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.