Rock solid evidence: Angola geology reveals prehistoric split between South America and Africa

An SMU-led research team has found that ancient rocks and fossils from long-extinct marine reptiles in Angola clearly show a key part of Earth's past -- the splitting of South America and Africa and the subsequent formation of the South Atlantic Ocean.

With their easily visualized "jigsaw-puzzle fit," it has long been known that the western coast of Africa and the eastern coast of South America once nestled together in the supercontinent Gondwana -- which broke off from the larger landmass of Pangea.

The research team says the southern coast of Angola, where they dug up the samples, arguably provides the most complete geological record ever recorded on land of the two continents moving apart and the opening of the South Atlantic Ocean. Rocks and fossils found date back from 130 million years ago to 71 million years.

"There are places that you can go to in South America, for instance, where you can see this part of the split or that part of it, but in Angola, it's all laid out in one place," said Louis L. Jacobs, SMU professor emeritus of Earth Sciences and president of ISEM. Jacobs is the lead author of a study published in The Geological Society, London, Special Publications.

"Before this, there was not a place known to go and see the rocks on the surface that really reflected the opening of the South Atlantic Ocean, because they're now in the ocean or eroded away," Jacobs said.

Angola rocks and fossils tell the whole story

Africa and South America started to split around 140 million years ago, causing gashes in Earth's crust called rifts to open up along pre-existing weaknesses. As the tectonic plates beneath South America and Africa moved apart, magma from the Earth's mantle rose to the surface, creating a new oceanic crust and pushing the continents away from each other. And eventually, the South Atlantic Ocean filled the void between these two newly-formed continents.

Scientists have previously found evidence of these events through geophysics and well cores drilled through the ocean floor.

But these tell-tale signs have never been found in one place, or been so clearly visible for anyone to see, said study co-author Michael J. Polcyn, research associate in the Huffington Department of Earth Sciences and senior research fellow, ISEM at SMU.

"It's one thing for a geophysicist to be able to look at seismic data and make inferences from that," he said. "It's quite another thing to be able to take a school field trip out to the rock formations, or outcrops, and say this is when the lava was spreading from eastern South America. Or this was when it was a continuous land."

Essentially, Angola presents the opportunity for someone to easily walk through each phase of this geologically significant chapter in Earth's history.

"That gives Angola major bragging rights," Jacobs said.

Jacobs, Polcyn and Diana P. Vineyard -- who is a research associate at SMU -- worked with an international team of paleontologists, geologists and others to analyze both the rock formations they found in eight different locations on the coast and the fossils within them.

Fieldwork in Angola's Namibe Province began in 2005. At that time, the research team recognized particular types of sediments, which gave them a good indication of what the western coast of Africa had been like at various stages millions of years ago. For instance, fields of lava revealed volcanic outpourings, and faults or breaks showed where the continents were being rifted apart. Sediments and salt deposits showed ocean flooding and evaporation, while overlying oceanic sediments and marine reptiles showed completion of the South Atlantic Ocean.

Paleontologists, meanwhile, discovered fossils in Angola from large marine reptiles that had lived late during the Cretaceous Period, right after the Atlantic Ocean was completed and while it grew wider.

By bringing together experts from a wide range of fields, "we were able to document when there was no ocean at all, to when there was a fresh enough ocean for those reptiles to thrive and have enough to eat," Vineyard said.

Many of the ancient fossils are currently on display at the Smithsonian's National Museum of Natural History "Sea Monsters Unearthed: Life in Angola's Ancient Seas" exhibit, which was co-produced with SMU -- a nationally-ranked Dallas-based private university.

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Paleontologists unearth what may be the largest known marine reptile

The fossilised remains of a second gigantic jawbone measuring more than two metres long has been found on a beach in Somerset, UK.

Experts have identified the bones as belonging to the jaws of a new species of enormous ichthyosaur, a type of prehistoric marine reptile. Estimates suggest the oceanic titan would have been more than 25 metres long.

Father and daughter, Justin and Ruby Reynolds from Braunton, Devon, found the first pieces of the second jawbone to be found in May 2020, while searching for fossils on the beach at Blue Anchor, Somerset. Ruby, then aged 11, found the first chunk of giant bone before searching together for additional pieces.

Realising they had discovered something significant, they contacted leading ichthyosaur expert, Dr Dean Lomax, a palaeontologist at The University of Manchester. Dr Lomax, who is also a 1851 Research Fellow at the University of Bristol, contacted Paul de la Salle, a seasoned fossil collector who had found the first giant jawbone in May 2016 from further along the coast at Lilstock.

Dr Dean Lomax said: "I was amazed by the find. In 2018, my team (including Paul de la Salle) studied and described Paul's giant jawbone and we had hoped that one day another would come to light. This new specimen is more complete, better preserved, and shows that we now have two of these giant bones -- called a surangular -- that have a unique shape and structure. I became very excited, to say the least."

Justin and Ruby, together with Paul, Dr Lomax, and several family members, visited the site to hunt for more pieces of this rare discovery. Over time, the team found additional pieces of the same jaw which fit together perfectly, like a multimillion-year-old jigsaw.

Justin said: "When Ruby and I found the first two pieces we were very excited as we realised that this was something important and unusual. When I found the back part of the jaw, I was thrilled because that is one of the defining parts of Paul's earlier discovery."

The last piece of bone was recovered in October 2022.

The research team, led by Dr Lomax, revealed that the jaw bones belong to a new species of giant ichthyosaur that would have been about the size of a blue whale. Comparing the two examples of the same bone with the same unique features from the same geologic time zone supports their identifications.

The team have called the new genus and species Ichthyotitan severnensis, meaning "giant fish lizard of the Severn."

The bones are around 202 million years old, dating to the end of the Triassic Period in a time known as the Rhaetian. During this time, the gigantic ichthyosaurs swam the seas while the dinosaurs walked on land. It was the titans' final chapter, however -- as the story told in the rocks above these fossils record a cataclysm known as the Late Triassic global mass extinction event. After this time, giant ichthyosaurs from the family known as Shastasauridae go extinct. Today, these bones represent the very last of their kind.

Ichthyotitan is not the world's first giant ichthyosaur, but de la Salles' and Reynolds' discoveries are unique among those known to science. These two bones appear roughly 13 million years after their latest geologic relatives, including Shonisaurus sikanniensis from British Columbia, Canada, and Himalayasaurus tibetensis from Tibet, China.

Dr Lomax added: "I was highly impressed that Ruby and Justin correctly identified the discovery as another enormous jawbone from an ichthyosaur. They recognised that it matched the one we described in 2018. I asked them whether they would like to join my team to study and describe this fossil, including naming it. They jumped at the chance. For Ruby, especially, she is now a published scientist who not only found but also helped to name a type of gigantic prehistoric reptile. There are probably not many 15-year-olds who can say that! A Mary Anning in the making, perhaps."

Ruby said: "It was so cool to discover part of this gigantic ichthyosaur. I am very proud to have played a part in a scientific discovery like this."

Further examinations of the bones' internal structures have been carried out by master's student, Marcello Perillo, from the University of Bonn, Germany. His work confirmed the ichthyosaur origin of the bones and revealed that the animal was still growing at the time of death.

He said: "We could confirm the unique set of histological characters typical of giant ichthyosaur lower jaws: the anomalous periosteal growth of these bones hints at yet to be understood bone developmental strategies, now lost in the deep time, that likely allowed late Triassic ichthyosaurs to reach the known biological limits of vertebrates in terms of size. So much about these giants is still shrouded by mystery, but one fossil at a time we will be able to unravel their secret."

Concluding the work, Paul de la Salle added: "To think that my discovery in 2016 would spark so much interest in these enormous creatures fills me with joy. When I found the first jawbone, I knew it was something special. To have a second that confirms our findings is incredible. I am overjoyed."

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Ancient sea monster remains reveal oldest mega-predatory pliosaur

The fossils of a 170-million-year-old ancient marine reptile from the Age of Dinosaurs have been identified as the oldest-known mega-predatory pliosaur -- a group of ocean-dwelling reptiles closely related to the famous long-necked plesiosaurs. The findings are rare and add new knowledge to the evolution of plesiosaurs. The study has been published in the journal Scientific Reports.

The fossils were found 40 years ago in north-eastern France. An international team of palaeontologists from the Naturkunde-Museum Bielefeld in Germany, the Institute of Paleobiology of the Polish Academy of Sciences in Warsaw, Poland, the Natural History Museum in Luxembourg and The Museum of Evolution at Uppsala University in Sweden have now analysed them and identified them as a new pliosaur genus: Lorrainosaurus.

Pliosaurs were a type of plesiosaur with short necks and massive skulls. They appeared over 200 million years ago, but remained minor components of marine ecosystems until suddenly developing into enormous apex predators. The new study shows that this adaptive shift followed feeding niche differentiation and the global decline of other predatory marine reptiles over 170 million years ago.

Lorrainosaurus is the oldest large-bodied pliosaur represented by an associated skeleton. It had jaws over 1.3 m long with large conical teeth and a bulky 'torpedo-shaped' body propelled by four flipper-like limbs.

"Lorrainosaurus was one of the first truly huge pliosaurs. It gave rise to a dynasty of marine reptile mega-predators that ruled the oceans for around 80 million years," explains Sven Sachs, a researcher at the Naturkunde-Museum Bielefeld, who led the study.

This giant reptile probably reached over 6 m from snout to tail, and lived during the early Middle Jurassic period. Intriguingly, very little is known about plesiosaurs from that time.

"Our identification of Lorrainosaurus as one of the earliest mega-predatory pliosaurs demonstrates that these creatures emerged immediately after a landmark restructuring of marine predator ecosystems across the Early-to-Middle Jurassic boundary, some 175 to 171 million years ago. This event profoundly affected many marine reptile groups and brought mega-predatory pliosaurids to dominance over 'fish-like' ichthyosaurs, ancient marine crocodile relatives, and other large-bodied predatory plesiosaurs," adds Daniel Madzia from the Institute of Paleobiology of the Polish Academy of Sciences, who co-led the study.

Pliosaurs were some of the most successful marine predators of their time.

"Famous examples, such as Pliosaurus and Kronosaurus -- some of the world's largest pliosaurs -- were absolutely enormous with body-lengths exceeding 10 m. They were ecological equivalents of today's Killer whales and would have eaten a range of prey including squid-like cephalopods, large fish and other marine reptiles. These have all been found as preserved gut contents," said senior co-author Benjamin Kear, Curator of Vertebrate Palaeontology and Researcher in Palaeontology at The Museum of Evolution, Uppsala University.

The recovered bones and teeth of Lorrainosaurus represent remnants of what was once a complete skeleton that decomposed and was dispersed across the ancient sea floor by currents and scavengers.

"The remains were unearthed in 1983 from a road cutting near Metz in Lorraine, north-eastern France. Palaeontology enthusiasts from the Association minéralogique et paléontologique d'Hayange et des environs recognised the significance of their discovery and donated the fossils to the Natural History Museum in Luxembourg," said co-author Ben Thuy, Curator at the Natural History Museum in Luxembourg.

Other than a brief report published in 1994, the fossils of Lorrainosaurus remained obscure until this new study re-evaluated the finds. Lorrainosaurus indicates that the reign of gigantic mega-predatory pliosaurs must have commenced earlier than previously thought, and was locally responsive to major ecological changes affecting marine environments covering what is now western Europe during the early Middle Jurassic.

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Whale-like filter-feeding discovered in prehistoric marine reptile

A remarkable new fossil from China reveals for the first time that a group of reptiles were already using whale-like filter feeding 250 million years ago.

New research by a team from China and the UK has shown details of the skull of an early marine reptile called Hupehsuchus that indicate it had soft structures such as an expanding throat region to allow it to engulf great masses of water containing shrimp-like prey, and baleen whale-like structures to filter food items as it swam forward.

The team also found that the Hupehsuchus skulls show the same grooves and notches along the edges of its jaws similar to baleen whales, which have keratin strips instead of teeth.

"We were amazed to discover these adaptations in such an early marine reptile," said Zichen Fang of the Wuhan Center of China Geological Survey, who led the research. "The hupehsuchians were a unique group in China, close relatives of the ichthyosaurs, and known for 50 years, but their mode of life was not fully understood."

"The hupesuchians lived in the Early Triassic, about 248 million years ago, in China and they were part of a huge and rapid re-population of the oceans," said Professor Michael Benton, a collaborator at the University of Bristol's School of Earth Sciences. "This was a time of turmoil, only three million years after the huge end-Permian mass extinction which had wiped out most of life. It's been amazing to discover how fast these large marine reptiles came on the scene and entirely changed marine ecosystems of the time."

"We discovered two new hupehsuchian skulls," said Professor Long Cheng, also of the Wuhan Center of China Geological Survey, who directed the project. "These were more complete than earlier finds and showed that the long snout was composed of unfused, straplike bones, with a long space between them running the length of the snout. This construction is only seen otherwise in modern baleen whales where the loose structure of the snout and lower jaws allows them to support a huge throat region that balloons out enormously as they swim forward, engulfing small prey."

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Fossil of mosasaur with bizarre 'screwdriver teeth' found in Morocco

Scientists have discovered a new species of mosasaur, a sea-dwelling lizard from the age of the dinosaurs, with strange, ridged teeth unlike those of any known reptile. Along with other recent finds from Africa, it suggests that mosasaurs and other marine reptiles were evolving rapidly up until 66 million years ago, when they were wiped out by an asteroid along with the dinosaurs and around 90% of all species on Earth.

The new species, Stelladens mysteriosus, comes from the Late Cretaceous of Morocco and was around twice the size of a dolphin.

It had a unique tooth arrangement with blade-like ridges running down the teeth, arranged in a star-shaped pattern, reminiscent of a cross-head screwdriver.

Most mosasaurs had two bladelike, serrated ridges on the front and back of the tooth to help cut prey, however Stelladens had anywhere from four to six of these blades running down the tooth.

"It's a surprise," said Dr Nick Longrich from the Milner Centre for Evolution at the University of Bath, who led the study. "It's not like any mosasaur, or any reptile, even any vertebrate we've seen before."

Dr Nathalie Bardet, a marine reptile specialist from the Museum of Natural History in Paris, said: "I've worked on the mosasaurs of Morocco for more than 20 years, and I'd never seen anything like this before -- I was both perplexed and amazed!"

That several teeth were found with the same shape suggests their strange shape was not the result of a pathology or a mutation.

The unique teeth suggest a specialised feeding strategy, or a specialised diet, but it remains unclear just what Stelladens ate.

Dr Longrich said: "We have no idea what this animal was eating, because we don't know of anything similar either alive today, or from the fossil record.

"It's possible it found a unique way to feed, or maybe it was filling an ecological niche that simply doesn't exist today. The teeth look like the tip of a Phillips-head screwdriver, or maybe a hex wrench.

"So what's it eating? Phillips head screws? IKEA furniture? Who knows."

The teeth were small, but stout and with wear on the tips, which seemed to rule out soft-bodied prey. The teeth weren't strong enough to crush heavily armoured animals like clams or sea urchins, however.

"That might seem to suggest it's eating something small, and lightly armoured -- thin-shelled ammonites, crustaceans, or bony fish -- but it's hard to know," said Longrich. "There were weird animals living in the Cretaceous- ammonites, belemnites, baculites -- that no longer exist. It's possible this mosasaur ate something, and occupied a niche, that simply doesn't exist anymore, and that might explain why nothing like this is ever seen again.

"Evolution isn't always predictable. Sometimes it goes off in a unique direction, and something evolves that's never been seen before, and then it never evolves again."

The mosasaurs lived alongside dinosaurs but weren't dinosaurs. Instead, they were giant lizards, relatives of Komodo dragons, snakes, and iguanas, adapted for a life at sea.

Mosasaurs evolved around 100 million years ago, and diversified up to 66 million years ago, when a giant asteroid hit the Yucatan Peninsula in Mexico, plunging the world into darkness.

Although scientists have debated the role of environmental changes towards the end of the Cretaceous in the extinction, Stelladens, along with recent discoveries from of Morocco, suggests that mosasaurs were evolving rapidly up to the very end -- they went out at their peak, rather than fading away.

The new study shows that even after years of work in the Cretaceous of Morocco, new species are continuing to be discovered. The reason may be that most species are rare.

The authors of the study predict that in a very diverse ecosystem, it may take decades to find all of the rare species.

"We're not even close to finding everything in these beds," said Longrich, "This is the third new species to appear, just this year. The amount of diversity at the end of the Cretaceous is just staggering."

Nour-Eddine Jalil, a professor at the Natural History Museum and a researcher at Univers Cadi Ayyad in Morocco, said: "The fauna has produced an incredible number of surprises -- mosasaurs with teeth arranged like a saw, a turtle with a snout in the form of snorkel, a multitude of vertebrates of various shapes and sizes, and now a mosasaur with star-shaped teeth.

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Fossil CSI: Giant extinct marine reptile graveyard was likely ancient birthing grounds

Today's marine giants -- such as blue and humpback whales -- routinely make massive migrations across the ocean to breed and give birth in waters where predators are scarce, with many congregating year after year along the same stretches of coastline. Now, new research from a team of scientists -- including researchers with the Smithsonian Institution, Vanderbilt University, the Natural History Museum of Utah, the University of Utah, University of Nevada, Reno, University of Edinburgh, University of Texas at Austin, Vrije Universiteit Brussels and University of Oxford -- suggests that nearly 200 million years before giant whales evolved, school bus-sized marine reptiles called ichthyosaurs may have been making similar migrations to breed and give birth together in relative safety.

The findings, published today in the journal Current Biology, examine a rich fossil bed in the renowned Berlin-Ichthyosaur State Park (BISP) in Nevada's Humboldt-Toiyabe National Forest, where many 50-foot-long ichthyosaurs (Shonisaurus popularis)lay petrified in stone. Led by Neil Kelley, Vanderbilt University scientist and former Smithsonian's National Museum of Natural History Peter Buck postdoctoral fellow, and co-authored by the museum's curator of fossil marine mammals Nicholas Pyenson, the study offers a plausible explanation as to how at least 37 of these marine reptiles came to meet their ends in the same locality -- a question that has vexed paleontologists for more than half a century.

"We present evidence that these ichthyosaurs died here in large numbers because they were migrating to this area to give birth for many generations across hundreds of thousands of years," Pyenson said. "That means this type of behavior we observe today in whales has been around for more than 200 million years."

Over the years, some paleontologists have proposed that BISP's ichthyosaurs -- predators resembling oversized chunky dolphins that have been adopted as Nevada's state fossil -- died in a mass stranding event such as those that sometimes afflicts modern whales, or that the creatures were poisoned by toxins from a nearby harmful algal bloom. The problem is that these hypotheses lack strong lines of scientific evidence to support them.

To try to solve this prehistoric mystery, the team combined newer paleontological techniques such as 3D scanning and geochemistry with traditional paleontological perseverance by poring over archival materials, photographs, maps, field notes and drawer after drawer of museum collections for shreds of evidence that could be reanalyzed.

Although most well-studied paleontological sites excavate fossils so they can be more closely studied by scientists at research institutions, the main attraction for visitors to the Nevada State Park-run BISP is a barn-like building that houses what researchers call Quarry 2, an array of ichthyosaurs that have been left embedded in the rock for the public to see and appreciate. Quarry 2 has partial skeletons from an estimated seven individual ichthyosaurs that all appear to have died around the same time.

"When I first visited the site in 2014, my first thought was that the best way to study it would be to create a full-color, high-resolution 3D model," Kelley said. "A 3D model would allow us to study the way these large fossils were arranged in relation to one another without losing the ability to go bone by bone."

To do this, Kelley, Pyenson and the research team collaborated with Jon Blundell, a member of the Smithsonian Digitization Program Office's 3D Program team, and Holly Little, a long-time collaborator with Pyenson and the 3D Program's team and currently the informatics manager in the museum's Department of Paleobiology. While Pyenson and Kelley were physically measuring bones and studying the site using traditional paleontological techniques, Little and Blundell used digital cameras and a spherical laser scanner to take hundreds of photographs and millions of point measurements that were then stitched together using specialized software to create a 3D model of the fossil bed.

To further home in on what might have befallen these extinct marine reptiles, the team collected tiny samples of the rock surrounding the fossils and performed a series of geochemical tests to look for signs of environmental disturbance.

One test measured mercury, which often accompanies large-scale volcanic activity, and found no significantly increased levels. Other tests examined different types of carbon and determined that there was no evidence of sudden increases in organic matter in the marine sediments that would result in a dearth of oxygen in the surrounding waters (though, like whales, the ichthyosaurs breathed air).

These geochemical tests revealed no signs that these ichthyosaurs perished because of some cataclysm that would have seriously disturbed the ecosystem in which they died. Kelley, Pyenson and other colleagues on the research team continued to look beyond Quarry 2 to the surrounding geology and all the fossils that had previously been excavated from the area.

The geologic evidence indicates that when the ichthyosaurs died, their bones eventually sank to the bottom of the sea, rather than along a shoreline shallow enough to suggest stranding, ruling out another hypothesis. Even more telling, though the area's limestone was chockfull of large adult Shonisaurus specimens, other marine vertebrates were scarce. The bulk of the other fossils at BISP come from small invertebrates such as clams and ammonites (spiral-shelled relatives of today's squid).

"There are so many large, adult skeletons from this one species at this site and almost nothing else," Pyenson said. "There are virtually no remains of things like fish or other marine reptiles for these ichthyosaursto feed on, and there are also no juvenile Shonisaurus skeletons."

The researchers' paleontological dragnet had eliminated some of the potential causes of death and started to provide intriguing clues about the type of ecosystem these marine predators were swimming in, but the evidence still did not clearly point to an alternative explanation.

The research team found a key piece of the puzzle when they discovered tiny ichthyosaur remains among new fossils collected at BISP and hiding within older museum collections. Careful comparison of the bones and teeth using micro-CT X-ray scans at Vanderbilt University revealed that these small bones were in fact embryonic and newborn Shonisaurus.

"Once it became clear that there was nothing for them to eat here, and there were large adult Shonisaurus along with embryos and newborns but no juveniles, we started to seriously consider whether this might have been a birthing ground," Kelley said.

Further analysis of the various strata in which the different clusters of ichthyosaur bones were found also revealed that the ages of the many fossil beds of BISP were separated by at least hundreds of thousands of years, if not millions.

"Finding these different spots with the same species spread across geologic time with the same demographic pattern tells us that this was a preferred habitat that these large oceangoing predators returned to for generations," Pyenson said. "This is a clear ecological signal, we argue, that this was a place that Shonisaurus used to give birth, very similar to today's whales. Now we have evidence that this sort of behavior is 230 million years old."

Kelley said the next step for this line of research is to investigate other ichthyosaur and Shonisaurus sites in North America with these new findings in mind to begin to recreate their ancient world -- perhaps by looking for other breeding sites or for places with greater diversity of other species that could have been rich feeding grounds for this extinct apex predator.

The 3D scans of the site are now available for other researchers to study and for the public to explore via the open-source Smithsonian's Voyager platform, which is developed and maintained by Blundell's team members at the Digitization Program Office. An interactive digital experience about the research team's study, including a 3D model of ichthyosaur sites analyzed, is also available on the Digitization Program Office's website.

"Our work is public," Blundell said. "We aren't just scanning sites and objects and locking them up. We create these scans to open up the collection to other researchers and members of the public who can't physically get to the Smithsonian."

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Fossils of giant sea lizard that ruled the oceans 66 million years ago discovered

Researchers have discovered a huge new mosasaur from Morocco, named Thalassotitan atrox, which filled the apex predator niche. With massive jaws and teeth like those of killer whales, Thalassotitan hunted other marine reptiles -- plesiosaurs, sea turtles, and other mosasaurs.

At the end of the Cretaceous period, 66 million years ago, sea monsters really existed. While dinosaurs flourished on land, the seas were ruled by the mosasaurs, giant marine reptiles.

Mosasaurs weren't dinosaurs, but enormous marine lizards growing up to 12 metres (40 feet) in length. They were distant relatives of modern iguanas and monitor lizards.

Mosasaurs looked like a Komodo dragon with flippers instead of legs, and a shark-like tail fin. Mosasaurs became larger and more specialised in the last 25 million years of the Cretaceous, taking niches once filled by marine reptiles like plesiosaurs and ichthyosaurs. Some evolved to eat small prey like fish and squid. Others crushed ammonites and clams. The new mosasaur, named Thalassotitan atrox, evolved to prey on all the other marine reptiles.

The remains of the new species were dug up in Morocco, about an hour outside Casablanca. Here, near the end of the Cretaceous, the Atlantic flooded northern Africa. Nutrient rich waters upwelling from the depths fed blooms of plankton. Those fed small fish, feeding larger fish, which fed mosasaurs and plesiosaurs -- and so on, with these marine reptiles becoming food for the giant, carnivorous Thalassotitan.

Thalassotitan, had an enormous skull measuring 1.4 metres (5 feet long), and grew to nearly 30 feet (9 metres) long, the size of a killer whale. While most mosasaurs had long jaws and slender teeth for catching fish, Thalassotitan had a short, wide muzzle and massive, conical teeth like those of an orca. These let it seize and rip apart huge prey. These adaptations suggest Thalassotitan was an apex predator, sitting at the top of the food chain. The giant mosasaur occupied the same ecological niche as today's killer whales and great white sharks.

Thalassotitan's teeth are often broken and worn, however eating fish wouldn't have produced this sort of tooth wear. Instead, this suggests that the giant mosasaur attacked other marine reptiles, chipping, breaking, and grinding its teeth as it bit into their bones and tore them apart. Some teeth are so heavily damaged they have been almost ground down to the root.

Fossilised remains of prey

Remarkably, possible remains of Thalassotitan's victims have been discovered. Fossils from the same beds show damage from acids, with teeth and bone eaten away. Fossils with this peculiar damage include large predatory fish, a sea turtle, a half-meter long plesiosaur head, and jaws and skulls of at least three different mosasaur species. They would have been digested in Thalassotitan's stomach before it spat out their bones.

"It's circumstantial evidence," said Dr Nick Longrich, Senior Lecturer from the Milner Centre for Evolution at the University of Bath and lead author on the study, published in Cretaceous Research.

"We can't say for certain which species of animal ate all these other mosasaurs. But we have the bones of marine reptiles killed and eaten by a large predator.

"And in the same location, we find Thalassotitan, a species that fits the profile of the killer -- it's a mosasaur specialised to prey on other marine reptiles. That's probably not a coincidence."

Thalassotitan was a threat to everything in the oceans -- including other Thalassotitan. The huge mosasaurs bear injuries sustained in violent combat with other mosasaurs, with injuries to their face and jaws sustained in fights. Other mosasaurs show similar injuries, but in Thalassotitan these wounds were exceptionally common, suggesting frequent, intense fights over feeding grounds or mates.

"Thalassotitan was an amazing, terrifying animal," said Dr Nick Longrich, who led the study. "Imagine a Komodo Dragon crossed with a great white shark crossed with a T. rex crossed with a killer whale."

The new mosasaur lived in the final million years of the Age of Dinosaurs, a contemporary of animals like T. rex and Triceratops. Along with recent discoveries of mosasaurs from Morocco, it suggests that mosasaurs weren't in decline before the asteroid impact that drove the Cretaceous mass extinction. Instead, they flourished.

Professor Nour-Eddine Jalil, a co-author on the paper from the Museum of Natural History in Paris, said: "The phosphate fossils of Morocco offer an unparalleled window on the paleobiodiversity at the end of Cretaceous.

"They tell us how life was rich and diversified just before the end of the 'dinosaur era', where animals had to specialise to have a place in their ecosystems. Thalassotitan completes the picture by taking on the role of the megapredator at the top of the food chain."

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Extinct swordfish-shaped marine reptile discovered

A team of international researchers from Canada, Colombia, and Germany has discovered a new marine reptile. The specimen, a stunningly preserved metre-long skull, is one of the last surviving ichthyosaurs -- ancient animals that look eerily like living swordfish.

"This animal evolved a unique dentition that allowed it to eat large prey," says Hans Larsson, Director of the Redpath Museum at McGill University. "Whereas other ichthyosaurs had small, equally sized teeth for feeding on small prey, this new species modified its tooth sizes and spacing to build an arsenal of teeth for dispatching large prey, like big fishes and other marine reptiles."

"We decided to name it Kyhytysuka which translates to 'the one that cuts with something sharp' in an indigenous language from the region in central Colombia where the fossil was found, to honour the ancient Muisca culture that existed there for millennia," says Dirley Cortes, a graduate student under the supervision of Hans Larsson and Carlos Jaramillo of the Smithsonian Tropical Research Institute.

The big picture of ichthyosaur evolution is clarified with this new species, the researchers say. "We compared this animal to other Jurassic and Cretaceous ichthyosaurs and were able to define a new type of ichthyosaurs," says Erin Maxwell of the State Natural History Museum of Stuttgart (a former graduate student of Hans Larsson's lab at McGill). "This shakes up the evolutionary tree of ichthyosaurs and lets us test new ideas of how they evolved."

According to the researchers, this species comes from an important transitional time during the Early Cretaceous period. At this time, the Earth was coming out of a relatively cool period, had rising sea levels, and the supercontinent Pangea was splitting into northern and southern landmasses. There was also a global extinction event at the end of the Jurassic that changed marine and terrestrial ecosystems. "Many classic Jurassic marine ecosystems of deep-water feeding ichthyosaurs, short-necked plesiosaurs, and marine-adapted crocodiles were succeeded by new lineages of long-necked plesiosaurs, sea turtles, large marine lizards called mosasaurs, and now this monster ichthyosaur" says Dirley Cortes.

"We are discovering many new species in the rocks this new ichthyosaur comes from. We are testing the idea that this region and time in Colombia was an ancient biodiversity hotspot and are using the fossils to better understand the evolution of marine ecosystems during this transitional time," she adds. As next steps the researchers are continuing to explore the wealth of new fossils housed in the Centro de Investigaciones Paleontológicas of Villa de Leyva in Colombia. "This is where I grew up," says Cortes "and it is so rewarding to get to do research here too."

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Newly identified mosasaur was fish-hunting monster

Researchers at the University of Cincinnati identified a new species of mosasaur -- an 18-foot-long fish-eating monster that lived 80 million years ago.

UC assistant professor-educator Takuya Konishi and his student, UC graduate Alexander Willman, named the mosasaur Ectenosaurus everhartorum after paleontologists Mike and Pamela Everhart. The mosasaur inhabited the Western Interior Seaway in what today is western Kansas.

The discovery was announced this week in the Canadian Journal of Earth Sciences.

The newly identified mosasaur marks only the second species in the genus Ectenosaurus.

"Mosasaurs in western Kansas have been well sampled and well researched. Those two factors create tall odds when you try to find something new," Konishi said.

Mosasaurs were enormous marine reptiles, some as big as school buses. They inhabited oceans around the world during the Cretaceous period around the time of Tyrannosaurus rex. If Ectenosaurus clidastoides with its long, slender jaws resembles a gharial crocodile, Konishi said the new species is closer to a false gharial crocodile with notably blunter jaws.

Konishi, who teaches in the Biological Sciences Department of UC's College of Arts and Sciences, first encountered the fossil in 2004 while working as a graduate student in systematics and evolution. Konishi was studying fossils of Platecarpus, a different genus of mosasaur in storage at Fort Hays State University's Sternberg Museum of Natural History, when he recognized something odd about one specimen.

"It wasn't a platecarpus. The frontal bone above the eye socket was much longer. The bones of Platecarpus should have had a broader triangle," he said. "That was one telltale sign."

Konishi suspected the specimen was a type of ectenosaur, only one species of which had been identified. But the teeth seemed all wrong. The now-empty sockets that would have contained the mosasaur's sharp, curved teeth in the unidentified specimen would have extended around the front of its mouth, unlike other recognized species that has a toothless rostrum, the bony protuberance at the front of the mouth.

For years, the fossils puzzled him.

"Some things just stick in your mind and they're hard to let go," he said.

But the mystery would have to wait because Konishi was busy finishing his doctoral degree and launching an academic career that would bring him to UC's College of Arts and Sciences.

The first mosasaur fossils were found in the Netherlands a half-century before anyone used the term "dinosaur." Mosasaurs began to capture the nation's attention after the Civil War when the nation's premier paleontologists, Othniel Charles Marsh and Edward Drinker Cope, began to study Cretaceous limestone in Kansas in a partnership that became a bitter public feud. Since then, Kansas has become world-renowned for mosasaur research.

Generations of experts have come to Kansas to study its specimens, which are on display at museums around the world.

"It's a famous place for mosasaur research. It's quite well known," Konishi said. "So I thought I don't have to be the guy to place a stake. I'm sure someone will catch it. But nobody did."

Ectenosaur is unusual for how few specimens have been found in the genus compared to other mosasaurs, Konishi said.

"In western Kansas we have over 1,500 mosasaur specimens. Out of those we can only find one specimen each representing these two species of ectenosaur," Konishi said. "That's sort of crazy."

When Konishi confirmed with the Sternberg Museum that no other researchers were studying the specimen, he asked them to ship the fossils to UC. When he opened the carefully bubble-wrapped contents, his initial impressions were confirmed.

"By then I had looked at all the other known Platecarpus specimens under the sun, as it were. And this specimen was distinct from the others," he said. "To me it was so obvious."

At the same time, Konishi's student Willman inquired about working on a research project. He received a UC Undergraduate STEM Experience grant to help with the taxonomic identification.

"I was beyond excited to be part of the discovery," Willman said.

The third author on the study, Michael Caldwell, is a professor of biology at the University of Alberta, Edmonton.

Willman illustrated the fossils in painstaking detail to help scientists understand the morphological differences that make the mosasaur unique.

"I was very happy with how he brought these broken bones to life," Konishi said. "It helped make our case very convincing to anyone that this is something new that warrants the establishment of a new taxon."

The researchers dedicated the project to the late Dale Russell, whose work has had a profound impact in North American mosasaur paleontology, Konishi said. But they named the mosasaur for the Everharts, a Kansas couple who have spent more than 30 years sharing their fossils with museums and leading research field trips in the fossil-rich Smoky Hill Chalk.

"We're still in a little bit of shock at the news. It's very exciting," Pamela Everhart said.

"It's a great honor," said Mike Everhart, author of "Oceans of Kansas" about mosasaurs and other prehistoric life that inhabited the Western Interior Seaway during the Cretaceous Period.

Mosasaurs are very special to him, he said.

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