Impression of Stenopterygius quadrissis, a type of ichthyosaur
Dotted Zebra / Alamy Stock Photo
Prehistoric Earth was home to monsters. They included a 2.5 meter long millipede, a flying reptile with an 11 meter wingspan, and a snake weighing more than a ton. But common sense says that if you're looking for the biggest animal of all time, there's no need to go back in time. Blue whales are known for reach 30 meters The length and weight reach 199 tons. In more than 500 million years of animal evolution, even the largest dinosaurs have no equal.
Conventional wisdom may be wrong. The fossil record may hide animals that were even larger than blue whales. For decades, evidence has trickled in that truly gigantic superpredators swam the oceans 200 million to 250 million years ago. Now, a series of discoveries and reanalyses of previous findings have dramatically supported this claim.
The impact is far-reaching. We don't know exactly what this giant animal looked like, and it doesn't even have a name. But we are beginning to understand how such gigantic creatures were able to feed themselves in prehistoric oceans. If confirmed to be larger than a blue whale, it would indicate that we may have significantly underestimated how large toothed carnivores can grow. More than that, the discovery that such a Leviathan emerged so soon after the most devastating mass extinction in Earth's history suggests that we may need to rethink the factors driving evolution on such a grand scale. ing.
When dinosaurs ruled the land, several groups of marine reptiles also ruled.
Paleontologist at Flinders University brian chu and his colleagues described a new genus and species of Devonian tetrapod fish based on several nearly complete skulls and postcranial skeletons.
rebuilding the life of Harajikadectes zumini. Image credit: Brian Choo, Flinders University.
“Tetrapodomorpha “It consists of tetrapods and their closest fish relatives, the oldest records of which are from the Pragians of China,” said Dr Chu and co-authors.
“This group diversified greatly in both marine and freshwater habitats during the Middle to Late Devonian, giving rise to several distinct lineages, including the earliest quadrupeds.”
“Tetrapods flourished after the Devonian limbless fish tetrapods experienced a marked decline in diversity during the Carboniferous, but only survived into the early Permian before disappearing from the fossil record. There were only a handful of representative animals.”
This new species of tetrapod lived about 380 million years ago and was up to 45 to 50 centimeters long.
with scientific name Harajikadectes zuminithis fish is particularly distinctive for its large opening at the top of its skull.
“These spire-like structures are thought to facilitate air breathing at the surface, and modern African bichir fish have similar structures for taking in air at the surface,” said Dr Chew. Ta.
“This feature appears in multiple tetrapomodorf lineages at about the same time during the middle to late Devonian period.”
“In addition to Harajikadectes zumini Large spiracles also appeared from central Australia. gogonathus El Pisto Stegarian from Western Australia Tiktaalik — are the closest relatives of four-limbed quadrupeds. ”
“And it shows up in unrelated places.” Pickeringius Western Australian stingray fin fish first described in 2018. ”
with Dr. Chu Harajikadectes zumini fossil. Image credit: Flinders University.
Professor John Long from Flinders University said: “This synchronous emergence of air-breathing adaptations may have coincided with a period of reduced atmospheric oxygen during the mid-Devonian.”
“The ability to supplement gill breathing with oxygen from the air may have provided an adaptive advantage.”
“We discovered this new form of lobe-finned fish in one of the most remote fossil sites in all of Australia, the Harajika Sandstone Formation in the Northern Territory, about 200km west of Alice Springs. It dates from the mid-Devonian period. Late period, approximately 380 years ago.'' 1 million years old. ”
“It's difficult to pinpoint the location. Harajikadectes zumini sit in this group of fishes because they appear to have convergently acquired a mosaic of specialized features characteristic of widely separate branches of the tetrapod radiation. ”
of findings will appear in Journal of Vertebrate Paleontology.
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brian chu other. A new species of pedunculated tetrapod fish that lived in the middle to late Devonian period of central Australia. Journal of Vertebrate Paleontology, published online on February 5, 2024. Doi: 10.1080/02724634.2023.2285000
Multiple sclerosis is an autoimmune disease that occurs when the immune system starts attacking the nerves.
Katerina Conn/Science Photo Library
The largest genetic database of ancient humans to date is shedding new light on why people vary in modern conditions such as multiple sclerosis (MS) and other genetic traits such as height.
One of the findings is that the genes behind MS may have become more common because they helped people resist infections transmitted from animals.
Other findings include why Alzheimer’s disease is more common in some groups than others and why people in northern Europe tend to be taller than people in the southern part of the continent. Includes description.
“What happened thousands of years ago can have a very serious impact on the health and longevity of people living today,” he says. Evan Irving Pease at the University of Copenhagen, Denmark.
The genes of people of European and Western Asian ancestry have been shaped by three major waves of migration. Modern hunter-gatherer humans first arrived in these areas about 45,000 years ago. Then, about 11,000 years ago, a wave of farmers arrived from the Middle East, followed by a further influx of pastoralists, now called the Yamnaya, from the Eurasian steppe.
To understand how these popular movements shaped the modern medical landscape, Irving Pease's team collected bone and tooth samples from approximately 5,000 ancient sites found in museum collections across Europe and Western Asia. The oldest one is 34,000 years old.
The latest study reports on the first batch of samples analyzed based on approximately 1600 individuals. The researchers compared these people to the genetic data of 410,000 people in a huge medical dataset called the UK Biobank, and analyzed only white participants to select participants with European ancestry. did.
The research team started by focusing on MS, an autoimmune disease that occurs when the immune system begins to attack nerves, often leading to progressive disability.What previous research has found 233 genetic variants associated with increased risk of MS.
Among modern people in the UK, those at high genetic risk of multiple sclerosis are more likely to have Yamnaya ancestry, a study has shown. The research team also found that some of these MS-predisposing genetic mutations first arose in the Yamnaya tribe and became more frequent among their descendants as they spread westward through Europe.
Given that some of the 233 variants associated with MS also affect the immune system, and that the Yamnaya people have lived among animals, researchers believe that the genes behind MS are probably The researchers concluded that the species may help protect against bacteria and viruses that can be transmitted to humans. animal.The team has previously shown that Some MS risk variants are associated with partial resistance to tuberculosis.
In another paper, researchers have revealed how our ancestry influences our genetic risk for Alzheimer's disease. Modern humans are more likely to have a gene called . Apo E4If you have more ancestors from Europe's first hunter-gatherers, you have a higher risk of developing Alzheimer's disease.
Another variant of this gene is Apo E2The result is a lower risk of Alzheimer's disease, which likely occurred in the incoming Yamnaya people because it provided protection against malaria and unknown viral infections, the researchers wrote in their paper.
Variants that protect against Alzheimer's disease do not confer a reproductive advantage, so they may not have been selected by evolution to have an effect on dementia, given that dementia typically develops long after people have had children. Yes, researchers say. benjamin trumbull from Arizona State University and was not involved in any research.
“The great thing about this paper is that they go further back in time and say what was advantageous or disadvantageous at that time,” Trumbull said. “Too often we look at our modern environment and say: [a certain gene] Purely harmful. We have to consider what the selection pressures were at different points in time. ”
A further finding from the analysis is that among people living in Europe, those with more Yamnaya ancestry tend to be taller, which explains why Northern Europeans are, on average, taller than Southern Europeans. This may explain why it is so expensive.
What is the strongest animal in the world? This is an important question, especially if you are moving and can’t afford to hire movers.
But suppose you have an animal that helps you get around. Which one should you choose? What is the strongest animal? Who can lift the most weight?
To answer this most important question, we have compiled a list of the strongest animals on Earth today. Get ready to journey through a world of brute force as you marvel at incredibly strong birds, muscular polar bears, and powerful punching cows.
10. Harpy Eagle – Can lift 18 kg (twice its own body weight)
A female harpy eagle (Harpia harpyja) carries prey such as a skinned and half-eaten coati (Nasua nasua) to her nest. Pousada Curpila Dalaras, southwestern Brazil.Photo credit: Alamy
Female harpy eagles are the strongest birds in the world. Females are stronger than males and can lift up to 18 kg, about twice their own body weight. This is useful when choosing prey and means a greater variety of animals are available for dinner.
They are apex predators at the top of the food chain. And when you see strength like this, you can see why.
9. Leopard – Can lift 125 kg (about twice its body weight).
A leopard (Panthera pardus) takes shelter in a tree at Sabi Sands Nature Reserve in Mpumalanga, South Africa.Photo credit: David Silverman/Getty Images
The average male leopard weighs between 30 kg and 70 kg, and the largest leopards can lift weights of 125 kg using strong jaw muscles and powerful legs and claws.
Leopards are not as strong as rivals like tigers and lions, so after hunting they need this strength to pull large prey up trees to protect them from rivals. This ability is also useful for storing food out of reach for later consumption.
Researchers used tools from geology and genetics to find evidence of changes in how the first organisms ate, based on molecular fossils and traces of organic matter in rocks from billions of years ago. is made clear. Modern annelids, like earthworms and this bearded fireworm, retain genes that make certain lipids that most animals have lost.
Paleontologists led by David Gold are uncovering the evolution of early life through chemical signatures in ancient rocks and genetic studies. They found that changes in sterol lipids in the rocks corresponded with significant changes in animal diets and increases in algae, shedding light on life more than a billion years ago.
Paleontologists are gaining glimpses of life over the past billion years based on chemical signatures in ancient rocks and the genetics of living animals. Research results announced on December 1st nature communications Combining geology and genetics, it shows how changes in the early Earth prompted changes in the way animals ate.
Molecular paleontology: bridging geology and biology
David Gold, an associate professor in the Department of Earth and Planetary Sciences at the University of California, Davis, works in the new field of molecular paleontology, which uses tools from both geology and biology to study the evolution of life. . A new technique allows researchers to recover chemical signatures of life from ancient rocks where animal fossils are rare.
Lipids in particular can survive in rocks for hundreds of millions of years. Trace amounts of sterol lipids derived from cell membranes have been found in rocks dating back 1.6 billion years. Most animals now use cholesterol, a 27-carbon (C27) sterol, in their cell membranes. In contrast, fungi typically use C28 sterols, and plants and green algae produce C29 sterols. C28 and C29 sterols are also known as phytosterols.
Tracking the evolution of life through chemical markers
C27 sterols have been found in rocks that are 850 million years old, and traces of C28 and C29 appear about 200 million years later. This is thought to reflect the increased diversity of life at this time and the evolution of the first fungi and green algae.
Without actual fossils, it’s difficult to say much about the animals and plants these sterols come from. However, genetic analysis by Gold and colleagues has shed some light.
Don’t make it, eat it
Most animals cannot make phytosterols themselves, but they can obtain them by eating plants and fungi. Recently, annelids (a group that includes segmented worms and common earthworms) smt, required to make long-chain sterols.by seeing smt Gold and colleagues used the genes of different animals to create family trees. smt first within annelids and then across animals in general.
They discovered that this gene originated long before the evolution of the first animals and then underwent rapid changes around the same time that phytosterols appeared in the rock record. After that, most animal lineages smt gene.
“Our interpretation is that these phytosterol molecular fossils document an algae outbreak in the ancient oceans, when animals had easy access to phytosterols from this increasingly abundant food source. “We think they may have abandoned production of phytosterols,” Gold said. “If we are right, the history smt Genes record changes in animals’ feeding strategies early in evolution. ”
Reference: “A common origin of sterol biosynthesis suggests changes in feeding strategies in Neoproterozoic animals” T. Brunoir, C. Mulligan, A. Sistiaga, KM Vuu, PM Shih, SS O’Reilly, RE Summons, DA Gold, November 31, 2023; nature communications. DOI: 10.1038/s41467-023-43545-z
The co-authors of this paper are: hers Tessa Brunoir and Chris Mulligan of the University of California, Davis; Ainara Sistiaga, University of Copenhagen. KM Vuu and Patrick Shih, Joint BioEnergy Institute, Lawrence Berkeley National Laboratory; Shane O’Reilly, Atlantic Institute of Technology, Sligo, Ireland. Roger Sammons, Massachusetts Institute of Technology. This research was supported in part by a grant from the National Science Foundation.
One day in the fall of 2020, Daniella Ressler I drove home with a car full of jumping spiders. Her lab was closed due to COVID-19 restrictions, so Rosler had no choice but to take the specimens home after spending the day corralling them in a dry field. That night, when she happened to check on them, the spiders hanging and not moving “I’ve never seen this before,” says Rosler, a behavioral ecologist at the University of Konstanz in Germany. She immediately returned to the scene with her colleagues. “We started photographing them just out of curiosity,” she says.
They observed the same behavior, but only at night. Even stranger, a few months later, close monitoring of the lab using a night vision camera revealed that there wasn’t just a spider present. He was twitching slightly, but his eyes were moving.. This is similar to what happens when humans dream, and creates an irresistible expectation that spiders are dreaming too.
Jumping spiders aren’t the only non-human animal in which evidence of dream states has recently been discovered. Signs of dreams, and even nightmares, can be found in every species of the animal kingdom, from pigeons to octopuses. “Once you understand the functions involved in dreaming, it makes perfect sense that animals dream,” Ressler says. But still, questions remain. Do other animals dream like us, and if so, what are they dreaming about? This is not easy to understand, but it is worth doing, as it may help us understand the purpose of human dreams.
Shaman, a hairy armadillo cub, cries after being fed custom baby milk
Roshan Patel/Smithsonian National Zoo/Conservation Biology Institute
Killer whale milk has a blindingly fishy smell. Seal milk has a rich orange color. Reindeer milk is about as thick as eggnog, which is probably appropriate. I’m not tempted to try it, and I can see other exotic milks stacked floor-to-ceiling on shelves. I put on my fluffy winter jacket and went inside the freezer that houses the world’s largest collection of animal milk. It contains milk from everything from shrews to two-toed sloths and giant anteaters.
Housed at the Smithsonian’s National Zoo in Washington, D.C., this collection is more than just a shelf of curiosities, it’s a vital resource for zoo workers here and at zoos around the world tasked with nourishing orphaned infants. By studying all this white and not-so-white stuff, scientists at the Smithsonian Institution hope to create custom infant formulas that give the animals in their care the best possible start in life. I can.
However, as our understanding of milk grew, we realized that milk lacked an important element: microorganisms. Now, as they investigate the diversity of microorganisms found in different milks and the benefits these organisms provide, they aim to recreate this in milk produced in the lab. This is not only to better help the young animals in the zoo, but also to help some animals survive. The rarest species in the wild.
Killer whale milk tastes fishy
Espen Bergersen/npl/Alamy
“The goal is not necessarily to freeze and archive milk…
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