Tag Archives: ichthyosaur

Ichthyosaurs were predatory marine reptiles that swam the world’s oceans while dinosaurs walked the land.

Ichthyosaur may have had blubber, which means the ‘sea monster’ may have been warm-blooded

Researchers have identified a well-preserved ichthyosaur specimen, complete with skin and, most remarkably, a blubber. The incredible discovery suggests that the 180-million-year-old sea creature may have been warm-blooded.

Ichthyosaurs were predatory marine reptiles that swam the world’s oceans while dinosaurs walked the land.

Ichthyosaurs were predatory marine reptiles that swam the world’s oceans while dinosaurs walked the land.

“Ichthyosaurs are interesting because they have many traits in common with dolphins, but are not at all closely related to those sea-dwelling mammals,” said co-author Mary Schweitzer, professor of biological sciences at North Carolina State University and visiting professor at Lund University, Sweden. “We aren’t exactly sure of their biology either. They have many features in common with living marine reptiles like sea turtles, but we know from the fossil record that they gave live birth, which is associated with warm-bloodedness. This study reveals some of those biological mysteries.”

Ichthyosaurus (“fish lizard” in Greek) was a large marine reptile which was perfectly adapted to ocean life. Its dolphin-like body featured a small sail-fin on its back and advanced flippers that allowed the creature to swim at high speeds, perhaps as fast as 33 km per hour (21 mph). The reptile could grow to 1.8 meters (6 feet) in length and weighed around 90 kg (200 pounds).

Paleontologists have been lucky enough to find an abundance of ichthyosaur fossils. Thanks to these findings we’ve come to know that the ancient sea creature had large ear bones that allowed it to locate both prey and predators, or that it used to give birth to live young instead of laying eggs as a fish would. Eventually, Ichthyosaurus was outcompeted by the arrival of better adapted marine animals such as pliosaurs and plesiosaurs.

Some scientists have compared ichthyosaurus with modern toothed whales, based on estimates of their swimming speed, which would imply they were warm-blooded. It seems that they were on to something since a new study, which described a wonderfully preserved specimen, identified a blubber.

The blubber is a thick layer of vascularized adipose tissue under the skin of modern marine mammals, such as cetaceans, pinnipeds, and sirenians. It basically insulates vital organs, keeping them warm while in cold climates. Its discovery in an ichthyosaurus suggests that the ancient marine reptile was also warm-blooded, an extremely rare occurrence among reptiles. Modern leatherback sea turtles also have a blubber, which along with other measures for heat retention and control, allow it to venture into very cold waters.

“This is the first direct, chemical evidence for warm-bloodedness in an ichthyosaur, because blubber is a feature of warm-blooded animals,” Schweitzer says.

The Stenopterygius ichthyosaur specimen was discovered in Holzmaden quarry, Germany. For years it was stored at the Urweltmuseum Hauff in Germany, until researchers at Lund University in Sweden examined it.

Photographic (top) and diagrammatic (bottom) representation of the 85-cm-long fossil (which corresponds to roughly half of the original length of the animal). Credit: Johan Lindgren.

Photographic (top) and diagrammatic (bottom) representation of the 85-cm-long fossil (which corresponds to roughly half of the original length of the animal). Credit: Johan Lindgren.

Besides the blubber, the research team was also able to trace the animal’s flexible skin. Microscopic analysis of this tissue suggests that ichthyosaur was countershaded, meaning it had a dark upper surface and light belly. This camouflage pattern would have helped the animals avoid Jurassic predators such as flying pterosaurs, attacking from above, and pliosaurs from below.

“Both morphologically and chemically, we found that although Stenopterygius would be loosely considered ‘reptiles,’ they lost the scaly skin associated with these animals—just as the modern leatherback sea turtle has,” Schweitzer says. “Losing the scales reduces drag and increases maneuverability underwater.

It’s a bit too early to claim that the Early Jurassic sea creature was warm-blooded, though. But since ichthyosaur fossils are very common, we could have a confirmation once more specimens showing blubber are found.

The findings appeared in the journal Nature.

Illustration of Shonisaurus, a 69-foot ichthyosaur similar to the newfound ichthyosaur. Credit: NOBUMICHI TAMURA.

Ichthyosaur jaw-bone might have belonged to largest animal ever

Paleontologists have come across an astonishing 205-million-year-old jaw-bone that, judging from its size, must have belonged to one of the largest animals ever.

Illustration of Shonisaurus, a 69-foot ichthyosaur similar to the newfound ichthyosaur. Credit: NOBUMICHI TAMURA.

Illustration of Shonisaurus, a 69-foot ichthyosaur similar to the newfound ichthyosaur. Credit: NOBUMICHI TAMURA.

The prehistoric bone belongs to a giant ichthyosaur, a marine reptile that lived during the Early Jurassic Period. These reptiles, which resembled dolphins, used to dominate all kinds of watery environments — both near and far from shore — and diversified in dozens of genera. Competition from other species, however, eventually drove them to extinction. The last ichthyosaur disappeared from the fossil record 25 million years before the giant asteroid impact that wiped out the dinosaurs.

Giant jaws

The 205-million-year-old remains recently described in the journal PLOS ONE have solved a 19th-century mystery. In 1850, beachgoers to southern England had discovered such huge fossils by the shore that paleontologists thought they were dealing with some kind of long-necked sauropods. Now, thanks to the newly identified jawbone found by British fossil collector Paul de la Salle, we know that the ancient creature is actually one of the largest-known ichthyosauri. In fact, it might have belonged to the largest creature on Earth — larger than a blue whale, which currently holds such a title.

The jawbone described by de la Salle and colleagues measures 3.1 feet (96 centimeters) in length. A comparative examination of the jawbone suggests it belongs to a giant kind of ichthyosaur called shastasaurid, which hails from the Triassic, which lasted from 251 million to 199 million years ago. The new species doesn’t have a name yet, but the individual in question has been tentatively christened ‘the Lilstock specimen’ for now.

Judging from the size of the shastasaurid’s jawbone, researchers estimate the animal must have been more than 85 feet (26 meters) long, which would make it the largest ichthyosaur on record — up to 25 percent larger than the previous record holder, Shonisaurus sikanniensis, a 69-foot-long (21 m) individual previously discovered in British Columbia.

The reassembled jaw bone, which belonged to the 85-foot ichthyosaur. Credit: DEAN LOMAX, THE UNIVERSITY OF MANCHESTER.

The reassembled jaw bone, which belonged to the 85-foot ichthyosaur. Credit: DEAN LOMAX, THE UNIVERSITY OF MANCHESTER.

“As the specimen is represented only by a large piece of jaw, it is difficult to provide a size estimate, but by using a simple scaling factor and comparing the same bone in S. sikanniensis, the Lilstock specimen is about 25% larger. Other comparisons suggest the Lilstock ichthyosaur was at least 20-25 m. Of course, such estimates are not entirely realistic because of differences between species,” said Dean Lomax, an ichthyosaur expert at the University of Manchester.

“Nonetheless, simple scaling is commonly used to estimate size, especially when comparative material is scarce.”

Besides suggesting that this giant sea creature might have been the largest creature ever to roam the Earth, the findings have helped settle a long-standing debate regarding the 19th-century fossils found near the village of Aust in Gloucestershire, England. The very large fossilized bones and fragments had been initially interpreted as belonging to some large terrestrial dinosaurs, but this never quite made sense. The discovery of the Lilstock specimen refutes previous identifications and also the most recent assertion that the Aust bones represent an early experiment of dinosaur-like gigantism in terrestrial reptiles.

Dean added: “One of the Aust bones might also be an ichthyosaur surangular. If it is, by comparison with the Lilstock specimen, it might represent a much larger animal. To verify these findings, we need a complete giant Triassic ichthyosaur from the UK – a lot easier said than done!”

Impressive 170-million-year old “sea monster” fossil found in Scotland

An ancient ichthyosaur fossil was recently unearthed in Scotland. Ichthyosaurs are extinct reptiles which ruled the seas during much of the Mesozoic era.

The fossilized remains of 170 million year old ichthyosaur has finally been made available for display after being stored for more than 50 years.
(Photo : Ryan Somma (Ichthyosaur Uploaded by FunkMonk)/Wikimedia Commons)

While dinosaurs roamed the earth, ichthyosaurs were the kings of the seas. Based on fossil evidence, they first appeared approximately 250 million years ago and at least one species survived until about 90 million years ago. They grew up to sixteen meters in length and had many features that resembled both modern fish and dolphins.

However, while there are plenty of ichthyosaur fossils, this one comes from a period when such fossils are particularly rare – 170 million years ago.

“The Middle Jurassic is one of the most poorly known times in the history of dinosaurs and in the history of other reptiles like ichthyosaurs,” says University of Edinburgh’s Steve Brusatte, part of the team examining the fossil. The “spectacular” find, he says, “has a lot of potential.”

It took two generations for the fossil to receive proper appreciation. The fossil, dubbed as Storr Lochs Monster, was first discovered in 1966 by an amateur paleontologist called Norrie Gillies while he was having a stroll near the Storr Lochs power station in Edinburgh. Realizing what he’d found, he sent a letter to the Royal Scottish Museum and a team was sent to investigate the fossil.

But after the fossil was transferred to the museum, it was simply left in its concrete case and locked somewhere in storage and all but forgotten – as it too often happens. Fast forward a few decades and Allan Gillies, son of Norrie Gillies and an engineer at the power station where the fossil was found, contacted Stephen Brusatte, a professor at University of Edinburg and one of the lead researchers analyzing the fossil.

“Dad’s not around to see it himself, but I know he’d be very, very pleased to know that it’s finally being displayed, and he’d also be very pleased to know that it’s the company he worked for that helped to make it happen,” Allan told National Geographic. “It’s sort of completing the story.”

Dad found the fossil, and his son helped with the fundraising for the fossil analysis. Ultimately, working together from over time, the two made it happen – the ichthyosaur fossil was removed from its concrete casing and is up for display in the museum. It’s a testament that anyone can make a difference in science if they’re truly passionate about it.

Paleontologists still don’t know what species it is, but they’re slowly unveiling its mysteries.

“This new ichthyosaur can and, I’m sure, will tell us a good few things about ichthyosaur paleobiology, and marine reptiles more generally,” says Benjamin Moon of Britain’s University of Bristol. Very little fossil material is known from that time period, he says, so this new specimen will help fill a gap.

 

Ichthyosaurs were predatory marine reptiles that swam the world's oceans while dinosaurs walked the land. They appeared in the Triassic period, dying out around 25 million years before the extinction event that wiped out the dinosaurs. much more streamlined, fish-like form built for speed. One species has been calculated to have a cruising speed of 36 km/h. These enormous predators remained at the top of the food chain until they were replaced by the plesiosaurs.

Oldest ‘fish-lizard’ bridges Ichthyosaur evolutionary gap

One of the most long-lived and fiercest marine predator in history was the ichthyosaur, and a recent fossil find from China bridges an important gap in the creature’s evolutionary history.

Truly, a fish and a lizard

Ichthyosaurs were predatory marine reptiles that swam the world's oceans while dinosaurs walked the land. They appeared in the Triassic period, dying out around 25 million years before the extinction event that wiped out the dinosaurs.  much more streamlined, fish-like form built for speed. One species has been calculated to have a cruising speed of 36 km/h. These enormous predators remained at the top of the food chain until they were replaced by the plesiosaurs.

Ichthyosaurs were predatory marine reptiles that swam the world’s oceans while dinosaurs walked the land. They appeared in the Triassic period, dying out around 25 million years before the extinction event that wiped out the dinosaurs. much more streamlined, fish-like form built for speed. One species has been calculated to have a cruising speed of 36 km/h. These enormous predators remained at the top of the food chain until they were replaced by the plesiosaurs.

The ichthyosaur (Greek for “fish lizard”), which lived from about 248 million years ago to about 95 million years ago, has been liken by many with modern day dolphins since both exhibit streamline muscular body, dorsal fins specially evolved to cut through water, a propulsive tail and keen insight. The similarities end here, however. While dolphins are peaceful mammals, the ichthyosaur was a fierce marine predator which could grow to up to 20 meters in length and had sharp teeth in long jaws.

The name fish lizard comes from its evolutionary lineage. Like many reptiles of their time, the ichthyosaur forefathers were land reptiles who made the return back to the sea, again just like the dolphin’s mammalian ancestors, which is why biologists like to give the two as perfect examples of convergent evolution. A side-proof is the fact that the ichthyosaur was an air breather.

ichthyosaur

Illustration of C. lenticarpus laying low. Credit: STEFANO BROCCOLI

While the animal was perfectly adapted to a marine lifestyle, scientists have been looking for a missing link in fossil records that might help paint a clear picture of how the land to water transition took place. Now they have it. Meet Cartorhynchus lenticarpus, the smallest ichthyosaur to date.

“[..]now we have this fossil showing the transition. There’s nothing that prevents it from coming onto land,” said Prof Motani, who is the first author of a paper published in the journal Nature.

Luckily for paleontologists, a complete skeleton of C. lenticarpus. was discovered in China in 2011, where an adult specimen was unearthed from 248 million-year-old marine sediments. From the findings, researchers reckon that the ancient ichthyosaur must have measured only 40 cm in length and weighed only 2 kilograms. Most importantly, however, is that the animal had  small and widely separated forelimbs, which means it had cartilage-filled flippers instead of legs. At the same time, it had thicker bones than previously described ichthyosaurs, which helped it swim through rough coastal waves before entering the deep sea – like a scuba diver’s weight bell.

Image credit: Stefano Broccoli / University of Milan.

Image credit: Stefano Broccoli / University of Milan.

Thus, C. lenticarpus “is the closest thing we have to a terrestrial ancestor” of ichthyosaurs, says Valentin Fischer, a vertebrate paleontologist at the University of Liège in Belgium, who wasn’t connected to the research.

[RELATED] The most devastating mass extinction in Earth’s history happened much faster

The ancient ichthyosaur evolved only a couple millions years after the end-of-Permian mass extinctions, which wiped out as many as 90% of the species on land and 70% of those in the oceans. A growing debate is how long it took for life on Earth to recover from such a calamity, caused by a global warming event, and C. lenticarpus will help with setting this timeline.

“This was analogous to what might happen if the world gets warmer and warmer. How long did it take before the globe was good enough for predators like this to reappear? In that world, many things became extinct, but it started something new,” Prof Motani said.

“These reptiles came out during this recovery.”

 

The arranged vertebrae of a fossilized ichthyosaurs resemble the pattern of suckers on a cephalopod's tentacle, evidence of a possible bad showdown with a kraken-like ancient creatures. (c) Mark McMenamin

‘Kraken’ ancient lair shows signs of a vicious predator

The arranged vertebrae of a fossilized ichthyosaurs resemble the pattern of suckers on a cephalopod's tentacle, evidence of a possible bad showdown with a kraken-like ancient creatures. (c)  Mark McMenamin

The arranged vertebrae of a fossilized ichthyosaur resemble the pattern of suckers on a cephalopod's tentacle, evidence of a possible bad showdown with a kraken-like ancient creatures. (c) Mark McMenamin

Hundreds of millions of years ago the Earth surface and oceans were inhabited by fierce predators of huge proportions by today’s standards. In those times, more than ever maybe, the saying that there’s always a bigger fish was cruelly true. For instance, a recent study of the fossils remains of an ichthyosaur, a giant school bus-sized predators which used to roam ancient oceans, shows evidence of a gruesome death at the hands of a cephalopod-like sea monster resembling the mythological kraken.

Mark McMenamin, a paleontologist at Mount Holyoke College in Massachusetts, has studied the remains of this particular specimen and is convinced that a kraken-like sea monster, most likely 100 meters long, drowned or broke the necks of the ichthyosaur before dragging the corpses to its lair, akin to an octopus’s midden. His study will be presented today(Oct. 10) at the annual meeting of the Geological Society of America in Minneapolis.

Evidence of such an event is apparently evident in the markings on the bones of the remains of nine 45-foot (14 meter) ichthyosaur of the species Shonisaurus popularis, a big toothed predator of the deeps from the Triassic period. In the 1950s, paleontologists launched theories that the ichthyosaur succumbed to an accidental stranding or a toxic plankton bloom. McMenamin is now ammmin to prove that the beast died in shallow water.

“I was aware that anytime there is controversy about depth, there is probably something interesting going on,” McMenamin said. And when he and his daughter arrived at the park, they were struck by the remains’ strangeness, particularly “a very odd configuration of bones.”

Illustration of ichthyosaurs

Illustration of ichthyosaurs

The fossil markings suggest that the ichthyosaur was not killed and buried at the same time. Instead, researchers conclude, after studying the bones configuration, that it had been carried away to the “kraken’s lair” after being killed.

The arranged vertebrae resemble the pattern of sucker disks on a cephalopod’s tentacle, which the researchers suggest this pattern reveals a self-portrait of the mysterious beast. McMillan tried to look for evidence of just this, and he was more or less fortunate. Video taken by staff at the Seattle Aquarium showed that a large octopus in one of their large tanks had been killing the sharks.

“We think that this cephalopod in the Triassic was doing the same thing,” McMenamin said. More supporting evidence: There were many more broken ribs seen in the shonisaur fossils than would seem accidental, as well as evidence of twisted necks.

“It was either drowning them or breaking their necks,” McMenamin said.

If McMenamin’s hypothesis is correct, than this should be easily asserted by this alleged kraken’s fossils. Well, here’s the funny part – cephalopods don’t fossilize well and scientists wouldn’t expect to find their remains from so long ago. McMenamin has to prepare a solid case.

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