Wednesday, October 28, 2020

A Paleontologist Visits the Zoo

 As a paleontologist, I really like the skeletons of animals. And on a trip back in 2017 to the local Hogle Zoo in Salt Lake City, wasn't I surprised to find they had some fantastic displays of the skulls of the animals. I also tried to take accompanying shots of the animals but I figure I will probably need to get better shots. But overall I was excited. I also have some shots here from the local Living Planet Aquarium, which I also visited around the same time.

When you first walk in you are greeted by these giraffe statues, so why not start with the giraffe. 

Here's our giraffe friends. They actually have several giraffe skulls around the park.

Here is a large giraffe skull within the area where you can feed the giraffes.

And these two were embedded within the walls surrounding the giraffe enclosure.

They had these skull guides throughout the park as well. Here comparing the predator to the prey skulls of the African lion and zebras.

And for comparison, here is the real life lion.

And the real life zebra.

Moving on we have here the elephant skull. Which, on a side note, was mistaken for a cyclops skull back in ancient Greece days.

And the lovely owners of the same type of skull.

Some Bald Eagle pieces including the skull and the foot.

And the Bald Eagle themselves

The sea lion and the seal skulls. Now both of these animals are present at the zoon but they are rather difficult to get good pictures of because they are so quick.

Here's a close up shot of the sea lion's head.

And there's a shot with more of the sea lion's body.

And here is the seal.

Another shot of the seal.

They also had some skeletons hanging up. Here is the sea lion.

And the seal skeleton.

Moving on to the bears. Here is their display of the bear skulls. They didn't have any black bears that I saw so I just have photos of the grizzly and the polar bears.

Here is also a full model of the polar bear skull they had on display.

Here's a shot of the grizzly bear. You can see one in the background too in the den.

And a close up shot of the polar bear.

Here is the plaque for the otter skull. However I didn't have a picture of the otters from the Hogle Zoo. But I was able to grab a photo from the Living Planet Aquarium.

Here is the river otter from the Living Planet Aquarium.

That is it for the animal/skull combos that I could find. Both places had some other skulls on display though.

A sperm whale skull. 

A walrus skull. Now if there isn't a skull that more accurately defines what the animal looked like I don't know. Just looking at this skull screams "walrus" to me.

A porpoise skull.

And at the aquarium, a Megalodon jaw. However, the jaw of Megalodon (more accurately referred to as Carcharocles megalodon) has never been found since it is cartilage and decays away before it can fossilize. The jaw is a reconstruction based on what scientists think it might have looked like comparing the size of the Megalodon tooth (which are real fossils) to modern day closely related sharks. 

Tuesday, October 27, 2020

Geology of the National Parks in Pictures - Indiana Dunes National Park

 My next post about the Geology of the National Parks Through Pictures is a park we visited back in 2008 on our move out to Utah from New York. It was actually the only park we hit up on the trip out.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website


We had initially visited this park when it was still Indiana Dunes National Seashore. And since we had the dogs with us while we were moving across country we were limited on where we could go. But this seemed like a nice park to let them get out and run around for a bit. At the time I wasn't also taking geologically themed photos, so these are what I have. 

Walking down to the lakeshore. Indiana Dunes sits at the southern extent of Lake Michigan, the third largest Great Lake, and the sixth largest lake in the world. Lake Michigan and the surrounding landscape was a product of glaciation. Glaciers are like giant bulldozers made of ice and snow. During the last Ice Age, over 10,000 years ago, glaciers had come through and plowed out the basin in which Lake Michigan now sits. Eventually the weather got too warm for the glaciers and they started to melt. At that point, the glaciers start acting like conveyor belts, transporting rocks, soil, sand, boulders, and anything else that gets in their way to the end point of the glacier. Here all that debris gets dumped into one giant pile known as a moraine. The material within the pile is called till and is composed of all the glacial debris with a large amount of clay produced by the grinding action of the glacier. Towards the end of the Ice Age, as the glaciers started to retreat, they formed a moraine near the southern tip of Lake Michigan called the Valparaiso Moraine. Before there was Lake Michigan though, there was another lake. Lake Michigan formed from glacial Lake Chicago, a lake roughly the same shape as Lake Michigan but the water level was much higher. Lake Chicago formed about 12,000 years ago and was dammed to the south by the Valparaiso Moraine along the northern edge of Indiana. 

As Lake Chicago slowly dwindled down to the present day Lake Michigan about 2,000 years ago, several lakeshore benches were cut into the moraine at different elevations. The present lake level is at 580 feet above sea level, while there are lakeshore terraces located at 605, 620, and 640 feet above sea level. Much of the sand that forms Indiana Dunes comes from reworking of the Valparaiso Moraine. Walking towards the shore you come across this large flat area before descending abruptly to the beach. This large flat area is the last lake level of Lake Chicago before it lowered to the present day Lake Michigan levels. This is the 605 feet above sea level beach terrace known as the Tolleston stage. The Tolleston stage of Lake Chicago lasted from 8,000 to about 2,000 years ago. 

We are getting excited for our beach trip, looking out from the edge of the Tolleston stage terrace.

On the slope down from the Tolleston stage terrace to the modern day Lake Michigan. The sand dunes built up over time along all the stages of Lake Chicago as well as the modern day Lake Michigan. The sand, much of it reworked glacial deposits, are moved about the shore by a couple of processes. Winds are able to pick up the sand and blow them across the beach surface to accumulate behind the beach, also known as the foredunes. The foredunes are just above high tide levels of the water that would erode away much of the sand accumulation. Longshore currents also move sand along the beach. The longshore currents are currents that move parallel to the shore. These currents travel east to west and carry sand deposited from up-current river deltas and replenish any sand lost during the year from storm activities or other natural erosional events. 

One of the major features of dunes that prevents them from continually being destroyed during storms and high winds are the grasses that grow on them. These fast growing grasses act as anchors as well as wind baffles that end up not only preventing sand from being blow away but actively promote dune growth. The baffle slows the wind down, causing whatever sand the wind is carrying to drop out. 

Here, with a view along the lakeshore itself, you can see the foreshore dunes off to the left with their rather significant slope up to the lake terraces. You can also see the disparate sizes of the sediment along the foreshore of the beach. Here the larger sized sediment is located along the water-beach interface, This is because the finer sand size particles are either blown further up-beach or carried back out into the lake by larger waves. 

You can see the rather course sediment along the shoreline pretty well here. Much of this coarser sediment would have been brought here with the glaciers from further up north, mostly from Canada. Then the sediment would have been reworked by stream and lake water erosion over the last 12,000 years.


Monday, October 26, 2020

Dinos in Pop Culture - Playgrounds Featuring the Dino Death Pose

 While playing with my daughter at a local park, I came across this hidden dinosaur, that brought up a couple of questions in mind. First off, what was this model based on? And why was the dinosaur positioned the way it was? I had my thoughts based on previous research I had done but I figured I would delve into it deeper. 

The dinosaur in question could be found on the back side of this rock climbing wall. 

To answer the first question, the mold appears to be modeled on the Gorgosaurus specimen at the Royal Tyrell Museum in Alberta, Canada. Gorgosaurus is a tyrannosaurid that is most closely related to Albertosaurus (hence the original identification of the below fossil as an Albertosaurus). It lived during the Late Cretaceous time period between 76.6 and 75.1 million years ago in Alberta, Canada and potentially Montana, USA. 

Gorgosaurus from the Royal Tyrell Museum in Alberta. Image courtesy of the Royal Tyrell Museum.

The first thing that is noticeable about the playground mold is that it is not an exact match for the museum specimen though. The mold skull is far smaller, the neck has many fewer vertebrae, and the curve of the neck isn't as pronounced, among a host of other issues. But the general feel of the playground dino is the same as the actual fossil. The location of the limb bones is near exact as well as the general posture of the dinosaur. It's as if someone tried to create a simplified image of the real dinosaur to the point of being wrong but "close enough".

Death Pose

Another noticeable thing about the dinosaur (in both cases), is the position of the body. This position is frequently referred to as the "death pose" (technically called the "opisthotonic posture"), and this is far from the only fossil to be found in a similar situation. Typically, what you see with this posture is that the head is curled backwards towards the tail and the tail is curled forward (as much as possible) towards the head. But why are so many fossils found this way? 

Upon initial discovery, it was thought that the animals lived like this while they were alive. However, that has proven to be false, so something must of happened to their bodies between the time that they were healthy and alive to the time that they were locked in stone (i.e. fossilized) forever. There are a couple of theories on what can cause this body position, but they can be boiled down to two: 
  1.     Things that happened to the animal while it was alive.
  2.     Things that happened to the animal after it died.
Scientists have been debating this for decades but it likely comes down to both sides are potentially correct. There are things that can cause the animal to be posed like this during life and after death. 

In life, this posture is possible by severe neurological (brain) damage, which would result in a curved spine while pulling the head and heels backwards. This situation can be produced by multiple causes including meningitis, tetanus, poisoning, asphyxiation, as well as a host of other diseases. While these causes have most notably been recorded in humans, animals are not immune from them either, specifically brain damage from drowning or asphyxiation and/or poisoning. These are instances where the "death throes" that produce this posture could be created in life, or more accurately called "perimortem", or near death.

There is also research that shows this posture can be created after death (postmortem). The bend of the spine is most naturally backwards. In most animals bending the neck downwards takes a lot of force, while upwards is quite natural.  But after death, although the muscles initially relax, ligaments and tendons start to contract, forcing the spine around as they shrink. Desiccation of the corpse has also been attributed as a cause of post-mortem spinal curve.  

As a side note: The tail on a dinosaur does not typically curl backwards as it does in mammals. You can actually see this in the Gorgosaurus fossil above, where the tail, even though it is bent upwards, does not actually curve towards the end. Dinosaurs have vertically stiff tails that stick out to counterbalance their heads. This stiff tail is not capable of bending up or down, but can sway side to side. This stiffness is preserved in death.

Sunday, October 25, 2020

Geologic State Symbols Across America - Idaho

   The next state up for the Geological State Symbols Across America is:


You can find any of the other states geological symbols on my website here: (being updated as I go along).

                                                                                                  Year Established
State Gem: Star Garnet                                                                     1967
State Fossil: Hagerman Horse Fossil (Equus simplicidens)              1988

I also have some Geology of the National Parks Through Pictures that I have done for Idaho previously. These include:

State Gem - Star Garnet

67-4505. STATE GEM DESIGNATED. The star garnet is hereby declared to be the official state stone, or state gem, of the state of Idaho. 

History: [67-4505, added 1967, ch. 33, sec. 1, p. 56.]
Prior to being polished, the star garnet will be found with the same dodecahedral crystal pattern found in other garnets. Image courtesy of

Garnet is typically thought of as one specific mineral, however garnet is actually a series of very similar minerals. This mineral series varies in chemical composition, resulting in different mineral names, however the chemical composition of all of the garnets share a generalized chemical composition: X3Y2(SiO4)3, where "X" can be Ca, Mg, Fe2+, or Mn2+, and "Y" can be Al, Fe3+, Mn3+, V3+, or Cr3+. Along with the different chemical compositions, there are different colors and hardnesses associated with each one as well. Crystals of garnet typically form in 12-sided "balls", that can be easy to identify within the rocks that they are found in. The name "garnet" comes from the Latin, "granatus" meaning "like a grain" because of this ball-crystal habit. Garnet is formed from the metamorphism of shale minerals, and can be found in most foliated metamorphic rocks such as schist and gneiss. Garnets can also be found in some igneous rocks including granites and granitic pegmatites. Garnet has been used as a gemstone since ancient Egypt, however recently garnet has obtained significant usage as an abrasive. Since garnet is a rather hard mineral and has no cleavage, it typically breaks into sharp edged fragments, and therefore produces a good grit for water-jet cutting or sandblasting. Garnet is a very common mineral and even high grade gemstone quality specimens can be fairly cheap.

A polished example of a star garnet. Image courtesy of

The Star Garnets are a rare variety of garnet which contain an "asterism", which is the star effect across the surface of the gem. This feature is more commonly seen in sapphires and rubys as well as other minerals. The star effect is caused by the inclusion of the mineral rutile within the garnet crystal. Star garnets are typically a deep brownish-red or reddish-black, producing almost a purplish hue. After careful polishing, the alignment of the rutile produces a reflection of light that produces a 3-dimensional star light pattern. The most common stars are the 4-rayed star (as pictured), however a 6-rayed star is possible, although very rare. The Star Garnet has most commonly been found in India and Idaho, however small amounts have also been found in Russia, Brazil, and North Carolina. Within Idaho, Star Garnets are found in the northern parts of the state near St. Maries, an area known as the Emerald Creek Garnet Area. The public is allowed to collect here for a small permit fee.

State Fossil - Hagerman Horse Fossil (Equus simplicidens)

67-4507. STATE FOSSIL DESIGNATED. The Hagerman Horse Fossil (species Equus simplicidens originally described as Plesippus shoshonensis) is hereby designated and declared to be the state fossil of the state of Idaho.  
History: [67-4507, added 1988, ch. 44, sec. 1, p. 50.] 
Some select representations of horse species over the past 55 million years. Image courtesy of Biology LibreTexts

Horses are one of the modern day species that has a remarkable fossil history. One of the earliest known relatives to modern day horses is the species Hyracotherium, more commonly known as eohippus or the "Dawn Horse" (although there is some scientific debate about whether Hyracotherium and Eohippus are two distinct species are just different examples of the same species). Hyracotherium lived around 55 million years ago and was about the size of a modern dog, much smaller than modern day horses. Evolutionarily, horses are within the order Perissodactyla, which are the odd-toes ungulates. This means that horses and their relatives, tapirs and rhinoceroses, typically have one or three toes. Hyracotherium was initially adapted for tropical forests, however as the landscape slowly dried and cooled over time, new horse species evolved to be adapted for the dryer, prairie habitat. With the development of the prairies approximately 20 million years ago, the new horse species had evolved larger and more adapted for grazing. Over the last 55 million years, over 50 species of horses evolved, with lineages often branching and living coevally, however the only horse genus left alive today is Equuswhich includes not only horses but zebras and donkeys as well

Fossil of the Hagerman horse, Equus simplicidens, from the Hagerman Fossils Beds National Monument Visitor's Center.

Among the myriad of horse species that have evolved was the species known as the Hagerman horse, Equus simplicidens. The Hagerman horse, first named in 1892 by Edward Drinker Cope, is the oldest known species of Equus. Equus simplicidens lived during the Ice Age, specifically the Pliocene and Pleistocene epochs, approximately 1.8 to 3.5 million years ago. Despite the name, the Hagerman horse is actually closely related to a modern day zebra, Grevy's Zebra (Equus grevyi). It is known from fossils all over North America, however the densest concentration of fossils is in Idaho where over 200 individuals had been found at Hagerman Fossil Beds National Monument. The fossil beds are comprised of two distinct bone beds, one of which was thought to be a periodically dried up river. There is some debate about how the horses died, but one theory is that the horses came here to drink, but upon finding the water not there died of thirst. Seasonal rains then came in, swept the horses up, and piled them upon a riverbank, where they were then covered over with sediment and eventually fossilized. Another theory is that the horses were killed during a flood while trying to cross the river. However, because so many of the horses were found within one location, it has helped scientists to determine that these horses were likely herd animals. 


Wednesday, October 21, 2020

Geology of the National Parks in Pictures - Craters of the Moon

My next post about the Geology of the National Parks Through Pictures is a park we visited back in 2012 that I had wanted to hit up since it was close enough to me in southern Idaho.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website


Craters of the Moon National Monument and Preserve

My standard park sign picture, but this time with the little one.

Here is a lava tube entrance. Craters of the Moon is located within a region of the US known as the Snake River Plain. The Snake River Plain was created as the North American plate slid of over the Yellowstone Hotspot. A hotspot is a volcano that stays in one place while the plates slide over it, like Hawaii. 
Pathway of the Yellowstone Hotspot across Idaho. Image courtesy of the Digital Geology of Idaho

Craters of the Moon falls to the northwest of the Picabo Volcanic Field, which is dated to 10.3 million years ago. This is the time when the Yellowstone hotspot was located at this point and had erupted. However, the volcanic activity that we see at Craters is not directly related to the Yellowstone hotspot. 

At Craters we can see the result of that volcanic activity by the remnants of lava flows, lava tubes, and other volcanic features. Here we can see a pretty good view of the landscape that has many trees and shrubs but is still pretty barren. There are three separate lava fields within the National Park that range in age from 15,000 years to 2,000 years old, all far younger than the 10.3 million year old Picabo eruption. Craters of the Moon is found along a track of land known as the "Great Rift". 

Within the are there are a lot of dead trees hanging about. The Great Rift is an area of crustal thinning associated with the expansion of the Basin and Range area, as well as deflation of the crust following the passage of the hotspot. So, although the volcanic activity is not a direct result of the Yellowstone hotspot, it still played a role. The combined effect of the crustal thinning and the deflation produced areas of increased volcanic activity, with one of the largest areas being Craters of the Moon.

The above shows multiple rift zones within the Snake River Plain. The large grey areas aligning with the Great Rift represent Craters of the Moon. Image courtesy of the NPS

Within the region remains a lot of extinct volcanoes including this cinder cone. A cinder cone is a volcano that is created by the eruption of lava blocks that eventually pile up to create this rather steep sided pile of rock. He we are climbing up the largest of the cinder cones, Inferno Cone.

 Panoramic view from the top of Inferno Cone.

 View from Inferno Cone of a couple of smaller cinder cones.

Another view of the same lava flow, this time a little further up. You can see both types of basaltic lava flows here, pahoehoe and 'a'a. Pahoehoe lava is the smooth lava, that often has a ropey texture, while 'a'a lava is a more blocky, sharp lava. 'a'a' lava was named for the sound people made when walking across it barefoot. Here you can see a nice transition from the pahoehoe to the aa style lava.

Some nice 'a'a, splatter lava.

 View of an 'a'a lava flow showing large chunks of volcanic rocks.

A lava tube is formed when flowing lava starts to solidify when it is contact with the air, eventually forming a crust on the lava flow. The crust continues to build up as the lava continues to flow through the tube, eventually forming this open space within the lava flow. Here I am entering one of the lava tubes.

 Some nice ribbon pahoehoe lava. I really love the fine cracks that run perpendicular to the ribbon folds.

View looking out of one of the smaller lava tubes, Dewdrop Cave.

Within the largest lava tube in the park, Indian Tunnel. Several places along the length of the tube, the ceiling has caved in giving visitors a nice walk even without the need of a headlamp.