Connect with us

Published

on

A new study has found that a single mysterious event about 19 million years ago wiped nearly the entire population of sharks. Scientists behind the new research say that studying the shark teeth buried in deep-sea sediment, revealed that the current diversity among sharks is only a tiny remnant of a much larger variety that existed back then. They say this unidentified major ocean extinction caused the reduction in the shark diversity by over 70 percent and nearly a complete loss in total abundance. The cause of this event remains a mystery, scientists said.

Researchers say that this single event led to the virtual disappearance of sharks from open-ocean sediments, declining in abundance by almost 90 percent. They added that the abrupt extinction was independent of any known global climate event.

According to the research report published in the journal Science, modern shark forms began to diversify within two to five million years after the near extinction, but they represent only a sliver of what sharks once were.

A report in Life Science quoted Elizabeth Sibert, a postdoctoral fellow at Yale University’s Institute for Biospheric Studies and co-author of the study, as saying, “Sharks have been around for 400 million years; they’ve weathered a lot of mass extinctions.”

The study into the ichthyolites, microscopic fossils of shark scales, found in most types of sediments but are tiny and relatively rare when compared to other microfossils, led to the discovery, Sibert told Live Science.

While scientists in the 1970s and ’80s studied ichthyolites, only a few researchers examined them before Sibert, who investigated them for her doctorate, which she completed in 2016. “A lot of what I’ve done in my early career as a scientist was figuring out how to work with these fossils, what kinds of questions we can ask about them,” Sibert said.

For their new study, Sibert and Leah Rubin, a co-author who was an undergraduate student at the College of the Atlantic in Bar Harbor, Maine at the time of the research, studied sediment cores extracted many years ago by deep-sea drilling projects from two different sites: one in the middle of the North Pacific, and the other in the middle of the South Pacific.

“We picked those sites particularly because they are far away from land and they’re far away from any influences of changing ocean circulation or ocean currents,” Sibert said.

Rubin, who is now going to be a doctoral student at the State University of New York College of Environmental Science and Forestry, said that the extreme nature of this decline in the diversity of sharks was the most surprising aspect of the study to them as well. The million-dollar question, Rubin says, is what caused it?

The paper is just the beginning, Sibert says, and hopes it’s going to be a really interesting next decade to figure out more about what happened at the time that caused the extinction among sharks.


Interested in cryptocurrency? We discuss all things crypto with WazirX CEO Nischal Shetty and WeekendInvesting founder Alok Jain on Orbital, the Gadgets 360 podcast. Orbital is available on Apple Podcasts, Google Podcasts, Spotify, Amazon Music and wherever you get your podcasts.

Continue Reading

Science

Indian Ocean Anomaly Challenges Ekman’s Ocean Current Theory

Published

on

By

Indian Ocean Anomaly Challenges Ekman’s Ocean Current Theory

A study published in Science Advances has identified a significant anomaly to Vagn Walfrid Ekman’s widely-accepted theory on wind-driven ocean currents. Conducted by a team of researchers from NOAA, the Indian National Center for Ocean Information Services and the University of Zagreb, the study focused on the Bay of Bengal in the Indian Ocean. Data spanning several years from a buoy stationed off India’s eastern coast was examined, revealing that ocean currents in this region deflect leftward, contradicting the theory’s predictions for the Northern Hemisphere.

Ekman’s Theory and Its Longstanding Influence

The Ekman theory, developed in 1905 by Swedish oceanographer Vagn Walfrid Ekman, asserts that surface ocean currents are deflected 45 degrees to the right of wind direction in the Northern Hemisphere due to the Coriolis force. Successive layers beneath the surface exhibit similar patterns, forming the Ekman spiral. This mechanism, though robust, assumes idealised conditions, including uniform ocean depth and density. Variations such as those observed in the Bay of Bengal highlight its limitations.

Findings from the Bay of Bengal

As per the study, according to data collected over several years, currents in the Bay of Bengal were found to veer leftward despite prevailing winds, defying Ekman’s predictions. This anomaly underscores the need to reassess assumptions about global oceanic patterns. The researchers suggested that local factors, including unique regional wind patterns and oceanic dynamics, could play a significant role.

Implications for Climate Models

It was noted in a statement by the researchers that the findings could influence future climate modelling efforts. If exceptions to Ekman’s theory exist in the Bay of Bengal, others might also occur globally, underscoring the need for more detailed oceanographic studies. Discussions have also highlighted the potential deployment of a NASA satellite system to monitor wind and surface currents comprehensively.

This study has brought attention to gaps in understanding wind-driven currents, stressing the importance of revisiting established models as global warming continues to impact ocean behaviour.

For the latest tech news and reviews, follow Gadgets 360 on X, Facebook, WhatsApp, Threads and Google News. For the latest videos on gadgets and tech, subscribe to our YouTube channel. If you want to know everything about top influencers, follow our in-house Who’sThat360 on Instagram and YouTube.


World Labs Unveils AI System That Can Generate 3D Interactive Worlds Using an Image



Samsung Galaxy Z Fold 7, Galaxy Z Flip 7 to Debut With Larger Displays: Report

Related Stories

Continue Reading

Science

ISRO’s PSLV-C59 to Launch ESA’s Proba-3 Mission for Sun Corona Study

Published

on

By

ISRO's PSLV-C59 to Launch ESA's Proba-3 Mission for Sun Corona Study

The Indian Space Research Organisation (ISRO) has scheduled the launch of the PSLV-C59 rocket carrying the Proba-3 spacecraft for December 4, 2024, at 4:08 PM IST, as per reports. The mission, a dedicated commercial venture of NewSpace India Limited (NSIL), will take off from the First Launch Pad at the Satish Dhawan Space Centre, Sriharikota. According to reports, this will mark the 61st mission of the Polar Satellite Launch Vehicle (PSLV) and the 21st use of its XL configuration.

Mission Overview

As per sources, Proba-3, a project developed by the European Space Agency (ESA), is an In-Orbit Demonstration (IOD) mission aimed at showcasing precision formation flying. The spacecraft consists of two components: the Coronagraph Spacecraft (CSC) and the Occulter Spacecraft (OSC). These satellites, launched in a stacked arrangement, will operate in tandem, maintaining a precise distance of 150 meters. The innovative configuration will enable the creation of artificial solar eclipses, allowing extended observation of the Sun’s corona.

Scientific Objectives

Reports indicate that the mission’s primary objective is to explore the Sun’s corona, the outermost layer of its atmosphere, to enhance understanding of solar dynamics and space weather. Instruments aboard the spacecraft have been designed to block the Sun’s intense light, facilitating detailed study of solar phenomena that are otherwise difficult to observe. Proba-3’s ability to continuously monitor the corona for up to six hours is expected to yield valuable scientific data.

Collaboration and Technology

The mission highlights significant collaboration between ISRO and ESA. Reportedly, the PSLV-XL rocket, equipped with additional strap-on boosters, will carry a payload weighing approximately 550 kg. The precision formation flying technology demonstrated by Proba-3 is expected to pave the way for advanced techniques in space exploration. The launch preparations at the Satish Dhawan Space Centre are underway, and all systems are reportedly on track for the scheduled liftoff.

Continue Reading

Science

Meet Homo juluensis: A newly discovered ancient human species

Published

on

By

Meet Homo juluensis: A newly discovered ancient human species

A new ancient human species, Homo juluensis, has been identified by researchers, marking a significant step in understanding human evolution in the Middle Pleistocene epoch. According to findings published in PaleoAnthropology in May 2024, the discovery is based on fossil evidence unearthed in China, with specimens dating between 220,000 and 100,000 years ago. The species, known as “big head people,” is characterised by large skulls, blending features seen in modern humans, Neanderthals and Denisovans.

Fossil Evidence and Characteristics

The fossils forming the basis of this new classification were recovered from sites in Xujiayao and Xuchang in northern and central China, as per reports. Excavations at Xujiayao in the 1970s yielded over 10,000 stone tools and 21 fossil fragments, representing at least 10 individuals. These fossils display large, wide crania with Neanderthal-like characteristics, yet also share traits with modern humans and Denisovans. Four additional ancient skulls discovered at Xuchang exhibit similar features.

The research team, led by Christopher Bae, an anthropologist at the University of Hawai’i and Xiujie Wu, a paleoanthropologist at the Chinese Academy of Sciences, concluded that these fossils represent a distinct hominin population. The findings indicate a likely continuity of hybridisation among Middle Pleistocene hominins, which shaped human evolution in eastern Asia.

Naming and Expert Perspectives

In a statement to Nature Communications, published in November 2024, the researchers advocated for using Homo juluensis to clarify eastern Asia’s complex fossil record. While some experts, such as Chris Stringer of the Natural History Museum in London, have suggested the fossils might align more closely with Homo longi, the designation of Homo juluensis has gained traction.

The name, according to Bae, in a statement, was introduced to improve scientific communication. Paleoanthropologist John Hawks of the University of Wisconsin–Madison noted in a blog post that such terminology allows clearer reference to this population’s place in the human evolutionary narrative. The discovery underscores the intricate relationships within ancient hominin groups and their evolutionary significance.

Continue Reading

Trending