Duck-billed dinosaur discovery in Alaska


This 2017 video is called Prehistoric Subject Files Ep. 16: – Lambeosaurus.

From the Perot Museum of Nature and Science in the USA:

First-confirmed occurrence of a lambeosaurine dinosaur found on Alaska’s North Slope

March 29, 2019

Paleontologists from Hokkaido University in Japan, in cooperation with paleontologists from the Perot Museum of Nature and Science in Dallas, Texas, have discovered the first-confirmed occurrence of a lambeosaurine (crested ‘duck-billed’ dinosaur) from the Arctic — part of the skull of a lambeosaurine dinosaur from the Liscomb Bonebed (71-68 Ma) found on Alaska’s North Slope. The bonebed was previously known to be rich in hadrosaurine hadrosaurids (non-crested ‘duck-billed’ dinosaurs).

The discovery proves for the first time that lambeosaurines inhabited the Arctic during the Late Cretaceous. In addition, the numeric abundance of hadrosaurine fossils compared to the lambeosaurine fossils in the marine-influenced environment of the Liscomb Bonebed suggests the possibility that hadrosaurines and lambeosaurines had different habitat preferences.

The paleontologists’ findings were published today in Scientific Reports, an open-access, multi-disciplinary journal from Nature Research dedicated to constructive, inclusive and rigorous peer review. The paper — entitled “The first definite lambeosaurine bone from the Liscomb Bonebed of the Upper Cretaceous Prince Creek Formation, Alaska, United States” — is co-authored by Yoshitsugu Kobayashi, Ph.D., and Ryuji Takasaki, of Hokkaido University, in cooperation with Anthony R. Fiorillo, Ph.D., of the Perot Museum of Nature and Science. Other authors are Ronald Tykoski, Ph.D. of the Perot Museum and Paul McCarthy, Ph.D., of the University of Alaska.

“This new discovery illustrates the geographic link between lambeosaurines of North America and the Far East”, said Takasaki. “Hopefully, further work in Alaska will reveal how closely the dinosaurs of Asia and North America are connected.”

The newly discovered fossil, which is housed in the collections of the Perot Museum of Nature and Science, is a supraoccipital, one of the bones that forms the braincase. The new supraoccipital differs from those of hadrosaurines by the presence of large supraoccipital bosses and it’s short, front-to-back length. Since these features are commonly seen in other members of Lambeosaurinae, the newly discovered supraoccipital was assigned to that group.

“This first definitive evidence of a crested hadrosaur in the Cretaceous Arctic tells us that we still have much to learn about the biodiversity and the biologically productive environments of the ancient north, and that the story these fossils tell us is continually evolving,” adds Dr. Fiorillo.

Background. The Arctic is an extreme environment that is low in temperature, lacks sunlight during winters, and has seasonally limited food resources. Though it was warmer during the Late Cretaceous, the Arctic was surely one of the most challenging places to live for large vertebrates at the time. The Prince Creek Formation on the North Slope of Alaska is a world-famous rock unit for studying dinosaurs of the ancient Arctic. Because the dinosaurs found there lived in the ancient Arctic, rather than tropical or sub-tropical conditions, these dinosaurs challenge much of what we think we know about dinosaurs. The Liscomb Bonebed (71-68 Ma), which was deposited near the ancient Arctic shoreline, is especially rich in dinosaur bones, with more than 6,000 bones collected from it thus far.

More than 99% of dinosaur fossils known from the Liscomb Bonebed are hadrosaurs, a group of large, duck-billed herbivorous dinosaurs who lived during the Late Cretaceous and were found throughout much of the northern hemisphere. All of the hadrosaur fossils from the Liscomb Bonebed were long considered to belong to a hadrosaurine duck-billed dinosaur called Edmontosaurus. Up until now, all of the hadrosaurids known from across the Arctic, including those from the Liscomb Bonebed, were considered to belong to crest-less hadrosaurines.

The discovery of a fossil from a lambeosaurine hadrosaurid in the Liscomb Bonebed is historically important for Japanese paleontologists. The first “Japanese” dinosaur, Nipponosaurus, is a lambeosaurine hadrosaur. Based on the new discovery, Hokkaido University and the Perot Museum together used this discovery to further investigate the ecology of the Arctic hadrosaurids.

Significance

1. The first Arctic lambeosaurine: The new discovery indicates Arctic inhabitance and adaptation of lambeosaurines for the first time. In addition, the fossil’s morphological similarities to the same bone in the skull of southern Canadian lambeosaurines suggest faunal interactions between the Arctic and the mid-latitudes.

2. Implication on habitat preferences: While the Liscomb Bonebed is known for numerous hadrosaurine fossils, the newly discovered bone represents the only definite lambeosaurine fossil from the site. The same trend is also known in mid-latitude localities of North America and eastern Asia, which were also deposited in near-shore environments. On the other hand, more lambeosaurine fossils are found in deposits laid down in inland environments. Therefore, we hypothesize that lambeosaurines favored inland environments, while hadrosaurines preferred coastal environments, a trend likely to have been independent of latitude. Different habitat preferences might have been a strategy to avoid excessive competition between the two groups of ‘duck-billed’ dinosaurs.

Future plans

Although the new discovery reveals Arctic inhabitance by lambeosaurines, more specific taxonomic status and potential functional adaptations to the severe Arctic environment remain unknown due to incompleteness of the specimen. Additional excavation and further research will help answer these questions.

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Dinosaur extinction fossils discovery


This 20 September 2017 video from the USA is called Dinosaur fossil experts calling on amateurs to help dig in North Dakota.

From the University of California – Berkeley in the USA:

66-million-year-old deathbed linked to dinosaur-killing meteor

Fossil site preserves animals killed within minutes of meteor impact

March 29, 2019

Summary: Paleontologists have found a fossil site in North Dakota that contains animals and plants killed and buried within an hour of the meteor impact that killed the dinosaurs 66 million years ago. This is the richest K-T boundary site ever found, incorporating insects, fish, mammals, dinosaurs and plants living at the end of the Cretaceous, mixed with tektites and rock created and scattered by the impact. The find shows that dinosaurs survived until the impact.

The beginning of the end started with violent shaking that raised giant waves in the waters of an inland sea in what is now North Dakota.

Then, tiny glass beads began to fall like birdshot from the heavens. The rain of glass was so heavy it may have set fire to much of the vegetation on land. In the water, fish struggled to breathe as the beads clogged their gills.

The heaving sea turned into a 30-foot wall of water when it reached the mouth of a river, tossing hundreds, if not thousands, of fresh-water fish — sturgeon and paddlefish — onto a sand bar and temporarily reversing the flow of the river. Stranded by the receding water, the fish were pelted by glass beads up to 5 millimeters in diameter, some burying themselves inches deep in the mud. The torrent of rocks, like fine sand, and small glass beads continued for another 10 to 20 minutes before a second large wave inundated the shore and covered the fish with gravel, sand and fine sediment, sealing them from the world for 66 million years.

This unique, fossilized graveyard — fish stacked one atop another and mixed in with burned tree trunks, conifer branches, dead mammals, mosasaur bones, insects, the partial carcass of a Triceratops, marine microorganisms called dinoflagellates and snail-like marine cephalopods called ammonites — was unearthed by paleontologist Robert DePalma over the past six years in the Hell Creek Formation, not far from Bowman, North Dakota. The evidence confirms a suspicion that nagged at DePalma in his first digging season during the summer of 2013 — that this was a killing field laid down soon after the asteroid impact that eventually led to the extinction of all ground-dwelling dinosaurs. The impact at the end of the Cretaceous Period, the so-called K-T boundary, exterminated 75 percent of life on Earth.

“This is the first mass death assemblage of large organisms anyone has found associated with the K-T boundary”, said DePalma, curator of paleontology at the Palm Beach Museum of Natural History in Florida and a doctoral student at the University of Kansas. “At no other K-T boundary section on Earth can you find such a collection consisting of a large number of species representing different ages of organisms and different stages of life, all of which died at the same time, on the same day.”

In a paper to appear next week in the journal Proceedings of the National Academy of Sciences, he and his American and European colleagues, including two University of California, Berkeley, geologists, describe the site, dubbed Tanis, and the evidence connecting it with the asteroid or comet strike off Mexico’s Yucatan Peninsula 66 million years ago. That impact created a huge crater, called Chicxulub, in the ocean floor and sent vaporized rock and cubic miles of asteroid dust into the atmosphere. The cloud eventually enveloped Earth, setting the stage for Earth’s last mass extinction.

“It’s like a museum of the end of the Cretaceous in a layer a meter-and-a-half thick,” said Mark Richards, a UC Berkeley professor emeritus of earth and planetary science who is now provost and professor of earth and space sciences at the University of Washington.

Richards and Walter Alvarez, a UC Berkeley Professor of the Graduate School who 40 years ago first hypothesized that a comet or asteroid impact caused the mass extinction, were called in by DePalma and Dutch scientist Jan Smit to consult on the rain of glass beads and the tsunami-like waves that buried and preserved the fish. The beads, called tektites, formed in the atmosphere from rock melted by the impact.

Tsunami vs. seiche

Richards and Alvarez determined that the fish could not have been stranded and then buried by a typical tsunami, a single wave that would have reached this previously unknown arm of the Western Interior Seaway no less than 10 to 12 hours after the impact 3,000 kilometers away, if it didn’t peter out before then. Their reasoning: The tektites would have rained down within 45 minutes to an hour of the impact, unable to create mudholes if the seabed had not already been exposed.

Instead, they argue, seismic waves likely arrived within 10 minutes of the impact from what would have been the equivalent of a magnitude 10 or 11 earthquake, creating a seiche (pronounced saysh), a standing wave, in the inland sea that is similar to water sloshing in a bathtub during an earthquake. Though large earthquakes often generate seiches in enclosed bodies of water, they’re seldom noticed, Richards said. The 2011 Tohoku quake in Japan, a magnitude 9.0, created six-foot-high seiches 30 minutes later in a Norwegian fjord 8,000 kilometers away.

“The seismic waves start arising within nine to 10 minutes of the impact, so they had a chance to get the water sloshing before all the spherules (small spheres) had fallen out of the sky,” Richards said. “These spherules coming in cratered the surface, making funnels — you can see the deformed layers in what used to be soft mud — and then rubble covered the spherules. No one has seen these funnels before.”

The tektites would have come in on a ballistic trajectory from space, reaching terminal velocities of between 100 and 200 miles per hour, according to Alvarez, who estimated their travel time decades ago.

“You can imagine standing there being pelted by these glass spherules. They could have killed you,” Richards said. Many believe that the rain of debris was so intense that the energy ignited wildfires over the entire American continent, if not around the world.

“Tsunamis from the Chicxulub impact are certainly well-documented, but no one knew how far something like that would go into an inland sea,” DePalma said. “When Mark came aboard, he discovered a remarkable artifact — that the incoming seismic waves from the impact site would have arrived at just about the same time as the atmospheric travel time of the ejecta. That was our big breakthrough.”

At least two huge seiches inundated the land, perhaps 20 minutes apart, leaving six feet of deposits covering the fossils. Overlaying this is a layer of clay rich in iridium, a metal rare on Earth, but common in asteroids and comets. This layer is known as the K-T, or K-Pg boundary, marking the end of the Cretaceous Period and the beginning of the Tertiary Period, or Paleogene.

Iridium

In 1979, Alvarez and his father, Nobelist Luis Alvarez of UC Berkeley, were the first to recognize the significance of iridium that is found in 66 million-year-old rock layers around the world. They proposed that a comet or asteroid impact was responsible for both the iridium at the K-T boundary and the mass extinction.

The impact would have melted the bedrock under the seafloor and pulverized the asteroid, sending dust and melted rock into the stratosphere, where winds would have carried them around the planet and blotted out the sun for months, if not years. Debris would have rained down from the sky: not only tektites, but also rock debris from the continental crust, including shocked quartz, whose crystal structure was deformed by the impact.

The iridium-rich dust from the pulverized meteor would have been the last to fall out of the atmosphere after the impact, capping off the Cretaceous.

“When we proposed the impact hypothesis to explain the great extinction, it was based just on finding an anomalous concentration of iridium — the fingerprint of an asteroid or comet,” said Alvarez. “Since then, the evidence has gradually built up. But it never crossed my mind that we would find a deathbed like this.”

Key confirmation of the meteor hypothesis was the discovery of a buried impact crater, Chicxulub, in the Caribbean and off the coast of the Yucatan in Mexico, that was dated to exactly the age of the extinction. Shocked quartz and glass spherules were also found in K-Pg layers worldwide. The new discovery at Tanis is the first time the debris produced in the impact was found along with animals killed in the immediate aftermath of the impact.

“And now we have this magnificent and completely unexpected site that Robert DePalma is excavating in North Dakota, which is so rich in detailed information about what happened as a result of the impact,” Alvarez said. “For me, it is very exciting and gratifying!”

Tektites

Jan Smit, a retired professor of sedimentary geology from Vrije Universiteit in Amsterdam in The Netherlands who is considered the world expert on tektites from the impact, joined DePalma to analyze and date the tektites from the Tanis site. Many were found in near perfect condition embedded in amber, which at the time was pliable pine pitch.

“I went to the site in 2015 and, in front of my eyes, he (DePalma) uncovered a charred log or tree trunk about four meters long which was covered in amber, which acted as sort of an aerogel and caught the tektites when they were coming down,” Smit said. “It was a major discovery, because the resin, the amber, covered the tektites completely, and they are the most unaltered tektites I have seen so far, not 1 percent of alteration. We dated them, and they came out to be exactly from the K-T boundary.”

The tektites in the fishes’ gills are also a first.

“Paddlefish swim through the water with their mouths open, gaping, and in this net, they catch tiny particles, food particles, in their gill rakers, and then they swallow, like a whale shark or a baleen whale,” Smit said. “They also caught tektites. That by itself is an amazing fact. That means that the first direct victims of the impact are these accumulations of fishes.”

Smit also noted that the buried body of a Triceratops and a duck-billed hadrosaur proves beyond a doubt that dinosaurs were still alive at the time of the impact.

“We have an amazing array of discoveries which will prove in the future to be even more valuable,” Smit said. “We have fantastic deposits that need to be studied from all different viewpoints. And I think we can unravel the sequence of incoming ejecta from the Chicxulub impact in great detail, which we would never have been able to do with all the other deposits around the Gulf of Mexico.”

“So far, we have gone 40 years before something like this turned up that may very well be unique,” Smit said. “So, we have to be very careful with that place, how we dig it up and learn from it. This is a great gift at the end of my career. Walter sees it as the same.”

Biggest Tyrannosaurus rex ever discovered


This 28 February 2018 video from Canada says about itself:

Scotty the T. rex will be Saskatchewan’s next provincial emblem

Scotty, a 65 million-year-old Tyrannosaurus rex skeleton discovered in 1991, won a public vote to become Saskatchewan’s first provincial fossil.

From the University of Alberta in Canada:

Paleontologists report world’s biggest Tyrannosaurus rex

Nicknamed ‘Scotty’, the record-breaking rex is also the largest dinosaur skeleton ever found in Canada

March 22, 2019

University of Alberta paleontologists have just reported the world’s biggest Tyrannosaurus rex and the largest dinosaur skeleton ever found in Canada. The 13-metre-long T. rex, nicknamed “Scotty”, lived in prehistoric Saskatchewan 66 million years ago.

“This is the rex of rexes”, said Scott Persons, lead author of the study and postdoctoral researcher in the Department of Biological Sciences. “There is considerable size variability among Tyrannosaurus. Some individuals were lankier than others and some were more robust. Scotty exemplifies the robust. Take careful measurements of its legs, hips, and even shoulder, and Scotty comes out a bit heftier than other T. rex specimens.”

Scotty, nicknamed for a celebratory bottle of scotch the night it was discovered, has leg bones suggesting a living weight of more than 8,800 kg, making it bigger than all other carnivorous dinosaurs. The scientific work on Scotty has been a correspondingly massive project.

The skeleton was first discovered in 1991, when paleontologists including T. rex expert and UAlberta professor Phil Currie were called in on the project. But the hard sandstone that encased the bones took more than a decade to remove — only now have scientists been able to study Scotty fully-assembled and realize how unique a dinosaur it is.

It is not just Scotty’s size and weight that set it apart. The Canadian mega rex also lays claim to seniority.

“Scotty is the oldest T. rex known,” Persons explains. “By which I mean, it would have had the most candles on its last birthday cake. You can get an idea of how old a dinosaur is by cutting into its bones and studying its growth patterns. Scotty is all old growth.”

But age is relative, and T. rexes grew fast and died young. Scotty was estimated to have only been in its early 30s when it died.

“By Tyrannosaurus standards, it had an unusually long life. And it was a violent one,” Persons said. “Riddled across the skeleton are pathologies — spots where scarred bone records large injuries.”

Among Scotty’s injures are broken ribs, an infected jaw, and what may be a bite from another T. rex on its tail — battle scars from a long life.

“I think there will always be bigger discoveries to be made,” said Persons “But as of right now, this particular Tyrannosaurus is the largest terrestrial predator known to science.”

A new exhibit featuring the skeleton of Scotty is set to open at the Royal Saskatchewan Museum in May 2019.

Dinosaur age hatchling bird, new study


Feathers revealed in a ~125 million-year-old fossil of a bird hatchling shows it came 'out of the egg running'. Specimen MPCM-LH-26189 from Los Hoyas, Spain is preserved between two slabs of rock: (a) 'counter' slab under normal light (b) Laser-Stimulated Fluorescence (LSF) image combining the results from both rock slabs. This reveals brown patches around the specimen that include clumps of elongate feathers associated with the neck and wings and a single long vaned feather associated with the left wing. (c) Normal light image of the main slab. Scale is 5mm. Credit: Copyright Kaye et al. 2019

From The University of Hong Kong:

Ancient birds out of the egg running

Feathers revealed in a 125 million-year-old fossil of a bird hatchling shows it came out of the egg running

March 21, 2019

The ~125 million-year-old Early Cretaceous fossil beds of Los Hoyas, Spain have long been known for producing thousands of petrified fish and reptiles. However, one special fossil stands unique and is one of the rarest of fossils — a nearly complete skeleton of a hatchling bird. Using their own laser imaging technology, Dr Michael Pittman from the Department of Earth Sciences at The University of Hong Kong and Thomas G Kaye from the Foundation for Scientific Advancement in the USA determined the lifestyle of this ~3cm long hatchling bird by revealing the previously unknown feathering preserved in the fossil specimen.

Chickens and ducks are up and about within hours of hatching, they are “precocial”. Pigeons and eagles are “altricial”, they stay in the nest and are looked after by their parents. How do you tell if a hatchling came “out of the egg running” or was “naked and helpless in the nest”? Feathers. When precocial birds hatch they have developed down feathers and partly developed large feathers and can keep warm and get around without mum’s help. “Previous studies searched for but failed to find any hints of feathers on the Los Hoyas hatchling. This meant that its original lifestyle was a mystery”, says Dr Pittman.

Hypothetical fleshed-out reconstruction of MPCM-LH-26189. The fact that MPCM-LH-26189 is so well preserved and conserves some soft-tissue associated chemistry (see Supplementary Note 1, Supplementary Figs 2-5, and Supplementary Table 2), while showing no feathers or chemical evidence for plumage suggest that the baby bird might have been largely featherless when it died. However, this cannot be confirmed, and so the individual was reconstructed with juvenile plumage hypothesized for perinate enantiornithines. The silhouettes inset are those of the juvenile bird and an unspecified sympatric cockroach to give a sense of scale. By Raúl Martín

This reconstruction of the hatchling is from 2018, when its feathers had not been discovered yet.

Michael Pittman and Thomas Kaye brought new technology to the study of Los Hoyas fossils in the form of a high power laser. This made very small chemical differences in the fossils become visible by fluorescing them different colours, revealing previously unseen anatomical details. They recently had tremendous success with the first discovered fossil feather which they disassociated from the famous early bird Archaeopteryx by recovering the chemical signature of its fossil quill, a key part of the feather’s identification that had been previously unverified for ~150 years. The new results on the hatchling bird finally answered the question about its lifestyle as it did indeed have feathers at birth and was thus precocial and out of the egg running. The feathers were made of carbon which has low fluorescence using Laser-Stimulated Fluorescence (LSF), but the background matrix did glow making the feathers stand out in dramatic dark silhouette. “Previous attempts using UV lights and synchrotron beams failed to detect the feathers, underscoring that the laser technology stands alone as a new tool in palaeontology” added Tom Kaye, the study‘s lead author.

This discovery via new technology demonstrates that some early birds adopted a precocial breeding strategy just like modern birds. Thus, in the time of the dinosaurs, some enantiornithine bird babies had the means to avoid the dangers of Mesozoic life perhaps by following their parents or moving around themselves. “One of the feathers discovered was of a substantial size and preserves features seen in other hatchlings. It indicates that our hatchling had reasonably well-developed flight feathers at the time of birth”, says Jesús Marugán-Lobón, a co-author from the Universidad Autónoma of Madrid, Spain. This and other “illuminating” discoveries are adding to our knowledge of ancient life with details surviving in the fossil record that were never thought possible even a couple decades ago.

Dinosaur age bird with fossil egg discovered


MOMMY BIRD  This ancient avian, named Avimaia schweitzerae, lived about 110 million years ago in what is now northwestern China. Analyses of the fossil revealed that the bird’s body contained an unlaid egg (lighter brown smudge) when it died. Photo A.M. Bailleul et al/Nature Communications 2019

By Carolyn Gramling, 6:00am, March 20, 2019:

In a first, a fossilized egg is found preserved inside an ancient bird

The offspring may have been the cause of its mother’s demise, scientists suspect

About 110 million years ago, a sparrow-sized bird died with her egg still inside her body. That egg, crushed and flattened by pressure over time, is the first unlaid bird egg known to be preserved in a fossil, researchers report March 20 in Nature Communications.

The fossil was unearthed 11 years ago in northwestern China. In 2018, paleontologists led by Alida Bailleul of the Key Laboratory of Vertebrate Evolution and Human Origins in Beijing took a closer look, and noticed something odd: The bird had a strange sheet of tissue between her pubic bones. Examining a piece of the tissue under a microscope, Bailleul found that it was from an egg.

The bird, a newly identified species, was named Avimaia schweitzerae in honor of paleontologist Mary Schweitzer’s work on fossilized soft tissues (SN: 12/24/16, p. 15). Further analyses revealed more surprises. The mother bird’s skeleton contains traces of medullary bone, a calcium-bearing tissue that aids in eggshell formation (SN: 4/16/16, p. 16). It’s the strongest evidence yet that ancient birds produced this tissue during reproduction.

And the egg’s cuticle, the outermost layer of shell, contains tiny mineral spheres similar to spheres in the egg cuticles of modern waterfowl such as quails and ducks. The spheres, thought to protect embryos from microbial infections, have never before been seen in any fossilized eggs.

But all was not well with this bird and her embryo. The eggshell has two layers instead of the usual one, suggesting that the egg had remained too long in the abdomen. And the egg’s layers are extremely thin, thinner than a sheet of paper. In modern birds, particularly small birds experiencing extreme stress, these symptoms can indicate a deadly condition known as egg-binding, in which a bird is unable to lay the egg. In fact, the researchers suggest, the unlaid egg may have ultimately killed the mother.

Dinosaur age mammal discovery in Tanzania


Side view of the lower jaw of Galulatherium jenkinsi, the most complete mammal yet know from the Cretaceous Period of the African continent, and named this week by researchers from Ohio University. Credit : Patrick O'Connor, Ohio University

From Ohio University in the USA:

Rukwa Rift Basin Project names new Cretaceous mammal from East African Rift System

March 18, 2019

Ohio University researchers announced a new species of mammal from the Age of Dinosaurs, representing the most complete mammal from the Cretaceous Period of continental Africa, and providing tantalizing insights into the past diversity of mammals on the planet.

The National Science Foundation-funded OHIO team, in collaboration with international colleagues, identified and named the new mammal in an article published today in Acta Paleontologica Polonica. This nearly complete lower jaw represents the first named mammal species from the Late Cretaceous Period (100-66 million years ago) of the entire African continent. The squirrel-sized animal was probably related to a group of southern hemisphere mammals known as gondwanatherians, yet a bizarre combination of features (including evergrowing and enamel-less peg-like teeth) make it challenging to easily place within any group of mammals yet known, living or extinct.

The new mammal is named Galulatherium jenkinsi, a name based on the Galula rock unit (itself derived from one of the local villages in the field area) and therium, Latin for beast, with the species name “jenkinsi” honoring the late Farish Jenkins, distinguished professor of anatomy and organismic biology at Harvard University and a strong supporter of the Rukwa Rift Basin Project early in its development.

The type and only specimen of Galulatherium was discovered in 2002, when Rukwa Rift Basin Project researchers found a bone fragment eroding from Cretaceous-age red sandstones in the Rukwa Rift Basin in southwestern Tanzania. After painstakingly removing the rock from the delicate specimen, the team announced the discovery of a new mammal in 2003, yet they conservatively refrained from establishing a name for the enigmatic new species until additional details of its anatomy could be revealed. In the intervening years, improvements in high-resolution x-ray computed tomography enabled the team to document detailed anatomy of the specimen and to establish Galulatherium as a species new to science.

“The analysis of Galulatherium has been a collaborative process, engaging with a group of experts to tackle the unique morphology of this specimen,” noted Dr. Patrick O’Connor, professor of anatomy at Ohio University and lead author of the paper. “Additional information gleaned from density-based microCT analyses, particularly the presence of ever-growing, enamel-less teeth, has allowed us to compare Galulatherium with other Mesozoic and early Cenozoic mammals, as well as with modern groups like sloths, in order to establish the best anatomical and functional analogs for this unique type of dentition.”

Gonwanatherian mammals are best known from Cretaceous and early Cenozoic rock units in Madagascar and Argentina, with other specimens known from India and Antarctica. Members of the research team have worked across the globe in search of early mammals.

“The fact that this is the first discovery of an identifiable mammal fossil in the Late Cretaceous of all of mainland Africa is incredibly exhilarating on so many levels,” added co-author David Krause, curator of paleontology at the Denver Museum of Nature and Science. “The needle is very small and the haystack is very big. And we know that there are so many more needles to find there.”

The perplexing story of Galulatherium and identifying its closest relatives is just the starting point. Getting ANY insight into what mammals lived on the continent during this time is groundbreaking, but it seems that Galulatherium is not a predecessor of any of the mammals that live on Africa today. So what happened to it and its kin? Were they wiped out at the end of the Cretaceous? When did the ancestors of Africa’s extant mammalian lineages arrive on the continent? Or were they living alongside Galulatherium and just have not yet been found?

“All great questions that will only be answered with the discovery of additional fossils, underscoring the need for exploratory research in places like the Rukwa Rift Basin and elsewhere on the continent,” added O’Connor.

The study included experts from several institutions to pore over the tiny jaw. Yet the specimen preserved a truly unique combination of anatomical features, making it difficult to place in the existing framework of mammalian evolution, and ultimately raising more questions than it answers.

“What began with the description of a compact specimen became a broader quest to understand how this jaw fits into the complex puzzle of mammalian evolution,” said Dr. Nancy Stevens, Ohio University professor and co-author on the paper.

Galulatherium is not the only animal discovered by the research team in the Rukwa Rift Basin. Other Cretaceous-age finds include bizarre relatives of early crocodiles and three distinct species of long-necked herbivorous sauropod dinosaurs. Finds from younger rocks in the region contain the oldest evidence of the split between monkeys and apes. Taken together, these findings from the East African Rift reveal a crucial glimpse into ancient ecosystems of Africa and encourage additional field exploration on the continent.

Other Cretaceous findings by the Rukwa Rift Basin Project research team in the Rukwa Rift Basin include:

  • Mnyamawantuka moyowamkia — titanosaurian sauropod dinosaur, Rukwa Rift Basin
  • Shingopana songwensis — titanosaurian sauropod dinosaur, Rukwa Rift Basin
  • Rukwatitan bisepultustitanosaurian sauropod dinosaur, Rukwa Rift Basin
  • Pakasuchus kapilimai — mammal-like crocodile, Rukwa Rift Basin

The team has also made discoveries in the younger Paleogene deposits of the Rukwa Rift Basin:

  • Early evidence for monkey-ape split, Rukwa Rift Basin
  • Oldest fossil evidence of venomous snakes, Rukwa Rift Basin
  • Early evidence of insect farming — Fossil Termite Nests, Rukwa Rift Basin
  • Bobcat-sized carnivore, Rukwa Rift Basin

The study was funded by the US National Science Foundation Division of Earth Sciences, the National Geographic Society, the Ohio University Heritage College of Osteopathic Medicine, and the OHIO Office of the Vice President for Research and Creative Activity.

What a young Tyrannosaurus rex ate


This video says about itself:

T-Rex: Attack of the Dinosaur | Walking with Dinosaurs in HQ | BBC

The mother Tyrannosaurus breaks her fast to provide a kill to feed her young. Even though they are small and vulnerable, the young T-Rex‘s already have a fierce competitive streak.

Broadcast in 1999, Walking with Dinosaurs set out to create the most accurate portrayal of prehistoric animals ever seen on the screen.

From the University of Wisconsin Oshkosh in the USA:

Teenage T. rex was already chomping on prey

March 11, 2019

New research from the University of Wisconsin Oshkosh indicates that even as a teenager the Tyrannosaurus rex showed signs that it would grow up to be a ferocious predator.

In a study published last week in the peer-reviewed journal Peerj — the Journal of Life and Environmental Sciences, UWO scientists reported evidence that a juvenile T. rex fed on a large plant-eating dinosaur, even though it lacked the bone-crushing abilities it would develop as an adult.

While studying fossils from an Edmontosaurus — a plant-eating Hadrosaurid or duck-billed dinosaur, UWO vertebrate paleontologist Joseph Peterson noticed three large, v-shaped, bite marks on a tail bone and wondered, “Who made these?”

Peterson knew that T. rex — a member of the meat-eating dinosaur suborder known as Theropoda — was “a likely culprit.”

“We suspected that T. rex was responsible for the bit marks, because in the upper Cretaceous rock formation, where the hadrosaur was discovered, there are only a few carnivorous dinosaurs and other reptiles in the fossil record. Crocodile fossils are found there, but such a crocodile would have left tooth marks that are round rather than the elliptical punctures we found on the vertebra,” Peterson explained.

“There also were small Velociraptor-like dinosaurs, but their teeth are too small to have made the marks. Finally, an adult T. rex would have made punctures that would have been too large! That’s when we started considering a juvenile tyrannosaur.”

To test the hypothesis, Peterson and geology student Karsen Daus, of Suamico, coated the fossil with a silicon rubber to make a silicone peel of the puncture marks.

They found that the dimensions of the “teeth” better matched a late-stage juvenile T. rex (11 to 12 years) than an adult (approximately 30 years).

“Although this T. rex was young, it really packed a punch,” Peterson said.

“This is significant to paleontology because it demonstrates how T. rex — the most popular dinosaur of all time — may have developed changes in diet and feeding abilities while growing,” he said. “This is part of a larger, ongoing research initiative by many paleontologists to better understand how T. rex grew and functioned as a living creature over 65 million years ago.”

Most theropod feeding traces and bite marks are attributed to adults; juvenile tooth marks rarely have been reported in the literature, he added.

“We really are in the ‘Golden Age’ of paleontology,” Peterson said. “We are learning more now than we ever thought we would know about dinosaurs. And, we’re learn more about how they grew up.”