Bi Di Miss American Pie: Number Two Greek and Latin Roots!

A little while ago, I started a new series all about the Latin and Greek roots in the scientific names of different animals!  IN THE LAST POST, we examined animals with the Greek and Latin roots for "one," and today, we are going to kick it up a notch: exactly one notch, to be precise!  Today, we are going to examine the roots for the word "two!"  Let's begin with the cardinal (i.e. one, two three, etc.) form in Greek!  There are actually several roots that work here, but the one most commonly seen in binomial nomenclature is the root "di!"  Let's DIve right in!

• Our first "di" today is a small flying creature called Dimorphodon, a member of the extinct group of reptiles called pterosaurs.  The name "Dimorphodon" comes from three roots, "di," "morph," and "don."  "Di," of course, means "two."  In this context, the root word "morph" means "form."  In mythology and fantasty, a being that can take more than one form is often said to be able to morph their appearance.  Finally, the root word "don" is one of my favorites (and is used a whole lot in giving animals their scientific names): it means "tooth."  Altogether now: two-form tooth.  This name refers to the fact that Dimorphodon actually has two different types of teeth in its jaw.  For mammals, that's nothing special, but amongst reptiles, that is pretty rare!

• Dimetrodon-another animal with two kinds of teeth!  "Di" and "don" still mean the same thing as they did in Dimorphodon (above), but there is a new root in between: "metro."  For this root, think of the term "metric."  The name "Dimetrodon" actually means "two measures of teeth!"  Dimetrodon's two types of teeth would, in the groups that it is ancestral to, one day evolve to become the varied types of teeth that we see in the mouths of mammals!  Dimetrodon is more closely related to mammals than it is to any group of living reptile, and all of us mammals did evolve from a Dimetrodon-like ancestor!  So remember, if anyone ever tells you that Dimetrodon is a dinosaur, tell them that Dimetrodon actually lived around 40 million years before the first dinosaur ever walked the Earth!  That'll show them.

Dimetrodon (left) attacks the primitive amphibian Eryops.  Much like in the skull of Dimorphodon, you can clearly see the much larger teeth in the front of the skull and the smaller teeth in the back of the skull of Dimetrodon.

• Let's travel forward to the Late Cretaceous Period, time of Tyrannosaurus and Triceratops, to meet Didelphodon, a primitive mammal about the size of the living Virginia opossum!  As a matter of fact, it is from the opossum that Didelphodon gets its name: "Didelphodon" translates to "opossum tooth," as Didelphis is the genus name for the Virginia opossum and several related species of opossum!  In turn, "Didelphis" means "double womb," which presumably refers to the fact that the opossum, like all marsupials, has its internal reproductive tracts where the baby will develop for a bit, and its external pouch, where the baby will develop until full term.  

• A fourth animal with "two" and "tooth" in its name is Diprotodon!  The middle root, "pro," in this name means "forward," like the word "proceed."  So the name "Diprotodon" actually means "two forward teeth."  A quick examination of the skull of this massive mammal quickly reveals why!  Although it looks like it might be some sort of ungodly large rodent, Diprotodon is actually a hippopotamus-sized wombat, the largest marsupial known to have walked the Earth!

• Diceratops is a genus of ceratopsian dinosaur that is often considered to actually be a Triceratops.  The name, which means "two-horned face," was later discovered to already belong to a type of insect, and changed to the name Nedoceratops.  Some other paleontologists believe that Nedoceratops is really the same animal as Triceratops, but I don't really know enough about Nedoceratops to have an informed opinion on the matter.  However, paleontologist Jack Horner believes that Nedoceratops is an intermediate growth form between Triceratops and Torosaurus, and since I don't agree with his ideas of Triceratops ontogeny and that I think Triceratops and Torosaurus are definitely distinct dinosaurs, that leads me to suspect that Nedoceratops is more likely distinct, and certainly doesn't bridge the gap between Triceratops and Torosaurus.

• The name of Diplodocus, which means "double beam" originates from the two rows of chevron that are on the underside of the animal.  This was originally thought to be a feature unique to Diplodocus, a defining characteristic that would set it apart from other closely related sauropods.  Since Diplodocus was named by paleontologist Othniel Charles Marsh in the late 1800s, this feature has since been discovered on a number of other sauropods, including Barosaurus, also from the Morrison Formation, like Diplodocus.

• Dilophosaurus, one of the stars of the original Jurassic Park movie, gets its name from the two crests on its head.  Last time, we met Monolophosaurus, which means "single-crested lizard."  Therefore, Dilophosaurus means "two-crested lizard!"  

While it is the Greek cardinal root for "two" that is used most frequently in binomial nomenclature, it is the Latin root that is most often used for multiples (i.e. once, twice, thrice, etc.), the root "bi."  You can probably think of several words right off the top of your head that use this root!  In fact, the word "biped," used to describe creatures that walk on two feet (as opposed to, say, a quadruped), comes from the two roots "bi" and "ped," with "ped" meaning "foot" in Latin.  So literally, "biped" means "two feet!"  Let's look at a few more!

• Marshosaurus bicentesmus - A theropod dinosaur from the Morrison Formation (one who has received "Full-Post Status," as you can see by clicking HERE).  The exact relationships of Marshosaurus to other theropods isn't exactly clear, but some people think it might even be some sort of primitive coelurosaur, while others think it is more closely related to Megalosaurus and kin.  Regardless of its phylogenetic relationships, the name of Marshosaurus is quite exciting!  The genus name "Marshosaurus" honors the famous paleontologist Othniel Charles Marsh, who did a lot of work in the Morrison Formation.  The species name "bicentesmus" refers to the fact that the species was described in 1976, the bicentennial of the United States.  The bicentennial is, of course, a 200 year anniversary, and the "bi" in the name distinguishes a 200 year anniversary from a 100 year anniversary, or a centennial.

Here are two shots of a specimen of Marshosaurus that were on display in the lab at the Denver Museum of Nature and Science last year.  This first picture is the right maxilla, which would have made up part of the front section of the animals snout.

Here we have more of the same specimen, on display at the same time and the same place.  You can see several vertebrae and ribs in this shot.

• Baeolophus bicolor - This is the scientific name of the tufted titmouse, a small woodland bird native to much of the eastern half of the United States.  These little birds live in holes in trees that have been abandoned by woodpeckers, and are closely related to chickadees and, of course, the other titmice.  I couldn't figure out what the genus name "Baeolophus" means, but it is pretty apparent that the species name "bicolor" refers to the fact that this little bird is gray on its back, and white on its underside.  Some of the other species in the genus, such as the juniper titmouse (Baeolophus ridgwayi), are simply all gray.  

• Diceros bicornis - Here we have the scientific name of the black rhinoceros, a "Critically Endangered" species of African rhino.  According to some sources, the black rhino often prefers to eat Acacia leaves, presumably employing its prehensile upper lip to avoid the plants thorns.  The black rhino has pretty poor vision, with much better auditory and olfactory sensing capabilities.  Humans are easily the most dangerous threat to the black rhinoceros, with lions and the spotted hyena occasionally taking young black rhinos as prey, and even more rarely attacking adults.  The scientific name of the black rhinoceros literally means "two-horn two-horn."  As we have already established, both "di" and "bi" are roots that mean two.  Both "ceros" and "corn" are roots that refer to horns: think "Triceratops" for ceros (three-horned face), and "unicorn" for corn (one-horn).  

Works Cited:

The Ancestral Australian Aborigines As a Possible Cause for the Extinction of Australia's Pleistocene Marsupial Megafauna

A few weeks ago, in my Anthropology class, we had to do a cultural profile of one culture group of humans.  I chose the Australian Aborigines and, having just finished Tim Flannery's excellent book "Chasing Kangaroos," this whole concept of the Ancestral Aborigines being the possible cause of the extinction of Australia's Pleistocene megafauna was still quite fresh in my mind, so I included it in the paper.  I thought it was pretty interesting, and so I have decided to share it with ya'll, too, with a few brief modifications to make it more Blog friendly!  Hope you enjoy, and if you want a more comprehensive look at the topic, I highly recommend "Chasing Kangaroos!"

Interestingly, paleontologists today are using the Australian Aborigines to help them figure out when Australia's Pleistocene megafauna went extinct.  While today, there are no native animals larger than the red kangaroo, Pleistocene Australia was a very different place, as was the rest of the world.  The Pleistocene Epoch was the time of the Ice Age megafauna.  With the exception of Africa and south-east Asia, in most places nowadays, the Pleistocene megafauna is extinct, but back then, the megafauna were a world-wide phenomenon.  In Eurasia, there were the giant mammoths and rhinoceroses, the cave lions and hyenas, the Irish elk, and the giant polar bear.  In North America, there were the mammoths and mastodons, the short-faced bear, the giant bison, the dire wolf, the giant beavers, and the saber-toothed cats.  In South America, there were the giant ground sloths, the armored glyptodonts, and many large relatives of elephants.  

Australia also had its fair share of Pleistocene megafauna, with marsupial lions, the giant short-faced kangaroos, the hippo-sized wombat Diprotodon, and echidnas that were the size of sheep.  There are two main hypothesis when it comes to what caused the extinction of all these animals: climate change, or hunting by early human arrivals on Australia, the first Aborigines.  No one could figure out whether it really was the Aborigines that had hunted the megafauna to extinction, though, because no one could figure out the date that the megafauna had gone extinct, nor could they figure out the date that humans first arrived on Australia.  Some people believed that the megafauna survived until around 6,000 years ago, while others believed that they went extinct a great many years prior.  The same difficulties confronted those scientists attempting to determine when humans first arrived.  The sediments of Australia are notoriously hard to date, and since the animals of Australia are so unique (especially following the extinction of the dinosaurs), scientists were unable to correlate their data with other places around the world.[1] 

As more scientific discoveries were made, a new method of dating rocks was discovered, called optically stimulated luminescence (or OSL for short).  Using OSL, paleontologists were successfully able to date many different specimens of the various marsupial Pleistocene megafauna, and found that, while many of them approached the 46,000 years ago mark, none of them passed it.  Many different specimens were used from all across Australia, but they all said the same thing: 46 was the answer. 

Meanwhile, with the new OSL tool in their bag, other scientists headed off to sites of known human habitation to attempt to date them as well, and these efforts proved to be successful.  One of the main places that they dated was a place known as Devil’s Lair, a known area of ancient Aboriginal inhabitance.  What was especially important about Devil’s Lair was that there was sediment present for the last 63,000 years, meaning that instead of just a snapshot of time, the scientists had an uninterrupted sequence of time to figure out when humans started living there.  As the scientists dated the sediments with the first signs of human inhabitance, they came up with the magic number: 46,000.  Other sites came up with the same number too, including Lake Mungo, the oldest human burial known from Australia.  At Lake Mungo, the dates were a bit less precise, ranging from between 45,000 and 47,000 years ago, but the data still seems to point in the same direction.  The ancestral Aborigines arrived on the continent at around the same time that Australia’s Pleistocene megafauna went extinct.  With this new dating technique, scientists were also able to determine that there was no significant climate change for many thousands of years on either side of the 46,000 mark, effectively ruling out that hypothesis.  So it seems that, for a time, the people who believe themselves as part of the land and the natural world around them actually destroyed a significant part of it.

[1] For example, paleontologists studying dinosaurs of the Late Jurassic Morrison Formation here in Colorado are able to look at closely related dinosaurs in other parts of the world like the UK and southern Africa (keep in mind that the continents were all together in one big landmass back then.)  That way, if the paleontologists are unable to determine the dates of, say, the Tendaguru Formation in Tanzania, they can look to the studies done on the rocks of the Morrison Formation for an accurate estimation.  This is a luxury that paleontologists, archaeologists and other scientists working in Australia simply do not have. 

Mildura on Dwellable

The Function of Cheek Pouches

A possible ancestor of Diprotodon (the largest mammal known from anytime in Australia, as well as the largest known marsupial known from anywhere in the world, and a relative of the wombat), the skull of Euryzygoma dunense, another extinct, megafaunal, eight foot long, quadrupedal herbivorous marsupial, is quite interesting: it has two extended cheekbones.  This gives Euryzygoma the unusual mammalian property of its skull being wider than it is long.  Although to most this probably doesn’t actually seem all that exciting, the extended cheekbones have led to two interesting theories regarding their function in the living animal.  One we will look at in a few weeks (the week of August 3rd to be more precise), but the other one we will look at now.

The hypothesis came about when the skull of Euryzygoma was first described.  The scientists who first described Euryzygoma thought that the lateral extensions of the zygomatic arch resembled those seen in squirrels, gophers and various types of Old World Monkeys, like the macaque and the baboon. 

 In the living animals just described, these lateral extensions function as cheek pouches, which make it so that the animals that possess them can store food in them.  That is why you so often see a squirrel running around with its cheeks puffed out.   

Some scientists think that Euryzygoma might have used its cheek pouches to store water; thus, it would not need to spend so much time near waterholes that were most likely infested with large crocodiles.  This would also help Euryzygoma travel longer distances during a drought, enabling it to move greater distances to reach waterholes that other animals would simply unable to reach, having a much more limited range.