Mosasaur egg discovery in Antarctica?


This October 2018 video says about itself:

Mosasaurs were Earth’s last great marine reptiles. Learn about the surprising places they’d hunt, how some species dwarfed even the Tyrannosaurus rex, and how key physical adaptations allowed these reptiles to become a prehistoric apex predator.

From the University of Texas at Austin in the USA:

First egg from Antarctica is big and might belong to an extinct sea lizard

June 17, 2020

In 2011, Chilean scientists discovered a mysterious fossil in Antarctica that looked like a deflated football. For nearly a decade, the specimen sat unlabeled and unstudied in the collections of Chile’s National Museum of Natural History, with scientists identifying it only by its sci-fi movie-inspired nickname — “The Thing.”

An analysis led by researchers at The University of Texas at Austin has found that the fossil is a giant, soft-shell egg from about 66 million years ago. Measuring in at more than 11 by 7 inches, the egg is the largest soft-shell egg ever discovered and the second-largest egg of any known animal.

The specimen is the first fossil egg found in Antarctica and pushes the limits of how big scientists thought soft-shell eggs could grow. Aside from its astounding size, the fossil is significant because scientists think it was laid by an extinct, giant marine reptile, such as a mosasaur — a discovery that challenges the prevailing thought that such creatures did not lay eggs.

“It is from an animal the size of a large dinosaur, but it is completely unlike a dinosaur egg,” said lead author Lucas Legendre, a postdoctoral researcher at UT Austin’s Jackson School of Geosciences. “It is most similar to the eggs of lizards and snakes, but it is from a truly giant relative of these animals.”

A study describing the fossil egg was published in Nature on June 17.

Co-author David Rubilar-Rogers of Chile’s National Museum of Natural History was one of the scientists who discovered the fossil in 2011. He showed it to every geologist who came to the museum, hoping somebody had an idea, but he didn’t find anyone until Julia Clarke, a professor in the Jackson School’s Department of Geological Sciences, visited in 2018.

“I showed it to her and, after a few minutes, Julia told me it could be a deflated egg!” Rubilar-Rogers said.

Using a suite of microscopes to study samples, Legendre found several layers of membrane that confirmed that the fossil was indeed an egg. The structure is very similar to transparent, quick-hatching eggs laid by some snakes and lizards today, he said. However, because the fossil egg is hatched and contains no skeleton, Legendre had to use other means to zero in on the type of reptile that laid it.

He compiled a data set to compare the body size of 259 living reptiles to the size of their eggs, and he found that the reptile that laid the egg would have been more than 20 feet long from the tip of its snout to the end of its body, not counting a tail. In both size and living reptile relations, an ancient marine reptile fits the bill.

Adding to that evidence, the rock formation where the egg was discovered also hosts skeletons from baby mosasaurs and plesiosaurs, along with adult specimens.

“Many authors have hypothesized that this was sort of a nursery site with shallow protected water, a cove environment where the young ones would have had a quiet setting to grow up,” Legendre said.

The paper does not discuss how the ancient reptile might have laid the eggs. But the researchers have two competing ideas.

One involves the egg hatching in the open water, which is how some species of sea snakes give birth. The other involves the reptile depositing the eggs on a beach and hatchlings scuttling into the ocean like baby sea turtles. The researchers say that this approach would depend on some fancy maneuvering by the mother because giant marine reptiles were too heavy to support their body weight on land. Laying the eggs would require the reptile to wriggle its tail onshore while staying mostly submerged, and supported, by water.

“We can’t exclude the idea that they shoved their tail end up on shore because nothing like this has ever been discovered”, Clarke said.

First frog fossil from Antarctica discovered


This video says about itself:

Saturday, 25 April 2020

First frog fossil found on Antarctica

In 2015, Thomas Mörs reached for a frog in the sand — but the frog didn’t hop away. That’s because the frog had been fossilized 40 million years ago.

By Maria Temming, April 23, 2020 at 11:00 am:

The first frog fossil from Antarctica has been found

An ancient amphibian sheds light on when the continent iced over

The first fossil of a frog found in Antarctica gives new insight into the continent’s ancient climate.

Paleontologists uncovered fragments of the frog’s hip bone and skull in 40-million-year-old sediment collected from Seymour Island, near the tip of the Antarctic Peninsula.

Scientists have previously found evidence of giant amphibians that walked Antarctica during the Triassic Period, over 200 million years ago, but no traces on the continent of amphibians like those around today (SN: 3/23/15). The shape of the newly discovered bones indicates that this frog belonged to the family of Calyptocephalellidae, or helmeted frogs, found today in South America.

The fossilized frog’s modern relatives live exclusively in the warm, humid central Chilean Andes. This suggests that similar climate conditions existed on Antarctica around 40 million years ago, researchers report April 23 in Scientific Reports.

That offers a clue about how fast Antarctica switched from balmy to bitter cold (SN: 4/1/20). Antarctica quickly froze over after splitting from Australia and South America, which were once all part of the supercontinent Gondwana (SN: 10/10/19). But some geologic evidence suggests that ice sheets began forming on Antarctica before it fully separated from the other southern continents about 34 million years ago.

“The question is now, how cold was it, and what was living on the continent when these ice sheets started to form?” says study coauthor Thomas Mörs, a paleontologist at the Swedish Museum of Natural History in Stockholm. “This frog is one more indication that in [that] time, at least around the Peninsula, it was still a suitable habitat for cold-blooded animals like reptiles and amphibians.”

Antarctic penguins and climate change


This 8 April 2020 video says about itself:

Antarctica, climate change and a tale of two penguins

Jonathan Watts visits Antarctica with a team of scientists to look at how human activity and rising temperatures are creating winners and losers among penguins – and why this should be a warning to us all.

Food wrapping, fishing gear and plastic waste continue to reach the Antarctic. Two new studies detail how plastic debris is reaching sub-Antarctic islands: here.

Dinosaur age rainforest discovery in Antarctica


This 2016 video says about itself:

Discovery of fossil “voice box” of Antarctic bird suggests dinosaurs couldn’t sing.

Researchers have found the oldest known fossil vocal organ of a bird … in Antarctica. The voice box is from a species related to ducks and geese that lived during the age of dinosaurs more than 66 million years ago.

A National Science Foundation-funded team led by the University of Texas at Austin discovered the ancient vocal organ called a syrinx–and its apparent absence from non-bird dinosaur fossils of the same age. Researchers believe the organ may have originated late in the evolution of birds after the origin of flight. Drawing on their research, team leader Julia Clarke said that other dinosaurs may not have been able to make noises similar to modern bird calls, but most likely made closed-mouth sounds similar to ostrich booms that don’t require a syrinx.

The organ was found in a fossil species called Vegavis iaai. The fossil was discovered in 1992 on Vega Island in the Antarctic Peninsula by a team from the Argentine Antarctic Institute. It was named in 2005 by Clarke and Argentine colleagues. But, it wasn’t until 2013 Clarke discovered the fossil syrinx in the new specimen and began analysis. The international team may figure out what dinosaurs sounded like, gaining insight into the origins of bird song. The findings appear in the October 12 issue of “Nature”.

From Imperial College London in England:

Traces of ancient rainforest in Antarctica point to a warmer prehistoric world

April 1, 2020

Researchers have found evidence of rainforests near the South Pole 90 million years ago, suggesting the climate was exceptionally warm at the time.

A team from the UK and Germany discovered forest soil from the Cretaceous period within 900 km of the South Pole. Their analysis of the preserved roots, pollen and spores shows that the world at that time was a lot warmer than previously thought.

The discovery and analysis were carried out by an international team of researchers led by geoscientists from the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Germany and including Imperial College London researchers. Their findings are published today in Nature.

Co-author Professor Tina van de Flierdt, from the Department of Earth Science & Engineering at Imperial, said: “The preservation of this 90-million-year-old forest is exceptional, but even more surprising is the world it reveals. Even during months of darkness, swampy temperate rainforests were able to grow close to the South Pole, revealing an even warmer climate than we expected.”

The work also suggests that the carbon dioxide (CO2) levels in the atmosphere were higher than expected during the mid-Cretaceous period, 115-80 million years ago, challenging climate models of the period.

The mid-Cretaceous was the heyday of the dinosaurs but was also the warmest period in the past 140 million years, with temperatures in the tropics as high as 35 degrees Celsius and sea level 170 metres higher than today.

However, little was known about the environment south of the Antarctic Circle at this time. Now, researchers have discovered evidence of a temperate rainforest in the region, such as would be found in New Zealand today. This was despite a four-month polar night, meaning for a third of every year there was no life-giving sunlight at all.

The presence of the forest suggests average temperatures were around 12 degrees Celsius and that there was unlikely to be an ice cap at the South Pole at the time.

The evidence for the Antarctic forest comes from a core of sediment drilled into the seabed near the Pine Island and Thwaites glaciers in West Antarctica. One section of the core, that would have originally been deposited on land, caught the researchers’ attention with its strange colour.

The team CT-scanned the section of the core and discovered a dense network of fossil roots, which was so well preserved that they could make out individual cell structures. The sample also contained countless traces of pollen and spores from plants, including the first remnants of flowering plants ever found at these high Antarctic latitudes.

To reconstruct the environment of this preserved forest, the team assessed the climatic conditions under which the plants’ modern descendants live, as well as analysing temperature and precipitation indicators within the sample.

They found that the annual mean air temperature was around 12 degrees Celsius; roughly two degrees warmer than the mean temperature in Germany today. Average summer temperatures were around 19 degrees Celsius; water temperatures in the rivers and swamps reached up to 20 degrees; and the amount and intensity of rainfall in West Antarctica were similar to those in today’s Wales.

To get these conditions, the researchers conclude that 90 million years ago the Antarctic continent was covered with dense vegetation, there were no land-ice masses on the scale of an ice sheet in the South Pole region, and the carbon dioxide concentration in the atmosphere was far higher than previously assumed for the Cretaceous.

Lead author Dr Johann Klages, from the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, said: “Before our study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1000 ppm. But in our model-based experiments, it took concentration levels of 1120 to 1680 ppm to reach the average temperatures back then in the Antarctic.”

Visit to Dear Kitty blog from Antarctica


This October 2019 video says about itself:

Join a team of marine scientists as they embark on an unprecedented journey across the Great Southern Ocean and beyond to Antarctica.

Today, for the first time ever, WordPress stats recorded a visit to Dear Kitty. Some blog from Antarctica.

Welcome, visitor, like visitors from all continents are welcome here! This brings back fond memories from when I was in the Antarctic.

How emperor penguins stay warm by huddling


This 27 December 2019 video about emperor penguins says about itself:

How Does Huddling Help Penguins Stay Warm? | BBC Earth

The centre of a penguin huddle can reach temperatures of up to 37 degrees C! How exactly does piling in help these snow animals stay so warm?

Antarctic gentoo penguins build nests


This 16 December 2019 video says about itself:

Gentoo Penguins Build Love Nests! | Penguin Post Office | BBC Earth

Why have a rock on your finger when you can have them in a nice neat pile? These Gentoo penguins have the right idea.

On a tiny island in Antarctica, there’s a post office surrounded by jaw-dropping scenery and 4,000 Gentoo penguins… Every summer, as tourists turn up in their hundreds to see the penguins and to send a postcard, the birds rush to find a partner and raise their young. This extraordinary four-month drama starts when the first penguin hops onto the island and continues until the last one leaves and the post office closes its doors for winter.

I was privileged to see these Port Lockroy penguins.

Before dinosaur extinction, life in trouble


This 2018 BBC video is called How did an Asteroid Drive the Dinosaurs to Extinction? | Earth Unplugged.

From Northwestern University in the USA:

Earth was stressed before dinosaur extinction

Fossilized seashells show signs of global warming, ocean acidification leading up to asteroid impact

December 11, 2019

Summary: By measuring the chemistry of fossilized seashells collected in Antarctica, researchers discovered that Earth was already experiencing carbon cycle instability before the asteroid impact that wiped out the dinosaurs.

New evidence gleaned from Antarctic seashells confirms that Earth was already unstable before the asteroid impact that wiped out the dinosaurs.

The study, led by researchers at Northwestern University, is the first to measure the calcium isotope composition of fossilized clam and snail shells, which date back to the Cretaceous-Paleogene mass extinction event. The researchers found that — in the run-up to the extinction event — the shells’ chemistry shifted in response to a surge of carbon in the oceans.

This carbon influx was likely due to long-term eruptions from the Deccan Traps, a 200,000-square-mile volcanic province located in modern India. During the years leading up to the asteroid impact, the Deccan Traps spewed massive amounts of carbon dioxide (CO2) into the atmosphere. The concentration of CO2 acidified the oceans, directly affecting the organisms living there.

“Our data suggest that the environment was changing before the asteroid impact,” said Benjamin Linzmeier, the study’s first author. “Those changes appear to correlate with the eruption of the Deccan Traps.”

“The Earth was clearly under stress before the major mass extinction event,” said Andrew D. Jacobson, a senior author of the paper. “The asteroid impact coincides with pre-existing carbon cycle instability. But that doesn’t mean we have answers to what actually caused the extinction.”

The study will be published in the January 2020 issue of the journal Geolology, which comes out later this month.

Jacobson is a professor of Earth and planetary sciences in Northwestern’s Weinberg College of Arts and Sciences. Linzmeier was a postdoctoral researcher with the Ubben Program for Climate and Carbon Science at the Institute for Sustainability and Energy at Northwestern when the research was conducted. He is now a postdoctoral fellow at the University of Wisconsin-Madison in the Department of Geoscience.

‘Each shell is a snapshot’

Previous studies have explored the potential effects of the Deccan Traps eruptions on the mass extinction event, but many have examined bulk sediments and used different chemical tracers. By focusing on a specific organism, the researchers gained a more precise, higher-resolution record of the ocean’s chemistry.

“Shells grow quickly and change with water chemistry,” Linzmeier said. “Because they live for such a short period of time, each shell is a short, preserved snapshot of the ocean’s chemistry.”

Seashells mostly are composed of calcium carbonate, the same mineral found in chalk, limestone and some antacid tablets. Carbon dioxide in water dissolves calcium carbonate. During the formation of the shells, CO2 likely affects shell composition even without dissolving them.

For this study, the researchers examined shells collected from the Lopez de Bertodano Formation, a well-preserved, fossil-rich area on the west side of Seymour Island in Antarctica. They analyzed the shells’ calcium isotope compositions using a state-of-the-art technique developed in Jacobson’s laboratory at Northwestern. The method involves dissolving shell samples to separate calcium from various other elements, followed by analysis with a mass spectrometer.

“We can measure calcium isotope variations with high precision,” Jacobson said. “And those isotope variations are like fingerprints to help us understand what happened.”

Using this method, the team found surprising information.

“We expected to see some changes in the shells’ composition, but we were surprised by how quickly the changes occurred,” Linzmeier said. “We also were surprised that we didn’t see more change associated with the extinction horizon itself.”

A future warning

The researchers said that understanding how the Earth responded to past extreme warming and CO2 input can help us prepare for how the planet will respond to current, human-caused climate change.

“To some degree, we think that ancient ocean acidification events are good analogs for what’s happening now with anthropogenic CO2 emissions,” Jacobson said. “Perhaps we can use this work as a tool to better predict what might happen in the future. We can’t ignore the rock record. The Earth system is sensitive to large and rapid additions of CO2. Current emissions will have environmental consequences.”

Brad Sageman and Matthew Hurtgen, both professors of Earth and planetary sciences at Northwestern, are co-senior authors of the paper.

The study, “Calcium isotope evidence for environmental variability before and across the Cretaceous-Paleogene mass extinction,” was supported by the Ubben Program for Climate and Carbon Science at Northwestern University, the David and Lucile Packard Foundation (award number 2007-31757) and the National Science Foundation (award numbers EAR-0723151, ANT-1341729, ANT-0739541 and ANT-0739432.

Antarctic penguins, Robert Falcon Scott till today


This 13 January 2018 video is called Antarctica Ross Sea. Part 21. Cape Adare. Adélie Penguins mating.

By Carolyn Gramling, December 6, 2019 at 10:00 am:

‘A Polar Affair’ delves into a centurylong cover-up of penguin sex

A new book surveys penguin biology and Antarctic exploration history

A Polar Affair
Lloyd Spencer Davis
Pegasus Books, $29.95

On March 29, 1912, British explorer Robert Falcon Scott wrote the final diary entry of his ill-fated quest to reach the South Pole. That same day, more than 350 kilometers away, naval surgeon and zoologist George Murray Levick was hunkered down within a snowbank at Cape Adare, observing Adélie penguins.

Levick had accompanied Scott to Antarctica, but was not one of the five expedition members on the final trek to the pole. The return journey claimed the lives of all five. Levick survived the expedition, however, and in 1914, published a manuscript summarizing his observations — the first scientific descriptions of Antarctic penguins.

But he left something out.

During his months observing Adélie penguins, which included an entire breeding cycle, Levick witnessed the birds engaging in same-sex mating rituals. He also saw the birds engage in a variety of other sexual behaviors that in humans we might call promiscuity, infidelity, even prostitution. Levick recorded these scandalous details in a second manuscript, “The sexual habits of the Adélie penguin”, in 1915. But the manuscript was stamped “Not for Publication” and remained unpublished for nearly a century.

In 2012, the manuscript resurfaced in a scientific journal. Penguin biologist and author Lloyd Spencer Davis, who had thought he was the first to record same-sex behavior in Antarctic penguins in 1996, was dismayed and intrigued. So Davis embarked on a personal quest to understand how and why Levick’s observations had been buried in the first place — seemingly by his own wishes.

The result of that quest is Davis’ book A Polar Affair, an entertaining, chatty and sometimes salacious romp through polar exploration history, penguin biology and Victorian mores.

Each of the book’s five sections opens with a brief essay — Homosexuality, Divorce, Infidelity, Rape, Prostitution — that highlights how tempting it can be, whether in Victorian or modern times, to view penguin sexual behaviors through an anthropomorphic lens.

But the driving force of A Polar Affair isn’t really to understand these sexual behaviors, Davis writes. Instead, what he really wants to understand is “why Murray Levick would discover the dirty side of penguins and then try to cover it up.”

Davis delves into Levick’s personal history, hunting down his field notes and retracing his long, frostbitten months studying Cape Adare’s penguin colony.

Davis’ investigations are interspersed with a sweeping history of polar exploration that is by turns fascinating and frustrating. He also includes stories from his own penguin studies. The narrative meanders through the exploits of a wide-ranging cast of explorers who have since lent their names to bits of Antarctica’s geography, from James Clark Ross to Fabian Gottlieb von Bellingshausen.

Early expeditions led to key innovations to manage challenges such as the bitter cold and ever-present nutrient deprivation. And many of those innovations, we learn, came to bear in the 1911–1912 race to the South Pole between Robert Falcon Scott and Norwegian Roald Amundsen. (Amundsen got there first, beating Scott by about one month.) This rich and often intimate history can be riveting stuff. But much of it is also well-trodden ground, and at times, I found myself flipping ahead, wanting to get back to Levick and his penguins.

Other digressions, though, particularly Davis’ discussions of whether there are evolutionary benefits to penguins’ same-sex mating or nonmonogamous behaviors, are fascinating. Is same-sex mating a case of mistaken identity, in that male and female penguins are monomorphic, looking much alike? Is promiscuity among penguins related to the female’s inclination to build a stronger nest, one that is shored up by stones earned through offering sex?

These are questions with which Davis and other penguin biologists still wrestle. And A Polar Affair doesn’t come to a tidy answer for why Levick suppressed his most startling findings. But the book’s unique approach to polar exploration history makes for an engaging read. And by the end, Davis does come to terms with his need to understand his predecessor and with his own dismay at being scooped a century ago. The journey in discovery, he suggests, was satisfying. “It doesn’t really matter who was the first to see a bit of male-on-male action in penguins,” he writes, “any more than it probably matters who was first to stand on an arbitrary piece of ice and drive a flagpole into it.”

Antarctica, beauty and climate change


This 21 October 2019 video says about itself:

See Antarctica Like Never Before | National Geographic

Here at the bottom of the world, a place all but free of human settlement, humanity is scrambling one of the ocean’s richest wildernesses. Fossil-fuel burning thousands of miles away is heating up the western peninsula faster than almost anywhere else. (Only the Arctic compares.) Hear National Geographic photographer Cristina Mittermeier share her love and fears for this beautiful place.