Wyoming Dinosaur Ranch Blog

Upper Cretaceous Dinosaurs are actually pretty uncommon in the world. The most common and most well known being the browsing Triceratops.   Triceratops was a giant of a fellow.  Much like the animal shown in Jurassic Park (the movie).  They were the cows of their time being herbivores in contrast to their carnivorous arch enemy Tyrannosaurus rex.  Every ecosystem needs a grazing animal to facilitate the energy conversion from sunlight to plant matter, from plant matter to meat, from meat to upper level carnivore.  The end of the Cretaceous period was no exception.  The amount of vegetation must have been staggering to behold.  Cycads, ginkos, deciduous trees of all kinds, numerous flowing plant were abundant but there was NO grass yet.  It hadn’t evolved by the time the dinosaurs died out at the end of the Cretaceous.  Triceratops were the cows of their day, but they didn’t eat grass like our cows do today.  Their diet consisted of any luckless leaf they could reach, their cobble filled stomach could grind up probably anything they could pass through their system.  They did have teeth but not front teeth, only rows of teeth along each side top and bottom.  The front of their jaws were terminated in a beak of material similar to a birds beak which effectively scissored off any thing they could get between the edges.  Anyone who has been bitten by a parrot can identify with that.

The Cretaceous version of Triceratops was well along their evolutionary ladder being bigger (more robust), and well defended with three large horns and a bony shield back over their necks.  Earlier animals were much smaller, less armored and poorly adapted to face the evolving predators that appeared late in the Cretaceous.  It was an arms race to the level that the “Cold War” never reached.  Predators got faster and bigger, prey got better defended and just plain harder to get.  Horns, armor, tails with clubs, and various other defensive weapons were developed by prey to defend their lives.  (The mammals just hid down in the weeds and tried not to be seen.) So what is dinosaur science really about?

Preserved Triceratops footprints can be upwards of  20 inches wide which illustrates a leg bigger than an african rhinoceros.  They were not rhinos though. Falling into the pit of modern analogy is useful but the pit is full of problems.  Comparing modern large animals with ancient dinosaurs will prevent an unbiased observation from occurring.  So such analogies are only useful to the public and are widely ignored in the scientific literature.  Remember that science is a detective story.  Observations of the fossils records provide insight to what went on in the past.  My favorite tidbit of outcrop wisdom is: “Things are what they actually are, not what they seem, or what you have been told they are.”  I try to make my students realize that the story told in the rocks is one that has many possibilities but only one right answer. Paleontology is the search for the way things actually are (were).

I am currently slowly digging out a Triceratops (named Doug) that has already provided 5 complete ribs, a dozen partial ribs , a lower left jaw, a dozen vertebra in large blocks, several isolated vertebra, and a beautiful partial horn.  Much more remains in the outcrop.  He is a fair sized animal with one of his big ribs only being 6 feet long.  What magnificent creatures they must have been.  It will take years to get him out of the hill side he is in since he would probably dwarfs  a F350 Superduty pickup and his pelvis will weigh over a ton. Paleontology is the study of biological process over time.  The act of Paleontology is the practice of patience over time.

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“Darn that old Gumbo!”  is a phrase you hear all too much this time of year.  But what is that “old Gumbo”.  Geologically speaking, “gumbo” is a garbage basket term that refers to sticky soil that usually very high in clay.  The term can refer to any kind of clay but some kinds of clay are more sticky than others.  Remember that clay is actually a size term in geology.  It has to do with very small particles less that 1/256 of a mm in size (darn small as there are 25 mm to the inch!).  This is smaller than silt and considerably smaller than sand sized particles.  These size terms have no relationship to composition.  For example, you can have sand that is rich is quartz, or feldspar or even exotic material like magnetite or garnet.  So you can have a quartz sand or a garnet sand.  Clays have the same thing going on.  A rare clay can contain particles made of quartz grains that are very small or the small particles can be made of some other exotic material as well.

Almost all clays are weathering by products of another material called Feldspar.  Feldspar is the second most common mineral on the planet (after quartz) and easily breaks down into clay minerals.  These clay minerals have exotic names like Illite, Kaolinite, and Smectite.  Montmorillinite is another exotic name in the geologic literature.  It is the last clay, Montmorillinite that I will focus on here.  The common name for Montmorillinite is Bentonite.  Bentonite is actually a byproduct of weathered volcanic ash.  The ash was originally wind sorted from its original volcanic source.  Bentonite actually contains as many as 33 different clay minerals in the mix.  Most of these minerals consist of booklets of flat sheets (like mica) but are obviously very small.  This gives the material very interesting properties.  Besides medicinal uses (which I will not get into), the clay has a tremendous capacity for absorbing water and expanding its surface area (swelling.)  A single quart bottle of Bentonite (when hydrated and a total surface area of 960 square yards).  The individual platelets of Bentonite also have a negative charge on the flat surface and a positive charge on the edges.  This gives it great ability to adsorb toxins like heavy metals and pesticides by literally attracting the toxins like flies to sticky fly paper.  This ability to attract and hold impurities make Bentonite a valuable mineral for industry.  What a great place to live when the rest of the world want to buy our dirt!  Colony, Wyoming, for example, is a place build on and paid for by Bentonite production.

One of the less than desirable effects of Bentonite occurs when you try to put a building on soils rich in the clay.  When the soil gets wet, it swells which is only a problem if you want your building to stay level, not have cracked concrete floors.  Engineers are trained to look at the tendency of certain soils to swell and often suggest avoiding certain building sites based on the presence of Bentonite in the soil.  The only choice you have if you have build on a Bentonite rich soil, is to keep it dry.  This same property make Bentonite valuable for sealing ponds and dams.  The swelling property seals leaks automatically as soon as the material gets wet.

Some of you may know that I like to play with extreme 4X4 trucks.  There isn’t a 4X4 truck made (or any other vehicle for that fact) that can drive up a hill covered in wet Bentonite.  My advice is, if you have Bentonite on your place, let it dry out before you try to pass over the “Gumbo”.

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