The Morrison Biota

Stegosaurus lived in western North America during the Late Jurassic Period, about 150 million years ago (MYA). Today, we find its remains in the Morrison Formation, named after the tiny town of Morrison in Colorado. What was going on in Colorado at that time? What was the depositional environment like, the environment that laid down the sediment that would one day become the famed Morrison Formation?

Well, according to paleontologist Dr. Robert Bakker in an article about the re-discovery in 2002 of some old paleontological quarries (CLICK HERE TO LEARN MORE) in the Smithsonian Magazine, the environment was very much like the kind of environment seen in Uganda today: a “hot tropical woodland that was dry for most of the year.”

What about the animals, though? Dr. Bakker also said in the article that to “understand the Late Jurassic, you need to understand the common animals, which means Apatosaurus.” Most people are familiar with this massive animal: about 100 feet long (around the length of three school buses put end to end to end), and weighing around as much as eight African elephants, Apatosaurus was definitely a heavyweight of the Morrison biota!

What other animals were running around though? There are a great many dinosaurs, as well as many other animals, that were living in this area at that time, but in this post we are only going to look at one more: Camptosaurus and Allosaurus. All right, I lied. We’ll look at two more.

First off, we have Camptosaurus. To be honest, Camptosaurus doesn’t really look all that special. A small- to mid-sized ornithopod, Camptosaurus was only about fifteen feet long, and didn’t really appear to have any obvious defenses. However, discoveries of articulated Camptosaurus skeletons (indicating that the bones were fossilized were they were deposited, i.e. where the animal died, and weren’t washed together in a big mumble-jumble like at Dinosaur National Monument) in close conjunction with articulated Stegosaurus skeletons seems to indicate that these two herbivores liked to hang out together. But why? Why would they open themselves up to competition and potential conflict like that? Well, analysis of the brains and skulls of these two animals suggests that perhaps by hanging out together, the dinosaurian duo could avoid much deadlier conflict. Studies have shown that the sensory organs of Camptosaurus and Stegosaurus would have differed in very critical ways. The sense of Stegosaurus would have been akin to a rhinoceros, or perhaps myself as well (at least without my contacts), in that it would have had a pretty good sense of smell, but not very good vision. Camptosaurus, on the other hand, appears to have had quite acute vision, which has led to an interesting proposition by researchers: that Camptosaurus acted as a lookout for herds of Camptosaurus and Stegosaurus. If a predator was spotted (say, an Allosaurus or a Ceratosaurus), then Camptosaurus would have been able to alert the herd, and Stegosaurus would have been able to move to the forefront to defend them all against attack.

The last dinosaur that we are going to look at today is Allosaurus, a large, meat-eating theropod dinosaur. It occurs to me as I type this that I have done a very thorough job on Allosaurus before, so instead of typing this all again, I am going to be lazy and redirect you to another post that I did awhile back, entitled “23-Fact Tueday: Allosaurus.” Hidden within the post (but not too hard to find) are 23 Facts about Allosaurus. Yeah. Pretty much says it in the title. Anyways, check out that post to learn more about Allosaurus, as well as the rest of the Morrison ecosystem! And make sure to check back tomorrow, as we learn about stegosaurs from the rest of the world!

Want to learn more about Stegosaurus?  Well, check out the Homebase for Stegosaurus Week HERE to partake in more of the festivities!  

Simba, Pumbaa, and Other Swahili Names From "The Lion King"

Recently I decided to learn a bit of Swahili, and I have stumbled across a few things that I thought were quite interesting!  For instance, did you know that "Safari" meant "Trip" in Swahili?  I certainly didn't!  And the old movie entitled "Hatari!" actually means "Danger!" in Swahili!  Who knew! 

As I continued to learn more, I came across something else interesting.  As I was learning the animal names, I found that "Duma" meant "Cheetah," which excited me, as one of the main cheetah stars from BBC's "Big Cat Diary," one of the later seasons, is named Duma.  Next, I found out that "Chui" meant "Leopard...." and guess what?  There was a leopard named Chui, too!

Then, I found that "Simba" meant "Lion."  There was, of course, a lion that went by the name of Simba, in the first season of Big Cat Diary, I believe.  I had just assumed he was named after Simba from "The Lion King," which is still a possibility, but it could really go either way.


But I think it clear where the name of "Simba" came from for the Lion King.  As a matter of fact, many of the characters have names that mean something else in other languages.  For example, Ed, the hyena, is actually short for "Edward" in English.  Below is a list of others.

1. Nala - Gift
2. Pumbaa - Simpleton
3. Rafiki - Friend
4. Sarabi - Mirage
5. Shenzi - Uncouth
6. Sarafina - Bright Star
7. Banzai - Skulk, or Lurk

Animal Spotlight: The Okapi

For years, Europeans who traveled to Africa heard tell of a mysterious rainforest animal that they came to refer to as the "African Unicorn."  Apparently, Sir Harry Johnston, the British governor of Uganda, rescued a small group of the native inhabitants, often called the pygmies, from a foreign show person, who, sadly, was most likely going to use his abductees for a circus or freak show.  Upon their rescue at Johnston's hand, they repaid him by giving him information about the animal.

Now we know the animal as the okapi, or Okapia johnstoni, named in honor of Sir Harry Johnston.  Despite the zebra-like stripes on its tail, the okapi is not all that closely related to the zebra, and is actually a very close relative of the giraffe.  Although they may not look super similar, they both have ossicones on their head, similar to the base of DEER antlers.  Ossicones are not only possessed by both the okapi and the giraffe, but also by extinct relatives of both, such as Sivatherium and Climacoceras.

The okapi is listed as "NEAR THREATENED" by the IUCN.  Honestly, I was surprised that it wasn't at least listed as "VULNERABLE," and "ENDANGERED" or worse would not have surprised me at all, given its reclusive nature, its beautiful pelt, and the very fact that humans didn't have much proof of its existence until 1901, when Sir Henry Johnston sent back a carcass to England.  I suppose, however, that its reclusive nature likely helps it to evade human influences a great deal, coupled with the fact that the rainforest that it inhabits is not too heavily tread.  And I guess the fact that it was really made known to science only a little more than one hundred years ago couldn't have hurt either, as it would be soon entering into an age when nature was offered greater protection than in the 1800s. 

Like the COELACANTH and THE MOUNTAIN PYGMY POSSUM, the okapi is often referred to as a "LIVING FOSSIL."  Its habitat consists of montane rainforests in the Central African Republic (CAR) and the DEMOCRATIC REPUBLIC OF THE CONGO (DRC).

Arthur the Aardvark

Almost everybody has heard of Arthur Read from the popular PBS show "Arthur."  What a lot of people don't realize is that Arthur is an aardvark.  And even more people don't usually even know what an aardvark is.

A fossorial (burrowing, like terrestrial or marine), nocturnal mammal from Africa, the aardvark is an insectivore, its favorite food being termites, and is labeled as "Least Concern" by the IUCN.  The aardvark, as you can see below, inhabits an incredibly large portion of Africa, including South Africa, Ethiopia, Kenya, Tanzania, Uganda, Mozambique, the Democratic Republic of the Congo (DRC), Burundi, Somalia, Angola, and many others.

The aardvark has several important adaptations for its burrowing, insectivorous life style.  Perhaps the most important are the large claws on its front limbs.  These claws enable the aardvark to not only dig out immense burrows for habitation use, but also to dig into termite mounds to extract a meal.  Interestingly, when the aardvark leaves its burrow to dig a new one, the old burrow is often taken up by the African wild dog, where the pups shelter until they are old enough to leave the protection of the burrow.

The aardvark also has thick skin, which keep the termites from biting it, allowing it to feast in relative peace.  A further adaptation to keep insects (as well as dust) out is in its nose: it can close its nose, preventing both bugs and dust from invading its breathing passages.  Finally, another very important insectivorous adaptation is the tongue of the aardvark.  The long, sticky tongue of the aardvark is usually about 12 inches long, equivalent to about one-sixth the length of the animal!  Long, sticky tongues are a fairly common adaptation for termite-eaters such as the numbat (Myrmecobius fasciatus), pangolins (Manis sp.), and the giant anteater (Myrmecophaga tridactyla) among them.

A southern tamandua (Tamandua tetradactyla) shows off its extraordinarily long tongue during an animal demonstration at one of Denver Zoo's teen career days.  Tamanduas are also insectivorous, and clearly also possess an amazing tongue.

The Cichlids of the African Rift Lakes

Three of the largest lakes in the world reside in the 3,700 mile long Rift Valleys of Africa.  These lakes, Lakes Victoria (located in the countries of Kenya, Uganda and Tanzania), Tanganyika (split between Burundi, the Democratic Republic of the Congo [DRC], Tanzania, and Zambia), and Malawi (located between Malawi, Mozambique and Tanzania), rank among the top ten largest lakes in the world; third, seventh, and ninth, respectively.  (For some reason, these rankings differ upon where you look.  Lake Victoria as the third largest lake seems pretty universal, but the ranks of Tanganyika and Malawi differ for whatever reason.  You'd think that it would be pretty universal, but I suppose not.)  Besides being such large lakes, these lakes are important for other reasons, perhaps the most important reason (for biologists, at least) being their isolation.

You see, the three great lakes are islands, of a sort.  According to Websters, the definition of an island is "a land mass smaller than a continent and surrounded by water."  The Rift Valley lakes are essentially the opposite; "a body of water smaller than an ocean and surrounded by land."  For our purposes, an island is just something that has been isolated for a time, and allowed its flora and fauna to flourish in new and interesting ways.

And flourish it did in the Rift Valley lakes.  If you were to visit these lakes, snorkel or scuba in their waters, you would most likely notice a wide variety of fish.  You would not be wrong in this assessment; however, you might be surprised to find that most of these types of fish are belonging to a group called the cichlids (SICK-lids), and that all 1,650 plus species of these cichlids descended from a common ancestor.  While the dates of when the common ancestor of the various cichlids came to be trapped in their respective lakes, it has been estimated that the cichlids of Lake Malawi all evolved from a common ancestor trapped 700,000 years ago, and those of Lake Victoria around 12,000 years ago.  Trapped in these growing lakes while they were being formed, this small group of fish quickly came to dominate their new home, exploding in biodiversity to adapt to the wide variety of niches left open to them.

Tenuous can this biodiversity be, as recent logger-based erosion has shown.  Logging nearby to one of the lakes resulted in rapid erosion.  This erosion caused a great deal of silt to build up in one of the lakes.  This, of course, caused the water to become quite murky; think about your average beach, and how murky the water often is near the shore.  Many of the cichlids that lived in this area relied upon visual identification to recognize members of the same species for mating purposes.  With the cloudy, muddled water, this became quite difficult.  As a result, many fish from closely related species ended up mating with each other and, in the case of many of the couplings, resulted in viable offspring.  These viable offspring in turn bred with other species, lowering, at least temporarily, the biodiversity of the cichlids in this particular corner of the lake.

Blantyre on Dwellable