The dinosaur leg was reportedly preserved as debris from the impact rained down.
“We’ve got so many details with this site that tell us what happened moment by moment, it’s almost like watching it play out in the movies. You look at the rock column, you look at the fossils there, and it brings you back to that day,” Robert DePalma, the University of Manchester graduate student who leads the Tanis dig in North Dakota, told BBC News on Wednesday.
The network has spent three years filming there for a show that’s set to air in just over a week.
Along with the leg, researchers said they found fish, a fossil turtle, small mammals, skin from a triceratops, the embryo of a flying pterosaur and a fragment from the asteroid.
The network said the remains have been jumbled together, with spherules linked to the impact site off the Yucatan Peninsula.
Particles from tree resin contained inclusions that “imply an extra-terrestrial origin.”
Professor Paul Barrett, from London’s Natural History Museum, looked at the leg and deemed the dinosaur a scaly Thescelosaurus.
The limb, he noted, looks like it was “ripped off really quickly,” suggesting that the creature died “more or less instantaneously.”
The question remains: Did it actually die on the exact day?
One professor told the BBC he wants to see more peer-reviewed articles and additional independent assessments.
“Those fish with the spherules in their gills, they’re an absolute calling card for the asteroid. But for some of the other claims – I’d say they have a lot circumstantial evidence that hasn’t yet been presented to the jury,” professor Steve Brusatte, from the University of Edinburgh, said.
Julia Musto is a reporter for Fox News Digital. You can find her on Twitter at @JuliaElenaMusto.
The controversial study looked at a dataset of 37 specimens.
The iconic Tyrannosaurus rex, or “T. Rex,” might need to be re-categorized into three distinct species, according to researchers.
The Tyrannosaurus rex is the only recognized species of the group of dinosaurs Tyrannosaurus to date – though previous research has reportedly acknowledged variation across Tyrannosaurs skeletal remains.
In a controversial new study published Tuesday in the peer-reviewed journal Evolutionary Biology, South Carolina and Maryland paleontologists conducted an analysis of skeletal remains they said reveal physical differences in the femur and other bones and dental structures.
Based on a dataset of 37 specimens, the group looked at the robustness in the femur of 24 specimens and measured the diameter of the base of teeth or space in the gums to assess if specimens had one or two slender teeth resembling incisors.
According to an accompanying release, the scientists observed that the femur varied across specimens, with two times more robust femurs than svelte ones across specimens. Robust femurs were also found in some juvenile specimens and “gracile” femurs were found in some that were full adult size, suggesting that variation is not related to growth.
Dental structure also varied and those with one incisorform tooth were correlated with often having higher femur gracility.
Visitors look at a 67 million year-old skeleton of a Tyrannosaurus Rex dinosaur, named Trix, during the first day of the exhibition “A T-Rex in Paris” at the French National Museum of Natural History in Paris, France, June 6, 2018. (REUTERS/Philippe Wojazer)
They explained the Tyrannosaurus specimens “exhibit such a remarkable degree of proportional variations, distributed at different stratigraphic levels, that the pattern favors multiple species at least partly separated by time; ontogenetic and sexual causes being less consistent with the data.”
“Variation in dentary incisiform counts correlate with skeletal robusticity and also appear to change over time,” the authors noted.
28 specimens could be identified in distinct layers of sediment at the Lancian upper Maastrichtian formations in North America – which was estimated to be from between 67.5 to 66 million years ago – and the paleontologists compared Tyrannosaurus specimens with other theropod species found in lower layers of sediment.
Only robust Tyrannosaurus femurs were found in the lower layer of sediment – and variation was not different to that of other theropod species – which the release said indicates that just one species of Tyrannosaurus likely existed at this point.
However, the variation in Tyrannosaurus femur robustness in the top layer of the sediments was higher, suggesting the specimens had physically developed into more distinct forms and other dinosaur species.
“We found that the changes in Tyrannosaurus femurs are likely not related to the sex or age of the specimen,” lead author Gregory Paul said in a statement. “We propose that the changes in the femur may have evolved over time from a common ancestor who displayed more robust femurs to become more gracile in later species. The differences in femur robustness across layers of sediment may be considered distinct enough that the specimens could potentially be considered separate species.”
Based on that evidence, the researchers said three morphotypes – what Science Direct defines as any of a group of different types of individuals of the same species in a population – and two additional species of Tyrannosaurus were “diagnosed” and named.
“One robust species with two small incisors in each dentary appears to have been present initially, followed by two contemporaneous species (one robust and another gracile) both of which had one small incisor in each dentary, suggesting both anagenesis and cladogenesis occurred,” they continued.
Evolution can take place by anagenesis, in which changes occur within a lineage. Whereas, in cladogenesis, a lineage splits into two or more separate lines.
The authors nominated two potential species: “Tyrannosaurus imperator” and “Tyrannosaurus regina.”
Tyrannosaurus imperator relates to specimens found at the lower and middle layers of sediment, with more robust femurs and usually two incisor teeth.
Tyrannosaurus regina is linked to specimens from the upper and possibly middle layers of sediment, with slenderer femurs and one incisor tooth.
The Tyrannosaurus rex was identified in the upper and possibly middle layer of sediment, with more robust femurs and only one incisor tooth.
The authors acknowledged that they cannot rule out that variation is due to extreme individual differences, or atypical sexual dimorphism, rather than separate groups. They also cautioned that the location within sediment layers is not known for some specimens.
Reaction to the study from scientists has been largely skeptical, with some claiming the paper does not have enough evidence to reach its conclusions – and raising concerns over some of the specimens included in the study to National Geographic.
Paul told The New York Times on Feb. 28 that he knows his proposal is provocative.
“I’m aware that there could be a lot of people who aren’t going to be happy about this,” he told the publication. “And, my response to them is: Publish a refutation.”
Julia Musto is a reporter for Fox News Digital. You can find her on Twitter at @JuliaElenaMusto.
Photo credit: José María Farfaglia, via MEF
A farmer in Chubut, Argentina made an incredible dinosaur discovery about three years ago. While working out in his fields, he stumbled across some fossilized dinosaur remains. Paleontologists from the nearby Museum of Paleontology Egidio Feruglio excavated the area and found about 150 incredibly well-preserved bones from seven individuals of a species that is likely the largest to ever walk the Earth.
The remains come from a newly-described species of titanosaur, which are large herbivorous sauropods. It lived in the late Mesozoic about 95 million years ago. This behemoth will not have a name until the findings are published in a scientific journal, but the researchers have claimed they will choose a title that pays tribute to the region, the farmer, and the dinosaur’s incredible size.
It is estimated to be an astonishing 40 meters (130 feet) long from head to tail and 20 meters (65 feet) tall. A creature this large would have likely weighed in at a hefty 77 tonnes (85 short tons), which is over eleven times more than Tyrannosaurs rex.
Researchers are currently comparing this species to Argentinosaurus, which is currently regarded as the largest dinosaur ever. However, Argentinosaurus is believed to weigh about 7 tonnes (7.7 tons) less than this new species, and has likely been officially dethroned as the largest terrestrial animal ever.
Understanding the true size of the dinosaurs is always open for some debate when there isn’t a complete skeleton. Assumptions must be made about the size and shape of missing bones, based on what they know about related species. However, there may be many more clues that have not yet been surfaced at the dig site.
José Luis Carballido, who is leading the dig has said in a press release on the museum’s website that the team is “[s]till working on this extraordinary site. We estimate that one fifth of the excavation process is completed, so there is still much work to do and probably much to discover.”
The researchers also found more than 60 teeth belonging to carnivorous species, who likely scavenged on the dead titanosaurs. Carballido claims that this opportunity came at a price, as the giant herbivores likely had incredibly thick skin that would have broken the carnivores’ teeth, though the teeth would have grown back.
Other fossils from the site indicate that when this giant dinosaur lived, the local landscape was quite green and lush with flowers and trees. The titanosaurs likely gathered near a source of water, and may have died after getting caught in mud.
The researchers note that the farmer’s family has been very accommodating during the excavation process as many pieces of large digging equipment have been brought in onto the land.
[All images credited to: Museum of Paleontology Egidio Feruglio]
The skull of the phytosaur Machaeroprosopus lottorum. (Texas Tech University)
A toothy, long-nosed skull found in Texas belonged to a “swamp monster” that lived more than 200 million years ago.
The creature is a previously unknown type of phytosaur, an extinct creature that hunted fish and other prey along the shallow edges of rivers and lakes. Dubbed Machaeroprosopus lottorum, the phytosaur probably measured about 18 feet long.
“They had basically the same lifestyle as the modern crocodile, by living in and around the water, eating fish, and whatever animals came to the margins of the rivers and lakes,” study researcher Bill Mueller, assistant curator of paleontology at the Museum of Texas Tech University, said in a statement. [Predator X: See Images of Ancient Monsters of the Sea]
Discovering something new Phytosaurs are a common find in the Cooper Canyon formation in Garza County, Texas, where the new species was discovered. This area is now dry and scrubby, but in the late Triassic, it was a conifer forest with fern underbrush and an oxbow lake where phytosaurs hunted.
In 2001, Doug Cunningham, a research field assistant at the Texas Tech museum, unearthed the new skull during a dig.
“When he found it, just the very back end of the skull was sticking out of the ground. The rest was buried,” Mueller said. “We excavated it and brought it into the museum to finish preparation.”
That preparation took years. Once the skull was out of the rock surrounding it, Mueller and his colleagues compared the features of the skull with other phytosaur skulls (more than 200 have been found in North America). They also analyzed another phytosaur skull, found 120 feet from the first.
They discovered that their specimens represented a male and female from a new species, which they named M. lottorum in honor of the Lott family, the owners of the ranch where the fossil was found.
Extinct monster Phytosaurs lived from about 230 million to 203 million years ago. They were one of the victims of the Triassic-Jurassic mass extinction, a huge die-off that wiped out many large land animals.
The new female’s skull is about 3 feet long, and she would have grown to be about 17 feet total length, Mueller said. The male would have been about a foot longer. M. lottorum‘s delicate snout suggests it ate mostly fish, and not more robust prey. It would have looked very much like an alligator or crocodile, but its nostrils were up near its eyes at the base of its snout, rather than at the end.
The researchers reported their findings in the September 2013 issue of the journal Earth and Environmental Science Transactions of the Royal Society of Edinburgh.
One little girl’s odd hobby has led to an extraordinary find for British paleontologists.
At the age of 9, Daisy Morris has discovered a new dinosaur species, which scientists have since named after her. The new creature has been dubbed Vectidraco daisymorrisae, the “Dragon from the Isle of Wight.”
Daisy was just 4 when she stumbled upon the fossilized remains of an unknown animal during a family walk on the beach in 2009. The family lives near the coast of England’s Isle of Wight — also known as the “dinosaur capital of Great Britain.”
“She has a very good eye for tiny little fossils,” her mother Sian Morris told BBC. Daisy apparently first began fossil hunting at age 3. “She found these tiny little black bones sticking out of the mud and decided to dig a bit further and scoop them all out,” her mother said.
“When Daisy and her family brought the fossilized remains to me in April 2009, I knew I was looking at something very special,” Simpson told the Daily Mail.
Over the past several years, the bones Daisy discovered have been thoroughly analyzed by paleontologists. The findings were finally published this Monday. The fossilized remains belong to a previously unknown genus and species of a small flying reptile called the pterosaur.