This is post number 300, and there are now more than 50,000 of you following along. Thanks, guys. For post #300, here’s some real-life sea monsters.
In 2001, researchers and students on Spitsbergen, in the arctic Svalbard archipelago, discovered the partial remains of a pleiosaur, a large marine reptilian that ruled the seas while dinosaurs ruled the land. Further excavation revealed that the fossil was far from alone. Researchers soon identified a single unit of shale named the Slottsmøya Member, in which a large amount of well-preserved and novel fossilized reptiles from the Jurassic era were found. Like the Burgess Shale, the researchers argue that this unit constitutes a Lagerstätte—“a sedimentary deposit that exhibits extraordinary fossil with exceptional preservation.”
Seasonal excavations at the site have been going on since then. Both the History and National Geographic channels have already produced documentaries about the site. The latter, named “Death of a Sea Monster”, is the source of the illustrations above. But apart from a couple scattered publications, the details haven’t been published in peer-reviewed journals until now. On September 30, the Norwegian Journal of Geology published a special issue dedicated entirely to the Slottsmøya Member. This harkens back to the old days of science, when scientists would go on expeditions for years, then spend many years analyzing their findings before they ever published anything. (Darwin famously sat on his discoveries for decades.) These days, it’s unusual for a research programme to go almost ten years before publishing everything at once. The journal is open access, so you can read all the articles for free.
Back to the main attraction, the marine reptiles! The total catch for the Slottsmøya member so far is: two new genera (three species) of plesiosauroids, one new species of pliosaur, and two new genera (two species) of ichthyosaurs. These were huge predators of the sea, illustrated above.
The ichthyosaurs look a bit like enormous, ferocious dolphins; the largest species was 21 meters long. They were at their largest in the Triassic era (around 200 million years ago), then grew smaller in the Jurassic, and died out some time before the dinosaurs. The Svalbard site stems from the Jurassic, and so the ichthyosaurs found there don’t approach the giant size of their ancestors. Still, in 2009, researchers found an ichthyosaur they estimate to be around 5.5 meters long. That isn’t small by any stretch of the imagination.
The Plesiosaurs, too, could reach beyond twenty meters in length. They are illustrated above by the long-necked, small-headed variant. There were also short-necked plesiosaurs with larger heads, and there is still debate about whether the two body types reflect an evolutionary relationship, or whether some long-necked plesiosaurs may in fact be more closely related to the short-necked ones than to its long-necked brethren. Both types of plesiosaurs were found at the site. One of the new genera was named Spitrasaurus, after Spitsbergen Travel, a local travel agency that sponsored the excavation.
The new species of pliosaur, or short-necked plesiosaur, is the kind that makes you especially grateful that the dinosaurs and their contemporary marine reptiles died out. The media nicknamed it Predator X and speculated that its giant jaws had the strongest bite of any creature, ever, dwarfing the Tyrannosaurus Rex. (The paper estimates the length to 10-13 meters, and doesn’t really speculate about how much force it could exert with its jaws. The skull is scientificially certified to be pretty fucking monstrous, though.)
The Plesiosaurs died out with the dinosaurs. It’s important to note, however, that neither the ichthyosaurs nor the plesiosaurs are dinosaurs (though their ancestors lived on land), despite their appearance and the presence of -saur in their names.