Piles of Fossil Poo: Providing a Peek into the Past

One headline reads “Giant Prehistoric Toilet Found” another refers to the discovery of an ancient latrine.  Don’t know how I missed those a few weeks ago. Surely had I seen that headline I would have had to clicked on it to find out what that was all about.   The actual title, The oldest known communal latrines provide evidence of gregarism in Triassic megaherbivores, of the research paper from which the popular press picked up the story may not sound so interesting to you.  But for me, the title told me they were talking about fossils which meant this was a story about fossil poop, or—to sound more scientific—coprolites.  If you have followed this blog you know that I have a fascination with coprolites and have written about what we can learn from them before (most recently –  Dino Doo Doo and the Genesis Flood).

This particular fossil find is really nothing all that special to geologists and paleontologists  as coprolites, fossil dung just in case you forgot, are very common in the fossil record. In this case the notable feature is the quantity of coprolites and the spatial context they are found.

Tens of thousands of rock nodules were found eroding from the side of hills in Argentina.  A close examination of these nodules revealed that they average rocks but rather preserved feces of a large extinct herbivorous mammal-like reptile.  That an herbivore was the culprit can be inferred from the contents of each fossil nodule: they were found to be composed exclusively of preserved plant remains rather than small bones which are found in carnivore or omnivore (plant and animal feeders) feces.

How are these coprolites evidence of a common latrine you might ask?  The density of feces (around 90 per square meter covering 900 square meters) was the first clue but then closer inspection of this poo-pile revealed that the feces were not all deposited at the same time and not all by the same animal. They are different sizes and some were more degraded than others at the time when they were finally preserved.  The scientists involved interpret these fossils as evidence that the herbivore that deposited all this material lived in a community structure where they had a community area where they all did their business.

So what animal was responsible for these tens of thousands of coprolites.  It didn’t take much detective work to find the likely culprit.  There are thousands of bones in the same rock formation that these coprolites were extracted. These bone all belong to the same animal.  That animal is an extinct form of large mammal-like reptile that reached up to 8 feet long.  Based on skeletons the picture to the right represents an artistic rendering of what this reptile might have looked like.

This type of behavior—having a communal latrine—is well known in large animals today such as rhinos but not reptiles.  Obviously, no one was there to witness these animals deposit these plant nodules but this interpretation of the data represent a most reasonable explanation that fits all of the observations.  The evidence they left behind is our witness to past behavior and events.

Large piles of poo – yet another challenge to the creationist’ paradigm.

Here is where I ask a familiar question for those that have read any of my other writings:  how might a young earth creationists (YEC) interpret this particular fossil find?   I expect that many lay Christians that believe the Earth must be young can read a story like this and they may see the dates (240 million years old) and gloss right over them and just assume that the dates are wrong. At the same time they probably would readily accept that a large animals really did exist and that these really are feces but other than that they probably wouldn’t consider the larger question of how this fossil location fits into the broader context of Earth’s history.

But it is the geological context in which these fossils were found that is relevant to the question of the age of the earth and why I chose to write about it here.  Simply put, most of these coprolites were found eroding from a hill that is just a small part of a much larger set of rock formations that include thousands of feet of rock layers. All of the coprolites where found in the same layers of rock and they have been found in multiple locations many miles apart.  The conventional geological explanation would be that 200 million years ago this area of what is today Argentina was a relatively flat land with wetlands where groups of these reptiles lived.  Large piles of dung built up in communal latrines but we would expect that this dung would eventually be decayed and eroded by typical processes. However, these dung piles were present when a volcanic eruption covered the whole area with a thick layer of ash that preserved the dung and many of the animals.  More layers of ash and then other sediments eventually were deposited here by additional volcanic activity. Much later, erosion took place forming the mountain and hills there today and that erosion brought these fossils back to the surface.

Young earth creationists propose an alternative history. In their history a massive global flood deposited tens of thousands of feet of sediments in this area over a period of a few days to maybe a few months.  As the global flood subsided, massive erosion  sculpted the rocks into these mountains and hills.  Therefore, these flood geology theories of YECs would undoubtedly interpret the rock formations from which these fossils were found as having formed right in the middle of a chaotic global flood only 4-6 thousand years ago.

So how does a group of strange-looking 8-foot long mammal-like reptiles survive the initial stages of a cataclysmic global flood in which 15,000 feet of sediments have already been deposited below where they gathered together? Even if they were running or swimming around during the flood and managed to find their way onto a small piece of land between waves how come these feces appear to have decayed for some period before being preserved? In fact we should note that the rocks show show desiccation cracks as if the soil in and around these coprolites had dried out before they were preserved.

Also, how would a pile of loose digested plant material survive the next huge wave of water bringing sediments in to cover them up?  In fact, the rock that these feces are preserved in is composed of material that geologist recognize as volcanic ash.   It was a massive ash fall that preserved these feces in the geological record.  How could a volcanic ash fall have happened in the middle of a global flood?

We could continue showing many examples of observations from the fossil record that do not fit logically into the YEC view of Earth’s history.   These are the same problems that we have seen with thousands of preserved dinosaur nests and footprints (see the figure below) that are located right in the middle of layers of rock that YECs propose were laid  down within hours or weeks of one another (see: Fossil Eggs, Nests, Flood and Stressed Pregnant Dinosaurs and Juvenile Dinosaur Fossils in a Nest: Testimony to Rapid Burial but Not in a Flood).

I mention research like that on coprolites because it illustrates, all too well, the difficulties YEC flood geology to explain fossils and the geological record.   Rather, viewed within their geological context the specific characteristics of these fossils finds are most easily interpreted within the context of a world of great age. Once one is familiar with the context of the data it is easy to recognize YEC explanations as being nothing more than ad-hoc attempts to hold onto a preconceived interpretation of the history of earth.

Anyone who examines the paleontological literature will be confronted with thousands of similar examples to that I have presented here and realize that flood geology provides a wholly  inadequate interpretive framework for understanding the world around them.

References:

The oldest known communal latrines provide evidence of gregarism in Triassic megaherbivores.  Fiorelli et al. 2013. Nature, Scientific Reports 3, Article number 3348.  doi:10.1038/srep0334