September 13, 2014 | David F. Coppedge

Giant Reptiles Roamed the Earth, Water, and Sky

Record-setting dinosaurs have been announced this month.

Big swimmer:  The most complete fossil ever of the rare Spinosaurus, larger than a T. rex, has been excavated in fluvial sandstone in the Moroccan Sahara (Science Now).  News reports are calling it an aquatic shark-grabber (New Scientist) based on dense leg bones, limb proportions, paddle-like feet and high nostrils.  The BBC News shows the excavation site where a private collector found it, a skeleton on display in a museum, a 3-D model of the skeleton, and artwork of the sail-backed creature, thought to be semi-aquatic: potentially the largest carnivorous dinosaur of all.  Calling it a “half-duck, half-crocodile” like creature, Live Science quotes an expert saying, “The animal we are resurrecting is so bizarre that it is going to force dinosaur experts to rethink many things they thought they knew about dinosaurs.”  The article also tells an Indiana-Jones-like story about its discovery.  The original paper is in Science Magazine; Michael Balter in the same issue gives some background and perspective, noting that Jurassic Park III got Spinosaurus wrong both in habitat and date (i.e., it was 30 million years earlier than T. Rex, and therefore never snapped one’s neck).  As usual, National Geographic accentuated art and drama over data.

Amazing FactsBig grazer:  This one’s a dreadnought even by name: Dreadnoughtus schrani, named for the new generation of steel battleships in the early 20th century, is the name given to a new “supermassive” species of titanosaur found in Patagonia (Science Daily).  But it could have been called “No Fear,” because what could have challenged it? (see Drexel Univ. press release).  The exceptionally complete skeleton (70% of the bones recovered) reveals a beast for the record books: 85 feet long and weighing an estimated 65 tons.  The BBC News has some artwork portraying the giant in its probable habitat.  A diagram on The Conversation compares it to other large animals and a Boeing 737.  Nature News says it was “probably one of the largest land animals ever.”  The NSF likens it to “T. rex times seven” in size.  Even then, it was not full grown; scientists estimate it was like a teenager.  The “astoundingly huge” individual took four field expeditions to excavate.  Live Science notes that it was found in flood deposits suggesting a river overflowed; CMI pointed out that the beast fits the description of the book of Job and the Genesis account of the Flood.  The Guardian reported the following tidbit: “Other work with Mary Schweitzer at North Carolina State University aims to recover ancient cells and soft tissue from the animal to understand its biological makeup.

Western big grazer:  Another giant titanosaur has been found across the world in Tanzania, reported Live Science.  Few sauropods have been found in sub-Saharan Africa, partly due to political instabilities, but this one may help fill in a “black hole” in the fossil record, the article states, because “the early evolutionary history outside of South America is fuzzy.”  Like the other giant from Patagonia, this one died in a “muddy floodplain,” we are told; its name Rukwatitan bisepultus indicates the region where it was found and the fact that it appears to have been buried twice (see also the press release and artwork from Ohio State).  R. bisepultus was a 15-toner, equal to 2 elephants, about a fifth of the size of Dreadnoughtus.  Staff writer Laura Geggel tossed a little incense to Darwin: “Like other titanosaurians and meat-eating theropods — dinosaurs that may have given flight to birds — Rukwatitan‘s neck bone was hollow and filled with air.”  And just like birds, it had two eyes!  But it had trouble getting off the ground, even with hollow bones.  Maybe a few feathers would have helped; none were reported.

Big flyer:  Another pterosaur species has been found that resembled a large pelican, suggesting it skimmed over lakes and scooped up fish into a pouch in its elongated mouth.  Live Science says it looks like a dragon that flew right out of the movie Avatar; in fact, it was named Ikrandraco avatar for the “ikran” creature in the movie.  National Geographic has artwork of its head profile, showing big eyes, a scoop and a possible throat pouch, just like a pelican.  But since pelicans and pterosaurs are unrelated, the article attributes the similarity to “convergent evolution.” The creature was found in the Liaoning Province in China, where a rich ecology once thrived 120 million Darwin years ago: “fish, frogs, turtles, other pterosaurs, feathered dinosaurs, birds and mammals, as well as many plants, such as ferns, conifers, gingkos, cycads and some flowering plants.”

Thick skinned:  Why is so much hadrosaur skin preserved?  Perhaps it was thicker than the skin on other dinosaurs, PhysOrg reports, based on thoughts by grad student Matt Davis of Yale.  He estimated that you have 31 times higher chance of skin being preserved in a fossil if you’re a hadrosaur.  Most of the mummified dinosaurs were hadrosaurs, like the famous Leonardo specimen of Edmontosaurus.  “Of 123 body fossils with skin (as opposed to trace fossil skin, such as footprints), 57—or 46%—were from hadrosaurs.”  The article did not question whether skin could survive for 65 million years or more, but mentions that a T. rex with skin was found once.  It’s not news any more to find hadrosaur skin, Davis said, because paleontologists now know to keep on the lookout for it and are finding it more often.  In the Hell Creek formation of Montana, for instance, about a fourth of hadrosaur fossils show evidence of preserved skin.  Some specimens have only scraps of skin, Davis said, while others have “enough skin to wrap around a car.”  Most examples are impressions of the skin, the article says; “the original soft tissue decayed long ago.”  The dinosaur mummies, though, “preserve most of the body skin”.

Nice to see some major discoveries of the big behemoths children (and adults) love.  Dinosaurs were created with intelligent design, just like all other animals.  The Darwin Years are mythical, as shown by the presence of soft tissue (see the CMI article).  If you can filter out the evolutionary propaganda, these big beasts and the stories of their discovery can remain amazing and fascinating.  Question: where were the hadrosaur feathers?

 

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