds and other collectors finds, animal specimens appear to be the rarest then bird specimens, snake specimens, turtle fish and so on. Bearing in mind that in the London Clay period land was possibly quite a distance from our collecting sites any animal coprolites or bird pellets tend to be rare.

[side note from Jess: I think when he says "animal" in the paragraph above, he means "mammal"]

If you look on page 179 of our London Clay book and refer to specimen 4 we believe this specimen to be stomach contents - of what - we are not sure. Although I have carried out prep work on it I didn't have to do a great deal. Besides the fact that there were "stomach stones" the bone contents were very degraded with the surface appearing to be etched by acid. The pebble on the right of the nodule has a smooth and a rough surface texture (shown by the line around it). The larger cream coloured pebble shown loose on the left of the specimen has a rough surface texture and is also very light in weight suggesting that it might have been worn away by acid seepage.

Considering that if a large animal/fish etc. is killed or dies from some calamity and it's body is deposited on the sea bed then the stomach contents are probably more likely to remain fairly intact. Animals scavenging the dead body would mostly strip the flesh/meat parts of the body and would probably not bother with the stomach contents which had mostly been digested. I have seen coprolite specimens from other sites which have contained fish scales which I am sure would not always be destroyed and would pass through the digestive system.

So after all that Jess, what I am saying is some of the specimens that are found containing bone fragments, or scales and vertebra could well be stomach contents rather than a coprolite. As the specimen is only 8mm long it could be a bird pellet but it could also be stomach contents of a large fish. I'm not sure if the above 'ramblings' help in any way but it's my observation and experience of specimens that we have found from the London Clay."

Jess

Jess

Thank you for this reply. It was very informative. For some reason I didn't see it when you posted it in 2015. I noticed the reply today when I came back to this thread to add an update.

Marco Sr.

[MarcoSr]

As an update to this thread, I donated all of the coprolites in this thread plus at least 12,000 others to the New Mexico Museum of Natural History and Science in 2015.

As a further update, I will be a co-author of a presentation by Adrian Hunt for the national meeting of the Geological Society of America in Denver this fall. An abstract has already been submitted titled “PROLIFIC NEW COPROFAUNA FROM THE EOCENE OF VIRGINIA”. This will be the first of a number of presentations and papers on these coprolites.

I don't want to give away too much information just yet on the presentation but the abstract contains this sentence "This represents the largest known pre-Quaternary coprofauna. "

Marco Sr.

[ynot]

As an update to this thread, I donated all of the coprolites in this thread plus at least 12,000 others to the New Mexico Museum of Natural History and Science in 2015.

As a further update, I will be a co-author of a presentation by Adrian Hunt for the national meeting of the Geological Society of America in Denver this fall. An abstract has already been submitted titled “PROLIFIC NEW COPROFAUNA FROM THE EOCENE OF VIRGINIA”. This will be the first of a number of presentations and papers on these coprolites.

I don't want to give away too much information just yet on the presentation but the abstract contains this sentence "This represents the largest known pre-Quaternary coprofauna. "

Marco Sr.

Wow! Nice fossils and great discussion.

Looking forward to see what the papers have to say.

Tony

[JohnJ]

As an update to this thread, I donated all of the coprolites in this thread plus at least 12,000 others to the New Mexico Museum of Natural History and Science in 2015.

As a further update, I will be a co-author of a presentation by Adrian Hunt for the national meeting of the Geological Society of America in Denver this fall. An abstract has already been submitted titled “PROLIFIC NEW COPROFAUNA FROM THE EOCENE OF VIRGINIA”. This will be the first of a number of presentations and papers on these coprolites.

I don't want to give away too much information just yet on the presentation but the abstract contains this sentence "This represents the largest known pre-Quaternary coprofauna. "

Marco Sr.

Looking forward to when you can post more about this, Marco. This kind of cooperation just makes me smile. Congrats.