The fossil record has provided us with so much information about plants, animals, and organisms that lived hundreds, thousands, millions, and even billions of years ago. But we are actually only seeing evidence of a tiny fraction of the species that lived then and even for those we do know about, there’s often much we still don’t know. Traditionally, dinosaurs have been depicted as drab and often terrible lizards but recent finds of soft tissues (skin, feathers, etc.) and an increased sense of imagination based on our current vibrant biodiversity has people thinking differently about how they looked and behaved.
Perhaps the most consequential day in the Earth’s recent history was when a massive asteroid struck the planet 66 million years ago. It resulted in earthquakes, tsunamis, fireballs raining from the sky, volcanoes, atmospheric heat shocks, wildfires, global winter, and the extinction of 75% of all species on Earth, including the dinosaurs. This video by Kurzgesagt leads us through what happened that day, minute by minute.
“The meteorite itself was so massive that it didn’t notice any atmosphere whatsoever,” said Rebolledo. “It was traveling 20 to 40 kilometers per second, 10 kilometers — probably 14 kilometers — wide, pushing the atmosphere and building such incredible pressure that the ocean in front of it just went away.”
These numbers are precise without usefully conveying the scale of the calamity. What they mean is that a rock larger than Mount Everest hit planet Earth traveling twenty times faster than a bullet. This is so fast that it would have traversed the distance from the cruising altitude of a 747 to the ground in 0.3 seconds. The asteroid itself was so large that, even at the moment of impact, the top of it might have still towered more than a mile above the cruising altitude of a 747. In its nearly instantaneous descent, it compressed the air below it so violently that it briefly became several times hotter than the surface of the sun.
“The pressure of the atmosphere in front of the asteroid started excavating the crater before it even got there,” Rebolledo said. “Then when the meteorite touched ground zero, it was totally intact. It was so massive that the atmosphere didn’t even make a scratch on it.”
Unlike the typical Hollywood CGI depictions of asteroid impacts, where an extraterrestrial charcoal briquette gently smolders across the sky, in the Yucatan it would have been a pleasant day one second and the world was already over by the next. As the asteroid collided with the earth, in the sky above it where there should have been air, the rock had punched a hole of outer space vacuum in the atmosphere. As the heavens rushed in to close this hole, enormous volumes of earth were expelled into orbit and beyond — all within a second or two of impact.
“So there’s probably little bits of dinosaur bone up on the moon,” I asked.
It’s only Monday, but I’m confident this will be my favorite read of the week. Since 2012, paleontologist Robert DePalma has been excavating a site in North Dakota that he thinks is “an incredible and unprecedented discovery”. What’s potentially so special about this site? Fossils from dinosaurs and other animals from thousands of years before the asteroid impact are very hard to come by, leading some to believe that dinosaurs died out before the impact, not because of it. DePalma believes the site preserves, as if in amber, the day, the precise and exact day (and perhaps even the exact hour), that the massive asteroid believed to have caused the extinction of the dinosaurs hit the Earth 65 million years ago.
As DePalma carefully excavated the upper layers, he began uncovering an extraordinary array of fossils, exceedingly delicate but marvellously well preserved. “There’s amazing plant material in there, all interlaced and interlocked,” he recalled. “There are logjams of wood, fish pressed against cypress — tree root bundles, tree trunks smeared with amber.” Most fossils end up being squashed flat by the pressure of the overlying stone, but here everything was three-dimensional, including the fish, having been encased in sediment all at once, which acted as a support. “You see skin, you see dorsal fins literally sticking straight up in the sediments, species new to science,” he said. As he dug, the momentousness of what he had come across slowly dawned on him. If the site was what he hoped, he had made the most important paleontological discovery of the new century.
The type of evidence present at the site is almost too good to believe:
He noted that every fish he’d found in the site had died with its mouth open, which may indicate that the fish had been gasping as they suffocated in the sediment-laden water.
“Most died in a vertical position in the sediment, didn’t even tip over on their sides,” he said. “And they weren’t scavenged, because whatever would have dug them up afterward was probably gone.”
Clues from the growth stages of animals and pollen found at the site might even point to what season it was when the asteroid struck…DePalma’s current guess is in autumn. And then there’s this, about a burrow that DePalma discovered:
“Any Cretaceous mammal burrow is incredibly rare,” he said. “But this one is impossible — it’s dug right through the KT boundary.” Perhaps, he said, the mammal survived the impact and the flood, burrowed into the mud to escape the freezing darkness, then died. “It may have been born in the Cretaceous and died in the Paleocene,” he said.
A scientific paper is forthcoming this week. I couldn’t find it online, but this piece in Science says that it’s generating some discussion and controversy already.
“Outcrops like [this] are the reasons many of us are drawn to geology,” says David Kring, a geologist at the Lunar and Planetary Institute in Houston, Texas, who wasn’t a member of the research team. “Those few meters of rock record the wrath of the Chicxulub impact and the devastation it caused.” But not everyone has fully embraced the find, perhaps in part because it was first announced to the world last week in an article in The New Yorker. The paper, in the Proceedings of the National Academy of Sciences (PNAS), does not include all the scientific claims mentioned in The New Yorker story, including that numerous dinosaurs as well as fish were buried at the site.
“I hope this is all legit-I’m just not 100% convinced yet,” says Thomas Tobin, a geologist at the University of Alabama in Tuscaloosa. Tobin says the PNAS paper is densely packed with detail from paleontology, sedimentology, geochemistry, and more. “No one is an expert on all of those subjects,” he says, so it’s going to take a few months for the research community to digest the findings and evaluate whether they support such extraordinary conclusions.
I’m eager to follow the progress of this story as more of the results are released and analyzed by the scientific community.
The sturgeon and paddlefish in this fossil tangle are key. They have small particles stuck in their gills. These are the spherules of molten rock kicked out from the impact that then fell back across the planet. The fish would have breathed in the particles as they entered the river.
The spherules have been linked chemically and by radiometric dating to the Mexican impact location, and in two of the particles recovered from preserved tree resin there are also tiny inclusions that imply an extra-terrestrial origin.
“When we noticed there were inclusions within these little glass spherules, we chemically analysed them at the Diamond X-ray synchrotron near Oxford,” explains Prof Phil Manning, who is Mr DePalma’s PhD supervisor at Manchester.
“We were able to pull apart the chemistry and identify the composition of that material. All the evidence, all of the chemical data, from that study suggests strongly that we’re looking at a piece of the impactor; of the asteroid that ended it for the dinosaurs.”
The program will air on BBC on April 15 and sometime later this year on PBS.
It’s difficult to know how a particular animal might have looked if you only use its skeleton as a guide. For example, we used to think dinosaurs were mostly scaly like lizards until evidence was uncovered that many kinds of dinosaur were more birdlike with feathers.
Most serious paleoart bases itself on the detailed findings of paleontologists, who can work for weeks or even years compiling the most accurate descriptions of ancient life they can, based on fossil remains. But Kosemen says that many dinosaur illustrations should take more cues from animals living today. Our world is full of unique animals that have squat fatty bodies, with all kinds of soft tissue features that are unlikely to have survived in fossils, such as pouches, wattles, or skin flaps. “There could even be forms that no one has imagined,” says Kosemen. “For example there could plant-eating dinosaurs that had pangolin or armadillo-like armor that wasn’t preserved in the fossil. There could also be dinosaurs with porcupine-type quills.”
Here are Kosemen’s drawings of a baboon and swans:
If you thought that photoshopping the characters from the 90s TV Dinosaurs into scenes from Jurassic Park would be impossible, well, Jen Lewis found a way.
(FYI, I loved Dinosaurs. I just looked at when it started airing and it came out much later than I thought…I was a senior in high school and continued watching it after heading off to college. I have clearly repressed the memory of how deeply uncool I was then. (“Then? Then?!!” cackles the narrator.))
Chris Rodley (who is also partially responsible for @MagicRealismBot) is using deep learning (aka artificial intelligence aka machine learning aka what do these things even mean anymore) to cross illustrations of dinosaurs with illustrations of flowers and 19th-century fruit engravings. All your favorites are here: tricherrytops, velocirapple, tree rex, pomme de pterodactyl, frondasaurus, stegosaurose, tuliplodocus. (via @robinsloan)
In 2011, an excavator operator working in a Canadian mine uncovered a group of unusual looking rocks. The rocks turned out to be the remains of a dinosaur called a nodosaur that died about 110 million years ago. The nodosaur was so well preserved that it looks like a stone statue of a dinosaur instead of just fossilized remains.
The more I look at it, the more mind-boggling it becomes. Fossilized remnants of skin still cover the bumpy armor plates dotting the animal’s skull. Its right forefoot lies by its side, its five digits splayed upward. I can count the scales on its sole. Caleb Brown, a postdoctoral researcher at the museum, grins at my astonishment. “We don’t just have a skeleton,” he tells me later. “We have a dinosaur as it would have been.”
The photos are amazing…it really does look like a statue.
As soon as Xing saw it, he knew it wasn’t a plant. It was the delicate, feathered tail of a tiny dinosaur.
“I have studied paleontology for more than 10 years and have been interested in dinosaurs for more than 30 years. But I never expected we could find a dinosaur in amber. This may be the coolest find in my life,” says Xing, a paleontologist at China University of Geosciences in Beijing. “The feathers on the tail are so dense and regular, this is really wonderful.”
Update: One last photo brings this meme to a fitting close. This is Chris Pratt himself, taming some children during a recent visit to a local children’s hospital.
Update: Ok, ok, one more and then that’s it, America needs to move on. Here’s the Dinosaur Curator of the Smithsonian’s National Museum of Natural History taming some actual dinosaurs, long-dead though they may be:
Very broadly, their tree confirmed established ideas about the evolutionary relationships among diplodocids. But the scientists also concluded that Apatosaurus and Brontosaurus were different enough to belong in their own genera. Many of the anatomical differences between the two dinosaurs are obscure, Tschopp says, but Apatosaurus’s stouter neck is an obvious one. “Even though both are very robust and massive animals, Apatosaurus is even more so,” he adds.
Tschopp and his team thought very carefully about their decision to reinstate Brontosaurus, and they expect some pushback. “We knew it would be a major finding because Brontosaurus is such a popular name,” he says. “I’m pretty sure there will be a scientific discussion around this. I hope there will be. That’s how science works.”
Huzzah! Now reinstate Pluto to full planetary status and we’ll be all set. See also The Kindly Brontosaurus. (via @coudal)
There’s a new king of the dinosaurs: Dreadnoughtus schrani. A skeleton of the species was unearthed in Argentina in 2005 and the results of the recently released analysis show this Dreadnoughtus was 85 feet long, weighed around 65 tons, and had a powerful “weaponized tail”. The kicker? It was not yet an adult and still growing when it died.
While other giants from Patagonia are known from a handful of bones, almost half of the Dreadnoughtus skeleton has been recovered. What’s more, the fossilised bones are in such good condition — even revealing where muscles attached — that the skeleton could provide unprecedented insights into the biology, movement and evolution of the group of huge plant-eating dinosaurs it belonged to, called the titanosaurian sauropods.
Dinosaur and bird feathers preserved in amber from a Late Cretaceous site in Canada reveal new insights into the structure, function, and color of animals that date back to about 78 million years ago.
Researchers led by University of Alberta paleontologist Ryan McKellar say these specimens represent distinct stages of feather evolution, from early-stage, single filament protofeathers to much more complex structures associated with modern diving birds. After analyzing the preserved pigment cells, the authors add that these feathered creatures may have also had a range of transparent, mottled, and diffused colors, similar to birds today. They can’t determine which feathers belonged to birds or dinosaurs yet, but they did observe filament structures that are similar to those seen in other non-avian dinosaur fossils. Their findings appear in the current issue of the journal Science.
Is there a word for a scientific fact that is accepted, only to be proven false some years later? Pluto Brontosaurus
and now Triceratops
I’m sure there are more of these, vagaries of science we learned as children ripped cruelly from our pathways in an effort to embarrass us in front of our children (well, your children, mine are imaginary). Let’s make a list? Hit me with an @reply if you know of something that should be on this list.
Update:
This post didn’t quite come out the way I wanted. The triceratops was only momentarily in danger as scientists decided to do away with the Torosaurus instead. Also, Jason wrote a post about a similar topic a couple months ago. Mesofacts are the name for facts that change slowly over time. It’s an important distinction, though, that these ‘facts’, Pluto and Brontosaurus, at least, were ripped away suddenly, instead of changing slowly over time. The only Twitter suggestion I thought fit completely was the loss of RBI as a telling baseball statistic.
The question of the popular Brontosaurus name verses the technically-correct Apatosaurus name came to a head in 1989 when the U.S. Post Office decided to release a set of four stamps illustrating “dinosaurs.” One in the series was a picture of a large sauropod labeled Brontosaurus. This upset some dinosaur enthusiasts who accused the Postal Service of promoting scientific illiteracy, an ironic accusation given the number of museums that had the animal mislabeled for decades. While there was a hue and cry over the Brontosaurus name, few even mentioned the other, more glaring error, which was the inclusion of a Pteranodon (a flying reptile) in a set of dinosaur stamps. By definition dinosaurs do not have wings.
I totally had no idea this had happened…I must have been brainwashed by all those hours of the Flintstones I watched as a child. (via unlikely words)
We now have a robust understanding of how sexual pressures — the pressures to find, impress, and seduce a mate — influence the evolution of males and females. So much so that if you tell me a fact, such as the average size difference between males and females in a species, or the proportion of a male’s body taken up by his testes, I can tell you what the mating system is likely to be. For example, where males are much bigger than females, fighting between males has been important - which often means that the biggest males maintain a harem. If testes are relatively large, females probably have sex with several males in the course of a single breeding episode.
Stay Connected