A new study published today in the scientific journal Ecology and Evoiution looks at the maximum possible sizes of dinosaurs, using the carnivore, Tyrannosaurus rex, as an example. Using computer modelling, Dr. Jordan Mallon of the Canadian Museum of Nature and Dr. David Hone of Queen Mary University of London, produced estimates that T. Rex might have been 70% heavier than what the fossil evidence suggests.

The researchers assert that the huge sizes attained by many dinosaurs make them a source of endless fascination, raising the question as to how these animals evolved to be so big. There are perennial claims and counter-claims about which dinosaur species was the largest of its group or even the largest ever.

Most dinosaur species are known from only one or a handful of specimens, so it’s extraordinarily unlikely that their size ranges will include the largest individuals that ever existed. The question remains: how big were the largest individuals, and are we likely to find them?

To address this question, Mallon and Hone used computer modelling to assess a population of T. rex. They factored in variables such as population size, growth rate, lifespan, the incompleteness of the fossil record, and more.

T. rex was chosen for the model because it is a familiar dinosaur for which many of these details are already well estimated. Body-size variance at adulthood, which is still poorly known in T. rex, was modelled with and without sex differences, and is based on examples of living alligators, chosen for their large size and close kinship with the dinosaurs.

The palaeontologists found that the largest known T. rex fossils probably fall in the 99th percentile, representing the top 1% of body size, but to find an animal in the top 99.99% (a one-in-ten-thousand individual) scientists would need to excavate fossils at the current rate for another 1,000 years.

The computer models suggest that the largest individual that could have existed (one in 2.5 billion animals) may have been 70% more massive than the current largest-known T. rex specimens (an estimated 15 tonnes vs 8.8 tonnes) and 25% longer (15 metres vs 12 metres).

The values are estimates based on the model, but patterns of discovery of giants of modern species tell us there must have been larger dinosaurs out there that have not yet been found. “Some isolated bones and pieces certainly hint at still larger individuals than for which we currently have skeletons,” says Hone.

This study adds to the debates about the largest fossil animals. Many of the largest dinosaurs in various groups are known from a single good specimen, so it’s impossible to know if that one animal was a big or small example of the species. An apparently large species might be based on a single giant individual, and a small species based on a particularly tiny individual — neither of which reflect the average size of their respective species.

The chances that palaeontologists will find the largest ever individuals for a given species are incredibly small. So, despite the giant skeletons that can be seen in museums around the world, the very largest individuals of these species were likely even larger than those on display.

Dr. Jordan Mallon, from the Canadian Museum of Nature, said: “Our study suggests that, for big fossil animals like T. rex, we really have no idea from the fossil record about the absolute sizes they might have reached. It’s fun to think about a 15 tonne T. rex, but the implications are also interesting from a biomechanical or ecological perspective.”

Reference:
Jordan C. Mallon, David W. E. Hone. Estimation of maximum body size in fossil species: A case study using Tyrannosaurus rex. Ecology and Evolution, 2024; 14 (7) DOI: 10.1002/ece3.11658

Note: The above post is reprinted from materials provided by Canadian Museum of Nature.

The most complete dinosaur discovered in this country in the last 100 years, with a pubic hip bone the size of a ‘dinner plate’, has been described in a new paper published today.

The specimen, which is around 125 million years old, was found in the cliffs of Compton Bay on the Isle of Wight in 2013 by fossil collector Nick Chase, before he tragically died of cancer.

Jeremy Lockwood, a retired GP and University of Portsmouth PhD student, helped with the dinosaur’s excavation and has spent years analysing the 149 different bones that make up the skeleton.

Jeremy determined that the skeleton represented a new genus and species, which he named Comptonatus chasei in tribute to Nick.

Jeremy said: “Nick had a phenomenal nose for finding dinosaur bones — he really was a modern-day Mary Anning. He collected fossils daily in all weathers and donated them to museums. I was hoping we’d spend our dotage collecting together as we were of similar ages, but sadly that wasn’t to be the case.

“Despite his many wonderful discoveries over the years, including the most complete Iguanodon skull ever found in Britain, this is the first dinosaur to be named after him.”

When it was first discovered, the specimen was thought to be a known dinosaur called Mantellisaurus, but Jeremy’s study revealed a lot more dinosaur diversity. Indeed, this is the second new genus to be described by Jeremy.

He said: “I’ve been able to show this dinosaur is different because of certain unique features in its skull, teeth and other parts of its body. For example its lower jaw has a straight bottom edge, whereas most iguanodontians have a jaw that curves downwards. It also has a very large pubic hip bone, which is much bigger than other similar dinosaurs. It’s like a dinner plate!”

Jeremy doesn’t know why the pubic hip bone, which is placed at the base of the abdomen was so big: “It was probably for muscle attachments, which might mean its mode of locomotion was a bit different, or it could have been to support the stomach contents more effectively, or even have been involved in how the animal breathed, but all of these theories are somewhat speculative.”

Jeremy named the dinosaur Comptonatus after Compton Bay where it was found and ‘tonatus’ is a latin word meaning ‘thunderous’.

“This animal would have been around a ton, about as big as a large male American bison. And evidence from fossil footprints found nearby shows it was likely to be a herding animal, so possibly large herds of these heavy dinosaurs may have been thundering around if spooked by predators on the floodplains over 120 million years ago.”

Dr Susannah Maidment, Senior Researcher and palaeontologist at the Natural History Museum and senior author of the paper completed whilst supervising Jeremy’s PhD, commented: “Comptonatus is a fantastic dinosaur specimen: one of the most complete to be found in the UK in a century.

“Its recognition as a new species is due to incredibly detailed work by NHM Scientific Associate Dr Jeremy Lockwood, whose research continues to reveal that the diversity of dinosaurs in southern England in the Early Cretaceous was much greater than previously realised.

“The specimen, which is younger than Brighstoneus but older than Mantellisaurus (two iguandontian dinosaurs closely related to Comptonatus) demonstrate fast rates of evolution in iguandontian dinosaurs during this time period, and could help us understand how ecosystems recovered after a putative extinction event at the end of the Jurassic Period.”

Despite only four new dinosaur species being described on the Isle of Wight in the whole of the 1900s, there have been eight new species named in the last five years.

Jeremy added: “This really is a remarkable find. It helps us understand more about the different types of dinosaurs that lived in England in the Early Cretaceous. This adds to recent research that shows that Wessex was one of the world’s most diverse ecosystems.”

The dinosaur has been added to the collections at the Dinosaur Isle Museum in Sandown on the Isle of Wight. The paper is published today in the Journal of Systematic Palaeontology.

Dr Martin Munt, Dinosaur Isle curator, said: “Ongoing research on the museum collection continues to reveal exciting new discoveries. Most of Nick’s most important finds have remained on the Island, a lasting legacy.

“We can look forward to many more new types of prehistoric creatures being discovered from the Island’s cliffs and collection.”

Mike Greenslade, General Manager for the National Trust on the Isle of Wight, said: “This extraordinary discovery at National Trust’s Compton Bay highlights the rich natural heritage of the Isle of Wight.

“Finding the most complete dinosaur in the UK in a century not only showcases the island’s palaeontological significance but also underscores the importance of preserving our landscapes for future generations to explore and learn from.

“Nick Chase’s remarkable find and Jeremy Lockwood’s dedicated research are a testament to the incredible history waiting to be uncovered here. We are thrilled to be part of this ongoing journey of discovery and scientific advancement.”

Reference:
Jeremy A. F. Lockwood, David M. Martill, Susannah C. R. Maidment. Comptonatus chasei , a new iguanodontian dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, southern England. Journal of Systematic Palaeontology, 2024; 22 (1) DOI: 10.1080/14772019.2024.2346573

Note: The above post is reprinted from materials provided by University of Portsmouth.

The age of dinosaurs wasn’t conducted solely above ground. A newly discovered ancestor of Thescelosaurus shows evidence that these animals spent at least part of their time in underground burrows. The new species contributes to a fuller understanding of life during the mid-Cretaceous — both above and below ground.

The new dinosaur, Fona [/Foat’NAH/] herzogae lived 99 million years ago in what is now Utah. At that time, the area was a large floodplain ecosystem sandwiched between the shores of a massive inland ocean to the east and active volcanoes and mountains to the west. It was a warm, wet, muddy environment with numerous rivers running through it.

Paleontologists from North Carolina State University and the North Carolina Museum of Natural Sciences unearthed the fossil — and other specimens from the same species — in the Mussentuchit Member of the Cedar Mountain Formation, beginning in 2013. The preservation of these fossils, along with some distinguishing features, alerted them to the possibility of burrowing.

Fona was a small-bodied, plant-eating dinosaur about the size of a large dog with a simple body plan. It lacks the bells and whistles that characterize its highly ornamented relatives such as horned dinosaurs, armored dinosaurs, and crested dinosaurs. But that doesn’t mean Fona was boring.

Fona shares several anatomical features with animals known for digging or burrowing, such as large bicep muscles, strong muscle attachment points on the hips and legs, fused bones along the pelvis — likely to help with stability while digging — and hindlimbs that are proportionally larger than the forelimbs. But that isn’t the only evidence that this animal spent time underground.

“The bias in the fossil record is toward bigger animals, primarily because in floodplain environments like the Mussentuchit, small bones on the surface will often scatter, rot away, or become scavenged before burial and fossilization,” says Haviv Avrahami, Ph.D. student at NC State and digital technician for the new Dueling Dinosaurs program at the North Carolina Museum of Natural Sciences. Avrahami is first author of the paper describing the work.

“But Fona is often found complete, with many of its bones preserved in the original death pose, chest down with splayed forelimbs, and in exceptionally good condition,” Avrahami says. “If it had already been underground in a burrow before death, it would have made this type of preservation more likely.”

Lindsay Zanno, associate research professor at NC State, head of paleontology at the North Carolina Museum of Natural Sciences and corresponding author of the work, agrees.

“Fona skeletons are way more common in this area than we would predict for a small animal with fragile bones,” Zanno says. “The best explanation for why we find so many of them, and recover them in small bundles of multiple individuals, is that they were living at least part of the time underground. Essentially, Fona did the hard work for us, by burying itself all over this area.”

Although the researchers have yet to identify the subterranean burrows of Fona, the tunnels and chamber of its closest relative, Oryctodromeus, have been found in Idaho and Montana. These finds support the idea that Fona also used burrows.

The genus name Fona comes from the ancestral creation story of the Chamorro people, who are the indigenous populations of Guam and the Pacific Mariana Islands. Fo’na and Pontan were brother and sister explorers who discovered the island and became the land and sky. The species name honors Lisa Herzog, the paleontology operations manager at the North Carolina Museum of Natural Sciences, for her invaluable contributions and dedication to the field of paleontology.

“I wanted to honor the indigenous mythology of Guam, which is where my Chamorro ancestors are from,” Avrahami says. “In the myth, Fo’na became part of the land when she died, and from her body sprung forth new life, which to me, ties into fossilization, beauty, and creation. Fona was most likely covered in a downy coat of colorful feathers. The species name is for Lisa Herzog, who has been integral to all this work and discovered one of the most exceptional Fona specimens of several individuals preserved together in what was likely a burrow.”

Fona is also a distant relative of another famous North Carolina fossil: Willo, a Thescelosaurus neglectus specimen currently housed at the museum and also thought to have adaptations for a semifossorial — or partially underground — lifestyle, research that was published late in 2023 by Zanno and former NC State postdoctoral researcher David Button.

“T. neglectus was at the tail end of this lineage — Fona is its ancestor from about 35 million years prior,” Avrahami says.

The researchers believe Fona is key to expanding our understanding of Cretaceous ecosystems.

“Fona gives us insight into the third dimension an animal can occupy by moving underground,” says Avrahami. “It adds to the richness of the fossil record and expands the known diversity of small-bodied herbivores, which remain poorly understood despite being incredibly integral components of Cretaceous ecosystems.”

“People tend to have a myopic view of dinosaurs that hasn’t kept up with the science,” Zanno says. “We now know that dinosaur diversity ran the gamut from tiny arboreal gliders and nocturnal hunters, to sloth-like grazers, and yes, even subterranean shelterers.”

The work appears in The Anatomical Record. Peter Makovicky of the University of Minnesota and Ryan Tucker of Stellenbosch University also contributed to the work.

Reference:
Haviv M. Avrahami, Peter J. Makovicky, Ryan T. Tucker, Lindsay E. Zanno. A new semi‐fossorial thescelosaurine dinosaur from the Cenomanian‐age Mussentuchit Member of the Cedar Mountain Formation, Utah. The Anatomical Record, 2024; DOI: 10.1002/ar.25505

Note: The above post is reprinted from materials provided by North Carolina State University. Original written by Tracey Peake

If you’ve ever snacked on raisins or enjoyed a glass of wine, you may, in part, have the extinction of the dinosaurs to thank for it. In a discovery described in the journal Nature Plants, researchers found fossil grape seeds that range from 60 to 19 million years old in Colombia, Panama, and Peru. One of these species represents the earliest known example of plants from the grape family in the Western Hemisphere. These fossil seeds help show how the grape family spread in the years following the death of the dinosaurs.

“These are the oldest grapes ever found in this part of the world, and they’re a few million years younger than the oldest ones ever found on the other side of the planet,” says Fabiany Herrera, an assistant curator of paleobotany at the Field Museum in Chicago’s Negaunee Integrative Research Center and the lead author of the Nature Plants paper. “This discovery is important because it shows that after the extinction of the dinosaurs, grapes really started to spread across the world.”

It’s rare for soft tissues like fruits to be preserved as fossils, so scientists’ understanding of ancient fruits often comes from the seeds, which are more likely to fossilize. The earliest known grape seed fossils were found in India and are 66 million years old. It’s not a coincidence that grapes appeared in the fossil record 66 million years ago-that’s around when a huge asteroid hit the Earth, triggering a massive extinction that altered the course of life on the planet. “We always think about the animals, the dinosaurs, because they were the biggest things to be affected, but the extinction event had a huge impact on plants too,” says Herrera. “The forest reset itself, in a way that changed the composition of the plants.”

Herrera and his colleagues hypothesize that the disappearance of the dinosaurs might have helped alter the forests. “Large animals, such as dinosaurs, are known to alter their surrounding ecosystems. We think that if there were large dinosaurs roaming through the forest, they were likely knocking down trees, effectively maintaining forests more open than they are today,” says Mónica Carvalho, a co-author of the paper and assistant curator at the University of Michigan’s Museum of Paleontology. But without large dinosaurs to prune them, some tropical forests, including those in South America, became more crowded, with layers of trees forming an understory and a canopy.

These new, dense forests provided an opportunity. “In the fossil record, we start to see more plants that use vines to climb up trees, like grapes, around this time,” says Herrera. The diversification of birds and mammals in the years following the mass extinction may have also aided grapes by spreading their seeds.

In 2013, Herrera’s PhD advisor and senior author of the new paper, Steven Manchester, published a paper describing the oldest known grape seed fossil, from India. While no fossil grapes had ever been found in South America, Herrera suspected that they might be there too.

“Grapes have an extensive fossil record that starts about 50 million years ago, so I wanted to discover one in South America, but it was like looking for a needle in a haystack,” says Herrera. “I’ve been looking for the oldest grape in the Western Hemisphere since I was an undergrad student.”

But in 2022, Herrera and his co-author Mónica Carvalho were conducting fieldwork in the Colombian Andes when a fossil caught Carvalho’s eye. “She looked at me and said, ‘Fabiany, a grape!’ And then I looked at it, I was like, ‘Oh my God.’ It was so exciting,” recalls Herrera. The fossil was in a 60-million-year-old rock, making it not only the first South American grape fossil, but among the world’s oldest grape fossils as well.

The fossil seed itself is tiny, but Herrera and Carvalho were able to identify it based on its particular shape, size, and other morphological features. Back in the lab, they conducted CT scans showing its internal structure that confirmed its identity. The team named the fossil Lithouva susmanii, “Susman’s stone grape,” in honor of Arthur T. Susman, a supporter of South American paleobotany at the Field Museum. “This new species is also important because it supports a South American origin of the group in which the common grape vine Vitis evolved,” says co-author Gregory Stull of the National Museum of Natural History.

The team conducted further fieldwork in South and Central America, and in the Nature Plants paper, Herrera and his co-authors ultimately described nine new species of fossil grapes from Colombia, Panama, and Perú, spanning from 60 to 19 million years old. These fossilized seeds not only tell the story of grapes’ spread across the Western Hemisphere, but also of the many extinctions and dispersals the grape family has undergone. The fossils are only distant relatives of the grapes native to the Western Hemisphere and a few, like the two species of Leea are only found in the Eastern Hemisphere today. Their places within the grape family tree indicate that their evolutionary journey has been a tumultuous one. “The fossil record tells us that grapes are a very resilient order. They’re a group that has suffered a lot of extinction in the Central and South American region, but they also managed to adapt and survive in other parts of the world,” says Herrera.

Given the mass extinction our planet is currently facing, Herrera says that studies like this one are valuable because they reveal patterns about how biodiversity crises play out. “But the other thing I like about these fossils is that these little tiny, humble seeds can tell us so much about the evolution of the forest,” says Herrera.

This study was authored by Fabiany Herrera (Field Museum), Mónica Carvalho (University of Michigan), Gregory Stull (National Museum of Natural History, Smithsonian Institution), Carlos Jarramillo (Smithsonian Tropical Research Institute), and Steven Manchester (Florida Museum of Natural History, University of Florida).

Reference:
Fabiany Herrera, Mónica R. Carvalho, Gregory W. Stull, Carlos Jaramillo, Steven R. Manchester. Cenozoic seeds of Vitaceae reveal a deep history of extinction and dispersal in the Neotropics. Nature Plants, 2024; DOI: 10.1038/s41477-024-01717-9

Note: The above post is reprinted from materials provided by Field Museum.

What do you get when you cross Norse mythology with a 78-million-year-old ancestor to the Triceratops? Answer: Lokiceratops rangiformis, a plant-eating dinosaur with a very fancy set of horns.

The new dinosaur was identified and named by Colorado State University affiliate faculty member Joseph Sertich and University of Utah Professor Mark Loewen. The dinosaur’s name, announced today in the scientific journal PeerJ, translates roughly to “Loki’s horned face that looks like a caribou.”

Loewen and Sertich, co-lead authors of the PeerJ study, dubbed the new species Lokiceratops (lo-Kee-sare-a-tops) rangiformis because of the unusual, curving blade-like horns on the back of its frill — the shield of bone at the back of the skull — and the asymmetrical horns at the peak of the frill, reminiscent of caribou antlers.

“The dinosaur now has a permanent home in Denmark, so we went with a Norse god, and in the end, doesn’t it just really look like Loki with the curving blades?” Loewen said, referring to the trickster god’s weapon of choice.

Loewen, a paleontologist at the Natural History Museum of Utah, and Sertich, a paleontologist with the Smithsonian Tropical Research Institute, are both scientific consultants for the Museum of Evolution in Denmark, Lokiceratops’ new home.

“It’s one of those stories with a happy ending, where it didn’t go to somebody’s mansion,” Sertich said. “It ended up in a museum, where it will be preserved forever so people can study it and enjoy visiting it.”

New dinosaur discovery

Lokiceratops was discovered in 2019 in the badlands of northern Montana, two miles (3.2 kilometers) south of the U.S.-Canada border. Sertich and Loewen helped reconstruct the dinosaur from fragments the size of dinner plates and smaller. Once they had pieced the skull together, they realized the specimen was a new type of dinosaur.

Estimated to be 22 feet (6.7 meters) long and weigh 11,000 pounds (5 metric tonnes), Lokiceratops is the largest dinosaur from the group of horned dinosaurs called centrosaurines ever found in North America. It has the largest frill horns ever seen on a horned dinosaur and lacks the nose horn that is characteristic among its kin.

“This new dinosaur pushes the envelope on bizarre ceratopsian headgear, sporting the largest frill horns ever seen in a ceratopsian,” Sertich said in a press release announcing the dinosaur’s unveiling at the Natural History Museum of Utah, where a replica is displayed. “These skull ornaments are one of the keys to unlocking horned dinosaur diversity and demonstrate that evolutionary selection for showy displays contributed to the dizzying richness of Cretaceous ecosystems.”

Sertich likened dinosaur horns to feathers on birds. Birds use feather colors and patterns to differentiate their own species among other, similar species of birds.

“We think that the horns on these dinosaurs were analogous to what birds are doing with displays,” Sertich said. “They’re using them either for mate selection or species recognition.”

What Loki’s horns tell us about dinosaurs

Lokiceratops was excavated from the same rock layer as four other dinosaur species, indicating that five different dinosaurs lived side by side 78 million years ago in the swamps and coastal plains along the eastern shore of Laramidia, the western landmass of North America created when a seaway divided the continent. Three of these species were closely related but not found outside the region.

“It’s unheard-of diversity to find five living together, similar to what you would see on the plains of East Africa today with different horned ungulates,” Sertich said.

Unlike the broad range of large wild mammals that roam the U.S. West today, such as elk, these ancient animals were geographically limited, he added. Loki’s discovery provides evidence that these species evolved rapidly within a small area, a process sometimes seen in birds.

By the time Triceratops came onto the scene 12 million years later, regional differences had been homogenized into just two species of horned dinosaurs from Canada to Mexico — possibly in response to a more homogenous climate, Sertich said.

The study shows that dinosaur diversity has been underestimated and presents the most complete family tree of horned dinosaurs to date.

“Lokiceratops helps us understand that we only are scratching the surface when it comes to the diversity and relationships within the family tree of horned dinosaurs,” Loewen said.

Reference:
Mark A. Loewen, Joseph J. W. Sertich, Scott Sampson, Jingmai K. O’Connor, Savhannah Carpenter, Brock Sisson, Anna Øhlenschlæger, Andrew A. Farke, Peter J. Makovicky, Nick Longrich, David C. Evans. Lokiceratops rangiformis gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs. PeerJ, 2024; 12: e17224 DOI: 10.7717/peerj.17224

Note: The above post is reprinted from materials provided by Colorado State University. Original written by Jayme DeLoss.