Dinosaur footprints discovery in French caves


This 2016 video says about itself:

Incredible caves are all over the world, for this list we’ve compiled the top 10 most astonishing caves. Each have they own unique facts, history, looks and location but they are all awesome and astounding in their own ways.

10. Ellison’s Cave, USA – 0:08 Ellison’s Cave is a pit cave located on Pigeon Mountain in the Appalachian Plateaus of Northwest Georgia. It is the 12th deepest cave in the United States and features the deepest, unobstructed underground pitch in the continental US named Fantastic Pit. 9. Ice Cave, Russia – 0:43 This incredible cave near the Mutnovsky Volcano in Russia is the result of volcanic fed hot springs running through ice to create an ice cave that has a very shallow roof allowing sunlight to pass through. This cave was discovered by accident in 2012 and is nearly 980 ft. long. 8. Cave of the Swallows, Mexico – 1:12 The Cave of the Swallows is an open air pit cave in San Luis Potosí, Mexico. The mouth of the cave is 160 by 203 feet wide further widening to a room approximately 994 by 442 ft wide.[2] The floor of the cave is a 1214 ft free fall drop from the top making it the largest known cave shaft in the world, the second deepest pit in Mexico and perhaps the 11th deepest in the world. 7. Waitomo Glowworm Cave, New Zealand – 1:45 The Waitomo Glowworm Caves on the North Island of New Zealand is known for it’s spectacular glowworms. This species of glowworms is found exclusively in New Zealand and are the size of an average mosquito. If you are so keen to see the glow worms you can join an organized boat tour that goes right underneath them. 6. Phraya Nakhon Cave, Thailand – 2:15 Phraya Nakhon Cave in Thailand is located 4 hours south of Bangkok. It’s a fairly accessible cave to the public as it is only a 30 minute sweaty hike to reach the cave. King Chulalongkorn built the Kuha Karuhas pavilion inside the cave in 1890, when he fell in love with the beauty of the cave during his visit. If you want there is a Boat that will drop you off in some murky water at the entrance of the cave for 300 Baht but is only operational in good weather conditions. 5. Antelope Canyon, USA – 2:45 Antelope Canyon is primarily a water eroded rock canyon located near the city of Page, in the northern part of the state of Arizona Antelope Canyon is a known for its smooth, wavy walls of sandstone, caused mainly by flash flooding and rain 4. Batu Caves, Malaysia – 3:24 The Batu Caves contain a Buddhist temple created on the edge of a cliff in Myanmar, and is the unassuming entrance to Kyaut Sae Cave. Legend has it, that in the 13th century the massive cave was originally used as a place of hiding for locals who wanted to hide from the Mongols. 3. Fingal’s Cave, Scotland – 3:43 Fingal’s Cave, located in on an uninhabited island called Staffa, is 72 feet tall and 270 feet deep. This sea cave a one of a kind with visually astonishing hexagonal columns made of basalt. It was formed by the cooling on the upper and lower surfaces of the solidified lava which resulted in contraction and fracturing. 2. Son Doong Cave, Vietnam – 4:33 Son Doong Cave in Vietnam is the largest cave discovered on earth. It was discovered in 1991 by a local man but not fully explored until 2009. Son Doong Cave has a max depth of 490 feet and max length of 30,000 feet. It was created by a large vertical fault in the limestone that was flooded by river water which carved it’s way deep under the surface for millions of years. Having limestone walls that run in a nearly in a straight line allows for much greater stability, which is what has allowed this cave to get so big. 1. Naica Mine, Mexico – 5:23 This incredible cave was accidentally found by the Naica mining company as they were drilling deep for silver, lead and zinc. They noticed a large crystal which appeared to be made of ice but considering the temperature inside the cave is 136 Fahrenheit or 58 degrees Celsius they knew immediately it was a large rare crystal growth.

By John Pickrell, April 27, 2020 at 6:00 am:

Deep caves are a rich source of dinosaur prints for this paleontologist

Several deep caves in France are proving to be a surprising source of ancient tracks

Crawling through tight underground passages in southern France, paleontologist Jean-David Moreau and his colleagues have to descend 500 meters below the surface to reach the only known footprints of long-necked dinosaurs called sauropods ever found in a natural cave.

The team discovered the prints, left by behemoths related to Brachiosaurus, in Castelbouc Cave in December 2015 (SN: 2/21/18). But getting to the site might make even the most hardened field scientists balk. Wriggling through such dark, damp and cramped spaces every time they visit is challenging for elbows and knees, and even trickier when carrying delicate equipment such as cameras, lights and laser scanners.

It’s both physically exhausting and “not comfortable for someone claustrophobic”, with the researchers spending up to 12 hours underground each time, says Moreau, of the Université Bourgogne Franche-Comté in Dijon. It can be dangerous too, as some parts of the cave are periodically flooded, so accessing the deep chambers must be limited to periods of drought, he says.

Moreau has studied fossilized dinosaur footprints and plants for more than a decade in southern France’s Causses Basin, one of the richest areas for aboveground dinosaur tracks in Europe. When spelunkers chanced upon some underground prints in 2013, Moreau and his colleagues realized there could be lots of dinosaur prints within the region’s many deep, limestone caves. Footprints left in soft mud or sand hundred million years ago could have been turned to rock and forced underground over many eons.

And deep caves, being less exposed to wind and rain, “can occasionally offer larger and better-preserved surfaces [imprinted by dinosaur steps] than outdoor outcrops,” Moreau says.

Moreau’s team is the only one to have discovered dinosaur footprints in natural caverns, though prints also have been found around the world in human-made railway tunnels and mines. “The discovery of dinosaur tracks inside a natural karstic cave is extremely rare,” he says.

The first subsurface dinosaur prints that the team found were 20 kilometers away from Castelbouc at a site called Malaval Cave, reached via an hour-long clamber through an underground river with several 10-meter drops. “One of the main difficulties in the Malaval Cave is to walk taking care to not touch or break any of the delicate and unique [mineral formations],” Moreau says.

Those three-toed prints, each up to 30 centimeters long and detailed in 2018 in the International Journal of Speleology, were left by carnivorous dinosaurs walking upright on their hind legs through marshland about 200 million years ago.

In contrast, the five-toed herbivore tracks in Castelbouc Cave are each up to 1.25 meters long and were left by three enormous herbivorous sauropods that walked the shoreline of a sea about 168 million years ago. What’s more, these prints are on the cave’s ceiling 10 meters above the floor, the team reports in a study published online March 25 in Journal of Vertebrate Paleontology.

In fact, “the tracks we see on the roof are not ‘footprints’, they are ‘counterprints’”, Moreau explains. “The dinosaurs walked on a surface of clay, which is nowadays totally eroded to form the cave. Here, we only see the overlying layer [of sediment that filled in the footprints],” leaving reverse prints bulging out of the ceiling. It’s similar to what you’d see if you filled a footprint in mud with plaster and then washed all of the mud away to leave the cast.

The tracks are important as they hail from a time in the early to mid-Jurassic Period from 200 million to 168 million years ago when sauropods were diversifying and spreading across the world, but relatively few fossil bones have been found (SN: 12/1/15). These prints confirm that sauropods then inhabited coastal or wetland environments in what is now southern France.

Moreau is now leading researchers in exploring “another deep and long cave, which has yielded hundreds of dinosaur footprints”, he says. The team has yet to publish those results, which he says may prove to be the most exciting of all.

World’s oldest dinosaur eggs, new research


This 9 April 2020 video is called Synchrotron X-ray sheds light on some of the world’s oldest dinosaur eggs.

From the European Synchrotron Radiation Facility:

Synchrotron X-ray sheds light on some of the world’s oldest dinosaur eggs

Dinosaur ‘Easter eggs’ reveal their secrets in 3D thanks to X-rays and high-powered computers

April 9, 2020

An international team of scientists led by the University of the Witwatersrand in South Africa, has been able to reconstruct, in the smallest details, the skulls of some of the world’s oldest known dinosaur embryos in 3D, using powerful and non-destructive synchrotron techniques at the ESRF, the European Synchrotron in France. They found that the skulls develop in the same order as those of today’s crocodiles, chickens, turtles and lizards. The findings are published today in Scientific Reports.

University of the Witwatersrand scientists publish 3D reconstructions of the ~2cm-long skulls of some of the world’s oldest dinosaur embryos in an article in Scientific Reports. The embryos, found in 1976 in Golden Gate Highlands National Park (Free State Province, South Africa) belong to South Africa’s iconic dinosaur Massospondylus carinatus, a 5-meter long herbivore that nested in the Free State region 200 million years ago.

The scientific usefulness of the embryos was previously limited by their extremely fragile nature and tiny size. In 2015, scientists Kimi Chapelle and Jonah Choiniere, from the University of Witwatersrand, brought them to the European Synchrotron (ESRF) in Grenoble, France for scanning. At the ESRF, an 844 metre-ring of electrons travelling at the speed of light emits high-powered X-ray beams that can be used to non-destructively scan matter, including fossils. The embryos were scanned at an unprecedented level of detail — at the resolution of an individual bone cell. With these data in hand, and after nearly 3 years of data processing at Wits’ laboratory, the team was able to reconstruct a 3D model of the baby dinosaur skull. “No lab CT scanner in the world can generate these kinds of data,” said Vincent Fernandez, one of the co-authors and scientist at the Natural History Museum in London (UK). “Only with a huge facility like the ESRF can we unlock the hidden potential of our most exciting fossils. This research is a great example of a global collaboration between Europe and the South African National Research Foundation,” he adds.

Up until now, it was believed that the embryos in those eggs had died just before hatching. However, during the study, lead author Chapelle noticed similarities with the developing embryos of living dinosaur relatives (crocodiles, chickens, turtles, and lizards). By comparing which bones of the skull were present at different stages of their embryonic development, Chapelle and co-authors can now show that the Massospondylus embryos were actually much younger than previously thought and were only at 60% through their incubation period.

The team also found that each embryo had two types of teeth preserved in its developing jaws. One set was made up of very simple triangular teeth that would have been resorbed or shed before hatching, just like geckos and crocodiles today. The second set were very similar to those of adults, and would be the ones that the embryos hatched with. “I was really surprised to find that these embryos not only had teeth, but had two types of teeth. The teeth are so tiny; they range from 0.4 to 0.7mm wide. That’s smaller than the tip of a toothpick!,” explains Chapelle.

The conclusion of this research is that dinosaurs developed in the egg just like their reptilian relatives, whose embryonic developmental pattern hasn’t changed in 200 million years. “It’s incredible that in more than 250 million years of reptile evolution, the way the skull develops in the egg remains more or less the same. Goes to show — you don’t mess with a good thing!,” concludes Jonah Choiniere, professor at the University of Witwatersrand and also co-author of the study.

The team hopes to apply their method to other dinosaur embryos to estimate their level of development. They will be looking at the rest of the skeleton of the Massospondylus embryos to see if it also shares similarities in development with today’s dinosaur relatives. The arms and legs of the Massospondylus embryos have already been used to show that hatchlings likely walked on two legs.

Main findings:

  1. High powered X-rays were used to reconstruct the skulls of some of the world’s oldest known dinosaur embryos.
  2. The skull could be seen in 3D at an unprecedented level of detail.
  3. Dinosaur embryo skulls appear to develop in the same order as those of today’s crocodiles, chickens, turtles and lizards.
  4. These dinosaur embryos appear to have been fossilised at approximately 60% through their incubation period. This is much earlier than previously thought.
  5. The dinosaur embryos have two types of teeth that range in size from 0.4 to 0.7mm wide. One of these sets would have been shed or resorbed before hatching.

Why Jurassic crocodiles were big


This 2009 video says about itself:

Paul Sereno and his team of scientists and artists show us what the world looked like in an age when crocs ate dinosaurs.

From the University of Nebraska-Lincoln in the USA:

Water pressure: Ancient aquatic crocs evolved, enlarged to avoid freezing

Study pinpoints minimum survivable size of Jurassic crocodiles

March 30, 2020

Summary: Ancient crocodilian ancestors that abandoned land for water nearly 200 million years ago supposedly got larger because they were released from the constraints of gravity, territory and diet. But a new study suggests that the upper bounds of size in aquatic vs. landlocked crocs were similar — and that smaller aquatic species got larger mostly to avoid freezing in the frigid, heat-stealing depths.

Taking the evolutionary plunge into water and abandoning land for good, as some crocodilian ancestors did nearly 200 million years ago, is often framed as choosing freedom: from gravity, from territorial boundaries, from dietary constraints.

Water might inflict more pressure in the pounds-per-square-inch sense, the thinking went, but it also probably relieved some — especially the sort that kept crocs from going up a size or 10. If they wanted to enjoy the considerable spoils of considerable size, water seemed the easy way.

A recent study from the University of Nebraska-Lincoln’s Will Gearty, who compiled a database of 264 species stretching back to the Triassic Period, says that freedom was actually compulsion in disguise.

After analyzing the database of crocodyliforms — a lineage of crocodile-like species that share a common ancestor — Gearty found that the average weights of aquatic crocodyliforms did easily surpass their semi-aquatic and landlocked counterparts, sometimes by a factor of 100.

But the study suggests that this disparity represented a response to, not a release from, the pressures of natural selection. Rather than expanding the range of crocodyliform body sizes, as some longstanding theories would predict, taking to the water instead seemed to compress that range by raising the minimum size threshold needed to survive its depths. The maximum size of those aquatic species, by contrast, barely budged over time.

And when Gearty derived a set of equations to estimate the largest feasible body sizes under aquatic, semi-aquatic and terrestrial conditions?

“All three habitats had roughly the same upper limit (on size),” he said. “So even though it seems like you’re released from this pressure, you’re actually squeezed into an even smaller box than before.”

Two major factors — lung capacity and body heat — seem to have helped initiate the squeeze play. Prior research had proposed that aquatic crocodyliforms got big in part because they needed to dive deeply for food, including the choice prey that would sustain a larger size. Upon digging into the literature, though, Gearty learned that lung volume increases more or less in lockstep with body size.

“So you actually don’t have much excess lung volume to spare,” said Gearty, a postdoctoral researcher in biological sciences. “When you get bigger, (lung capacity) is just basically scaling up with your body size to accommodate that extra size. The amount of time you could stay underwater increases a little bit, but not that much.”

At larger sizes, the evolutionary tradeoff between the benefits of longer, deeper dives and the energy demands of finding more food probably also reached a stalemate, he said, that helped cement the aquatic ceiling on size.

As for the higher floor? That’s where the thermal conductivity of water cranked up the evolutionary heat, Gearty said. Unfortunately for the aquatic crocs, water steals heat far faster than air does. The issue was likely compounded by the fact that temperatures in the waters they occupied were lower than the air temperatures enjoyed by their land-dwelling counterparts.

That would have left smaller aquatic crocodyliforms with only bad options: limit the duration and depth of their dives so that they could regularly return to the surface and warm themselves in the sun, or risk freezing to death during deeper hunts for food. Whether by starvation or hypothermia, either would eventually spell doom.

“The easiest way to counteract that is to get bigger,” Gearty said.

Getting bigger was especially appealing because the volume of body tissue, which generates heat, increases faster than the surface area of the skin that surrenders it. But the unforgiving consequences of heat loss still limited the pool of ancestors from which aquatic crocodyliforms could evolve.

“They actually needed to start at a larger size,” Gearty said. “So it’s not like a marine crocodile could have just evolved from anywhere. It had to be evolving from some non-marine crocodile that was already a little larger than normal.”

The fossil records of the crocodyliforms allowed Gearty and Jonathan Payne, his former doctoral adviser at Stanford University, to pinpoint the minimum weight threshold for aquatic survival: 10 kilograms, or about 22 pounds. And when they plotted the relationships of heat loss and lung capacity to body mass, they discovered that the two slopes crossed at almost exactly the same value: 10 kilograms.

“We were able to explain, with these physiological equations, exactly why there were no marine crocodiles below a certain size,” Gearty said. “This indicates that these very fundamental physiological constraints and controls … actually may be some of the strongest forces for pushing animals to different body sizes through time. Not whether there’s an asteroid hitting the world, not whether you’re being (hunted) by some other animal — that just these physical and chemical properties of the world we live in are what drive this. And if you want to enter a new habitat, you need to conform to that new set of properties.”

The findings mostly reinforce a 2018 Gearty-led study that found similar trends among nearly 7,000 living and extinct mammal species. An elementary difference between mammals and reptiles, though, initially left the verdict in doubt.

“The whole (premise) of the marine mammal project was that these things are warm-blooded, and they have to keep their temperature up,” Gearty said. “They have to really worry about this heat loss. So the idea was, ‘Well, would the same constraint occur in cold-blooded organisms that are also living in the ocean?’

“There have been a couple papers suggesting that some of these marine crocodiles may have been somewhat warm-blooded, and so they may have been able to kind of reheat their own bodies. But even if that’s the case, they were still going to be losing heat like these marine mammals would. They were still constrained by these thermoregulatory controls.”

GREYHOUNDS AND DOLPHINS

With the help of an undergraduate student at Stanford and funding from the National Science Foundation, Gearty spent most of the summer of 2017 tracking down the fossil records that informed the new study.

“But that was to find the stuff that’s readily available online,” he said. “Then you’ve got, you know, undocumented books that you need to find, and they have to get shipped from Europe or somewhere. So there were a lot of these one-offs. I was still measuring specimen photos and getting records up until I submitted the paper in the middle of last year.”

Gearty said he was mostly spared the time and expense of traveling to museums and physically measuring fossil dimensions, as some of his colleagues have in the name of their own research. But the haphazardness of some older classifications and documentation still had him following false leads and trying to make sense of the nonsensible.

“A lot of the crocodiles that people have described in papers have never actually been documented the way they’re supposed to be,” he said. “Someone might say, ‘Here’s the Nebraska crocodile.’ It’s just a colloquial name. And you’ll be like, ‘I guess I’ve got to go find the Nebraska crocodile.’ You look this up, and you see that there’s this crocodile from Nebraska, and this one, and this one. You don’t know which one is the ‘Nebraska crocodile.’

“You need to follow this trail of breadcrumbs, sometimes, to find these papers that may or may not have ever been published on these crocodiles that may or may not have ever been found. Fortunately, I was able to get most of the specimens just from the literature. But it did take a lot of digging to find the last probably 10% of the crocodiles.”

Many of the terrestrial fossils, in particular, trace body shapes that barely resemble the low-slung profile of the modern crocodile.

“The example I like to give is: Imagine a greyhound, and then put a crocodile skull on it,” Gearty said. “There were things like that running around on land probably 200 million years ago.”

Though their maximum size remained almost constant, marine species did evolve two to three times faster than the semi-aquatic and terrestrial groups, Gearty found. Along with increasing the size of smaller aquatic species, natural selection molded body forms to surmount the challenges presented by water. Scales, plates and other drag-increasing skin deposits disappeared. Heads and tails flattened. Snouts narrowed.

“All of these were probably more dolphin-like than modern crocodiles, with even longer, thinner tails,” he said. “And some of them had very paddle-like feet, almost like flippers.”

Despite the fact that virtually all modern crocodile species are semi-aquatic, Gearty said those adaptations served the aquatic crocodyliforms well — more than 100 million years before mammals ventured into the deep.

“No one has talked about it much, but really, these things were quite successful,” he said. “And some of them weren’t even fazed by some of the big, (cataclysmic) events. When the asteroid hit that killed all the dinosaurs, one of the marine groups just kind of kept going like nothing happened. A lot of the terrestrial species went extinct, but this group just kept ticking along for a long time.”

Jurassic dinosaurs footprints discovery in Scotland


This June 2018 CBS TV video is called Isle of Skye a hotbed of dinosaur discoveries.

From PLOS:

Dinosaur stomping ground in Scotland reveals thriving middle Jurassic ecosystem

Dozens of footprints expand the list of dinosaurs known to have lived in the region

March 11, 2020

During the Middle Jurassic Period, the Isle of Skye in Scotland was home to a thriving community of dinosaurs that stomped across the ancient coastline, according to a study published March 11, 2020 in the open-access journal PLOS ONE by Paige dePolo and Stephen Brusatte of the University of Edinburgh, Scotland and colleagues.

The Middle Jurassic Period is a time of major evolutionary diversification in many dinosaur groups, but dinosaur fossils from this time period are generally rare. The Isle of Skye in Scotland is an exception, yielding body and trace fossils of diverse Middle Jurassic ecosystems, serving as a valuable location for paleontological science as well as tourism.

In this paper, dePolo and colleagues describe two recently discovered fossil sites preserving around 50 dinosaur footprints on ancient coastal mudflats. These include the first record on the Isle of Skye of a track type called Deltapodus, most likely created by a stegosaurian (plate-backed) dinosaur. These are the oldest Deltapodus tracks known, and the first strong evidence that stegosaurian dinosaurs were part of the island’s Middle Jurassic fauna. Additionally, three-toed footprints represent multiple sizes of early carnivorous theropods and a series of other large tracks are tentatively identified as some of the oldest evidence of large-bodied herbivorous ornithopod dinosaurs.

All tracks considered, these two sites expand the known diversity of what was apparently a thriving ecosystem of Middle Jurassic dinosaurs in Scotland, including at least one type of dinosaur (stegosaurs) not previously known from the region. These findings reflect the importance of footprints as a source of information supplemental to body fossils. Furthermore, the authors stress the importance of revisiting previously explored sites; these new sites were found in an area that has long been popular for fossil prospecting, but the trackways were only recently revealed by storm activity.

Lead author dePolo says: “These new tracksites help us get a better sense of the variety of dinosaurs that lived near the coast of Skye during the Middle Jurassic than what we can glean from the island’s body fossil record. In particular, Deltapodus tracks give good evidence that stegosaurs lived on Skye at this time.”

Author Brusatte adds: “These new tracksites give us a much clearer picture of the dinosaurs that lived in Scotland 170 million years ago. We knew there were giant long-necked sauropods and jeep-sized carnivores, but we can now add plate-backed stegosaurs to that roster, and maybe even primitive cousins of the duck-billed dinosaurs too. These discoveries are making Skye one of the best places in the world for understanding dinosaur evolution in the Middle Jurassic.”

Belemnites and dinosaur age global warming


This 2006 video says about itself:

A short video introducing belemnites which were extinct cousins of the squid, octopus and cuttlefish.

From the University of Erlangen-Nuremberg in Germany:

Why organisms shrink in a warming world

March 9, 2020

Everyone is talking about global warming. A team of palaeontologists at GeoZentrum Nordbayern at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) has recently investigated how prehistoric organisms reacted to climate change, basing their research on belemnites.

These shrunk significantly when the water temperature rose as a result of volcanic activity approximately 183 million years ago, during the period known as the Toarcian. The FAU research team published their results in the online publication Royal Society Open Science.

‘Belemnites are particularly interesting, as they were very widespread for a long time and are closely related to the squid of today,’ explains palaeontologist Dr. Patricia Rita. ‘Their fossilised remains, for example the rostrum, can be used to make reliable observations.’ Within the context of the DFG-funded research project ‘Temperature-related stresses as a unifying principle in ancient extinctions,’ the hypothesis was confirmed that climate has a significant influence on the morphology of adult aquatic organisms. The body size of dominant species fell by an average of up to 40 percent.

The team of researchers believe that this Lilliput effect was a precursor to the later extinction of the animals. It is still unclear whether rises in temperature influenced the organisms’ metabolism directly or indirectly, for example due to a shortage of food sources.

Jurassic South African dinosaur, other footprints, discovery


This 13 August 2018 video says about itself:

Take a look at some of the most important and valuable archaeological treasures in the world that are to be found in South Africa’s Great Karoo. It was through the study of Karoo fossils in the early years of the 20th century that scientific thought was influenced in acknowledging that mammals arose from reptiles.

And, as every one of us is a living fossil – containing within our genes the secrets of our ancestors – a journey into the Karoo is in some respects a voyage of self-discovery.

World-famous palaeontologist, Dr Robert Broom, was greatly excited by seeing one specimen in particular, and that was the Milleretta.

The Milleretta was the first well-preserved skull ever discovered of the group of reptiles that may have had as one of its members the ancestor of all mammal-like reptiles. To Broom, this skull was “the seed of the mammal race.” These prehistoric mammal-like reptiles left their mark in other ways too – such as visible footprints, dating about 250 million years ago – found at Sante Sana, also in the Graaff-Reinet district.

From PLOS:

The ‘firewalkers’ of Karoo: Dinosaurs and other animals left tracks in a ‘land of fire’

Several groups of reptiles persisted in Jurassic Africa even as volcanism ruined their habitat

January 29, 2020

In southern Africa, dinosaurs and synapsids, a group of animals that includes mammals and
their closest fossil relatives, survived in a “land of fire” at the start of an Early Jurassic mass extinction, according to a study published January 29, 2020 in the open-access journal PLOS ONE by Emese M. Bordy of the University of Cape Town and colleagues.

The Karoo Basin of southern Africa is well-known for its massive deposits of igneous rocks left behind by extensive basaltic lava flows during the Early Jurassic. At this time, intense volcanic activity is thought to have had dramatic impacts on the local environment and global atmosphere, coincident with a worldwide mass extinction recorded in the fossil record. The fossils of the Karoo Basin thus have a lot to tell about how ecosystems responded to these environmental stresses.

In this study, Bordy and colleagues describe and identify footprints preserved in a sandstone layer deposited between lava flows, dated to 183 million years ago. In total, they report five trackways containing a total of 25 footprints, representing three types of animals: 1) potentially small synapsids, a group of animals that includes mammals and their forerunners; 2) large, bipedal, likely carnivorous dinosaurs; and 3) small, quadrupedal, likely herbivorous dinosaurs represented by a new ichnospecies (trace fossils like footprints receive their own taxonomic designations, known as ichnospecies).

These fossils represent some of the very last animals known to have inhabited the main Karoo Basin before it was overwhelmed by lava. Since the sandstone preserving these footprints was deposited between lava flows, this indicates that a variety of animals survived in the area even after volcanic activity had begun and the region was transformed into a “land of fire”. The authors suggest that further research to uncover more fossils and refine the dating of local rock layers has the potential to provide invaluable data on how local ecosystems responded to intense environmental stress at the onset of a global mass extinction.

Bordy adds: “The fossil footprints were discovered within a thick pile of ancient basaltic lava flows that are ~183 million years old. The fossil tracks tell a story from our deep past on how continental ecosystems could co-exist with truly giant volcanic events that can only be studied from the geological record, because they do not have modern equivalents, although they can occur in the future of the Earth.”

How Jurassic pterosaurs fed, new research


This video is called TRILOGY OF LIFE – Walking with Dinosaurs – “Ramphorhynchus“.

By John Pickrell, January 27, 2020 at 5:00 am:

A squid fossil offers a rare record of pterosaur feeding behavior

A tooth embedded in a squid fossil tells a story of a battle at sea with the flying reptile

A fossil of a squid with a pterosaur tooth embedded in it offers extraordinary evidence of a 150-million-year-old battle at sea. While many pterosaur fossils containing fish scales and bones in their stomachs have revealed that some of these flying reptiles included fish in their diet, the new find from Germany is the first proof that pterosaurs also hunted squid.

The fossil was excavated in 2012 in the Solnhofen Limestone, near Eichstätt in Bavaria, where many Jurassic Period fossils of pterosaurs, small dinosaurs and the earliest known bird, Archaeopteryx, have been found. The region’s environment at the time was something like the Bahamas today, with low-lying islands dotting shallow tropical seas.

The embedded tooth fits the right size and shape for the pterosaur Rhamphorhynchus, paleontologists report online January 27 in Scientific Reports. They argue that the tooth was left by a pterosaur that swooped to the ocean surface to snap up the 30-centimeter-long squid from the extinct Plesioteuthis genus, but was unsuccessful, possibly because the squid was too large or too far down in the water column for the predator to manage.

“The Plesioteuthis squid wrestled it off and escaped, breaking at least one tooth off the pterosaur, which became lodged in [the squid’s] mantle,” says Jordan Bestwick, a paleontologist at the University of Leicester in England. “This fossil is important in helping us understand the dietary range of Rhamphorhynchus, and tells us about its hunting behavior.”

The fossil itself is unique, according to pterosaur researcher Taíssa Rodrigues at the Federal University of Espírito Santo in Vitorio, Brazil, who was not involved in the study. “It is very rare to find predator-prey interactions that include pterosaurs,” she says. “In the few cases we do have, pterosaurs were the prey of large fish. So it is great to see this the other way around.”

Paleontologist Michael Habib of the University of Southern California in Los Angeles says he suspects the squid was far too large for the pterosaur to haul out of the water. “The pterosaur was lucky that the tooth broke off,” says Habib, who was not involved with the study. “A squid of that size could probably have pulled it under.”

New Jurassic carnivorous dinosaur discovery


This 2001 video is called When Dinosaurs Roamed America.

From the Ludwig-Maximilians-Universität München in Germany:

Paleontology: Experiments in evolution

December 11, 2019

A new find from Patagonia sheds light on the evolution of large predatory dinosaurs. Features of the 8-m long specimen from the Middle Jurassic suggest that it records a phase of rapid diversification and evolutionary experimentation.

In life, it must have been an intimidating sight. The dimensions of the newly discovered dinosaur fossil suggest that this individual was up to 8 meters long, and its skull alone measured 80 centimeters from front to back. The specimen was uncovered by the Munich paleontologist Oliver Rauhut in Patagonia, and can be assigned to the tetanurans — the most prominent group of bipedal dinosaurs, which includes such iconic representatives as Allosaurus, Tyrannosaurus and Velociraptor. This is also the group from which modern birds are derived. The new find is the most complete dinosaur skeleton yet discovered from the early phase of the Middle Jurassic, and is between 174 and 168 million years old. The specimen represents a previously unknown genus, and Rauhut and his Argentinian colleague Diego Pol have named it Asfaltoventor vialidadi. The genus name includes both Greek and Latin components (including the Latin term for hunter), while also referring to the nature of the deposits in which the fossil was found and the species name honours the road maintance of Chubut, who helped in the recovery of the specimen.

Almost the entire skull is preserved, together with the complete vertebral column including parts of the pelvis, all the bones of both anterior extremities and parts of the legs. “The fossil displays a very unusual combination of skeletal characters, which is difficult to reconcile with the currently accepted picture of the relationships between the three large groups that comprise the tetanurans — Megalosauria, Allosauria and Coelurosauria,” says Rauhut, who is Professor of Palaeontology in the Department of Earth and Environmental Sciences at Ludwig-Maximilians-Universitaet (LMU) in Munich and Senior Curator of the Bavarian State Collection for Paleontology and Geology. He and his co-author Diego Pol, who is based in the Museo Paleontológico Egidio Feruglio in Trelew (Argentina), describe the find in a paper that appears in the online journal Scientific Reports. According to the authors, A. vialidadi exhibits a diverse set of skeletal traits, which combines characters that have so far been found to be specific for various other species of dinosaurs.

The unusual mixture of morphological features displayed by A. vialidadi prompted the authors to carry out a comparative analysis with other tetanurans. They noted that around the period to which the new find can be assigned, the geographical range of this group was rapidly expanding, while the different species developed very similar sets of skeletal features.

Rauhut links the explosive evolution of the group with an episode of mass extinction that had occurred in the late stage of the Lower Jurassic, about 180 million years ago. The two researchers therefore interpret the parallel development of similar external traits in different species as an example of evolutionary experimentation during the subsequent rapid expansion and diversification of the tetanurans. The prior extinction of potential competitors will have opened up new ecological niches for the groups that survived, and the tetanurans were apparently among those that benefited.

“This is a pattern that we also observe in many other groups of animals in the aftermath of mass extinctions. It holds, for example, for the expansion and diversification of both mammals and birds following the extinction of the dinosaurs at the end of the Cretaceous 66 million years ago,” says Rauhut. It could also explain why it is so difficult to unravel the phylogenetic relationships close to the origin of many highly diversified animal groups.

Jurassic crocodile identified 250 years after find


This video says about itself:

Meet the top 10 largest crocodiles in the world and history. These prehistoric crocodiles are really gigantic, you won’t believe they really existed.

Purussaurus
This is an extinct giant which lived in South America in the Miocene. A 4.7 feet long skull was found in Brazil, that’s why it’s estimated that this species measured 41 feet long and weighed 8.4 tons, making this one of the biggest crocodiles in history.

Mourasuchus
This extinct crocodile lived in the Miocene and its fossils were found in Peru. It’s thought that it measured 30 feet in length.

Smilosuchus
It’s also an extinct specimen that lived in the late stage of the Triassic period in north America.

Deinosuchus
It was an extinct species that could reach 39 feet in length and weight 8.5 tons.

Sarcosuchus
This species reached between 36 and 39 feet in length, because of this size it received the name of Super Croc, with which it has become famous.

Rhamphosuchus
This crocodile used to live in the Ganges river, in India, during the Miocene.

Gryposuchus
This extinct crocodile lived in south America between 23 million and 700 thousand years ago, in the Miocene, Pliocene and beginnings of the Pleistocene.

Stomatosuchus
It was a 32.8 feet crocodile that lived in the late Cretaceous in Egypt. It had a plain head seen from the top that looks a lot like a cricket bat.

Rutiodon
Was a reptile genre that lived at the end of the Triassic period, its name means creased tooth. It measured 26 feet in length and its fossils have been found in the eastern part of the United States.

Machimosaurus
This prehistoric crocodile specimen reached the length of 23.6 feet. It lived in the late Jurassic and early Cretaceous era, which means this was contemporaneous to the dinosaurs.

From the University of Edinburgh in Scotland:

Mysterious Jurassic crocodile identified 250 years after fossil find

September 12, 2019

Summary:.A prehistoric crocodile that lived around 180 million years ago has been identified — almost 250 years after the discovery of its fossil remains.

A fossil skull found in a Bavarian town in the 1770s has been recognised as the now-extinct species Mystriosaurus laurillardi, which lived in tropical waters during the Jurassic Period.

For the past 60 years, it was thought the animal was part of a similar species, known as Steneosaurus bollensis, which existed around the same time, researchers say.

Palaeontologists identified the animal by analysing fossils unearthed in the UK and Germany.

The team, which included scientists from the University of Edinburgh, also revealed that another skull, discovered in Yorkshire in the 1800s, belongs to Mystriosaurus laurillardi.

The marine predator — which was more than four metres in length — had a long snout and pointed teeth, and preyed on fish, the team says. It lived in warm seas alongside other animals including ammonites and large marine reptiles, called ichthyosaurs.

The discovery of fossils in present-day Germany and the UK shows that the species could easily swim between islands, much like modern saltwater crocodiles, researchers say.

The study, led by Naturkunde-Museum Bielefeld in Germany, is published in the journal Acta Palaeontologica Polonica. It was supported by the Palaeontographical Society, Leverhulme Trust and the Natural Sciences and Engineering Research Council of Canada.

Sven Sachs, of the Naturkunde-Museum Bielefeld, who led the study, said: “Mystriosaurus looked like a gharial but it had a shorter snout with its nasal opening facing forwards, whereas in nearly all other fossil and living crocodiles the nasal opening is placed on top of the snout.”

Dr Mark Young, of the University of Edinburgh’s School of GeoSciences, who was involved in the study, said: “Unravelling the complex history and anatomy of fossils like Mystriosaurus is necessary if we are to understand the diversification of crocodiles during the Jurassic. Their rapid increase in biodiversity between 200 and 180 million years ago is still poorly understood.”

Filter-feeding Jurassic pterosaurs, new study


This 23 October 2019 video says about itself:

Pterosaurs Size Comparison

Pterosaurs, meaning “winged lizards” were flying reptiles of the extinct clade or order Pterosauria. Pterosaurs existed during most of the Mesozoic: from the late Triassic to the end of the Cretaceous (228 to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.

From Uppsala University in Sweden:

Filter-feeding pterosaurs were the flamingos of the Late Jurassic

August 26, 2019

Modern flamingoes employ filter feeding and their feces are, as a result, rich in remains of microscopically-small aquatic prey. Very similar contents are described from more than 150 million-year-old pterosaur droppings in a recent paper in PeerJ. This represents the first direct evidence of filter-feeding in Late Jurassic pterosaurs and demonstrates that their diet and feeding environment were similar to those of modern flamingoes.

Pterosaurs were a diverse group of flying reptiles that roamed the skies during the age of dinosaurs. Skeletal fossils suggest that they, just like modern birds, adapted to diverse lifestyles and feeding habits. Direct evidence on diets such as gut contents, however, are rare and only known from a few pterosaur species.

Coprolites, that is fossil droppings, are surprisingly common fossils and they potentially hold valuable information on the diet of extinct animals. Unfortunately, it is often difficult to know which animal produced which dropping.

In a recent paper, researchers from Uppsala University and the Polish Academy of Sciences describe the contents of three coprolites collected from a surface with abundant pterosaur footprints in the Wierzbica Quarry in Poland. The coprolites’ size, shape and association to the tracks suggest that they were produced by pterosaurs, most probably belonging to a group called Ctenochasmatidae.

The fossil droppings were scanned using synchrotron microtomography, which works in a similar way to a CT-scanner in a hospital but with much stronger x-ray beams. This makes it possible to image the contents of fossils in three dimensions. The scans of the pterosaur coprolites revealed many microscopic food remains including foraminifera (small amoeboid protists with external shells), small shells of marine invertebrates and possible remains of polychaete worms.

“A reasonable explanation for how a pterosaur big enough to have produced the droppings ingested such small prey is through filter feeding,” says Martin Qvarnström, PhD student at Uppsala University and one of the authors of the article.

Some ctenochasmid pterosaurs are thought to have been filter feeders. Pterodaustro, which comes from the Cretaceous and is thus slightly younger than the Polish coprolites, possessed a sieving basket consisting of many long, thin teeth and was certainly a filter feeder. Older ctenochasmids did not possess such an obvious sieving basket, but some had elongated snouts with many slender teeth, also interpreted as adaptations for filter feeding. These pterosaurs were around at the time the droppings were made, and as the footprints from the site have also been attributed to ctenochasmids it is likely that such pterosaurs produced both the droppings and the footprints.

The modern Chilean flamingo, which is a filter feeder, can produce droppings full of foraminifera when feeding in coastal wetlands.

“The similar contents of the droppings of these flamingos and the pterosaur coprolites could be explained by similar feeding environments and mesh sizes of the filter-feeding apparatus. It appears therefore that the pterosaurs which produced the footprints and droppings found in Poland were indeed the flamingos of the Late Jurassic,” says Martin Qvarnström.