‘Asteroid, not volcanoes, killed dinosaurs’


This 2016 video says about itself:

How Asteroids Really Killed The Dinosaurs – Part 1 | Last Days of the Dinosaurs

In the clip from Last Days of the Dinosaur, we learn how the asteroids really killed the dinosaurs

Asteroid Day is celebrated every year on the 30th of June.

This 2016 video says about itself:

How Asteroids Really Killed The Dinosaurs – Part 2 | Last Day Of The Dinosaurs

Did you know that if the asteroid that wiped out the dinosaurs from the face of the Earth would have hit another location, they might still be alive? The shallow waters of the Gulf Of Mexico instantly vaporized as the asteroid hit, causing absolute destruction. This was the Last Day Of The Dinosaurs.

From Yale University in the USA:

In death of dinosaurs, it was all about the asteroid — not volcanoes

January 16, 2020

Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers. It was all about the asteroid.

In a break from a number of other recent studies, Yale assistant professor of geology & geophysics Pincelli Hull and her colleagues argue in a new research paper in Science that environmental impacts from massive volcanic eruptions in India in the region known as the Deccan Traps happened well before the Cretaceous-Paleogene extinction event 66 million years ago and therefore did not contribute to the mass extinction.

Most scientists acknowledge that the mass extinction event, also known as K-Pg, occurred after an asteroid slammed into Earth. Some researchers also have focused on the role of volcanoes in K-Pg due to indications that volcanic activity happened around the same time.

“Volcanoes can drive mass extinctions because they release lots of gases, like SO2 and CO2, that can alter the climate and acidify the world,” said Hull, lead author of the new study. “But recent work has focused on the timing of lava eruption rather than gas release.”

To pinpoint the timing of volcanic gas emission, Hull and her colleagues compared global temperature change and the carbon isotopes (an isotope is an atom with a higher or lower number of neutrons than normal) from marine fossils with models of the climatic effect of CO2 release. They concluded that most of the gas release happened well before the asteroid impact — and that the asteroid was the sole driver of extinction.

“Volcanic activity in the late Cretaceous caused a gradual global warming event of about two degrees, but not mass extinction,” said former Yale researcher Michael Henehan, who compiled the temperature records for the study. “A number of species moved toward the North and South poles but moved back well before the asteroid impact.”

Added Hull, “A lot of people have speculated that volcanoes mattered to K-Pg, and we’re saying, ‘No, they didn’t.'”

Recent work on the Deccan Traps, in India, has also pointed to massive eruptions in the immediate aftermath of the K-Pg mass extinction. These results have puzzled scientists because there is no warming event to match. The new study suggests an answer to this puzzle, as well.

“The K-Pg extinction was a mass extinction and this profoundly altered the global carbon cycle,” said Yale postdoctoral associate Donald Penman, the study’s modeler. “Our results show that these changes would allow the ocean to absorb an enormous amount of CO2 on long time scales — perhaps hiding the warming effects of volcanism in the aftermath of the event.”

The International Ocean Discovery Program, the National Science Foundation, and Yale University helped fund the research.

Feathered dinosaurs differed from birds


This 2013 BBC video says about itself:

With its feathered plumage acting as camouflage Sinornithosaurus moves unseen through the treetops. Recent studies suggest Sinornithosaurus was capable of hunting at night as well as delivering a lethal poison in its bite.

From San Diego Natural History Museum in the USA:

New feathered dinosaur shows dinosaurs grew up differently from birds

January 15, 2020

A new species of feathered dinosaur has been discovered in China, and described by American and Chinese authors and published today in the journal The Anatomical Record.

The one-of-a-kind specimen offers a window into what the earth was like 120 million years ago. The fossil preserves feathers and bones that provide new information about how dinosaurs grew and how they differed from birds.

“The new dinosaur fits in with an incredible radiation of feathered, winged animals that are closely related to the origin of birds“, said Dr. Ashley Poust, who analyzed the specimens while he was a student at Montana State University and during his time as a Ph.D. student at University of California, Berkeley. Poust is now postdoctoral researcher at the San Diego Natural History Museum.

“Studying specimens like this not only shows us the sometimes-surprising paths that ancient life has taken, but also allows us to test ideas about how important bird characteristics, including flight, arose in the distant past.”

Scientists named the dinosaur Wulong bohaiensis. Wulong is Chinese for “the dancing dragon” and references the position of the beautifully articulated specimen.

Wulong bohaiensis

About the discovery

The specimen was found more than a decade ago by a farmer in China, in the fossil-rich Jehol Province, and since then has been housed in the collection of The Dalian Natural History Museum in Liaoning, a northeastern Chinese province bordering North Korea and the Yellow Sea. The skeletal bones were analyzed by Poust alongside his advisor Dr. David Varricchio from Montana State University while Poust was a student there.

Larger than a common crow and smaller than a raven, but with a long, bony tail which would have doubled its length, Wulong bohaiensis had a narrow face filled with sharp teeth. Its bones were thin and small, and the animal was covered with feathers, including a wing-like array on both its arms and legs and two long plumes at the end of its tail.

This animal is one of the earliest relatives of Velociraptor, the famous dromaeosaurid theropod dinosaur that lived approximately 75 million years ago. Wulong’s closest well-known relative would have been Microraptor, a genus of small, four-winged paravian dinosaurs.

The discovery is significant not only because it describes a dinosaur that is new to science, but also because it shows connection between birds and dinosaurs.

“The specimen has feathers on its limbs and tail that we associate with adult birds, but it had other features that made us think it was a juvenile,” said Poust. To understand this contradiction, the scientists cut up several bones of the new dinosaur to examine under a microscope. This technique, called bone histology, is becoming a regular part of the paleontology toolbox, but it’s still sometimes difficult to convince museums to let a researcher remove part of a nice skeleton. “Thankfully, our coauthors at the Dalian Natural History Museum were really forward-thinking and allowed us to apply these techniques, not only to Wulong, but also to another dinosaur, a close relative that looked more adult called Sinornithosaurus.”

The bones showed that the new dinosaur was a juvenile. This means that at least some dinosaurs were getting very mature looking feathers well before they were done growing. Birds grow up very fast and often don’t get their adult plumage until well after they are full-sized. Showy feathers, especially those used for mating, are particularly delayed. And yet here was an immature dinosaur with two long feathers extending beyond the tip of the tail.

“Either the young dinosaurs needed these tail feathers for some function we don’t know about, or they were growing their feathers really differently from most living birds,” explained Poust.

An additional surprise came from the second dinosaur the scientists sampled; Sinornithosaurus wasn’t done growing either. The bone tissue was that of an actively growing animal and it lacked an External Fundamental System: a structure on the outside of the bone that vertebrates form when they’re full size. “Here was an animal that was large and had adult looking bones: we thought it was going to be mature, but histology proved that idea wrong. It was older than Wulong, but seems to have been still growing. Researchers need to be really careful about determining whether a specimen is adult or not. Until we learn a lot more, histology is really the most dependable way.”

In spite of these cautions, Poust says there is a lot more to learn about dinosaurs.

“We’re talking about animals that lived twice as long ago as T. rex, so it’s pretty amazing how well preserved they are. It’s really very exciting to see inside these animals for the first time.”

About the Jehol Biota

The area in which the specimen was found is one of the richest fossil deposits in the world. The Jehol biota is known for the incredible variety of animals that were alive at the time. It is also one of the earliest bird-rich environments, where birds, bird-like dinosaurs, and pterosaurs all shared the same habitat.

“There was a lot of flying, gliding, and flapping around these ancient lakes,” says Poust. “As we continue to discover more about the diversity of these small animals it becomes interesting how they all might have fit into the ecosystem.” Other important changes were happening at the same time in the Early Cretaceous, including the spread of flowering plants. “It was an alien world, but with some of the earliest feathers and earliest flowers, it would have been a pretty one.”

Rattlesnakes drink rainwater from their backs


This 2014 video from the USA is called Western Diamondback Rattlesnake – Behind the Adventure.

From the American Chemical Society in the USA:

How rattlesnakes‘ scales help them sip rainwater from their bodies

January 8, 2020

During storms in the southwestern U.S., some rattlesnakes drink rain droplets from scales on their backs. This unusual behavior could help them survive in a desert environment with infrequent rain. Now, researchers have figured out how the nanotexture of scales from these snakes helps them use their bodies to harvest rain. They report their results in ACS Omega.

The western diamondback rattlesnake (Crotalus atrox) from southern Arizona and other areas of the U.S. Southwest has been seen emerging from its den to harvest rain, sleet and even snow. The snake flattens its body and often forms a tight coil, presumably to maximize the area for water-gathering. As rain droplets coalesce on its back, the slithery reptile sucks water from the scales. Gordon Schuett, Konrad Rykaczewski and colleagues wanted to take a closer look at rattlesnake scales to determine what makes these serpents so adept at harvesting precipitation.

The researchers compared the surface wettability and nanotexture of scales from the western diamondback rattlesnake and two other species of desert-dwelling snakes that do not show rain-harvesting behavior: the desert kingsnake and the Sonoran gopher snake. The team dropped water onto the snakes’ backs, finding that the droplets beaded up, coalesced and stuck to the rattlesnake’s scales, whereas they formed shallow puddles that often slipped off the other snakes’ bodies. Scanning electron microscopy of rattlesnake scales revealed nanochannels that form a labyrinth-like network, but scales from the other two snakes did not show these same features. The rattlesnake’s dorsal scales aid in water collection by providing a sticky, hydrophobic surface that “pins” water droplets to the surface, the researchers say.

2019 South African wildlife highlights, video


This 4 December 2019 video from Kruger National Park in South Africa says about itself:

Best Wildlife Sightings of 2019

1. Eagle Catches Warthog

2. Honey Badger Saves Baby From Leopard

3. Half an Impala Tries Escaping Hyena

4. Wild Dog Plays Dead to Escape Lion

5. Leopards Fight as Warthog Escapes Them

6. Snake Eagle Ripping Snake Apart

7. Leopard Tries Escaping Lions

8. Elephant Tramples Rhinos

9. Leopard vs Croc

10. Python vs Leopard