Friday, May 24, 2013

Lions and Tigers: Less Than Meets The Eye

If you are in a zoo or out in the wild, differentiating between a lion and a tiger is much less impressive than many other feats, such as walking and chewing gum or recognizing that yellow snow is not for consumption.  However, when all you have is their bones, differentiating between the two becomes much more of a challenge.

According to the authors of the excellent book "The Big Cats and Their Fossil Relatives," around the turn of the century (meaning the 1800s to the 1900s), French paleontologist Marcelin Boule devised a number of criteria to differentiate the skeletons of these two animals from each other.  However, these criteria aren't just "the lion has an extra vertebra," or "the tiger has a striped femur."  Nothing that simple.  It's more like "the tiger has a slightly more pointy fronto-nasal suture as it reaches towards the posterior end of the skull."  Yeah.  For the most part, not all that explicit.  In the picture below (scanned from the Big Cat book mentioned above, all photo credit goes to them), you can see how subtle these differences can be.

So what are the implications for paleontologists?  Ultimately, it shows us all how very little we can actually figure out about animal behavior from their bones, as well as how very similar such different creatures can be.  Sure, looking at the skull of a lion or a tiger, most people would have little difficulty figuring out that they ate meat.  But would looking at that slightly pointier fronto-nasal suture in the tiger really show us how much less social it is compared to the lion?  Would the minute differences in the fronto-parietal suture reveal that the male lion sports a mane?  Would any sort of suture be able to tell us that the lion is one of very few cats to sport a solid colored coat (like the mountain lion and the jaguarundi), while the tiger sports orange and black stripes?  In the end, these minute differences in the bones remind us that we will probably never be able to learn everything there is to know about ancient and extinct species, and that there are probably many more extinct animals out there that are waiting to be discovered.  It's more than likely that we already have the bones: we just need to tools to differentiate between them.

This was the birthday post of Tom Bonan! Happy birthday, Tom! If you have a birthday coming up, just email me the date at cuyvaldar123946@gmail.com with the date and your favorite animals, and I will do my best to get a post in! And if you like what you are reading, please feel free to follow us here or via Facebook!

Thursday, May 23, 2013

Otters of the Old World

In the last post (which you can check out by clicking HERE), we learned all about the otters of the Americas   In this post, we are going to look at the otters from the rest of the world!  First though, we aren't going to be looking at the sea otter again, as we looked at it in the last post, and even though it can be found along the coast of Russia and Japan, you can just click the link above to learn about it from the last post.  So, just like an otter, let's dive on in!

We'll start with the Eurasian otter, found from Europe down south to northern Africa, and as far east as India, China, and the Malay Archipelago!

Before heading over to Africa, let's focus more on the Asian otters!  First off, we have the smooth-coated otter!  The smooth-coated otter is one of my favorite otters for many reasons!  First off, it has been tamed in some parts of India and Bangladesh to not only catch fish, but also to herd them into fishing nets!  That's pretty awesome!  This otter is very social, living in groups between around 2-11, and fighting off crocodiles.  Wait, what was that?  Did you say fighting off crocodiles?  Technically, no, I wrote it, and you didn't really need to ask, you could have just reread that line again.

Anyways, yes, the smooth-coated otter will actually fight off crocodiles!  More specifically, a certain type of crocodile called the mugger crocodile!  I can sense that a few of you are a little skeptic, so below is the link to a video!

Our next Asian otter is the Asian small-clawed otter!  We actually have these at the Denver Zoo, but I have never been able to get a good picture of them (nor the fishing cats!) due to the weird way the glass was built!  Anyways, the Asian small-clawed otter is the smallest otter in the world, and, like the smooth-coated otter, is very social, living in groups of around 2-15.

Our next otter, our last Asian otter, is the hairy-nosed otter.  Not a lot is known about the hairy-nosed otter: as a matter of fact, it was actually thought to be extinct until 1998.  Since then, numerous pockets of the animal have been rediscovered, but it is still highly at risk.  The hairy-nosed otter is currently labeled as "Endangered" by the IUCN.

On to the African otters!  The African otter with the widest range is the Cape clawless otter, so we'll look at it first!  As its name implies, the front foot of the Cape clawless otter is, in fact, clawless, except for vestigial fingernails.  The Cape clawless otter will inhabit marine habitats, so long as fresh water for drinking is close by!  The Cape clawless otter will dine on, amongst other things, octopus!

The African otter with the second widest range is the spotted-necked otter.  The markings on the spotted-necked otter are unique to each individual animal: just like human thumbprints, no two are alike!

The final African otter (in fact, the final otter altogether), is the Congo clawless otter.  The limited data that scientists have seems to indicate that, despite their similarities, the Congo clawless otter is, indeed, genetically distinct from the Cape clawless otter.  One interesting fact about the Congo clawless otter pertains to its diet: earthworms form a very important component of the diet of this particular otter in many parts of its range!  The otters will root around in the mud in search of their prey, oftentimes consuming up to three earthworms a minute!

Make sure to check out the first post in our "Otters of the World" duology by clicking HERE.  Furthermore, this was the birthday post of Julie Neher! Happy birthday, Julie! Want to see some cute (or ugly) baby animals featured here on your birthday? Well, if you have a birthday coming up, just email me the date at cuyvaldar123946@gmail.com with the date and your favorite animal, and I will do my best to get a post in! And if you like what you are reading, please feel free to follow us here or via Facebook!

Otters of the Americas

Most scientists today accept that there are thirteen extant (still living, opposite of extinct) otters in the world.  Of these, five are native only to the Americas, while one, the sea otter, lives in both the Old World and the New World!  In this post, though, we are going to be only looking at the New World otters, the otters of the Americas!  Let's start up north and work our way downwards!

If we're starting up north, then that would mean that our first otter of the day is the North American river otter!  The diet of the river otter is primarily composed of slow moving, bottom feeding fish, but will eat many other different animals given the opportunity!  Reports of river otters catching and eating snowshoe hare have been recorded, as well!

When my friend Masaki Kleinkopf, my father and I were able to go on a behind the scenes tour at the Cheyenne Mountain Zoo with my grandparents, one of the keepers at the grizzly bear enclosure told us a very interesting and funny story!  A few years ago, the four river otters had managed to create a hole in their enclosure large enough for them to squeeze through, and some of them escaped.  One of the river otters was never found, and to this day is still probably roaming the mountainside (unless it got eaten).  If I remember correctly, another one of the otters was captured a few weeks later farther down the mountain, swimming around.  The final two otters were much easier to capture, however, and this is the funny part of the story!  If I remember correctly, the zookeepers figured out that the otters were missing because they went up and visited the nearby grizzly bear enclosure.  Instead of being greeted with the typical blue pond loaded with fish, they were met with a vision of a bloodbath: the waters were red with blood, and there were fish parts everywhere!  And there, on the side of the pond, were two fat and happy otters!

In other river otter news, one was recently captured on a camera trap in Boulder, Colorado, the first such sighting in the area for around 100 years!  Click HERE to be directed to an article to learn more!

Next up, we have the sea otter, the heaviest mustelid, and the only other otter native to North America!  Sea otters also have the thickest fur of any mammal, with around an astonishing ONE MILLION HAIRS PER SQUARE INCH!  Now THAT'S a lot of hairs!  This unfortunately has attracted many, many poachers over the years, and sea otter populations the world over took a serious tumble.  However, in recent years, they have recovered to around two thirds their historical numbers, making it one of the most successful marine conservation movements ever!  The sea otter will also hold hands with other sea otters to avoid floating away from each other, and sometime will form what scientists call "rafts" of around 2,000 individuals!  Click HERE to learn more about the hand holding and the rafts!

Let's take this trip south of the Equator to Mexico, Central, and South America!  The next otter is the neotropical otter and, as you can see by the range map below, is native to all three of those places!  A solitary animal, not a great deal is known about its behavior and habits.

Next up is the second largest mustelid in the world (after the sea otter, of course), the aptly named giant otter!  Although much longer than the sea otter, the giant otter is much more slim.  It is, however, the longest mustelid, growing to lengths of about five and a half feet!  Unlike most mustelids, the giant otter is a fairly social animal, living in groups generally numbering between around four and thirteen individuals, usually composed of one pair of breeding individuals and their offspring from one or more generations.

One of the most interesting things that I have learned about the giant otter is entirely and categorically false: according to one TV show (I am pretty sure it was Survivorman), the giant otter is a threat to people.  I can't remember the exact quote, but in one episode in which he was in the Amazon, he says something along the lines of "I definitely have to watch out for jaguars and insects here, but I've also been told to watch out for the highly aggressive giant otter."  Which is total crap.  The giant otter is often regarded as a nuisance to indigenous peoples, but nowhere have I been able to find anyone saying that they can be dangerous to humans!  I don't recommend that show.

The second to last otter of the Americas is the marine otter.  Much of the marine otter's time is spent out of water, and it rarely, if ever, ventures into rivers or estuaries.  The marine otter is the second smallest otter (the only smaller otter being the Asian small-clawed otter), and, like the neotropical otter, not a lot is known about it.

Finally, we have the southern river otter, another otter about which not a great deal is know.  Although called a river otter, the southern river otter spends a great deal of time in both fresh and salt water.  Some people believe the southern river otter simply to be a sub-species of the North American river otter.

This was the birthday post of Julie Neher! Happy birthday, Julie! Want to see some cute (or ugly) baby animals featured here on your birthday? Well, if you have a birthday coming up, just email me the date at cuyvaldar123946@gmail.com with the date and your favorite animal, and I will do my best to get a post in! And if you like what you are reading, please feel free to follow us here or via Facebook!

Wednesday, May 22, 2013

When Is A Turtle Not A Turtle?

When it's a placodont!  All right, so they're technically not turtles.  Instead, they are a classic example of the fascinating phenomenon known as "convergent evolution," as we shall soon see!

Placodonts were a fascinating group of marine reptiles that lived during the Triassic Period in the Mesozoic Era, between around 235 and 200 million years ago (MYA), and thought to have a common ancestor with the long-necked plesiosaurs and the long-necked nothosaurs, all of which are in the large group called the saruopterygians.  As a group, the placodonts are sometimes referred to as "walrus turtles," due to their diet of molluscs and other shelled invertebrates and, of course, their general appearance.

Like the turtles and tortoises of today, the placodonts would not have been all that quick and nimble.  Their weight would have made them negatively buoyant, akin to the manatees and sea cows of today, meaning that they would have had no trouble swimming along the bottom of the ocean, snapping up molluscs and other shelled invertebrates, and using their large, flattened cheek and palatal teeth to crush them down.  It's also possible that they scraped algae off of marine rocks and swallowed it whole, letting it slowly digest in their massive guts!  Like modern sea turtles, the placodonts are thought to have been amphibious, spending most of  their time (sleeping, chillaxing, and other activities) on land, but dipping into the water to feed, akin to the extant marine iguana of the Galápagos Islands.

Although younger placodonts would have been especially vulnerable to predation from many different types of animals, many paleontologists puzzle over why the ponderous adult placodonts would have needed this armor, as there don't seem to be any marine predators capable of making a meal out of them that lived at the same time.  Of course, as we mentioned before, they probably spent much of their time on land and, as we also mentioned before, their awkward build would have left them particularly vulnerable to attack.  So to counter this, some of the placodonts started to evolve in a very turtle-like appearance. 

Placodus, the animal whose name is lent to the entire group, displays a single row of dermal ossifications above its neural spines down its back.  This dermal armor (a fancy way of saying "skin armor," in which the skin hardens into an armor like structure, as seen in the armadillo) would have helped to protect the animal from attack.  Earlier, more primitive genera, such as Paraplacodus, lack this dermal ossification.  However, other, more derived placodonts take this ossification of the dermals to a whole new level.

Remember Henodus, the first picture in this post? Henodus is one of those dermal armorers (I don't think that's actually a word) that took the ossification of the dermals to a whole new level.  Outwardly similar to the turtle shell, the placodont armor was composed of a number of polygonal ossicles, while the shells of turtles are composed of large plates.  Two other placodonts that were extremely well armored include Cyamodus, as well as the VERY turtle-looking creature, Placochelys

Like many other animals, the placodonts became extinct at the end of the Triassic Period.  Many groups did survive, however, and one of those groups that survived through to the Jurassic Period was actually the turtles!  220 MYA, the placodonts were sharing the seas with what would one day become the hard-shelled reptiles adored by so many people! 

This is the birthday post of Darlene Neher!  Happy birthday, Auntie Dar!  If you like what you are reading, please feel free to follow us here or via Facebook!  And remember, if you have a birthday coming up, just email me the date at cuyvaldar123946@gmail.com with the date and your favorite animal, and I will do my best to get a post in!

Saturday, May 11, 2013

Alphabet Animals: The Letter Q (Extinct)

In our last post, we looked at some extant, or still living (as opposed to extinct) animals whose name begins with the letter "Q."  Today, we are going to look at a few more of these animals, but this time we are going to be looking at some of those extinct animals!  Let's go, team!

1.  Quetzalcoatlus - One of the largest flying animals of all time, Quetzalcoatlus is not a dinosaur like it is often thought to be.  Instead, Quetzalcoatlus is a memeber of a distinct group of archosaurs (a large groups of reptiles that includes crocodilians and dinosaurs) called the pterosaurs.  Quetzalcoatlus lived in the Late Cretaceous Period of North America, between around 68-65 MYA.

2.  Qantassaurus - A small Australian ornithopod, Qantassaurus was named by paleontologist-couple Patricia Vickers-Rich and Tom Rich after the Australian airline Qantas.  Qantassaurus lived about 115 MYA, when Australia was still a little south of the Antarctic Circle!

3.  Qiaowanlong - A sauropod dinosaur from Yujinzi Basin of Gansu, China, Qiaowanlong was first discovered in 2007, and lived about 100 MYA in the Early Cretaceous Period.

4.  Quagga - An extinct subspecies of the plains zebra, the quagga was once found in the Karoo of South Africa, and was the first extinct creature to have its DNA studied by scientists.  The quagga was actually hunted to extinction by humans: the last wild one is thought to have been shot in the late 1870s, while the last specimen ever known to have existed died on August 12, 1883 at a zoo in Amsterdam in the Netherlands.

5. Qingxiusaurus - Described in 2008, Qingxiusaurus is yet another sauropod dinosaur whose name begins with a "Q."  Like Qiaowanlong, Qingxiusaurus was also found in China.  Qingxiusaurus lived much later than Qiaowanlong, however, in the Late Cretaceous Period.

6.  Qiupalong - An ornithomimosaur, or ostrich dinosaur, Qiupalong lived during the Late Cretaceous Period of China, and is the first ornithomimosaur that is definitively known from outside the Gobi Desert in Asia.

7.  Quaesitosaurus - With a name meaning "extraordinary lizard," Quaesitosaurus lived between around 85 and 70 MYA in Mongolia.  It was first discovered in 1983, and its skull was likened to that of a horse.

8.  Quilmesaurus - Native to Argentina during the Late Cretaceous Period, not a lot is known about Quilmesaurus.  It is estimated to have been between around 16 - 20 feet long.

9.  Qinlingosaurus - Yet another Late Cretaceous Asian sauropod, Qinlingosaurus was named after the Qinling Mountains of China in 1996.  

Friday, May 10, 2013

Alphabet Animals: The Letter Q (Extant)

Of the multitudes of animals, living and extinct, not a whole lot of them have names that start with the letter "Q."  Today, we are going to look at a few of these animals, so next time you are playing the Animal Alphabet game, you are quite prepared to handle whatever your opponent has to offer!  (Unless, of course, your opponent has also read this post, in which case you guys might reach a stalemate).  To make the post easier to deal with, I am splitting it up into two parts: the first one, this one, contains a list of some extant (still living, opposite of extinct) animals that begin with Q!  And yes, in the picture below, I know that the quagga is extinct....I just am too lazy to change the picture.  So you're going to have to find some way to deal with it.

1.  Quoll - A carnivorous marsupial native to Australia, New Guinea and Tasmania, the quoll is often called the marsupial cat.

2.  Quail - A collective name for a mid-sized bird that is often used for consumption by humans.

3.  Quokka - One of the first Australian mammals seen by Europeans and about the size of a domestic cat, the quokka is a marsupial, just like the quoll.  However, the quokka is a type of macropod, like the kangaroo and the wallaby.

4.  Quetzal - One of the most beautiful birds in the world (in my opinion, at least!), the quetzal is a member of the trogon family, and native to Mexico and Guatemala.

5.  Quail Thrush - Despite their name, the quail thrushes are neither quails, nor thrushes.  Native to Australia and New Guinea, the quail thrushes are close relatives of the jewel-babblers of New Guinea!  And yes, the jewel-babblers are, indeed, actual birds!
6. Quelea - A small nomadic bird native to Africa, the red-billed quelea is thought to be the most numerous bird in the world!
7.  Quahog - Also known as the hard clam, the quahog lives in the Atlantic Ocean along the coast of North America.

8.  Quique - A mustelid (often called the grison), just like the otter, the quique is native to South America.

9.  Quarter Horse - An American breed of horse that has been clocked at up to an astonishing 55 mph!

10.  Quarry Worm Salamander - An "Endangered" species of salamander that is endemic (native only to that one place) to Costa Rica.

11.  Queen Snake - A nonvenomous snake native to North America, the queen snake is very similar iin appearnace to the garter snake, and is often confused with it.

Thursday, May 9, 2013

Stegosaurus at the Morrison Natural History Museum (Stegosaurus Week)

So as you probably know (at least if you've been following us here for Stegosaurus Week), the whole point of the special week was to celebrate Stegosaurus Day at the Morrison Natural History Museum in Morrison, Colorado!  But what Stegosaurus-related exhibits does the Morrison Natural History Museum even have?  Well.  I am so glad you asked.  Let's dive on in!  
The first Stegosaurus-related thing that you will see is just a small exhibit, whose size is not a good representation of its importance.  The four groups of bones that you see here are part of the holotype specimen of Stegosaurus!  It was with these bones, as well as the rest of the specimen (part of which is at the Morrison Museum, the rest in the collections at Yale in Connecticut)  that paleontologist Othniel Charles Marsh first named and described the genus Stegosaurus in 1877, during the famous (or rather, infamous) Bone Wars.  Below, we have a picture with the four different groups of bones highlighted in red. 
The first bone that we see below is part of one of the plates of Stegosaurus!  The entire specimen actually extends back several inches, but the fossil part of the specimen is only on the very top layer.
Next, we have part of the femur of Stegosaurus!
Here we have two different types of vertebrae of Stegosaurus, lumbar and caudal (back and tail) vertebrae.
The next picture is an illustration by paleoartist Fabio Pastori of what this animal would have looked like.  Meet Stegosaurus armatus, one of four species of Stegosaurus that are currently considered to be valid!
Next, we have some more VERY interesting Stegosaurus fossils, as well as a cute little baby Stegosaurus model!  This little guy below is about a foot long, and is a life-size representation of the animal that would have made that footprint.  Besides being the very first baby Stegosaurus footprint discovered anywhere in the world, this footprint is especially interesting because it shows that the baby Stegosaurus was walking on its back legs, without its front legs touching the ground!
Here we have another Stegosaurus footprint: or rather, a trio of footprints!  The main footprint on this slab of Jurassic-aged rock contains what is largely considered to be the best adult Stegosaurus hind foot track in the world!
This footprint-containing slab is of particular importance to the paleontological community for another reason other than preservation quality: not only does the slab contain a very well preserved hindfoot track of an adult Stegosaurus, it also contains a forefoot track, probably from the same individual, as well as a partially crushed juvenile Stegosaurus track.  This partially crushed juvenile Stegosaurus track is of particular importance, as it seems to be pretty strong evidence that the adult and the juvenile were traveling together! 
Next, we have a cast of a skull of Stegosaurus, next to a cast of the foot of the animal, as well as a reconstruction of the foot itself! 
Next, we have a VERY interesting block of fossil-containing rock!
It all started when the block was brought into the museum because of the dinosaur bones, like the rib bone you can see below from an unidentified dinosaur....
....and these bones, on the back of the block.  It wasn't until the block was brought inside the museum that researchers noticed something that they hadn't been able to see outside: some tiny dinosaur footprints!
Here are two of the footprints, below.  The one on the left, about the size of the palm of my hand, is thought to belong to a mid-sized ornithopod, likely a hypsilophodont or a heterodontosaur, we don't really know.  The much smaller one on the right (which isn't much larger than a house cats) is even harder to identify, and could belong to a wide variety of dinosaurs.
  
Here is another picture by Fabio Pastori, depicting the small ornithopod that might have made the tracks.
The other tracks on the slab are by and large considered to be much more interesting.  What you are looking at below are some more baby Stegosaurus footprints!  Remember the baby Stegosaurus footprint that we discussed below, and remember the model of the animal that was thought to have made it?  The model is about the size of the animal that is thought to have made the little tracks on the left in the picture below!  What's particularly interesting about these footprints, however, is that they show the footprints of at least two individual Stegosaurus, each probably just a few months old, superimposed on each other!  This seems like pretty good evidence that these guys were also moving in groups, just like the other slab of Stegosaurus footprints shows us with older individuals!  The smaller footprint on the right (again, around the size of a domestic cat's footprint) is from a much smaller individual, probably just a hatchling!  It is also possible that this hatchling was moving with the other juveniles, as well!  
This is a model of the hatchling Stegosaurus that made the footprint on the right in the three pictures that we have above.
Finally, we have a size comparison of footprints of Stegosaurus at different ages!  The bottom one is from an infant Stegosaurus, maybe an inch and a half or so in diameter.  The top one is from an adult, larger than your average dinner plate!
Want to learn more about Stegosaurus and it's relatives? Well, check out the Homebase for Stegosaurus Week HERE to partake in more of the festivities!
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