Titanic Fearless Dinosaur Unearthed

I'm sure you've heard. The most complete skeleton of a titanosaur, a newly named species, Dreadnoughtus schrani, is being reported from Argentina.

It is not a bird. I mention that because we've been talking about how birds are dinosaurs lately (see:"Honey, I shrunk the dinosaurs" and "Flying Dinosaurs: A new book on the dinosaur bird link.").

Dreadnoughtus schrani is a sauropod. Brontosaurus, if it existed, would be a sauropod. These are the dinosaurs with the little heads, long necks, and long tails. In cartoons they are sometimes called "long-necks." Dreadnoughtus schrani is, as mentioned, a titanosaur, a particularly large long neck.

How does this relate to the other dinosaurs? The dinosaurs are part of a really big group of organisms that includes crocodiles, pterosaurs (those flying things) and so on. Within this group are the proper dinosaurs which you can think of as being divided into three groups. One group is the Ornithischia, named from the greek for "birdlike." These are not birds either, but their hips somewhat resemble bird hips. (Birds are "lizard hipped" dinosaurs, which completes the paleoirony.) The Ornithischia are separate from the other two groups which are the Sauropods and the Theropods. The Theropods include Tyrannosaurus rex and pigeons. The Sauropods includes the Brontosaurus-like dinosaurs, though of course, there is no such thing as Brontosaurus. Because people who name dinosaurs are, essentially, sadistic.

Anyway, Dreadnoughtus schrani is estimated to have been about 26 meters (85 feet) long. So if you live in a typical city lot it could eat the bushes on your front lawn while knocking over your garage out back with its tail. It would have weighted about 59 metric tons. That's about 65 regular tons. Nobody really knows what a ton is unless you are in certain professions, so that's about 33 cars, or about 70 head of cattle. So, the average American could replace the usual meat in their diet with meat from one well fed Dreadnoughtus schrani for about two centuries. Give or take. This is all based on the one specimen found in Argentina. But, that individual was not full grown. So, wow. I'm not sure if Dreadnoughtus schrani is the biggest sauropod, as there are others in this size range.

The specimen is about 45% complete as a skeleton, but about 70% of the bones in the body are represented. Unfortunately the head is missing. But really, where could it be? I'm sure they'll find it if they keep looking!

Titanosaurs were the major large dinos during the Mesozoic (252 - 66 mya) in the southern continents. This particular find dates to the Upper Cretaceous, the latest part of the Mesozoic.

From the paper:

(A) Reconstructed skeleton and body silhouette in left lateral view with preserved elements in white. (B) Left scapula and coracoid in lateral view. (C) Sternal plates in ventral view. (D) Left forelimb (metacarpus reconstructed) in anterior view. (E) Left pelvis (ilium partially reconstructed) in lateral view. (F) Left hind limb in anterior view (metatarsus and pes partially reconstructed and reversed from right). (G) Transverse ground thin section of humeral shaft, showing heavy secondary remodelling (arrow indicates extent of dense osteon formation), a thick layer of well-vascularized fibrolamellar bone, and a lack of lines of arrested growth or an external fundamental system. Abbreviations: acet, acetabulum; acf, acromial fossa; acp, acromial process; acr, acromial ridge; ast, astragalus; cc, cnemial crest; cof, coracoid foramen; cor, coracoid; dpc, deltopectoral crest; fem, femur; fhd, femoral head; fib, fibula; flb, fibrolamellar bone; gl, glenoid; hum, humerus; il, ilium; ilp, iliac peduncle; isc, ischium; isp, ischial peduncle; lt, lateral trochanter; mtI, metatarsal I; mtII, metatarsal II; of, obturator foramen; pop, postacetabular process; prp, preacetabular process; pu, pedal ungual; pub, pubis; pup, pubic peduncle; rac, radial condyle; rad, radius; sc, scapula; scb, scapular blade; sr, secondary remodelling; tib, tibia; tpp, tuberosity on preacetabular process; ul, ulna; ulc, ulnar condyle. Scale bars equal 1 m in (A) to (F) and 1 mm in (G). (Skeletal reconstruction by L. Wright, with G. Schultz.)

The name means "Fearless-creature guy-who-funded-expedition." According to the authors, this is specifically where the genus name comes from:

Dreadnought (Old English), fearing nothing; genus name alludes to the gigantic body size of the taxon (which presumably rendered healthy adult individuals nearly impervious to attack) and the predominant battleships of the early 20th century (two of which, ARA [Armada de la República Argentina] Rivadavia and ARA Moreno, were part of the Argentinean navy). Species name honours the American entrepreneur Adam Schran for his support of this research.

For more information:

The Scientific Report article (which appears to be Open Access): A Gigantic, Exceptionally Complete Titanosaurian Sauropod Dinosaur from Southern Patagonia, Argentina

An open access paper on how this type of dinosaur even walked: March of the Titans: The Locomotor Capabilities of Sauropod Dinosaurs.

Michael Balter with Science Mag: Giant dinosaur unearthed in Argentina

Mr. Dinosaur Brian Switek: Enormous New Dinosaur as Formidable as Its Namesake Battleship

Ian Sample at The Guardian, including a video: Battleship beast: colossal dinosaur skeleton found in southern Patagonia

Francie Diep at Scientific American: New "Dreadnought" Dinosaur Most Complete Specimen of a Giant

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"Nobody really knows what a ton is unless you are in certain professions, so that’s about 33 cars, or about 70 head of cattle."

The weight comparison for this thing that it would have been "equal to more than seven Tyrannosaurus Rex".

This does make me wonder how large the average adult would have been, and what percentage of its day it would have to spend feeding just to fuel the furnace. (Not to mention the mechanics of how the females would have had to squat in order to lay eggs instead of dropping them from what, two stories up?)

Informal question: why do so many of us find dinosaurs so cool?

We're gonna need a bigger museum...

By Norman Boss (not verified) on 06 Sep 2014 #permalink

Makes me admire Noah so much more. Think, there were two of them on the Ark!

By cosmicomics (not verified) on 06 Sep 2014 #permalink


It could have been an allegory for genetic material????

Brontosaurus aka Apatosaurus is a diplodocid, not a titanosaur. (Right?)

Visualising a ton: Think of a milk crate full of concrete. That's one cubic foot, which weighs 150 pounds. Now think of a cube that's three milk crates in each direction: 9 on the floor, 9 on top of those, 9 on top of those, total of 27 cubic feet or one cubic yard. That much concrete weighs 4,05 pounds, or fifty pounds more than two regular tons.

If our new dinosaur weighs 65 regular tons and its foot is about 2 feet long in each direction (rough guess from picture), then a single footprint is 4 square feet. Four feet on the ground = total ground contact area of 16 square feet. 65 tons divided by 16 square feet = ground pressure of 4.06 tons per square foot, or (4.06 x 2000) 8,120 pounds per square foot. One square foot = 144 square inches, so 8,120 divided by 144 = approx. 56.4 pounds per square inch.

So our dinosaur is putting approx. 56 pounds per square inch of pressure on the ground just standing there, and of course when it walks, its point pressure will be momentarily higher on each foot as its weight redistributes while walking.

If a 200 pound human has a foot that measures approx. 12" x 4", that's 48 square inches, so the human is putting 4.16 pounds per square inch on the ground. Our dinosaur's ground pressure per square inch is approx. 14 times as much as our human's. The dinosaur is going to be much more likely to sink in soft ground than the human. (Humans, take note: if you have to outrun a dinosaur, head for a swamp.)

As for reproduction, unless the evidence points to large dinosaurs remaining on their feet all their lives, they would have had a way to lie down to rest, and get back up again. Or if they deposited eggs while standing, the actual drop height would have been closer to 12' (rough estimate from the picture), which is still quite enough to damage an egg falling on solid ground. The dinosaurs might also have laid their eggs on soft ground or in or near water, or built some kind of soft nests into which to deposit eggs, or laid eggs from a lying-down position.

But the more difficult part would be fertilization. Assuming the usual nonhuman animal copulatory posture, about half the weight of the male is distributed onto the female's back: 32 tons. The total weight of two dinosaurs is distributed to six feet on the ground rather than eight, plus the likelihood of rhythmic increased point-loading of ground pressure during copulation. Alternately the female releases unfertilized eggs and the male fertilizes them in place, in a manner analogous to that of amphibians, plus or minus the difference in the composition of the eggs that might rule out that method.

With all that, the fact that these animals managed to exist at all is somewhat amazing. The sheer quantity of food needed, the risk of sinking into the soil during normal activities, the reproductive issues, etc., are all difficult issues to overcome. But anything that nature doesn't forbid, nature requires, whether in large measure or small.

Oops: "that much concrete weighs 4,050 lbs...." (keyboard error).

And a question: what kinds of ground conditions can support a ground pressure of 56 pounds per square inch?

"Think of a milk crate"

Thing of the past, better find a better object!

If you fill an average bathtub with water to about half-full, that's one-half an "abnormal" English ton (i.e., 2000 pounds avoirdupois, or 0.9 metric ton).

A cube, one meter on a side, filled with water, is one metric ton.

By Brainstorms (not verified) on 07 Sep 2014 #permalink

Re ground pressure, while 56 psi is a lot, it's not ridiculous. It's about the same as a human on a bicycle.

By Alphagamma (not verified) on 08 Sep 2014 #permalink