17 February 2016

It Came From Dinovember II: Return of the Dinosaur Drawings

Well, so much for getting a lot of posts in! Dinovember wrapped up well over two months ago, and over a month has passed since I began my review of what I produced for it, but... well, better late than never, right?

Kileskus aristotocus was tyrannosauroiding before T. rex made it cool.
[by the author]

Day 11: Kileskus aristotocus - Tyrannosaurus rex is the most famous dinosaur, and it certainly is easy to see why. It's one of the largest and most powerful killing machines ever evolved. However, T. rex was just one member of a lineage of meat-eating dinosaurs that encompassed a wide range of shapes and sizes. One of the oldest members of this lineage (called the Tyrannosauroidea) was a Russian dinosaur called Kileskus. It wasn't very big - probably only around 3 m (10 ft) long - and it lived in the Middle Jurassic, about 100 million years before its giant cousin T. rex. Since Kileskus belongs to the first major radiation of tyrannosauroids, called the proceratosaurids, it probably had a large, thin crest of bone atop its head, useful for showing off. Few tyrannosauroids are known to preserve good skin impressions, but some of the best ones clearly show these animals were covered by feathers, so Kileskus is here decked out in a fluffy coat, like I strongly, strongly suspect all tyrannosauroids (yes, even mighty T. rex) were.

At least when Lophorhothon atopus was around, it didn't have
to contend with hearing 'Sweet Home Alabama' all the damn time.
[by the author]
Day 12: Lophorhothon atopusAs I mentioned back in July, the eastern and western parts of North America used to be divided into two continents by a shallow seaway; the eastern continent, called Appalachia, has regrettably left us with a much poorer dinosaur fossil record than what has been found in western Laramidia. However 'poorer' is not the same as 'none,' and this dinosaur, Lophorhothon, is one of the examples found in the eastern US; specifically, it was the first nonavian dinosaur named from my home state of Alabama.

Exactly what sort of dinosaur Lophorhothon is isn't certain. It's certainly an ornithopod of some sort, a beaked plant-eating dinosaur. It was originally identified as a hadrosaur, or duckbill, but whether it's actually a member of this group or just a close, more primitive relative can't really be said with much confidence until better fossils are described. I imagined it as a relatively primitive hadrosaur, with a long skull featuring the raised nasal ridge that gave it its name, which means 'crested nose'.

Additionally, a new dinosaur from Alabama saw publication a couple of weeks ago, and it's known from fairly good fossils - a hadrosaur called Eotrachodon orientalis. Perhaps it's a relative of Lophorhothon, and they represent a distinctive Appalachian radiation of ornithopods...?

Intraspecific variation in Mamenchisaurus could get a little crazy - 
M. youngi is at the front, M. sinocanadorum towers over it at rear.
[by the author]
Day 13: Mamenchisaurus youngi and Mamenchisaurus sinocanadorum - Most genera of nonavian dinosaurs are represented by only one species, and often by only one specimen. Mamenchisaurus is one of only a handful of nonavian dinosaurs where most scientists recognise several species, and the variation between them could be dramatic, as you can plainly see. The smaller species in the front is called Mamenchisaurus youngi, and though it's one of the smallest of the Mamenchisaurus species, it's certainly not a little animal, measuring about 16 m (52 ft) long.  On the other hand, M. sinocanadorum, the animal at the back, must be one of the biggest creatures to have ever lived, growing about 35 m (115 ft) long and probably outweighing most whales. Mamenchisaurs are famous for their ridiculously long necks. In M. sinocanadorum, the neck could be about 17 m (56 ft) long, or longer than the entire bodies of some of its smaller relatives! I wish we saw more of this animal in dino pop culture, as unlike most of the super-giant dinosaurs, it's actually known from nearly all of its skeleton.

Some like it hot, but Nanuqsaurus hoglundi is not among them.
[by the author]
Day 14: Nanuqsaurus hoglundi - People often envision Earth during the Age of Reptiles as a global jungle. While it's true that overall the world was much warmer during the Mesozoic Era, characterising the whole planet as climatically uniform is just not accurate. Dinosaurs in the polar regions would've experienced long, dark winters that lasted months, and were probably very cold. Granted, not as cold as our modern polar regions, but still chilly enough for snow and ice during the winter.

Nanuqsaurus was a predator that lived on the North Slope of Alaska during the Late Cretaceous, just a few million years before its close relative Tyrannosaurus rex was prowling the warmer forests and floodplains further south. Compared to some of its close kin, Nanuqsaurus was pint-sized, full-grown at barely 6 m (20 ft) long. However, this Arctic dinosaur was probably a hardy predator, able to endure the dark and the cold for months one end. I imagine it was probably decked out in a dense coat of snow-white feathers for this purpose.

Hadrosaurs like Olorotitan arharensis give the
Black and White Guardians a run for their money when
it comes to the sheer outlandishness of their headgear.
[by the author]
Day 15: Olorotitan arharensis - I don't have much to say about the big lambeosaurine (hollow-crested) duckbill dinosaur Olorotitan except that it's a truly magnificent and elegant creature that was a real pleasure to draw, and that its ecosystem in end-Cretaceous Russia seems - so I've heard - to be known from some pretty good fossils that I seriously hope will soon see publication so we can build a better picture of what this place and time was like.

PMO X678 both sounds and looks a bit like a space alien.
[by the author]
Day 16: PMO X678 - Not all dinosaurs have been given proper scientific names. For that to happen, a specimen must be described and published in peer-reviewed scientific literature. For dinosaurs who don't yet have a scientific name, their specimen designations (and often nicknames as well) are used when talking about them. PMO X678 is one such unnamed dinosaur, a strange kind of very birdlike theropod called an oviraptorosaur - a group of toothless, beaked omnivores that appear to have been extremely diverse in Late Cretaceous Asia. Many oviraptorosaurs had large bony crests atop their heads, but PMO X678, with its mitre-like crest, is surely one of the most impressive. Hopefully it will be transferred to a museum (it's currently in private hands, and as such palaeontologists can't really study it) and properly described in the near future, so that the relationships of this intriguing group of birdlike dinosaurs in a time and a place where they seem to be at their most diverse can be better understood.

Qianzhousaurus sinensis is at top, Alioramus remotus is at bottom.
Or are they both
[by the author]
Day 17: Qianzhousaurus sinensis (and/or Alioramus remotus) - Studying prehistoric life is tricky. You can't always compare animals in the way a modern zoologist can, in a living ecosystem. Palaeontologists must reconstruct long-dead ecosystems as best they can, often going on little more than scraps. That's why this Dinovember drawing might be a taxonomic two-for-one, or it might not.

The lightly-built, slender-skulled Alioramus remotus and A. altai are two species of tyrannosaurs from Mongolia, known only from the fossils of animals that weren't yet fully-grown when they died. It had been long suggested that they were merely the immature individuals of another Asian tyrannosaur, built more like the big, robust, bone-crunching killers we find more familiar. Recently-described Qianzhousaurus sinensis is from Chinese sediments of the same age as Alioramus and is known from adult material, but still has the slim build and very elongate snout of smaller Alioramus, showing that these narrow-nosed tyrants were a group of predators in Late Cretaceous Asia that were distinct from their big, burlier kin.

However, just because Alioramus isn't the juvenile form of a more typical robust tyrannosaur, it may still belong with a known adult form -- it's possible (many palaeontologists would say probable) that Qianzhousaurus is just what Alioramus would look like all grown up. If that is indeed the case, the name Qianzhousaurus will be dropped, and all these creatures will be recognised as growth stages of the same genus, Alioramus.

Rajasaurus narmadensis probably had a gnarly head.
[by the author]
Day 18: Rajasaurus narmadensis - Rajasaurus was a large meat-eater from Late Cretaceous India. It belonged to a group of dinosaurs called abelisaurs, which had very short, basically vestigial arms and short, deep heads. Rajasaurus had a stout horn on top of its head, and some abelisaurs have rugose bone textures on their skull that might indicate they had keratin crests on their faces in life. I went for something like that here, but overall I'm not so happy with how it turned out. I was a little hesitant to get too carried away with extensiveness of this structure/detailing it, and I'm now thinking maybe I shouldn't have been as reserved - this drawing looks sort of unfinished now.

Scelidosaurus harrisonii is standing proud.
[by the author]
Day 19: Scelidosaurus harrisonii - When I drew this early armoured dinosaur, I decided to incorporate what appears to be a rarely-depicted aspect of its behaviour. Trackways from the Early Jurassic of Eastern Europe (can't find the paper right now, sorry) indicate that close relatives of Scelidosaurus at least occasionally walked bipedally, rather than on all fours. Interestingly, it seems that in the 19th century, Scelidosaurus was thought to have been (partially?) bipedal. Cool. Additionally, all those armour scutes were awful to draw.

So I wouldn't have to draw the body, this Tarchia kielanae is poking its
head out from behind the tree that is implied to be blocking the rest of it.
[by the lazy, lazy author]
Day 20: Tarchia kielanae - A huge armoured dinosaur from Asia, Tarchia had a big, flat, really really wide body covered in scutes that frankly I didn't feel like drawing after the questionable results of the Scelidosaurus you just saw. I decided to focus on Tarchia's big, weird, gnarly head but drew it too small and needed to fill more space. So, I incorporated the low-hanging boughs of a plane tree, which grew in the seasonally-dry woodland/scrubland that Tarchia inhabited. This was a fun way to practice plant drawing and to imply that the rest of the animal was out of sight. I didn't attempt to draw the rest of the dinosaur behind the branches because the very first sketches I tried showed that that would have been a mess.

Anyway, that's enough Dinovember for this part of February. Ten dinosaurs remain, I'll try to have them up soon so I can move on to other things - and other art!

-- M

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