The Bonebed Mystery at Hanson Ranch


The year was 1996. A rancher on Hanson Ranch in the badlands of eastern Wyoming introduced a group of creation scientists to an unusually large number of dinosaur fossils. They were all buried in one location. The scientists didn’t know it at the time, but they would be studying the Hanson Ranch Bonebed for the next two decades and onward in an attempt to solve the mystery of how the dinosaurs died and became buried here. Four scientists currently heading up fossil excavations at the site, Keith Snyder, Matthew McLain, Jared Wood, and Arthur Chadwick, summarized the past 20 years of research in a paper published in PLOS One in early 2020 [1]. What you are about to read is but a brief summary of their work and how the Hanson Ranch Bonebed confirms one of the most cataclysmic events recorded in the Book of Genesis.

The HR Bonebed contains a menagerie of organisms, many of which are unusual, but some are very similar to those found alive today. Fossils of freshwater and brackishwater mollusks, snails, skates (stingray-like fish), gar and other fish, crocodiles, and turtles, as well as mammal teeth and small bird bones have been found at the site. But what makes the HR Bonebed stand out is that it has been estimated to contain between 10,000 and 25,000 individual dinosaurs [2], including ceratopsians (horned dinosaurs), nodosaurs (armored dinosaurs), and theropods (meat-eating dinosaurs), just to name a few. However, more than 95% of the dinosaurs represented at the HR Bonebed actually come from just one species: a large duck-billed dinosaur called Edmontosaurus annectens.

The recent summary of HR Bonebed research by Keith Snyder and his team narrowed their focus to 13,000 elements (including about 8,400 identifiable bones) that have already been excavated in 506 square miles of the recovery area between 1996 and 2016. All of these fossils are currently being housed at Southwestern Adventist University in Keene, Texas. You can view them all online at

Edmontosaurus annectens

  • Very Common
  • 30-40 feet long (9-12 meters long), weighed 4-10 tons (4-9 metric tons)
  • Herbivore, eating conifer needles & twigs, seeds & fruit
  • Upper Cretaceous

By MCDinosaurhunter – Own work, CC BY-SA 3.0,

How did so many Edmontosaurus and other animals end up being buried together like this? To answer this question, we need to understand taphonomy, the study of what happens between the time an organism dies to when it either decays or is fossilized. Conventional paleontologists typically postulate that mega-bonebeds like the one at Hanson Ranch formed as animals slowly accumulated in one place over a long period of time. This is not unreasonable. Untold numbers of wildebeest and other herd animals die en route to fresh grazing pastures on their annual migrations. Many wildebeest are taken out by crocodiles or the raging current itself when the herd crosses a river. The body parts that don’t get eaten by crocodiles wash downriver, where they pile up along the riverbank, year after year, and are buried. At first glance, it seems quite conceivable that this narrative could explain the Hanson Ranch Bonebed.

Scheidt on Pixabay

That being said, the team identified several features of the Hanson Ranch Bonebed that contradict the conventional model of mega-bonebeds. Three observations in particular stuck out to them:

  1. The first and most obvious clue is that all of the fossils were graded within a three to six foot-thick layer of mudstone. In other words, most of the bones were disarticulated (not connected as they would be in life) and sorted by size. Femurs and other large bones were always at the base of the layer, while smaller and smaller bones like vertebrae and toe bones were situated toward the top.
  2. A second clue is that the bone fragments show little, if any, sign of weathering or abrasion. This indicates that they spent relatively little time exposed to the elements, with no more than weeks or months between the time of death and final burial. The bones didn’t wait around for sediment to slowly cover them.
  3. A third clue was that the Edmontosaurus bones were from older juveniles, subadults and adults. No young juveniles are known from the HR Bonebed, and the same can be said of other bonebeds containing duck-billed dinosaurs. If the Edmontosaurus of Hanson Ranch died and accumulated over a long period of time, we would expect a wider age distribution. This suggests that the younger members of the herd were separated from them at some point before the rest of the herd perished. As a side note, Snyder and team have suggested the HR Bonebed is of a herd just before a breeding seasonal.

Team member Art Chadwick, a professional taphonomist, had this to say about the site:

The only way I know how you could develop a graded bed is if you had a catastrophic process that transported these bones and laid them all in as a single event.

– Art Chadwick, taphonomist, from

What kind of catastrophe could kill thousands of dinosaurs and other animals before burying them in a three to six foot-thick layer of mudstone over an area of 80 acres?


Above, you can see the GPS measurements taken of the HR fossils at one quarry.

The HR Bonebed is just one segment of an extensive system of rock layers and fossil-rich deposits called the Lance Formation, which extends across much of Wyoming. Conventional paleontologists believe it was largely laid down by a network of meandering, braided streams flowing calmly across a coastal floodplain, not unlike the modern Gulf states. But this isn’t the type of environment one would expect mega-catastrophes like the one responsible for the HR Bonebed. To solve the mystery of what happened to Hanson Ranch’s dinosaurs, Dr. Snyder’s team had to think bigger than the HR Bonebed. Much bigger, in fact. Hanson Ranch is not the only Edmontosaurus-dominated bonebed; others have been identified across the western United States, Canada and even up in Alaska.

In taphonomy, the sediment containing the fossils can give just as much insight into the cause of death and/or burial of fossil organisms as the fossils themselves. Sometimes even more so. Many of the layers making up the Lance Formation are composed of sandstone. This is not unusual. What is unusual is that the sandstone layers are embedded with unusual swirly patterns called seismites. These occur when an earthquake causes water within the sediment to deform the layers. Geologists use the thickness of a seismite to estimate the power of the earthquake that created it. The deformed layers of sandstone in the Lance Formation are quite thick, some measuring over 15 feet in thickness! To put this into perspective, a 5.5 magnitude earthquake might leave behind a seismite one inch in thickness [3]. Clearly, the seismites in the Lance Formation were formed by earthquakes hundreds or thousands of times more powerful than any known from recent history. You likely would have felt it no matter where you stood on the continent of North America.

We can learn two very important facts from studying the Lance Formation seismites. First, the layers of deformed sediment were still waterlogged by the time the earthquake appeared. This means these very thick layers must have been laid down relatively quickly, otherwise the layer would have become too dry and rock hard to deform. Second, the Lance Formation was subjected to dozens of similarly-sized earthquakes in rapid succession around the time the HR Bonebed was laid down. Such huge earthquakes are generally attributed to the impact of an asteroid or comet, but there is only evidence for one such impact at the top of the Lance Formation, called the Chicxulub impact. What of the other earthquakes that occurred earlier? A more likely scenario is that these earthquakes were caused by movements of the earth’s tectonic plates, perhaps the same ones that formed the Rocky Mountains.

In-depth study of the orientation of fossils and the evidence of water current direction in the sediment entombing them offered additional information. Dr. Snyder and his team concluded that the Edmontosaurus did not die where they are buried. They were transported by water (likely in the form of an underwater debris flow) in an easterly direction to their final resting place.

With these pieces of data, we can begin to understand what catastrophic events took place that formed the bonebed now preserved at Hanson Ranch. This cataclysm was of a scale unprecedented in the modern world, but it fits very nicely with what we might expect to have resulted from a global Flood like the one described in the Book of Genesis, chapters 6-9.


The Hanson Ranch Bonebed presents clear evidence of a catastrophic event on par with the Genesis Flood. But among this evidence are two pieces of data that, on the surface, seem to contradict this explanation.

First, as mentioned before, most of the dinosaur bones were disarticulated. In order for this to happen, the dead dinosaurs would have needed sufficient time for their skin, tendons and ligaments that connected the bones in life to rot away. This process alone would have taken weeks or months.

[4] Citation below
Dinosaur bones with theropod gnaw marks.

Second, most fossils of theropods, such as raptors, troodontids, Nanotyrannus, and Tyrannosaurus, found at Hanson Ranch are not bones, but shed teeth. Like sharks and alligators, theropods would frequently lose teeth when they became old and worn while feeding and fighting, allowing new teeth to grow in their place. We know the Hanson Ranch theropods were feeding on the Edmontosaurus carcasses not only from the shed teeth, but also the gnaw marks on the bones themselves left.

If the Hanson Ranch dinosaurs drowned in the Flood, what catastrophe transported and buried their bones in their current location after they had time to decay and get gnawed on by scavengers?

The problem lies not with the Flood scenario itself, but our common mischaracature of it. We often conjure up the notion that the floodwaters instantaneously covered the earth, or that the entire earth’s surface was submerged during the entire Flood. However, a closer look at Scripture conveys a far more dynamic sequence of events than a mere rise and fall of global sea levels. In the Flood narrative of Genesis, it appears that the rising stage of the Flood is broken up into phases based on the power of water during each phase [5]. The floodwaters only became powerful sometime after the torrential rain started and the “fountains of the great deep” had begun breaking up (Genesis 7:11,17). After which, they became very, very powerful (Genesis 7:18) before returning to just powerful again (Genesis 7:19). Contrary to popular belief, there is no scriptural evidence that the floodwaters covered the entire earth’s surface throughout the entire duration of the Flood. After all, the Flood lasted for over a year, so it is much more likely that tides and alterations of the earth’s crust caused the sea level to fluctuate in cycles [6] over the course of that time. Some parts of the earth seem to have been submerged and exposed numerous times, while evidence like that seen at Hanson Ranch indicates that some plots of land were apparently above water for weeks or months at a time during the Flood.


Taking the above information into account, Dr. Snyder and his team were able to lay out a tentative sequence of events that starts with the sudden death of the Hanson Ranch dinosaurs and ends with their burial in present-day Wyoming.

Somewhere west of modern-day Wyoming, one or more large herds of Edmontosaurus annectens (along with other animals) were the victims of a catastrophic scenario in the early stages of the global Noahic Flood, possibly drowning. Their dramatic death was followed by a period of time during which they may have bloated and floated before washing up and accumulating along a nearshore environment. The bodies didn’t remain undisturbed for long. The stench of rotting flesh soon attracted tyrannosaurs, raptors, troodontids and small mammals, all drawn to the site by the prospect of an easy meal. The Edmontosaurus carcasses rotted in place for weeks or months, long enough for the flesh and ligaments to decay, but not so long that the bones became abraded or weathered. Sometime later, a very large earthquake, catastrophic flooding, or very likely both, catastrophically transported the dead animals that remained in a slurry of bones and muddy sediment called a debris flow. Since the bones remained in excellent condition during their journey, Snyder and his team believe that the slurry must have been highly viscous. The debris flow ended its journey in Wyoming, where it dumped the bones and sediment to form the graded bed that now exists at Hanson Ranch today.


The Hanson Ranch Bonebed is an eyeopener. It provides us with incredible insight into what the world was like during the global Flood of Noah’s day. This wasn’t the happy-go-lucky fairytale of a 40-day/40-night rainstorm and a cute bathtub-shaped ark stuffed with smiling, cheery animals; this was a historic, cataclysmic event that served as judgement upon a world wrought with mankind’s wickedness and the violence of both man and beast that then existed and was deluged with water and perished (2 Peter 3:6).


[1] Snyder, K., McLain, M., Wood, J. and Chadwick, A., 2020. Over 13,000 elements from a single bonebed help elucidate disarticulation and transport of an Edmontosaurus thanatocoenosis. Plos one, 15(5), p.e0233182.

[2] Chadwick, Art & Spencer, Lee & Turner, Larry. (2006). Preliminary depositional model for an upper cretaceous Edmontosaurus bonebed. Journal of Vertebrate Paleontology. 26. 49A-49A.

[3] Austin, S.A., 2012, November. Jerusalem earthquake of 33 AD: evidence within laminated mud of the Dead Sea, Israel. In 2012 GSA Annual Meeting in Charlotte. GSA.

[4] By Nicholas R. Longrich, John R. Horner, Gregory M. Erickson, Philip J. Currie –;jsessionid=A98501981DFE173B51C4610B2E971013, CC BY 2.5,

[5] Boyd, Steve. It’s for the Birds: Avian Fine-Tuning of Flood Chronology – How Knowing When Noah Opened the Window Opens a Window to Chronological Understanding. Answers in Genesis, Answers Research Journal, 26 Aug. 2020,

[6] Snelling, A. A Deeper Understanding of the Flood—A Complex Geologic Puzzle. Answers in Genesis, Answers Magazine, 1 Apr. 2014,

The views expressed in this article reflect those of the author.

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[…] Hanson Ranch, waar onder leiding van dr. Arthur Chadwick de Lance Formation ontsloten wordt.5 “Ze gebruiken hier de modernste apparatuur en technologie om de mysteries te ontrafelen die […]

robert byers
robert byers
February 9, 2021 12:02 AM

Excellent article in making a case. Great info and then great interp[retation. its just a killer great point these were collected suddenly, thus a spectrum of ages and not old age, So persuasive of the even obvious fact that all these types of fossils only could come from water sourced depopsition. then its universal nature equals a universal event. Fitting in with the witness. The bad guys must smell a problem. Well done.

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