ornithodire art references

Matt Martyniuk (author of the highly recommended Field Guide to Mesozoic Birds and Other Winged Dinosaurs) explains why it’s time to reconsider how we feather dromaeosaur wings and tails in paleoart.

tl;dr: Most dromies probably had larger wings than they’re usually depicted with, as well as a feather fan extending the whole length of the tail as in Archaeopteryx rather than restricted to the tip as in Microraptor. Saurian’s excellent Dakotaraptor demonstrates for us:

How to Draw Pterosaurs Texturing Animals with Basic Brushes! ✧･ﾟ:* \(◕‿◕✿)/ *:･ﾟ✧

Featuring Pterosaur trivias and irresponsible captions. I just whipped this up quickly in 2h so please yell at me if you find typos.

As per usual, available to download in PDF format for free from my store (although donations welcome too). My brushes are available there too, but I really really encourage you to make your own brushes. Seriously.

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Hi everyone, Jack here! This one’s gonna be a pretty quick and broad summary, because I am short on time, but we can go into more depth in a later instalment if you guys would like. (Also, sorry it’s a day late. I finished it on time but forgot to post the draft.) In the wake of Jurassic World (which I thoroughly enjoyed) hundreds of children (and adults, possibly) have been running around pretending to be Blue, Charlie, Echo, and Delta. The Raptor Squad have In case you didn’t read the title, today we’re going to be learning about the arms of a perfect reptilian death machine, which was about the size of a turkey and covered head-to-toe in wonderful feathers; Velociraptor. We’re going to be looking at what these arms looked like and how they would have been held.  Now, if you’d please do your best impersonation of a Velociraptor. If you’re anything like my younger self, it might look a bit like this:

(I draw DINOSAURS, NOT PEOPLE, OKAY???) Now, this is all very well and good, but the standard “raptor hand” is not quite right. This is because you are doing something no Velociraptor could ever do: pronating your wrists.  Pronation is where the radius twists over the ulna, allowing the palm of the hand to face toward the floor. You can do it very easily. Velociraptors, however, like all Theropod Dinosaurs, were incapable of doing this. Their palms would have faced inwards, as if they were about to do a karate chop. Below I’ve drawn a Velociraptor arm with the skeletal elements superimposed. I’ve also colour coded them just for you!

See that the back of the hand faces outward, and the palms would have faced eachother.  You might also notice that my Velociraptor has something more akin to a wing than an arm. This is because many Theropods would have had feathers. Velociraptor is very closely related to living birds, and that fact combined with physical evidence of quill knobs (where long, pennaceous feathers attach. This feature is found in birds, too) on Velociraptor’s ulna, as well as actual preserved feathers in many of Velociraptor’s relatives, would lead us to believe that not only did Velociraptor have feathers, but that these feathers would have been varied and complicated. 

Here I’ve done a side-by-side comparison of what the arm of Velociraptor may have looked like and a “Velociraptor” arm one might see in a film or a cartoon or five-year-old me’s sketchbook.  Not only is the one on the left more accurate, it also looks better. Almost as if it might have belonged to a real animal that actually existed on planet Earth. Astonishing! Anyway, let’s go into a bit more detail on those feathers.

Here’s a diagram, colour coded because I’m handy like that, showing a likely arrangement of the feathers on Velociraptor’s arm. The feathers would, like in modern birds, overlap in a complicated manner in order to prevent their being damaged when the arm was moved.The secondariy coverts always fold over the primary coverts, and the secondary remiges (remiges are the large feathers forming the edge of the wing) always fold over the primary remiges , although the primary coverts fold over the secondary remiges. I’d recommend using diagrams as reference until you think you have a pretty good grasp of the layout (I know I certainly dont!). And finally, this brings us to colour (warning; lots and lots of nerdy text.) In previous Art Corners I’ve stated that in protofeathers, quills, pycnofibres, and other integumentary structures, bright colours like blues and greens are unlikely, as the pigment that expresses those colours probably didn’t occur in many of those structures. This would mean that browns, blacks, whites, rusts, and other earthy colours are most likely in many feathered Dinosaurs, Velociraptor included.  “But some birds are blue and green!” you interject from somewhere in the back row. And you have a valid point. Although Bird feathers lack blue and green pigments (with the exception of parrots and turacos, which have blue and green pigments) they sometimes have something called “structural colour”. This means that they have microscopic structures on the surface of the feathers that are iridescent. These iridescent blues and greens are great for socio-sexual displays, and can be seen in many living birds.  “But some birds are bright pink! Or vibrant yellow!” you shout, more confidently this time, from the back. And you’re right again. Many birds sequester pigments called carotenoids from photosynthetic organisms like plants and fungi or from some sea creatures, which do not produce carotenoids, but also sequester them from photosynthetic organisms, and can express these pigments in their plumage. Carotenoids are responsible for bright pinks, reds, yellows, and oranges. Now, it is possible that Velociraptor could have expressed colours in its plumage through either of these methods. However, Velociraptor was a predator living in a desert, so the only purposes for bright colour would have been display, and bright colours would likely prove disadvantageous to Velociraptor, so despite the possibility that Velociraptor could have had bright, exciting colours, I will chose to use drabber, brown-ish colours when adding colour to the wing.

Hi, Jack here, and today we’re going to be going over “Prosauropods” or, more correctly, basal sauropodomorphs. It’s been a while since our last Art Corner post. Partly this has been due to exams, but I can’t pretend my poor time management skills aren’t partly to blame either. Anyway, let’s get on with it! Now, basal sauropodomorphs were a rather diverse group in terms of size, and were hangin’ about from about the mid-to-late Triassic right up to the the early Jurassic when “true” Sauropods (belonging to the group Sauropoda) began to emerge. I’m going to try to cover what I can in one post, but this won’t be a complete guide to basal sauropodomorphs (I’m going to call them “Prosauropods” from now on because it’s easier and catchier).  So, let’s begin! Right, so for practical purposes, we’re going to split the Prosauropods into two groups: Early Prosauropods and Late Prosauropods. This is not a legitimate taxonomic distinction, but it is useful for getting a grasp on the shapes involved.  Early Prosauropods, like Thecodontosaurus and Pantydraco (haha! Isn’t Welsh funny? It actually means “Dragon of  Pant-y-ffynnon”) were small-ish bipedal animals, and probably lived an omnivorous lifestyle, eating plants and small animals. They had long, slender bodies, long legs, and large tails. Below I’ve sketched a Thecodontosaurus, with basic anatomy and joints in blue, and a body outline in red. I’ve not shown integumentary structures, but well get to that later.

Many basal sauropodomorphs share a similar body plan. In earlier species, the head was relatively large, and the neck was not too long. In later Prosauropods, the head became smaller, the neck longer, and the body larger. You’re going to want references when blocking out the shape of your Prosauropod. Skeletal references. One excellent source of reference is Scott Hartman, who does splendid, up to date skeletal reonstructions. Hartman’s reconstructions can be found on his website skeletaldrawing.com, and are a brilliant resource to get an idea of the proportions of the animal you want to draw. Jaimie Headden also does fantastic skeletal reconstructions, many of which can be found at his website qilong.wordpress.com. I actually used Headden’s Thecodontosaurus skeletal as reference for the above sketch. Before we get any further, I will warn you: many Prosauropods are very poorly known, and skeletal reconstructions of some Prosauropods may not exist at all. In this circumstance, it is wise to base your reconstruction on better known relatives. The closer the relative, the better. If there are pictures of the fossils, I would advise looking at those, too, as sometimes the bones we do have can show traits that really set one Prosauropod apart from the rest. The skulls of Prosauropods can be varied in size and shape, but most are fairly long and rectangular. Some may taper a little towards the end of the snout. I’ve sketched a few skulls and also drawn the skin on top to show how they may have looked in life. 

You can see that the teeth are blunt and peg-like, and covered with lips. The current thinking is that many Dinosaurs would have had lips. You can also see that I have shown both Plateosaurus and Thecodontosaurus with fuzzy, fur like protofeathers covering much of the head. It is likely that these early Dinosaurs would have had some kind of filamentous covering. In Prosauropods, the hands also tend to follow a pattern. There are five digits. Digits I, II, and III are clawed, with digit I having a large, curved claw, while the vestigial digits IV and V are not clawed, and are barely visible.

You can see the hand from several angles here. Underlying skeletal anatomy is in blue, and the first two diagrams also show a coating of fuzzy feathers. Prosauropods could not pronate their wrists, meaning that their palms would have faced oneanother instead of facing backwards. I’ve drawn the arms of a standard Prosauropod from a side view both correctly and incorrectly to illustrate this.

And, while it’s easy to stick to this with bipedal Prosauropods, it’s not so easy with quadrupedal ones. Only a few Prosauropods were quadrupedal as adults (Riojasaurus and the Prosauropods that were very close to “true” Sauropods) although most would have been quadrupedal as hatchlings. When drawing these Prosauropods, it’s very tempting to draw the front feet like those of a cat, with the fingers facing forward. It’s important to remember that Prosauropods couldn’t pronate, even when walking on all fours. They would have walked on their fingers. Below I’ve drawn the forelimbs of a quadrupedal Prosauropod from the front and the side. Notice how the fingers don’t point forward, but also how the first finger, digit I, is tucked backwards to face inward. The fingers of quadrupedal Prosauropods were also noticeably shorter. I’ve also drawn them with a lot of padding, as is often seen in quadrupedal animals. 

Now, while some Prosauropods were quadrupedal, most weren’t. all they had to walk on were good old back limbs. These back limbs all followed a basic pattern: four exposed toes with a fifth vestigial metatarsal. And, while digits II, III, and IV were weight bearing and clawed, digit I, the hallux, was less crucial to weight bearing and held a large claw. What this claw was used for, we’re not entirely sure of. Below, I’ve drawn both the skeletal elements and the soft tissue of the foot from the front and the side.

Right, so now we’ve covered all that, let’s move onto the flesh – what their skin was like; what their scales were like; what their feathers were like.  Most reconstructions of Prosauropods show them with wrinkly, scaly skin all over. While we don’t have much in the way of skin impressions, we can make assumptions about what these animals looked like. Prosauropods belong to Dinosauria. Currently, the most likely theory is that filamentous integument is a basal characteristic of Dinosauria. That’s a fancy way of saying “Dinosaurs evolved from fuzzy ancestors”. What this means is that, while many Dinosaur lineages later lost this characteristic, many kept it. And, as sauropodomorpha is one of the oldest dinosaur lineages, Prosauropods may have had feathers. well, I say feathers, but these structures weren’t much like a bird’s feathers. They lacked barbs, and were more like quills or hairs. Smaller Prosauropods, which probably maintained their own body temperature, unlike lizards, amphibians, and crocodilians, probably would have benefited from these hair like structures to help keep them warm. This “fuzz” could have covered most of the body – perhaps even the hands and parts of the feet. Here I’ve sketched both a scaly texture and a fuzzy one, as well as showing a close up of the fuzzy structures.

It is worth noting that whilst the animal could have entirely fuzzy, it could also have had areas which were covered in scales or were just bare skin. The feet, for example, may have been scaly. However, they would not have had podotheca, which are the large scales you would see on a bird’s foot, as these had not evolved yet. And finally, how do we colour such fantastic beasts? Well, for scales and skin, any range of colours is possible – you can have blues, greens, blacks, whites, reds, purples, pinks, whatever – although it’s likely that drabber colours might be more common in many species, purely because bright colours aren’t just advertising to potential mates, they’re a big, brightly lit billboard attracting predators (though that’s not to say bright colours would certainly not be seen). As for the fuzz, well, we can be fairly certain that only some colours could be shown there, as, unlike today’s birds, Prosauropod fuzz lacked the structures needed to show blues and greens. They were limited to melanin-based colours. Black, white, yellow, red, orange, brown, and other earthy colours were most likely. Using all of the above information, I have reconstructed the obscure Indian Prosauropod Jaklapallisaurus. Because it’s poorly known, I based it on another member of the group (or “clade”), Plateosauridae, that it belongs: Plateosaurus. to I’ve shown scaly skin on the feet and snout, smooth skin (with a few hair-like quills) on the neck, and a fuzzy covering for the rest of the body, and I’ve coloured it in accordance to what colours we know were possible.

(source: http://www.newscientist.com/article/dn16636-birdlike-lungs-powered-giant-pterosaur-flight.html#.VUPXB_lVhBc)   Hi guys, Jack here with another instalment from the art corner, but before we start, I have an important note:  DO NOT use the work of David Peters as a basis for your palaeoillustration. Don’t get me wrong, he’s a great guy and a phenomenal artist, but his work is unsupported by pretty much every other study done on Pterosaurs, and is so far removed from scientific consensus that he may as well be talking about flying pancake monsters. Do not be fooled by his lovely illustrations and professional graphic design skills. Anything from his websites The Pterosaur Heresies  and Reptile Evolution is to be disregarded if you are looking to produce scientifically accurate Pterosaurs. Sorry David, but your methods are questionable and your conclusions are absurd. That being said, do not send David Peters hate mail. Do not hate on David Peters. If you want to read more about Peters’ work and why not to trust it, Darren Naish of Tetzoo fame explains here. Anyway, now that that’s out of the way, let’s draw some Pterosaur wings! As you may know, the word ‘Pterosaur’ means ‘Winged Reptile’. This is because they are reptiles, and have wings. Pterosaur wings are remarkable – highly sensitive membranes attached to an elongated fourth finger, with surprising durability (though often depicted as frail and primitive) and, in later Pterosaur species, incredible aerodynamic properties that rival and even out-class the wings of bats and birds.  If you’ve seen the previous Art Corner instalments, you’ll know that we always start from the bottom and work our way up, explaining the anatomy and purpose of our subject. Today is no different; let’s start with a skeleton! Unfortunately, the ever lovely Scott Hartman specialises in Dinosaurs, and Pterosaurs are not Dinosaurs, thus Pteranodon and Rhamphorhynchus  are the only Pterosaurs featured on his excellent website. However, there are Pterosaur skeletals out there (many of them, sadly, are Peters’) including the work of artist and Pterosaur-guru Mark Witton, whose artwork is not only beautiful, but also accurate. There also some great images of mounted Pterosaur skeletons. Using an image by the wonderful Witton as reference, I’ve sketched the shoulder and arm of two types of Pterosaur.

This diagram show both a pterodactyloid Pterosaur wing (top) and a non-pterodactyloid Pterosaur wing (bottom). I have colour coded them because I am captain helpful. Now, you may have several questions. “What it a pterodactyloid and why does it matter?” you may say. Well, that’s a good question. Pterodactyloidea was the clade of Pterosaurs with short tails and long metacarpus (that’s that long bone after the carpals and, by definition, part of the wrist. At the end of the metacarpus you can see three tiny fingers. These were mainly for walking on, though in smaller Pterosaurs they may also have served as tools to grip trees or rock faces.) Pterodactyloidea was highly diverse – some were tiny, crow-sized insect hunters, whilst others grew to the size of giraffes. When I say ‘non-pterodactyloids’ I am generalising, as there are multiple non-pterodactyloid clades within Pterosauria.  You may also ask “what is the long bit?” Well, that is a finger. One singular, stiffened finger. This finger supported the main wing membrane, and, although it was stiff, the joint at the first knuckle was slightly flexible, and the finger could be folded upwards when the Pterosaur was walking. Now, another thing you may ask is “What’s a pteroid bone?” – also a good question, and we’re going talk about it in a bit. But first, let’s stick some muscle on this bad boy.

Right, so here we’ve got the arm and shoulder muscles for a generic pterodactyloid Pterosaur (I haven’t done the same for the generic non-pterodactyloid, because the musculature is very similar in most Pterosaurs). You can see the massive shoulder muscles - these would have given Pterosaurs the strength needed for powered flight and also aided them in take off. (It probably looked like this .) Powerful chest muscles were anchored to the sternum and the underside of the arm. They also aided in flapping and take off. You can also see the powerful muscles which controlled the forearm, metacarpus and wing finger. Pterosaurs are often depicted as being skinny, lizard-like gliders with lazy lifestyles. This could not be further from the truth, as Pterosaurs were active and powerful fliers. They were also warm blooded, which brings us onto the skin, which was covered in fur-like structures known as Pycnofibres. These structures kept the Pterosaur warm. They covered most of the body, but not the wing membranes.

Here I have illustrated the wing of a Pterosaur as it would likely have appeared in life. The most prominent feature was the main wing membrane stretching from the fourth finger to the leg. This is known as the brachiopatagium. You can also see the uropatagium, the membrane in between the leg and the base of the tail. In earlier Pterosaurs this membrane was larger, and stretched further up the tail. A good example would be Dimorphodon, from the early Jurassic period. 

A Dinosaur Enthusiast™ told me this little mnemonic at ECCC this year and I’ve been trying to figure out a way to use it ever since then! I’ve seen a bunch of dino art because of Jurassic World (yay!) and although most people know that Jurassic Park dinos are naked and should have feathers, their poor broken wrists are often looked over. Remember, raptors (and other theropods) were clappers, not tappers!

The discovery of a bat-like dinosaur (well, more like a flying squirrel mimic) was just too exciting, so in this Sketchy Thursday this is what you get: Yi qi studies.

Had a lot of fun with the patagium, experimenting and see how many configurations were possible: ribcage, hip, tail, normal legs, fully feathered legs and so on. Two different positions were used for the styliform, both of which suggested by the actual fossil. I know that probably scansoriopterygids didn’t stick out their hindlimbs like bats and pterosaurs, but I’m just very curious to see how it would look like. We’ll see what future findings will tell us.

Second part of my Yi Qi variation series.

Since there is no strict consensus about how the wing structure might have looked like, I wanted to show the different models showed in the original paper as well as in other parts of the internet.

EDIT: Now with descriptions and credits ! By intellectual honesty, I decided to credit Smnt2000 as inspiration since he drew a similar concept. And while I had the idea practically at the same time, I wasn’t the first to finish it. Hence the credit to avoid any claim of plagiarism.