‘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.

Damselfly, dragonfly evolution, new resesarch


This 2014 video is called The Secret World of Dragonflies.

From the University of Minnesota in the USA:

Glimpse into ancient hunting strategies of dragonflies and damselflies

January 16, 2020

Dragonflies and damselflies are animals that may appear gentle but are, in fact, ancient hunters. The closely related insects shared an ancestor over 250 million years ago — long before dinosaurs — and provide a glimpse into how an ancient neural system controlled precise and swift aerial assaults.

A paper recently published in Current Biology, led by University of Minnesota researchers, shows that despite the distinct hunting strategies of dragonflies and damselflies, the two groups share key neurons in the circuit that drives the hunting flight. These neurons are so similar, researchers believe the insects inherited them from their shared ancestor and that the neurons haven’t changed much.

Gaining insight into their ability to quickly process images could inform technological advancements. These findings could inform where to mount cameras on drones and autonomous vehicles, and how to process the incoming information quickly and efficiently.

“Dragonflies and damselflies are interesting from an evolutionary point of view because they give us a window into ancient neural systems,” said Paloma Gonzalez-Bellido, assistant professor in the Department of Ecology, Evolution and Behavior in the College of Biological Sciences and senior author on the paper. “And because there are so many species, we can study their behavior and compare their neural performance. You can’t get that from fossils.”

A noticeable difference between dragonflies and damselflies is the shape and position of their eyes. Most dragonflies today have eyes that are close together, often touching along the top of their head. Whereas damselflies sport eyes that are far apart. The researchers wanted to know whether this made a difference in their hunting habits, and if it affected how their neural system detects moving prey.

Researchers found:

  • dragonflies and damselflies hunt prey differently, with dragonflies using a higher resolution area near the top of their eyes to hunt prey from below and damselflies leveraging increased resolution in the front of their eyes to hunt prey in front of them;
  • in dragonflies with eyes that merge at the top, the eyes work as if they were two screens of an extended display (i.e. the image of the prey, which would be equivalent to the mouse pointer, can fall on either the left or the right, but never in both screens at the same time);
  • damselflies eyes work as duplicated screens, where the prey image is seen by both eyes at once (i.e. they have binocular vision);
  • both designs have pros and cons, and their presence correlates with the type of prey and the environment;
  • despite different strategies, the neurons that transfer information about a moving target from the brain to the wing motor centers are nearly identical in the two groups — indicating they were inherited from the common ancestor.

The different hunting strategies pay off in different environments. Dragonflies tend to hunt in an open area, leveraging the contrast of the sky to help them spot their target. Although they can’t calculate depth using two images, they rely on other cues. Damselflies tend to hunt among vegetation, where the selective pressure for fast reaction may be absent, or the need for depth perception stronger.

Researchers are now looking to understand how the extended versus duplicated images are calculated in the brain, and how the information is implemented into muscle movements.

“There is still a lot we do not understand,” said Jack Supple, first author and a recent PhD graduate from Gonzalez-Bellidos laboratory. “We do not know how these neurons coordinate all the different muscles in the body during flight. If we tried to build a realistic robotic damselfly or dragonfly tomorrow we would have a difficult time.”

In addition to examining the differences amongst the two insect families, researchers continue to explore differences in species within each family. “While most dragonflies have eyes close together, there are a handful of species with eyes far apart,” said Gonzalez-Bellido. “Some of them are abundant in Minnesota and we are eager to leverage the new flight arena to study their behavior in a controlled setting.”

Researchers aim to collect at Cedar Creek Ecosystem Science Reserve and Itasca Biological Station and Laboratories this summer, both areas with diverse populations of dragonflies and damselflies.

Ancient scorpion, oldest land animal?


The fossil (left) was unearthed in Wisconsin in 1985. Scientists analyzed it and discovered the ancient animal's respiratory and circulatory organs (center) were near-identical to those of a modern-day scorpion (right). Images courtesy Andrew Wendruff

From Ohio State University in the USA:

Fossil is the oldest-known scorpion

Researchers think it was one of the first animals to spend time on land

January 16, 2020

Scientists studying fossils collected 35 years ago have identified them as the oldest-known scorpion species, a prehistoric animal from about 437 million years ago. The researchers found that the animal likely had the capacity to breathe in both ancient oceans and on land.

The discovery provides new information about how animals transitioned from living in the sea to living entirely on land: The scorpion‘s respiratory and circulatory systems are almost identical to those of our modern-day scorpions — which spend their lives exclusively on land — and operate similarly to those of a horseshoe crab, which lives mostly in the water, but which is capable of forays onto land for short periods of time.

The researchers named the new scorpion Parioscorpio venator. The genus name means “progenitor scorpion,” and the species name means “hunter.” They outlined their findings in a study published today in the journal Scientific Reports.

“We’re looking at the oldest known scorpion — the oldest known member of the arachnid lineage, which has been one of the most successful land-going creatures in all of Earth history,” said Loren Babcock, an author of the study and a professor of earth sciences at The Ohio State University.

“And beyond that, what is of even greater significance is that we’ve identified a mechanism by which animals made that critical transition from a marine habitat to a terrestrial habitat. It provides a model for other kinds of animals that have made that transition including, potentially, vertebrate animals. It’s a groundbreaking discovery.”

The “hunter scorpion” fossils were unearthed in 1985 from a site in Wisconsin that was once a small pool at the base of an island cliff face. They had remained unstudied in a museum at the University of Wisconsin for more than 30 years when one of Babcock’s doctoral students, Andrew Wendruff — now an adjunct professor at Otterbein University in Westerville — decided to examine the fossils in detail.

Wendruff and Babcock knew almost immediately that the fossils were scorpions. But, initially, they were not sure how close these fossils were to the roots of arachnid evolutionary history. The earliest known scorpion to that point had been found in Scotland and dated to about 434 million years ago. Scorpions, paleontologists knew, were one of the first animals to live on land full-time.

The Wisconsin fossils, the researchers ultimately determined, are between 1 million and 3 million years older than the fossil from Scotland. They figured out how old this scorpion was from other fossils in the same formation. Those fossils came from creatures that scientists think lived between 436.5 and 437.5 million years ago, during the early part of the Silurian period, the third period in the Paleozoic era.

“People often think we use carbon dating to determine the age of fossils, but that doesn’t work for something this old,” Wendruff said. “But we date things with ash beds — and when we don’t have volcanic ash beds, we use these microfossils and correlate the years when those creatures were on Earth. It’s a little bit of comparative dating.”

The Wisconsin fossils — from a formation that contains fossils known as the Waukesha Biota — show features typical of a scorpion, but detailed analysis showed some characteristics that were not previously known in any scorpion, such as additional body segments and a short “tail” region, all of which shed light on the ancestry of this group.

Wendruff examined the fossils under a microscope, and took detailed, high-resolution photographs of the fossils from different angles. Bits of the animal’s internal organs, preserved in the rock, began to emerge. He identified the appendages, a chamber where the animal would have stored its venom, and — most importantly — the remains of its respiratory and circulatory systems.

This scorpion is about 2.5 centimeters long — about the same size as many scorpions in the world today. And, Babcock said, it shows a crucial evolutionary link between the way ancient ancestors of scorpions respired under water, and the way modern-day scorpions breathe on land. Internally, the respiratory-circulatory system has a structure just like that found in today’s scorpions.

“The inner workings of the respiratory-circulatory system in this animal are, shape-wise, identical to those of the arachnids and scorpions that breathe air exclusively,” Babcock said. “But it also is incredibly similar to what we recognize in marine arthropods like horseshoe crabs. So, it looks like this scorpion, this lineage, must have been pre-adapted to life on land, meaning they had the morphologic capability to make that transition, even before they first stepped onto land.”

Paleontologists have for years debated how animals moved from sea to land. Some fossils show walking traces in the sand that may be as old as 560 million years, but these traces may have been made in prehistoric surf — meaning it is difficult to know whether animals were living on land or darting out from their homes in the ancient ocean.

But with these prehistoric scorpions, Wendruff said, there was little doubt that they could survive on land because of the similarities to modern-day scorpions in the respiratory and circulatory systems.

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.”

Neanderthals used seashells as tools, new research


This October 2014 video is called A Neanderthal Perspective on Human Origins.

From PLOS:

Neanderthals went underwater for their tools

Neanderthals collected clamshells and pumice from coastal waters to use as tools

January 15, 2020

Neanderthals collected clamshells and volcanic rock from the beach and coastal waters of Italy during the Middle Paleolithic, according to a study published January 15, 2020 in the open-access journal PLOS ONE by Paola Villa of the University of Colorado and colleagues.

Neanderthals are known to have used tools, but the extent to which they were able to exploit coastal resources has been questioned. In this study, Villa and colleagues explored artifacts from the Neanderthal archaeological cave site of Grotta dei Moscerini in Italy, one of two Neanderthal sites in the country with an abundance of hand-modified clamshells, dating back to around 100,000 years ago.

The authors examined 171 modified shells, most of which had been retouched to be used as scrapers. All of these shells belonged to the Mediterranean smooth clam species Callista chione. Based on the state of preservation of the shells, including shell damage and encrustation on the shells by marine organisms, the authors inferred that nearly a quarter of the shells had been collected underwater from the seafloor, as live animals, as opposed to being washed up on the beach. In the same cave sediments, the authors also found abundant pumice stones likely used as abrading tools, which apparently drifted via sea currents from erupting volcanoes in the Gulf of Naples (70km south) onto the Moscerini beach, where they were collected by Neanderthals.

These findings join a growing list of evidence that Neanderthals in Western Europe were in the practice of wading or diving into coastal waters to collect resources long before Homo sapiens brought these habits to the region. The authors also note that shell tools were abundant in sediment layers that had few stone tools, suggesting Neanderthals might have turned to making shell tools during times where more typical stone materials were scarce (though it’s also possible that clam shells were used because they have a thin and sharp cutting edge, which can be maintained through re-sharpening, unlike flint tools).

The authors add: “The cave opens on a beach. It has a large assemblage of 171 tools made on shells collected on the beach or gathered directly from the seafloor as live animals by skin diving Neanderthals. Skin diving for shells or freshwater fishing in low waters was a common activity of Neanderthals, according to data from other sites and from an anatomical study published by E. Trinkaus. Neanderthals also collected pumices erupted from volcanoes in the Gulf of Naples and transported by sea to the beach.”

Fossil seashells, sharks, butterflies in museum


This video is called Miocene fossil clam Pseudolarix amabilis, October 4 2019.

On 13 January 2019, again to Naturalis museum.

Once again, to its Life Science hall.

Marian was working on many, mostly very small, fossils from the Tortonian age; part of the Miocene age; over 7 million years old. The fossils were from France.

There are thousands of seashell species represented in the fossils. As it was then warmer, there was more biodiversity.

Marian sorted the fossil shells according to genus. Later, specialists would do research on the species.

There were also other fossils found at that spot. Like shark teeth, acorn barnacles, sea urchins, and coral.

Next to Marian, work was in progress on classifying 500,000 unclassified butterflies of the Naturalis collection.

This October 20189 Dutch video is about the Naturalis collection.

Precambrian worm-like fossil discovery


This March 2018 video says about itself:

Fossils found around the world suggest that multi-cellular life was not only present before the Cambrian Explosion, it was much more elaborate and diverse than anyone thought. This is the story of the sudden burst of diversity that marked the dawn of truly complex life on our planet.

A three-dimensional image of a 550 million-year-old fossilized tube (left, in red) with internal digestive tract (gold, left and right)

From the University of Missouri-Columbia in the USA:

Scientists find oldest-known fossilized digestive tract — 550 million years

January 10, 2020

A 550-million-year-old fossilized digestive tract found in the Nevada desert could be a key find in understanding the early history of animals on Earth.

Over a half-billion years ago, life on Earth was composed of simple ocean organisms unlike anything living in today’s oceans. Then, beginning about 540 million years ago, animal structures changed dramatically.

During this time, ancestors of many animal groups we know today appeared, such as primitive crustaceans and worms, yet for years scientists did not know how these two seemingly unrelated communities of animals were connected, until now. An analysis of tubular fossils by scientists led by Jim Schiffbauer at the University of Missouri provides evidence of a 550 million-year-old digestive tract — one of the oldest known examples of fossilized internal anatomical structures — and reveals what scientists believe is a possible answer to the question of how these animals are connected.

The study was published in Nature Communications, a journal of Nature.

“Not only are these structures the oldest guts yet discovered, but they also help to resolve the long-debated evolutionary positioning of this important fossil group,” said Schiffbauer, an associate professor of geological sciences in the MU College of Arts and Science and director of the X-ray Microanalysis Core facility. “These fossils fit within a very recognizable group of organisms — the cloudinids — that scientists use to identify the last 10 to 15 million years of the Ediacaran Period, or the period of time just before the Cambrian Explosion. We can now say that their anatomical structure appears much more worm-like than coral-like.”

The Cambrian Explosion is widely considered by scientists to be the point in history of life on Earth when the ancestors of many animal groups we know today emerged.

In the study, the scientists used MU’s X-ray Microanalysis Core facility to take a unique analytical approach for geological science — micro-CT imaging — that created a digital 3D image of the fossil. This technique allowed the scientists to view what was inside the fossil structure.

“With CT imaging, we can quickly assess key internal features and then analyze the entire fossil without potentially damaging it,” said co-author Tara Selly, a research assistant professor in the Department of Geological Sciences and assistant director of the X-ray Microanalysis Core facility.

The study, “Discovery of bilaterian-type through-guts in cloudinomorphs from the terminal Ediacaran Period,” was published in Nature Communications. Other authors include Sarah Jacquet from MU; Rachel Merz from Swarthmore College; Michael Strange from the University of Nevada, Las Vegas; Yaoping Cai from Northwest University in Xi’an, China; and Lyle Nelson and Emmy Smith from Johns Hopkins University.

Funding was provided by grants from the NSF Sedimentary Geology and Paleobiology Program (CAREER 1652351) and Instrumentation and Facilities Program (1636643). The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.