What makes dinosaurs dinosaurs?


This 2016 video says about itself:

Dinosaurs are a diverse group of animals of the clade Dinosauria.

They first appeared during the Triassic period, 231.4 million years ago, and were the dominant terrestrial vertebrates for 135 million years, from the start of the Jurassic (about 200 million years ago) until the end of the Cretaceous (66 million years ago), when the Cretaceous–Paleogene extinction event led to the extinction of most dinosaur groups at the end of the Mesozoic Era.

The fossil record indicates that birds are modern feathered dinosaurs, having evolved from theropod ancestors during the Jurassic Period. Birds were the only dinosaurs to survive the extinction event that occurred 66 million years ago.

By Carolyn Gramling, 4:00pm, February 21, 2018:

New fossils are redefining what makes a dinosaur

Defining what’s unique about these ‘fearfully great lizards’ gets harder with new finds

“There’s a very faint dimple here,” Sterling Nesbitt says, holding up a palm-sized fossil to the light. The fossil, a pelvic bone, belonged to a creature called Teleocrater rhadinus. The slender, 2-meter-long reptile ran on all fours and lived 245 million years ago, about 10 million to 15 million years before scientists think dinosaurs first appeared.

Nesbitt, a paleontologist at Virginia Tech in Blacksburg, tilts the bone toward the overhead light, illuminating a small depression in the fossil. The dent, about the size of a thumbprint, marks the place where the leg bone fit into the pelvis. In a true dinosaur, there would be a complete hole there in the hip socket, not just a depression. The dimple is like a waving red flag: Nope, not a dinosaur.

The hole in the hip socket probably helped dinosaurs position their legs underneath their bodies, rather than splayed to the sides like a crocodile’s legs. Until recently, that hole was among a handful of telltale features paleontologists used to identify whether they had their hands on an actual dinosaur specimen.

Another no-fail sign was a particular depression at the top of the skull. Until Teleocrater mucked things up. The creature predated the dinosaurs, yet it had the dinosaur skull depression.

The once-lengthy list of “definitely a dinosaur” features had already been dwindling over the past few decades thanks to new discoveries of close dino relatives such as Teleocrater. With an April 2017 report of Teleocrater’s skull depression (SN Online: 4/17/17), yet another feature was knocked off the list.

Today, just one feature is unique to Dinosauria, the great and diverse group of animals that inhabited Earth for about 165 million years, until some combination of cataclysmic asteroid and volcanic eruptions wiped out all dinosaurs except the birds.

“I often get asked ‘what defines a dinosaur’, ” says Randall Irmis, a paleontologist at the Natural History Museum of Utah in Salt Lake City. Ten to 15 years ago, scientists would list perhaps half a dozen features, he says. “The only one to still talk about is having a complete hole in the hip socket.”

The abundance of recent discoveries of dinosauromorphs, a group that includes the dinosaur-like creatures that lived right before and alongside early dinosaurs, does more than call diagnostic features into question. It is shaking up long-standing ideas about the dinosaur family tree.

To Nesbitt, all this upheaval has placed an even more sacred cow on the chopping block: the uniqueness of the dinosaur.

“What is a dinosaur?” Nesbitt says. “It’s essentially arbitrary.”

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Dinosaurs’ and birds’ locomotion


This 2016 video is called Dinosaur Walk Theory Video.

From PLOS:

Locomotion of bipedal dinosaurs might be predicted from that of ground-running birds

BIRDS Model uses just two inputs to predict terrestrial locomotion in extinct avian and non-avian dinosaurs

February 21, 2018

A new model based on ground-running birds could predict locomotion of bipedal dinosaurs based on their speed and body size, according to a study published February 21, 2018 in the open-access journal PLOS ONE by Peter Bishop from the Queensland Museum, Australia and colleagues.

Previous research has investigated the biomechanics of ground-dwelling birds to better understand the how bipedal non-avian dinosaurs moved, but it has not previously been possible to empirically predict the locomotive forces that extinct dinosaurs experienced, especially those species that were much larger than living birds. Bishop and colleagues examined locomotion in 12 species of ground-dwelling birds, ranging in body mass from 45g to 80kg, as the birds moved at various speeds along enclosed racetracks while cameras recorded their movements and forceplates measured the forces their feet exerted upon the ground.

The researchers found that many physical aspects of bird locomotion change continuously as speed increases. This supports previous evidence that unlike humans, who have distinct “walking” and “running” gaits, birds move in a continuum from “walking” to “running.” The authors additionally observed consistent differences in gait and posture between small and large birds.

The researchers used their data to construct the biomechanically informative, regression-derived statistical (BIRDS) Model, which requires just two inputs — body mass and speed — to predict basic features of bird locomotion, including stride length and force exerted per step. The model performed well when tested against known data. While more data are needed to improve the model, and it is unclear if it can be extrapolated to animals of much larger body mass, the researchers hope that it might help predict features of non-avian dinosaur locomotion using data from fossils and footprints.

European Union Brexit negotiations parody song


This 12 February 2018 parody music video from Britain is called Barnier the Dinosaur – “I Love EU”.

“The European Union‘s Brexit negotiator Michel Barnier now comes as a purple dinosaur.”

It is a parody of a song from the United States children’s TV show Barney & Friends. The original song is ‘I love you’, sung by the title character Barney, a purple Tyrannosaurus rex.

The lyrics are:

I love EU, EU love me
We’re the best economy
With a single market and customs union
We won’t miss Britain when they’re gone

I love EU, EU love me
We’re the biggest trade bloc, see
We’re a neoliberal Eurodisney park
Great Britain can get to fuck

Cretaceous dinosaur, mammal discovery in Maryland, USA


This video from ther USA says about itself:

Dinosaur Age Meets the Space Age at NASA Goddard

31 January 2018

In 2012, local dinosaur track expert Ray Stanford discovered a nodosaur track from the Cretaceous era on the campus of NASA’s Goddard Space Flight Center, in Greenbelt, Maryland. After the slab on which Stanford found the track was excavated, Stanford, paleontologist Martin Lockley, of University of Colorado at Denver, and others documented more than 70 dinosaur and mammal tracks imprinted in the sandstone. Their paper documenting the discovery was published Jan. 31, 2018, in the journal Scientific Reports. The 8-foot by 3-foot slab contains at least 26 mammal tracks.

From NASA/Goddard Space Flight Center in the USA:

Dinosaur age meets the space age

January 31, 2018

Summary: A slab of sandstone found on the campus of NASA’s Goddard Space Flight Center in Maryland may help scientists rewrite the history of mammal and dinosaur co-existence during the Cretaceous era.

A slab of sandstone discovered at NASA’s Goddard Space Flight Center contains at least 70 mammal and dinosaur tracks from more than 100 million years ago, according to a new paper published Jan. 31 in the journal Scientific Reports. The find provides a rare glimpse of mammals and dinosaurs interacting.

The tracks were discovered by Ray Stanford — a local dinosaur track expert whose wife, Sheila, works at Goddard. After dropping off Sheila at work one day in 2012, Stanford spotted an intriguing rock outcropping behind Sheila’s building on a hillside. Stanford parked his car, investigated, and found a 12-inch-wide dinosaur track on the exposed rock. Excavation revealed that the slab was the size of a dining room table and examination in the ensuing years found that it was covered in preserved tracks.

The remarkable Goddard specimen, about 8 feet by 3 feet in size, is imprinted with nearly 70 tracks from eight species, including squirrel-sized mammals and tank-sized dinosaurs. Analysis suggests that all of the tracks were likely made within a few days of each other at a location that might have been the edge of a wetland, and could even capture the footprints of predator and prey.

“The concentration of mammal tracks on this site is orders of magnitude higher than any other site in the world,” said Martin Lockley, paleontologist with the University of Colorado, Denver, a co-author on the new paper. Lockley began studying footprints in the 1980s, and was one of the first to do so. “I don’t think I’ve ever seen a slab this size, which is a couple of square meters, where you have over 70 footprints of so many different types. This is the mother lode of Cretaceous mammal tracks.”

After Stanford’s initial find, Stephen J. Godfrey, curator of paleontology at the Calvert Marine Museum, coordinated the excavation of the slab and produced the mold and cast that formed the basis of the scientific work.

The first track Stanford found was of a nodosaur — “think of them as a four-footed tank,” Stanford said. Subsequent examination revealed a baby nodosaur print beside and within the adult print, likely indicating that they were traveling together. The other dinosaur tracks include: a sauropod, or long-necked plant-eater; small theropods, crow-sized carnivorous dinosaurs closely related to the Velociraptor and Tyrannosaurus rex; and pterosaurs, a group of flying reptiles that included pterodactyls.

“It’s a time machine,” Stanford said. “We can look across a few days of activity of these animals and we can picture it. We see the interaction of how they pass in relation to each other. This enables us to look deeply into ancient times on Earth. It’s just tremendously exciting.”

The dinosaur tracks are impressive, but it is the collection of mammal tracks that make the slab significant. At least 26 mammal tracks have been identified on the slab since the 2012 discovery — making it one of two known sites in the world with such a concentration of prints. Furthermore, the slab also contains the largest mammal track ever discovered from the Cretaceous. It is about four inches square, or the size of a raccoon‘s prints.

Lockley and Stanford said most of these ancient footprints belong to what we would consider small mammals — animals the size of squirrels or prairie dogs. Most Cretaceous mammals discovered to date have been the size of rodents, their size usually determined only from their teeth. “When you have only teeth, you have no idea what the animals looked like or how they behaved,” Lockley said.

Lockley and Stanford believe the wide diversity and number of tracks show many of the animals were in the area actively feeding at the same time. Perhaps the mammals were feeding on worms and grubs, the small carnivorous dinosaurs were after the mammals, and the pterosaurs could have been hunting both the mammals and the small dinosaurs.

The parallel trackway patterns made by four crow-sized carnivorous dinosaurs suggests they were hunting or foraging as a group. “It looks as if they were making a sweep across the area,” Lockley said.

Several of the mammal tracks occur in pairs, representing hind feet. “It looks as if these squirrel-sized animals paused to sit on their haunches,” Lockley said. The team gave the new formal scientific name of Sederipes goddardensis, meaning sitting traces from Goddard Space Flight Center, to this unusual configuration of tracks.

“We do not see overlapping tracks — overlapping tracks would occur if multiple tracks were made over a longer period while the sand was wet,” said Compton Tucker, a Goddard Earth scientist who helped with the excavation, coordinated bringing in multiple scientists to study the tracks, and has worked to create a display of the cast in Goddard’s Earth science building. “People ask me, ‘Why were all these tracks in Maryland?’ I reply that Maryland has always been a desirable place to live.”

What is now Maryland would have been a much hotter, swampier place in the Cretaceous, when sea levels would have been hundreds of feet higher than today. As scientists continue to study the slab and compare the tracks to others found in the area and around the world, they will continue to discover more about prehistoric life that existed here.

“This could be the key to understanding some of the smaller finds from the area, so it brings everything together,” Lockley said. “This is the Cretaceous equivalent of the Rosetta stone.”

Dinosaur discovery in Egypt


This video says about itself:

29 January 2018

Bus-sized veggie dinosaur travelled across the Sahara

The ‘holy grail’ of dinosaur fossils has been found in the Sahara desert. Researchers have unearthed the remains of a long-necked, four-legged, school bus-sized titanosaur that lived roughly 80 million years ago.

The plant-eating Cretaceous Period dinosaur, named Mansourasaurus shahinae, was nearly 33 feet (10 metres) long and weighed 5.5 tons (5,000 kg). Very few fossils have been unearthed from the last days of the dinosaurs in Africa, and the latest discovery sheds light on this missing history. The find also reveals that at least some dinosaurs could move between Africa and Europe during the final days of the dinosaurs. Scientists say the dinosaur is an ‘incredible discovery’.

From Ohio University in the USA:

New Egyptian dinosaur reveals ancient link between Africa and Europe

Mansourasaurus shahinae helps fill in gaps of African dinosaurs of Late Cretaceous

January 29, 2018

When it comes to the final days of the dinosaurs, Africa is something of a blank page. Fossils found in Africa from the Late Cretaceous, the time period from 100 to 66 million years ago, are few and far between. That means that the course of dinosaur evolution in Africa has largely remained a mystery. But in the Sahara Desert of Egypt, scientists have discovered a new species of dinosaur that helps fill in those gaps: Mansourasaurus shahinae, a school-bus-length, long-necked plant-eater with bony plates embedded in its skin.

The fossilized remains of Mansourasaurus were unearthed by an expedition undertaken by the Mansoura University Vertebrate Paleontology (MUVP) initiative, an effort led by Dr. Hesham Sallam of the Department of Geology at Mansoura University in Mansoura, Egypt. Sallam is the lead author of the paper published today in the journal Nature Ecology and Evolution that names the new species. The field team included several of his students, many of whom — Ms. Iman El-Dawoudi, Ms. Sanaa El-Sayed, and Mrs. Sara Saber — also participated in the study of the new dinosaur. The creature’s name honors both Mansoura University and Ms. Mona Shahin for her integral role in developing the MUVP. According to Sallam, “The discovery and extraction of Mansourasaurus was such an amazing experience for the MUVP team. It was thrilling for my students to uncover bone after bone, as each new element we recovered helped to reveal who this giant dinosaur was.”

“Mansourasaurus shahinae is a key new dinosaur species, and a critical discovery for Egyptian and African paleontology”, says Dr. Eric Gorscak, a postdoctoral research scientist at The Field Museum and a contributing author on the study. Gorscak, who began work on the project as a doctoral student at Ohio University, where his research focused on African dinosaurs, adds, “Africa remains a giant question mark in terms of land-dwelling animals at the end of the Age of Dinosaurs. Mansourasaurus helps us address longstanding questions about Africa’s fossil record and paleobiology — what animals were living there, and to what other species were these animals most closely related?”

Late Cretaceous dinosaur fossils in Africa are hard to come by — much of the land where their fossils might be found is covered in lush vegetation, rather than the exposed rock of dinosaur treasure troves such as those in the Rocky Mountain region, the Gobi Desert, or Patagonia. The lack of a Late Cretaceous fossil record in Africa is frustrating for paleontologists since, at that time, the continents were undergoing massive geological and geographic changes.

During the earlier years of the dinosaurs, throughout much of the Triassic and Jurassic periods, all the continents were joined together as the supercontinent of Pangaea. During the Cretaceous Period, however, the continents began splitting apart and shifting towards the configuration we see today. Historically, it hasn’t been clear how well-connected Africa was to other Southern Hemisphere landmasses and Europe during this time — to what degree Africa’s animals may have been cut off from their neighbors and evolving on their own separate tracks. Mansourasaurus, as one of the few African dinosaurs known from this time period, helps to answer that question. By analyzing features of its bones, Sallam and his team determined that Mansourasaurus is more closely related to dinosaurs from Europe and Asia than it is to those found farther south in Africa or in South America. This, in turn, shows that at least some dinosaurs could move between Africa and Europe near the end of these animals’ reign. “Africa’s last dinosaurs weren’t completely isolated, contrary to what some have proposed in the past,” says Gorscak. “There were still connections to Europe.”

Mansourasaurus belongs to the Titanosauria, a group of sauropods (long-necked plant-eating dinosaurs) that were common throughout much of the world during the Cretaceous. Titanosaurs are famous for including the largest land animals known to science, such as Argentinosaurus, Dreadnoughtus, and Patagotitan. Mansourasaurus, however, was moderate-sized for a titanosaur, roughly the weight of an African bull elephant. Its skeleton is important in being the most complete dinosaur specimen so far discovered from the end of the Cretaceous in Africa, preserving parts of the skull, the lower jaw, neck and back vertebrae, ribs, most of the shoulder and forelimb, part of the hind foot, and pieces of dermal plates. Says study coauthor and dinosaur paleontologist Dr. Matt Lamanna of Carnegie Museum of Natural History, “When I first saw pics of the fossils, my jaw hit the floor. This was the Holy Grail — a well-preserved dinosaur from the end of the Age of Dinosaurs in Africa — that we paleontologists had been searching for for a long, long time.”

Also contributing to the Mansourasaurus research were experts on African paleontology from other institutions in Egypt and the US. MUVP student Iman El-Dawoudi played a particularly important role in the analysis of the new titanosaur, making numerous observations on its skeleton. “The combined effort of multiple institutions across the globe, not to mention the absolutely key role played by students on the project from the field, to the laboratory, to the final analysis and writeup of the results, exemplifies the collaborative nature of expeditionary sciences today,” notes Dr. Patrick O’Connor, study coauthor and professor of anatomy at the Ohio University Heritage College of Osteopathic Medicine.

Funding for the Mansourasaurus study was provided by grants from Mansoura University, the Jurassic Foundation, the Leakey Foundation, the National Geographic Society/Waitt Foundation, and the National Science Foundation (NSF).

“The discovery of rare fossils like this sauropod dinosaur helps us understand how creatures moved across continents, and gives us a greater understanding of the evolutionary history of organisms in this region,” says Dena Smith, a program director in NSF’s Division of Earth Sciences, which partially funded the laboratory portion of the research.

Scientific discoveries are often compared to finding the last missing puzzle piece to complete a picture; Gorscak says that since so little is known about African dinosaurs, Mansourasaurus is better likened to an earlier step in the puzzle-solving process. “It’s like finding an edge piece that you use to help figure out what the picture is, that you can build from. Maybe even a corner piece.”

“What’s exciting is that our team is just getting started. Now that we have a group of well-trained vertebrate paleontologists here in Egypt, with easy access to important fossil sites, we expect the pace of discovery to accelerate in the years to come,” says Sallam.

Arkansas dinosaur tracks in the USA


This video from the USA says about itself:

Acrocanthosaurus atokensis was the largest meat eating dinosaur in North America of the early to mid Cretaceous period. The most complete specimen was discovered just 10 miles from the Museum of the Red River in Idabel and it is now the State Dinosaur of Oklahoma.

This video from 2011 includes interviews with one of the principal excavators, Cephis Hall and Dr. Kenneth Carpenter of the USU Eastern Prehistoric Museum, who with Dr. Phillip J. Currie in 2000 described the find. Also interviewed are: Henry Moy of the Museum of the Red River, Neil Larson of the Black Hills Institute, Kyle Davies of the Sam Noble Museum, and Michael Bergland of mnfx.com.

From the University of Arkansas, Fayetteville in the USA:

Digitally preserving important Arkansas dinosaur tracks

January 16, 2018

Scientists using laser-imaging technology have documented and digitally preserved the first known set of theropod dinosaur tracks in the state of Arkansas.

The tracks, discovered in 2011 in a working gypsum quarry near Nashville, Ark., have since been destroyed. But high-resolution digital scans taken over a period of two weeks in 2011 allowed a team of researchers to study the tracks and determine that they were made by Acrocanthosaurus, a large carnivorous dinosaur. The findings extended the known range of Acrocanthosaurus 56 miles east, to the western shore of an ancient inland sea.

“It actually confirms that the main genus of large theropods in North America was Acrocanthosaurus”, said Celina Suarez, an assistant professor in the Department of Geosciences who was part of the team that documented and studied the tracks. “It now has been found in Wyoming, Utah, Oklahoma, Arkansas and Maryland, a huge range.”

Results of the study were recently published in the journal PLOS ONE. Researchers also created a detailed, publicly accessible online map of the site and the tracks. Brian Platt, an assistant professor of geology from the University of Mississippi, led the study. Researchers from the University of Arkansas Center for Advanced Spatial Technology (CAST) provided the scanning equipment and expertise.

The Rush to Preserve the Site

After the tracks were discovered, researchers received a $10,000 Rapid Grant from the National Science Foundation to quickly document the site. The U of A’s vice provost for research and economic development and the J. William Fulbright College of Arts and Sciences provided matching grants, for a total of $30,000.

The mining company moved its operations to allow researchers a short window of time to document the find. Researchers used LiDAR, which stands for light detection and ranging, because traditional methods would have taken too long, said Suarez. “From a technical standpoint, it’s important that the ability to rapidly scan such a large area is available to paleontologists. It was invaluable for this project since we had such little time to work.”

The site had two different sized Acrocanthosaurus tracks, suggesting both adult and younger animals walked the ancient tidal flat about 100 million years ago, during the Cretaceous Period. It also contained tracks made by sauropods, long-necked plant-eating dinosaurs.

LiDAR uses a pulsed laser to measure distances to the earth in tiny increments, generating a data “point cloud” that is used to digitally recreate a physical space. In this case, the equipment was mounted on a lift over the site. By analyzing carbon and oxygen isotopes of the rock at the track surface, researchers determined that the track surface was indeed the surface that the animals stepped on, rather than an underlying layer that remained when the original surface eroded.

The digital reconstruction of the trackway site: http://trackways.cast.uark.edu/index.html

Dinosaurs, lies and truth


This video says about itself:

LIES About Dinosaurs You PROBABLY Still Believe!

8 January 2018

Check out these lies about dinosaurs you probably still believe! From the largest and most dangerous dinosaurs like Tyrannosaurus rex and Brontosaurus to smaller ones like velociraptors, here are the top 10 myths about dinos debunked!