2015 in Mesozoic Paleontology

To cap off the year, I recently did another paneled, less serious drawing, this time celebrating the new (and old, in one case) Mesozoic fauna described this year:

January: Nundasuchus, a Early Triassic archosaur from Tanzania (hence the safari sign).

February: Ichthyosaurus anningae, a new species of Ichthyosaurus. Uncovered by Mary Anning, but was long mistaken for a plaster cast.

March: Metoposaurus algarvensis, a new species of the amphibian Metoposaurus from Early Triassic Portugal.

April: Brontosaurus, a re-established genus long considered synonymous with Apatosaurus.
May: Yi, a bat-winged, feathered theropod from Late Jurassic China.

June: Regaliceratops, a chasmosaurine ceratopsian from Late Cretaceous Alberta.

July: Wendiceratops, a centrosaurine ceratopsian from Late Cretaceous Alberta.

August: Gueragama, a mid-Cretaceous lizard from Brazil closely related to modern iguanas.

September: Ugrunaaluk, a Late Cretaceous hadrosaur from Alaska. The northmost non-avian dinosaur ever discovered.

October: Spinolestes, an Early Cretaceous mammal from Spain preserved with quill-like hair imprints.

November: Dakotaraptor, a Late Cretaceous dromaeosaur from South Dakota. Lived alongside Tyrannosaurus and Triceratops.
 
December: Kunbarrasaurus, an Early Cretaceous ankylosaur from Australia (hence the aurora australis).

Animalia Transalphabetica

Top Row (from left): Iraq (Malawania), China (Gigantoraptor, Tuojiangosaurus, Changchengornis, Mamenchisaurus, Qianzhousaurus), Egypt (Paralititan), Algeria (Carcharodontosaurus)

Middle Row: Israel (Tanystropheus), Japan (Phosphorosaurus), South Korea (Koreanosaurus), Russia (Liopleurodon)

Left Corner: India (Sanajeh)

Right Corner: Thailand (Siamosaurus)

As I've gone through my black dinosaur sketchbook, I've tried not just to cover a wide range of animals, but a wide range of animals from a wide range of places. While China, Mongolia, Argentina, and the western United States and Canada are inevitably represented by legions of colossal sauropods, tiny-to-titanic theropods, and ceratopsians great and small, I've also featured stegosaurs from Portugal, hadrosaurs from Italy and Russia, amphibians from Australia and Kazakhstan, and pterosaurs from Brazil.

Another idea that inspired this drawing was an insight by my college studio drawing professor: "Your signature and handwriting is a form of drawing." With that in mind, I decided to write out (or rather, draw) how these genera's names would be written out in their country of discovery. Initially, the United Kingdom was to be represented by Megalosaurus or Iguanodon, but I ultimately opted to use non-Phoenician alphabets, and use Arabic characters for both Arabic and Kurdish, the language from which Malawania's name comes.

Speaking of Malawania, initially its place would have been filled by the pterosaur Alanqa, representing Morocco. At some point, however, I opted to use the Iraqi ichthyosaur instead, but neglected to replace the name before drawing it (hence the smudge around the name). Another decision that informed choice of Iraq (as well as Algeria) instead of Morocco was that the latter's flag is much less striking (being a red flag with small green pentagram that would probably be covered by its ambassador animal).

Rather than listing all the dinosaurs representing China, I just wrote the traditional Chinese characters for "Too many to name". 

Sanajeh is written "ancient gape" in Sanskrit, its meaning in its language of origin. The same practice was used to transcribe Tanystropheus from Greek to Hebrew.

With each of the flags, it was important to capture the right color tone. I used different reds for the Iraqi flag's top band, most of China's flag, and the bottom of band of Russia's flag. I also used a darker red for Korea's flag than Japan's.

The one exception to flag backgrounds, of course, is Paralititan, represented in writing within an ancient Egyptian cartouche ("cartridge", the oblong shape that surrounds important people's names) and against the Great Pyramids at sunset.

One of the greatest joys and challenges of drawing dinosaurs is guessing their color patterns. Ultimately, however, I decided to keep the animals uncolored, in order to draw more attention to the countries' flags and respective scripts.

Frontier Ceratopsians

For most of the time that we've known about them, large ceratopsians seemed to be limited to North America. Smaller species were more widespread, inhabiting both North America and Asia, but were scarce elswhere. Overall the past five years, however, ceratopsian fossils have come in new shapes as well as from new places:

1. Ajkaceratops - 2010 - Hungary, 86-84 million B.C.E

2. Turanoceratops - 1989 - Uzbekistan, 90 million B.C.E.

3. Sinoceratops - 2010 - China, 72-66 million B.C.E.

4. Pachyrhinosaurus (perotorum) - 2012 - Alaska, 70-69 million B.C.E. (northmost ceratopsian and latest Pachyrhinosaurus species)

5. Koreaceratops - 2011 - South Korea, 103 million B.C.E.

6. Coahuilaceratops - 2010 - Mexico, 72.5-71 million B.C.E. (southmost large ceratopsian) 

The range ceratopsians inhabited may have gone even further: Two possible ceratopsians called Notoceratops and Serendipaceratops were identified from fragmentary bones in Argentina and Australia, respectively.

The Doom of Giants

Many of the largest mammals alive today are also among the most vulnerable. For the past three centuries, wildlife populations of African elephants, blue whales, giant pandas, and all species of tigers, rhinos, and gorillas have been hobbled both by habitat loss and human hunting (both for sport and resources of dubious real value like ivory). 

This phenomenon isn't limited to human times. Bus-sized nautiloids, 20-foot armored fish, gorgonopsids, sauropods, and basilosaurid cetaceans were all the biggest animals of their world and all were obliterated forever in mass extinctions at the end of the Ordovician, Devonian, Permian, Cretaceous, and Eocene, respectively.

While my output for endangered mammal drawings have slowed down of late, I did manage to draw two threatened giants in October that I've yet to post here:

Javan rhinoceros (Rhinoceros sondaicus)
Current Range: Ujung Kulon National Park, westernmost Java, Indonesia
Conservation Status: Critically endangered (58-61 as of March 2015)

Northern right whale (Eubalaena glacialis)
Current Range: From the east coast of Florida to the North Sea
Conservation Status: Endangered

Incidentally, pick up A Dynasty of Dinosaurs! It's an amazing dinosaur coloring book for more mature artists by paleontologists Jason Poole and Jason Schein. Here's a set of pages I've been coloring in lately:

While I'm not of the identity of each sauropod here, I know that number 2 (if we follow their heads left to right) is Amargasaurus, and I'm pretty sure that numbers 1, 5, 7, and 9 are Nigersaurus, Saltasaurus, Plateosaurus, and Lessemsaurus, respectively. Numbers 4 and 8 are almost certainly super-sized titanosaurs (possibly Dreadnoughtus and/or Paralititan?), while 3 and 6 are likely diplodocoids (Rebbachisaurus and Suuwassea, perhaps?).

In any case, great job Jasons!

A Thanksgiving Therizinosaur

I have to admit that I'm not enamored with many feathered theropods. While I recognize that dinosaur feathers underlines their connection to birds and so makes dinosaurs as a whole more relevant, these animals lose a bit of their mystique when you learn that they're not as alien as you might imagine.

There's an exception to every rule, however, and I can't help but be amazing by therizinosaurs. Known for decades only from a giant set of hands (belong to the type genus Therizinosaurus), these enigmas turned out to be the dinosaur precursor to the giant ground sloths -- herbivores that stood tall as they fed from the trees, pulling down the higher branches with an impressive set of claws.

Nothronychus is one of the earliest and mostly completely known therizinosaurs, as well as the first identified from North America. It has all the qualities that make these theropods so alien -- the giant claws, the long neck, the fat turkey body...In fact, the only thing remotely familiar about this dinosaur is the furcula, or wishbone, betraying its link, however distant, to modern dinosaurs.

Hope you all had a wonderful Thanksgiving!

Antiquarian Amphibians

For a few months of my sophomore year of college (Fall 2008-Spring 2009), I endeavored to fill a blank, hardcover drawing book with animals predating the dinosaurs. I had already completed similar projects with Mesozoic and Cenozoic fauna, but this one was to be more ambitious: Not only would I draw and color over a hundred animals belonging to groups alien to me, but this time, I would depict each organism's habitat in full color as well. Unfortunately, my workload only mounted while my interest in the Paleozoic (and sadly, drawing environments) waned.

However, when my enthusiasm was high, I did manage to complete a set of drawings focusing on early amphibians, specifically the temnospondyls and the lepospondyls. Both of these groups arose and diversified during the Carboniferous period (roughly 360 to 300 million years ago) but eventually died out during the early Cretaceous period (around 120 million years ago).

TEMNOSPONDYLS:

 Greererpeton

5 ft long

West Virginia

 Dendrerpeton

3.3 ft long

Nova Scotia

 Cochleosaurus

4-5.2 ft long

Czech Republic

LEPOSPONDYLS:

(Clockwise from left)

Phlegethontia

 3.3 ft long

 Czech Republic, Illinois, and Ohio

Microbrachis

 6 in long

 Czech Republic

Keraterpeton

1 ft long

Czech Republic and Ohio

Karoo's Dragons, Dragon Hunters, and Their Children

After Plateosaurus, Massospondylus is the poster child early sauropodomorph (or, as they were called before their ties to sauropods were clearer, prosauropods). Not only are they known from complete adult skeletons in Early Jurassic sites across southern Africa, but they are also the earliest dinosaurs known from eggs and embryos. Baby Massospondylus were big-headed quadrupeds, in stark contrast to their small-headed bipedal parents. Because they were born without teeth, and since adult tracks (but no adult bones) have been found in close proximity to fossilized nests, it's possible that Massospondylus provided their offspring with basic parenting -- perhaps cutting up and regurgitating vegetation for their brood like modern birds.

The contemporary Dracovenator may well have been these dinosaurs' chief predator. While it's known from only a few skull fragments, these bones seem to have belonged to a dilophosaur. This classification is probably best demonstrated by the end of a juvenile Dracovenator's snout, filled with snaggle teeth and arching between the nostril and front teeth, as in adult dilophosaurs.

Buried at Sea

One of the most interesting Early Cretaceous marine beds is the Paja Formation in central Colombia, dating back between 125 and 113 million B.C.E. Among the notable finds described from here include South American species of Kronosaurus and Platypterygius -- both better known from fossils in Australia -- an elasmosaurine plesiosaur called Callawayasaurus, and Desmatochelys padillae, described only this year and currently the oldest known sea turtle. Another surprise from this site, though, were ten tail vertebrae belonging to a brachiosaur, later named Padillasaurus. These sauropods are the tallest known dinosaurs, and until this year were only known from North America, Europe, and Africa. Ironically, most sauropods were regarded as amphibious, with legs too weak to support their bulk on land and high nostrils to allow them to breath while submerged. Both of these ideas have since been rejected, so the Padillasaurus probably died on land and had its remains washed out to sea.

Padillasaurus is hardly the first dinosaur to be buried at sea. The type of Archaeopteryx, one of the most famous fossils of all time, was excavated from the Late Jurassic Solnhofen Limestone in Bavaria, alongside fossilized ichthyosaurs, fish, and brittle stars. The carcasses of the ankylosaur Aletopelta and the hadrosaur Lophorhothon were both carried to sea between 80 and 75 million B.C.E (to Pacific and the Caribbean, which then covered northern Alabama, respectively).

One of the more recent and complete dinosaurs found in marine beds is Tethyshadros, uncovered in northern Italy and named for the ocean that covered most of Europe during the Late Cretaceous. This species is one of a handful of hadrosaurs known from Europe, and may have been a dwarf genus, just like the contemporaneous dinosaurs from Hațeg Island, now in modern Romania.

Giganotosaurus v. Mapusaurus

Both had huge skulls and knife-like teeth. Both roamed Patagonia about 100 million years ago. Both may have been bigger than T. rex, and both may have hunted the biggest-known dinosaurs.

From documentary depictions of these two carcharodontosaurs alone, you could be forgiven for thinking they were the same animal: In the second episode of Chased by Dinosaurs, a 2003 spin-off of the influential BBC miniseries Walking with Dinosaurs, host Nigel Marven travels back to mid-Cretaceous Argentina and witnesses a gang of Giganotosaurus isolate and slowly tire and bleed a 90-plus ton Argentinosaurus to death. Eight years later, in the fifth episode of the all-CGI BBC series Planet Dinosaur, a less-coordinated band of Mapusaurus hunt the same sauropod species, though in this case, the predators only manage to tear a strip of flesh from the beast's back and one of them ends up being crushed by a defending adult. Only hours or even days later do these theropods get to feast on their prize, long after it has expired from its wound.

Despite differences in these portrayals, the fossil record doesn't support them. There is no evidence either for relentless, disciplined hunting from Giganotosaurus, nor proof of less organized, more patient predation by Mapusaurus. Yet differences are there: Giganotosaurus hails from the Candeleros Formation, dating to about 100 to 97 million years ago, while fossils of Mapusaurus, though found nearby, are found in the younger Huincul Formation, the same site as Argentinosaurus. The circumstances of each dinosaur's discovery also differed, with Giganotosaurus found as one, mostly complete specimen and Mapusaurus found from several, crudely preserved individuals of different ages and sizes (hence their constant portrayal as more social hunters).

Physically, I had little idea of what separated the two, other than the maximum Giganotosaurus size estimates tended to be larger than those for Mapusaurus. The former dinosaur was my first subject in my Mesozoic sketchbook (see above) and yesterday I decided to draw the latter, based on the two mounts that dominate Google searches of this dinosaur.

The biggest difference I found between these animals was in their nasal crests: While those of Giganotosaurus' clearly diverge before arching over the eye, Mapusaurus' seemed lower and closer together, if not fused together in real life.

Asia's Vanishing Megafauna

As I drew up my list of species for this book of endangered mammals, I tried not to have too animals from one particular group or region of the world. Even so, Asia's vanishing megafauna will occupy a great deal of it. These species include not only charismatic conservation icons -- such as pandas, tigers, orangutans, and even the Asian elephant -- but also many overlooked species with close relatives that seem to be doing fine elsewhere.

Indian hog deer (Hyelaphus porcinus)
Current Range: Northern Pakistan and India to southern China
Conservation Status: Endangered

Dhole (Cuon alpinus)

Current Range: Swaths of Southeast Asia, from western China and southwestern India to Sumatra and Java

Conservation Status: Endangered

Sunda pangolin (Manis javanica)
Current Range: Southeast Asia, from Myanmar to Brunei
Conservation Status: Critically Endangered (unknown wildlife population)

Turkmenian kulan (Equus hemionus kulan)
Current Range: Turkmenistan
Conservation Status: Endangered

Amur leopard (Panthera pardus orientalis)
Current Range: Northeast China and east coastal Russia
Conservation Status: Critically Endangered (c. 57 in Russia and 12 in China as of February 2015)

Jurassic Giants: The Old, The New, and the Obscure

The most famous sauropods -- Apatosaurus, Diplodocus, Camarasaurus, Brachiosaurus, and now Brontosaurus again -- all hail from the Morrison Formation of the western United States, extending from Montana to New Mexico and the end of the Jurassic (roughly 155 to 145 million B.C.E.). These were hardly the first sauropods to evolve or be named, and while some genera from the Cretaceous (like Argentinosaurus and Dreadnoughtus) were even larger, the Late Jurassic is generally regarded as these dinosaurs' heyday, celebrated in documentaries like Walking with Dinosaurs and When Dinosaurs Roamed America.

Some Early Jurassic sauropods, though, do deserve a mention: Barapasaurus, from the Kota Formation in southeastern India, is one of the earliest definitive large sauropods, dating back to between 195 to 180 million B.C.E. It measured about 40 to 45 feet long and around 8 tons -- about the same length and weight as T. rex, and making it one of the largest animals ever to walk the Earth at the point in time. More importantly, however, are its front toes, which retain the large claws of the sauropods' bipedal antecedents, the plateosaurs (or prosauropods), hinting its primitive place. While most of the skeleton has been found, a Barapasaurus head is still unknown. The drawing below is based on a mount at the Indian Statistical Institute in Kolkata, whose staff gave it a very Diplodocus-like head.

Cetiosaurus, the first sauropod ever described, roamed modern England around 165 million B.C.E. On the face of it, it's a rather un-glamorous, undistinguished sauropod, being only about 50 feet long and around 12 tons, though its toes claws are much blunter than Barapasaurus'. Here too, the restored skull is speculative, displaying cranial chambers that characterize Camarasaurus as well as the pencil-like teeth of Apatosaurus and Diplodocus. This drawing is based on the "Rutland sauropod" specimen on display at the New Walk Museum, located in Leicester in central England.

Even some of the Morrison sauropods aren't classic dinosaurs. In 2012, paleontologists Emanuel Tschopp and Octávio Mateus described Kaatedocus, a new diplodocoid from lower (i.e. older) Morrison Formation beds in Wyoming. Earlier this year, same two paleontologists, along with Roger Benson, described Galeamopus, a rechristened former species of Diplodocus.

As with previous sauropod drawings, I've elected to make the sauropod necks the most colorful and intricately-patterned part of the animal for display and identity purposes. For Galeamopus, I actually adapted the calico cat's light orange and inky black fur, only as scales.

Virginia v. Brown

While commuting to and from a close friend's wedding in South Carolina this weekend, I visited two natural history museums I hadn't been to before: The Virginia Museum of Natural History in Martinsville and the Mace Brown Museum of Natural History in Charleston. Both were very much worth the visit, and their collections had a surprising number of items in common:

Pteranodons

Male Pteranodon (Virginia)

Pteranodon family (Brown)

Pteranodon father (Brown)

Pteranodon mother and chicks (Brown)

Ground sloths

Megalonyx (Virginia)

?Paramylodon (Brown)

Megalodon

Megalodon (Virginia)

Megalodon (Brown)

Whales

 Eobalaenoptera (Virginia)

Maiacetus (Brown)

Waipatiid whale (Brown)

The "Wando Whale" (Brown)

Although the Virginia Museum was much larger than Mace Brown (which consists primarily of two rooms at the College of Charleston's School of Sciences and Mathematics Building), it was a more general natural history museum, with a wings devoted to geology and modern animals in addition to fossils. Mace Brown's two exhibit rooms, in contrast, had more fossils than they knew what do with. In addition, admission was free, vindicating a hour-long trek to Charleston from the Isle of Palms morethan the Virginia Museum did for driving an hour out from Lynchburg.

Niobrara Aquarium

Lately I've taken a break from drawing dinosaurs and have focused more on modern animals as well as what naturalist Nigel Marven dubbed "the co-stars" of the prehistoric world. This two-page spread focuses on large fish known from Kansas' Niobrara Formation, which 87 to 82 million years ago was submerged beneath a shallow sea. The fish here were drawn to scale with one another, with one inch used for one meter. To give you an idea of their size, the smallest -- Enchodus -- was 1.5 meters (5 feet) long.

1) Cretoxyrhina mantelli

2) Xiphactinus audax

3) Scapanorhynchus rhaphiodon

4) Pachyrhizodus caninus 

5) Enchodus petrosus

6) Bonnerichthys gladius

7) Saurodon leanus

8) Protosphyraena perniciosa

9) Ptychodus mortoni

Ironically, I found Cretoxyrhina the hardest to re-create. Sharks are not only deceptively difficult to draw and while this particular species belonged to the same order of sharks as the great white, I didn't want it to be a Jaws clone. Add to that the fact that only shark teeth fossilize (as the rest of their skeletons are made of cartilage) and many clashing artistic depictions for comparison, and you have a very hard creature to capture on the page.

Choosing color schemes for these animals was also quite difficult, since none of these species were likely reef-dwellers, yet I didn't want them all to be blue or gray. Both Scapanorhynchus and Ptychodus I made brown -- the former to stay obscured in the deep waters where it may have hunted, the latter for camouflaging itself along the seafloor in order to avoid mosasaurs. Enchodus is actually related to modern salmon, so I gave it similar markings (though with goldenrod and reddish brown instead of olive green and bright pink). Bonnerichthys has no close living relatives, but since it was a filter-feeder I based its colors on a photo of basking shark with marbled markings.

Capturing the Cause

For some of my endangered species drawings, I attempt to also capture the reason(s) why an animal is threatened with extinction. Even in the remote Amazon and Pantanal, the pollution menaces the giant otter, while the Sumatran tiger's existence is threatened largely thanks to deforestation, its jungle kingdom supplanted to make way for acacia plantations.

 

Giant otter (Pteronura brasiliensis)

Current Range: Northern South America, especially the Amazon River and the Pantanal.

Conservation Status: Endangered

Ethiopian wolf (Canis simensis)

Current Range: Central Ethiopia

Conservation Status: Endangered

Somali wild ass (Equus africanus somaliensis)

Current Range: Northeast Africa, from eastern Eritrea to Somalia

Conservation Status: Critically Endangered (pop. c. 700-1000 in the wild)

Sumatran tiger (Panthera tigris sumatrae)

Current Range: Sumatra, Indonesia

Conservation Status: Critically Endangered (441-679 as of 2008)

Candeleros Tsunami

The third in my series of dinosaurs-amidst-disasters drawings, this one focuses on a small band of Limaysaurus attempting to outrun the rushing wall of water from a distant tsunami. Around 100 million years ago, the Andes were only just beginning to form, and though the Candeleros Formation is in modern Argentina, it is close enough to the modern Chilean border and Pacific that its inhabitants may occasionally have fallen afoul of these monster waves.

Tiouraren Titans

This spread sketch is from autumn of last year, depicting the sauropod Jobaria and the megalosaur Afrovenator. Both of these animals are known from the Tiouraren Formation in Niger, dating back to the mid-Jurassic (though previously believed to be from the early Cretaceous) and both are unusually complete dinosaurs. In retrospect, I'm not wild about the colors I gave the rearing Jobaria in the background and the legs on the Afrovenator look a little to spindly, but I'm otherwise happy with it. I decided the reverse the traditional image of a predator pursuing prey since I very much doubt a 1-ton, 25-foot long Afrovenator would be able to bring an adult Jobaria to the ground.

Close up on Afrovenator:
 

Carnivora Obscura

More endangered species. Lately, I've been focusing on lesser-known subspecies of iconic carnivores long menaced by over-hunting:

Asiatic lion (Panthera leo persica)
Current Range: The Gir Forest, Gujarat, India
Conservation Status: Endangered

Persian leopard (Panthera pardus ciscausica)
Current Range: Northern Middle East, from eastern Turkey to western Afghanistan
Conservation Status: Endangered

Darwin's fox (Lycalopex fulvipes)
Current Range: Southern coastal Chile, especially Chiloé Island
Conservation Status: Critically Endangered (pop. c. 320 estimated in 2008 -- 70 on the mainland, 250 on Chiloé Island)

Red wolf (Canis rufus/Canis lupus rufus)
Current Range: North Carolina and pockets of the southeastern United States
Conservation Status: Critically Endangered (pop. c. 300 estimated in 2007, mostly in captivity)

Formosan black bear (Ursus thibetanus formosanus)
Current Range: Taiwan
Conservation Status: Endangered