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Tyrannosaurus rex with scales

Tyrannosaurus full body with scales

Behold my masterpiece.

This is the fifth T. rex drawing that I’ve posted to this blog, and it is the hardest drawing that I have ever had to make. Every individual scale was done by hand, one by one. This drawing took me months to finish. To give you a better idea about the utterly insane amount of detail, the actual drawing of the dinosaur itself from the tip of its nose to the tip of its tail measures precisely 24 inches. Most of the drawn scales measure at only one millimeter in diameter.

As you can see, it is done in the same pose as my previous two full-body T. rex drawings, but I made some noteable improvements:

  1. Slightly changing the shape of the skull – my original one looked a little too much like Tarbosaurus rather than Tyrannosaurus.
  2. Not making the face as shrink-wrapped as the original head drawing was.
  3. Making the neck more detailed and fuller.
  4. Changing the position of the hands to be more anatomically correct.
  5. Making its body fatter – the original was too skinny.
  6. Making the tail thicker and fatter to properly counter-balance the now-heavier front half of the body.
  7. Changing the shape of the feet.

This drawing was made on several sheets of 8.5 x 11 printer paper, with just an ordinary No. 2 pencil…and a whole lot of patience.

Chasmosaurus

Chasmosaurus

Chasmosaurus was a common genus of ceratopsian dinosaur found in North America, especially Alberta, Canada circa 75 MYA. This creature is so recognizable due to its rectangle-shaped frill that it has given its name to a whole slew of other ceratopsians that are related to it – the “chasmosaurine” ceratopsians.

Made with regular No. 2 pencil on plain white printing paper. The actual drawing of the creature from the tip of the beak to the tip of the tail measures just a smidge over seven inches. Scanned at 600DPI to show as much of the detail as possible.

Keep your pencils sharp, everybody.

Anzu

Anzu

Anzu was a caenagnathid from the Hell Creek Formation. I wrote of its discovery and naming in an earlier post that you can read here. The caenagnathids were a primitive group of oviraptorosaurs, the “egg thief” dinosaurs. Anzu is so far the largest species from this group found in North America, measuring 10-13 feet long from nose-tip to tail-tip, and it was also one of the last of its kind.

In terms of this picture, the chicken-like wattles are purely conjecture on my part, as are the types of feathers and color patterns.

Lonchidion, a prehistoric shark

Lonchidion

This is a drawing of Lonchidion, a hybodont shark from the Mesozoic Era. There were at least eleven different species, one of which was found in the Hell Creek Formation. I won’t get into all of the particulars regarding this genus or the Hell Creek species in particular (L. selachos). Their size depended upon the species, some being very small. Lonchidion selachos may have been three feet long, judging by the size of its dorsal spines. The drawing is based upon the preserved remains of other hybodont sharks, because specimens from the Hell Creek Formation consist mostly of teeth, well-preserved specimens of any Lonchidion species are very rare, and as far as I am aware, they looked more or less like other well-known hybodonts.

Hybodont sharks are identified by their large dorsal fin spines as well as the four large spines atop their heads, which are really overly-enlarged denticle scales found all over the rest of the body. Hybodonts first appeared during the Carboniferous Period, but it was during the Jurassic that they came into their own. However, by the Cretaceous Period, they were being replaced by so-called “modern” sharks very similar to the ones we see today. Lonchidion was one of the last surviving members of its kind before the whole hybodont group (the few species that remained, anyway) was completely wiped out at the end of the Mesozoic Era 65 million years ago.

News: “Egg thief” dinosaur from Hell Creek FINALLY named!

All I can say is “It’s about time!!!”

After sitting around for years without an official description, a bird-like dinosaur found in the Hell Creek Formation has finally been given a name. I’m very happy about that. What I’m not happy about is the name that was actually chosen – Anzu wyliei, a name that I REALLY don’t find appealing.

Last year, I read that a bird-like dinosaur more commonly found in the Gobi Desert was discovered in North America. Furthurmore, I found out that it was actually on display in Pittsburgh, and had been for several years – it shows just how horribly behind the times I am. However, I was aghast when I learned that this creature didn’t even have a name. I asked “What the hell’s been taking them (meaning the scientists) so long?” Well now the wait is over.

Anzu (I’m actually shuddering as I’m writing the name – I just loathe the way that it sounds) was a member of a family of dinosaurs called Caenagnathidae. The caenagnathids were a sub-group within a super-family of theropods known as the oviraptorosaurs, or “egg thief lizards”. These very bird-like dinosaurs are well-known from Asia, especially China and Mongolia, but they are almost unheard of anywhere else. Oviraptorosaurs ranged in size from five to twenty-five feet long, and might have evolved from the ornithomimids, the “bird mimics”, commonly known as “ostrich mimics” due to their ostrich-like appearance. The most famous of them was Oviraptor, “egg thief” found in Mongolia by the adventurous Roy Chapman Andrews. The name came from the discovery of a partial skeleton lying on top of a nest of eggs. Chapman and his colleagues thought that the animal was in the process of plundering the nest when it was killed. It wasn’t until later when the insides of the eggs were carefully examined that paleontologists discovered that the preserved embryos were that of other oviraptorosaurs. This animal wasn’t preying upon the eggs – it was the mother.

The caenagnathids have had a confusing history, dating back to the early 20th Century. In the early 1920s, the famous paleontologist Charles W. Gilmore was fossil hunting in Alberta, Canada, when he found the remains of a new and strange creature known only from a pair of incomplete hands. In 1924, he gave them the name Chirostenotes pergracilis. Another dinosaur was named based upon an incomplete foot, and it was called Macrophalangia. By the late 1970s, scientists realized that these two animals were the same, and Chirostenotes became the official name.

But what sort of creature was Chirostenotes? It was clearly a theropod – a bipedal meat-eater – but the bone structure was unlike any other theropod known. In fact, it looked very bird-like. It was believed that Chirostenotes was most similar to another mysterious dinosaur called Elmisaurus, which came from Mongolia during the late Cretaceous Period.

For a long time, Chirostenotes was the only North American oviraptorosaur, specifically a caenagnathid. It was found in rocks dated to the Campanian Stage (80-70 MYA) of the Cretaceous Period. Then, in the 1960s, another oviraptorosaur – and a very early primitive one at that – was found, named Microvenator, “the little hunter”. It lived in Montana approximately 100 million years ago alongside Deinonychus and Tenontosaurus. This showed that oviraptorosaurs were present in North America for much longer than previously suspected.

It had been believed for a while that Chirostenotes and its kind had become extinct a millions of years before the dinosaurs’ exinction. However, in the 1990s, fossils of an animal which might have been an oviraptorosaur were found in Montana in rocks that dated to the very end of the Cretaceous Period – the famous Hell Creek Formation, the home of Tyrannosaurus rex. No oviraptorosaur fossils had ever been found there before. In 1994, Canadian paleontologist Phil Currie, an expert on theropod dinosaurs, published a paper on a fragment of a lower jaw found at the “Sue” site. Based upon it’s shape, it was obviously an oviraptorosaur, specifically a member of the family Caenagnathidae. However, this specimen was significantly larger than any previously-known specimens. It could have been a larger specimen of Chirostenotes, or it might have been a new species.

The problem was that Chirostenotes was known only from a few fragmentary finds – a complete or nearly-complete skeleton had never been found. Then, a pair of incomplete skeletons were found in Hell Creek, and were described in 1995. Ever since then, they have been housed in the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania. The staff at the Carnegie Museum even took these two skeletons, composited them together, and put the creature on display for the public! However, the creature still did not have a definitive identification. Paleontologists were uncertain as to whether “the Triebold specimens”, as they were called, were Chirostenotes or maybe another larger species.

In 2011, Matt Lamanna and other scientists announced that they were studying the Hell Creek oviraptorosaur in more detail. Based upon a preliminary view, they stated that it was very similar to Chirostenotes, but they shied away from going so far as to claim that it was a distinct species.

In 2013, a team from the Burpee Museum (the same museum famous for “Jane”, which might be either a Nanotyrannus or a juvenile T. rex, depending on who you ask) discovered the partial skeleton of a caenagnathid oviraptorosaur near the small town of Ekalaka, Montana. The bones were so large that they originally thought that they had found a T. rex; Professor Thomas Holtz of Maryland rushed to the site and confirmed the animal’s identity. This specimen was even larger than the Triebold specimens in the Carnegie Museum. It was affectionately nicknamed “Pearl”.

In 2014, Matt Lamanna and three other colleagues published a paper on the Triebold specimens collected from North and South Dakota. After an exhaustive analysis of the bones, they concluded that the Triebold specimens were not Chirostenotes or Caenagnathus, but constituted an entirely separate genus. They called it Anzu wyliei. According to Lamanna’s own report, the dinosaur was named after Anzu, a feathered bird-like demon from Mesopotamian mythology, and measured somewhere between ten to fifteen feet long.

What the heck does a Mesopotamian demon, feathered or otherwise, have to do with a North American dinosaur? I can understand if the fossils were found in Iraq, but they weren’t. I would actually be highly surprised if ANY dinosaur fossils were uncovered in Iraq. It would be a lot more fitting if it was given a traditional Greco-Latin name, something like Dakotaraptor, or maybe even named after a being from native Sioux Indian folklore, like Wakinyanoraptor (“Wakinyan” is the Sioux name for the thunderbird sky spirit).

But then again, what the heck does the white-skinned feathered serpent god from central Mexico have to do with an unusually large pterosaur from Texas, which neither looked anything remotely like a serpent, nor had feathers, nor came from Mexico? I’m talking about Quetzalcoatlus, for those of you who haven’t caught on. So I suppose I shouldn’t be too harsh. Still, Anzu … it just sounds SOOOOO wrong. Unfortunately, we’re all stuck with it.

The specimen uncovered by the team from the Burpee Museum is also likely a specimen of Anzu.

News: “Nanook of the North”? New tyrannosaur species from Alaska

Paleontologists have recently announced the discovery and naming of a new tyrannosaur species from Alaska. They have called it Nanuqsaurus hoglundi.

The discovery was made by a team of paleontologists working for the Perot Museum of Nature and Science, located in Dallas, Texas; the team was led by Prof. Anthony R. Fiorillo. The fossils were found at the Prince Creek Formation in Alaska in 2006 when the team was hunting for ceratopsians (that’s “horned-faced” dinos, like Triceratops and Styracosaurus). They consist of the front portion of the lower jaw (the bone is called the “dentary” because that’s the bone in the lower jaw that has the teeth in it) and two small pieces of the upper jaw. The pieces were collected, and then gathered dust for a while until Prof. Fiorillo and his associate Dr. Ronald Tykoski re-examined them.

Admitedly, it’s not that much to go on, but apparently, it was enough to create not only a new species, but a new genus. That doesn’t surprise me at all, as paleontologists are well known to be afflicted with what I call “neogenitis” – “the new genus disease”. They just can’t resist making up new names for things. The name Nanuqsaurus derives from the Inupiak word nanuq, meaning “polar bear”, and the ancient Greek word sauros, “lizard”. The species name is in honor of the philanthropist Forrest Hoglund.

The fossils date to 70 million years ago. It appears to be closely related to both Tyrannosaurus rex and a close relative called Tarbosaurus bataar which lived in Mongolia (some paleontologists consider Tarbosaurus bataar merely to be an Asian species of Tyrannosaurus – personally, I don’t buy it for a few reasons, but I won’t get into them here). Based upon the size of the remains, limited though they may be, Nanuqsaurus may have been only half the size of T. rex.

Professor Fiorillo suspects that the animal’s small size might be a reference to a limited food supply up in the Great un-White North of the late Cretaceous. Although only three small pieces were recovered, it is strongly plausible that a northern tyrannosaur like Nanuqsaurus would be covered in an insulating layer of feathery fuzz.

News: Some prehistoric marine reptiles may have been dark in color

Hot off the presses! Scientists have an idea about what color Mesozoic marine reptiles, which are sometimes Romantically referred to as “sea dragons”, were in life. Apparently, some of them were dark or even black in color.

The findings were published in an article in the scientific journal Nature.  A group of paleontologists led by Prof. Johan Lindgren analyzed the well-preserved remains of an ichthyosaur from the early Jurassic (193 MYA), a late Cretaceous mosasaur (85 MYA) and a leatherback turtle from the Tertiary Period (55 MYA). Fossil skin and other soft tissues is extremely rare because they usually decompose before fossilization can take place. Fossils that are so well preserved that you can actually see pigmentation cells under a microscope are almost unheard of; only a handful of other examples have been uncovered within the past ten or so years.

The pigmentation cells in question here are called “melanosomes”. For those of you who have a vague knowledge of ancient Greek, you’ll know that anything that has “mela” in it means that it’s black – skin cancer is called menaloma due to the dark patches it forms, unusually dark colored animals are called menanistic, and other examples. So, melanosomes are pigmentation cells that are black or very very dark in coloration.

For a marine reptile, being black all over would be a big benefit. It is commonly taught in elementary schools that black absorbs heat. Reptiles are cold-blooded, and staying warm is a constant concern, especially when they spend a considerable portion of their time in the water. As examples, the modern-day American Alligator and the Marine Iguana of the Galapagos Islands are both colored very dark. Being colored black would help them absorb heat more quickly than if they were colored light. Even most whales and dolphins, which are technically warm-blooded, are colored black in order to absorb heat, due to the often frigid conditions of the water that they dwell in.

The modern-day Leatherback Turtle is black on top, whith a little bit of white speckling and stripes along the top of its shell ridges. Therefore, it isn’t surprising that its early Cenozoic ancestor would be dark-colored as well.

Mosasaurs were enormous aquatic lizards which could reach over 50 feet long. Their closest surviving relatives are monitor lizards, like the Komodo Dragon. This isn’t the first time that mosasaurs have been in the news. Not so long ago, it was revealed that they may have suffered from “the bends”.

Lindgren and his colleagues propose that the ichthyosaur may have been colored completely dark all over, rather than being dark on top and light on the bottom (this is called “counter-shading”).

Note: This does NOT mean that ALL ichtyosaurs and mosasaurs were colored in this fashion. It merely means that membes of these particular species were colored this way.

Well, the new year certainly has gone off with a bang. I can’t wait to see what the other eleven and a half months will bring.

Triceratops

Triceratops

Triceratops was the last and largest of the ceratopsians, the “horn-faced” dinosaurs – other familiar members of this group include Chasmosaurus, Styracosaurus, and Protoceratops. Triceratops existed from about 70-65.5 MYA, and measured 30 feet long. There are currently two confirmed species: T. horridus and T. prorsus; the first one is the more famous and numerous of the two. They can be distiguished by their short nasal horns. Triceratops horridus has a short fat nasal horn, positioned a considerable way up the snout, and sticks more or less straight up, perpendicular to the line of the skull. Triceratops prorsus has a somewhat longer and thinner nasal horn, it is positioned more to the front of the nose, and it is angled forward.

There’s also been a dispute raging over the past few years as to whether or not another ceratopsian species named Torosaurus is actually another older age stage of Triceratops. This is really complicated, so I won’t even bother to get involved in this academic brawl. All I can say is that this subject appears to be just as hotly and intensely debated as the whole dispute regarding T. rex as a predator or scavenger.

The drawing which you see here is Triceratops horridus. One thing that you’ll notice is how large the head is in proportion with the rest of its body. This is not artistic license – the head really was that big! The second thing that you’ll notice is the lack of detail on the skull, showing instead a scarred but still mostly smooth surface. Paleontologists including Jack Horner and Peter Larson suspect that the top of Triceratops’ skull, including its distinctive neck frill, was covered in a layer of keratin, the same stuff that your fingernails are made of. This horny / keratinous covering might have been colored dark, as horn tends to be, or it might have been bright red due to the numerous blood vessels which are imbedded into the frill’s structure. Perhaps the males were brightly and vividly-colored, while the females were more drab and subdued.

Triceratops, regardless of which particular species, was a very populous animal. In the Hell Creek Formation, 60% of the dinosaur fossils found there belong to Triceratops.

I started drawing this picture months ago, but I got stalled with my classes and with the publication process of my book, and so I had to stick it on the shelf. These past few days, I’ve tackled it hard and completed it. I used my preferred medium, regular No.2 pencil.

Goodbye, and I hope that all of you had a good holiday.

Acheroraptor: A new “raptor” dinosaur from the Hell Creek Formation

A few days ago, scientists announced the discovery of a new species of dinosaur – Acheroraptor, “thief from Acheron”. I’m sorry to disappoint all of you Aliens fans, but no, this dinosaur is NOT named after Planet LV-426, code-named “Acheron”. The name actually refers to the Acheron River in ancient Greek mythology, “the River of Pain”. This name is an obvious pun on the name of the place where the fossils were discovered – the Hell Creek Formation in Montana.

Not much is known about this animal, but here are a few statistics. As you can probabaly guess, Acheroraptor is one of the “raptor” dinosaurs made famous by Jurassic Park. Raptors are divided up into two main groups: the dromaeosaurids and the troodontids. Acheroraptor was a dromaeosaurid, and this brings up another issue…

In an earlier post, I talked about Dromaeosaurus, a dromaeosaurid raptor from western North America. I had stated that its teeth had been found in several different locations, including the Hell Creek Formation. Well, that was perfectly true when I wrote it, but not anymore. For the past few decades, paleontologists had been finding raptor teeth in the HCF, and since they looked similar to the teeth of Dromaeosaurus, these teeth were ascribed to that genus. However, Dromaeosaurus was only known from Canada, and its fossils were found in rocks that were dated much older than the Hell Creek Formation – ten million years older, to be exact. But few other raptor dinosaurs were known from late Cretaceous western North America, and the teeth did look more or less similar to the teeth of Dromaeosaurus, and so that was the identification that was given. Now, paleontologists have discovered that all this time they were perpetuating a case of mistaken identity. It actually happens quite often in this particular science. It appears that the teeth which had been found in the HCF for decades actually belonged to this new species, not Dromaeosaurus.

Acheroraptor’s fossils were found in rocks dated to the extreme end of the Cretaceous Period, 65.5 million years ago, right when the dinosaurs became extinct. It therefore appears that Acheroraptor is the earliest-known raptor, geologically-speaking, being around right up the the point when the asteroid hit.

There are few fossils to go on, consisting of a partial maxilla, a partial dentary, and numerous isolated teeth. Based upon shape and size, paleontologists have determined that Acherorapror was a dromaeosaurid, rather closely related to Velociraptor, and have hypothesized that it may have reached ten feet long. Perhaps in the near future, more fossils will be uncovered which will give us a more complete picture of this animal.

And speaking of pictures, here’s my picture of Acheroraptor! – good segway, right? I further improved the wings from my old Troodon and Ornithomimus drawings, and I made the subject a little more three-dimensional. Rather than standing perfectly sideways, it’s positioned on an angle.

I drew the first sketch when I was giving my English students their final exam on Wednesday December 18, and then I polished off the final product when I got home. I had originally intended it to be a full scene with the dinosaur walking along a forest pathway, but I wanted to get a drawing posted right away, and I just didn’t have the time to make a full Henderson-esque setting.

UPDATE: The original Acheroraptor drawing has been removed, because it was too inaccurate.

The striking black-white color scheme is based upon the coloration of the Northern Goshawk. If this drawing was in color, I would have given my creature transparent glassy red eyes. Making this drawing was a real pleasure, and I’m surprised that doing it didn’t take as long as I had expected – only five days. Keep your pencils sharp!

Ornithomimus

Ornithomimus (“bird mimic”) is a dinosaur genus belonging to a group commonly known as the “ostrich dinosaurs” or “ostrich mimics”. This name comes from their very ostrich-like appearance, with toothless beaks, long swan-like S-shaped necks, and powerful muscular legs. There are currently two known species of Ornithomimus: O. velox and O. edmontonicus. This genus lived in western North America at the end of the Cretaceous Period, 75-65.5 MYA.

It was most likely omnivorous, and you can tell that by the size of its belly. Plant-eating animals need large guts to process their food, in contrast to carnivorous animals. If you look at specimens of Ornithomimus, or indeed any ornithomimid dinosaur, particularly ones which preserve the gastralia (belly ribs), you will see that they outline the stomach area. In contrast to the somewhat starved bodies portrayed by many paleo-artists following in Gregory Paul’s footsteps, they clearly show a wide belly. Look here to see an example: http://en.wikipedia.org/wiki/File:Ornithomimus_edmontonicus.jpg

People had suspected for a while that Ornithomimus and its kind had feathers. There were two reasons for this. Firstly, there was its obvious bird-like appearance. Anything which looked THAT bird-like just HAD to have feathers! Well, it’s an interesting point in terms of comparative anatomy, but there was really no hard evience to support it, and no real credible analysis of various dinosaur types and their relations to birds which suggested that ornithomimids had feathers. The second reason answered that last point. With advances in phylogeny (determining where different species fit into the scheme of life and how they are related to each other), paleontologists have determined that the ornithomimids belong to a large group of very bird-like dinosaurs called the maniraptorans. This group included the ornithomimids, therizinosaurs, oviraptors, and the “real” raptors – the Jurassic Park-style raptors, specifically the dromaeosaurids and the troodontids. Maniraptorans are the closest ancestors of birds, and many of them are known to have been feathered. This would imply that the ornithomids were feathered as well. This argument was a bit more convincing than the “it looks like a bird so it must have feathers” argument which was around during the 80s and 90s. However, although it made a good point, there was still no physical evidence to back it up. If ornithomimids were feathered, why hadn’t any feather fossils been found in association with their skeletons?

In the early 2000s, that changed. When three specimens were examined more closely, scientists discovered that two of them possessed “quill knobs” (the places where feathers attach onto the bones) on the arms, and a third specimen – a juvenile – actually had feather impressions along its neck, back, and legs. In 2012, a report was published in the academic journal Science demonstrating that at least one ornithomimid species, Ornithomimus edmontonicus, was covered in feathers throughout its life, and that the adults actually had modern pennaceous feathers on their arms forming flightless wings. Click here to see a preview of this article: http://www.sciencemag.org/content/338/6106/510.

Ornithomimus

This is a drawing of Ornithomimus based upon the findings in that report. As you can see, the arms sport fully-developed albeit flightless feathered wings. Also take note that the feathers do not cover the whole body all around, but only the top and sides – the underside is bare. The color is my own aesthetic guesswork. I decided to make the throat bright red, which (I like to imagine) was used as a courtship display similar to modern reptiles and birds.

Take care, everyone.