Jurassic crocodile identified 250 years after find


This video says about itself:

Meet the top 10 largest crocodiles in the world and history. These prehistoric crocodiles are really gigantic, you won’t believe they really existed.

Purussaurus
This is an extinct giant which lived in South America in the Miocene. A 4.7 feet long skull was found in Brazil, that’s why it’s estimated that this species measured 41 feet long and weighed 8.4 tons, making this one of the biggest crocodiles in history.

Mourasuchus
This extinct crocodile lived in the Miocene and its fossils were found in Peru. It’s thought that it measured 30 feet in length.

Smilosuchus
It’s also an extinct specimen that lived in the late stage of the Triassic period in north America.

Deinosuchus
It was an extinct species that could reach 39 feet in length and weight 8.5 tons.

Sarcosuchus
This species reached between 36 and 39 feet in length, because of this size it received the name of Super Croc, with which it has become famous.

Rhamphosuchus
This crocodile used to live in the Ganges river, in India, during the Miocene.

Gryposuchus
This extinct crocodile lived in south America between 23 million and 700 thousand years ago, in the Miocene, Pliocene and beginnings of the Pleistocene.

Stomatosuchus
It was a 32.8 feet crocodile that lived in the late Cretaceous in Egypt. It had a plain head seen from the top that looks a lot like a cricket bat.

Rutiodon
Was a reptile genre that lived at the end of the Triassic period, its name means creased tooth. It measured 26 feet in length and its fossils have been found in the eastern part of the United States.

Machimosaurus
This prehistoric crocodile specimen reached the length of 23.6 feet. It lived in the late Jurassic and early Cretaceous era, which means this was contemporaneous to the dinosaurs.

From the University of Edinburgh in Scotland:

Mysterious Jurassic crocodile identified 250 years after fossil find

September 12, 2019

Summary:.A prehistoric crocodile that lived around 180 million years ago has been identified — almost 250 years after the discovery of its fossil remains.

A fossil skull found in a Bavarian town in the 1770s has been recognised as the now-extinct species Mystriosaurus laurillardi, which lived in tropical waters during the Jurassic Period.

For the past 60 years, it was thought the animal was part of a similar species, known as Steneosaurus bollensis, which existed around the same time, researchers say.

Palaeontologists identified the animal by analysing fossils unearthed in the UK and Germany.

The team, which included scientists from the University of Edinburgh, also revealed that another skull, discovered in Yorkshire in the 1800s, belongs to Mystriosaurus laurillardi.

The marine predator — which was more than four metres in length — had a long snout and pointed teeth, and preyed on fish, the team says. It lived in warm seas alongside other animals including ammonites and large marine reptiles, called ichthyosaurs.

The discovery of fossils in present-day Germany and the UK shows that the species could easily swim between islands, much like modern saltwater crocodiles, researchers say.

The study, led by Naturkunde-Museum Bielefeld in Germany, is published in the journal Acta Palaeontologica Polonica. It was supported by the Palaeontographical Society, Leverhulme Trust and the Natural Sciences and Engineering Research Council of Canada.

Sven Sachs, of the Naturkunde-Museum Bielefeld, who led the study, said: “Mystriosaurus looked like a gharial but it had a shorter snout with its nasal opening facing forwards, whereas in nearly all other fossil and living crocodiles the nasal opening is placed on top of the snout.”

Dr Mark Young, of the University of Edinburgh’s School of GeoSciences, who was involved in the study, said: “Unravelling the complex history and anatomy of fossils like Mystriosaurus is necessary if we are to understand the diversification of crocodiles during the Jurassic. Their rapid increase in biodiversity between 200 and 180 million years ago is still poorly understood.”

Filter-feeding Jurassic pterosaurs, new study


This 23 October 2019 video says about itself:

Pterosaurs Size Comparison

Pterosaurs, meaning “winged lizards” were flying reptiles of the extinct clade or order Pterosauria. Pterosaurs existed during most of the Mesozoic: from the late Triassic to the end of the Cretaceous (228 to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.

From Uppsala University in Sweden:

Filter-feeding pterosaurs were the flamingos of the Late Jurassic

August 26, 2019

Modern flamingoes employ filter feeding and their feces are, as a result, rich in remains of microscopically-small aquatic prey. Very similar contents are described from more than 150 million-year-old pterosaur droppings in a recent paper in PeerJ. This represents the first direct evidence of filter-feeding in Late Jurassic pterosaurs and demonstrates that their diet and feeding environment were similar to those of modern flamingoes.

Pterosaurs were a diverse group of flying reptiles that roamed the skies during the age of dinosaurs. Skeletal fossils suggest that they, just like modern birds, adapted to diverse lifestyles and feeding habits. Direct evidence on diets such as gut contents, however, are rare and only known from a few pterosaur species.

Coprolites, that is fossil droppings, are surprisingly common fossils and they potentially hold valuable information on the diet of extinct animals. Unfortunately, it is often difficult to know which animal produced which dropping.

In a recent paper, researchers from Uppsala University and the Polish Academy of Sciences describe the contents of three coprolites collected from a surface with abundant pterosaur footprints in the Wierzbica Quarry in Poland. The coprolites’ size, shape and association to the tracks suggest that they were produced by pterosaurs, most probably belonging to a group called Ctenochasmatidae.

The fossil droppings were scanned using synchrotron microtomography, which works in a similar way to a CT-scanner in a hospital but with much stronger x-ray beams. This makes it possible to image the contents of fossils in three dimensions. The scans of the pterosaur coprolites revealed many microscopic food remains including foraminifera (small amoeboid protists with external shells), small shells of marine invertebrates and possible remains of polychaete worms.

“A reasonable explanation for how a pterosaur big enough to have produced the droppings ingested such small prey is through filter feeding,” says Martin Qvarnström, PhD student at Uppsala University and one of the authors of the article.

Some ctenochasmid pterosaurs are thought to have been filter feeders. Pterodaustro, which comes from the Cretaceous and is thus slightly younger than the Polish coprolites, possessed a sieving basket consisting of many long, thin teeth and was certainly a filter feeder. Older ctenochasmids did not possess such an obvious sieving basket, but some had elongated snouts with many slender teeth, also interpreted as adaptations for filter feeding. These pterosaurs were around at the time the droppings were made, and as the footprints from the site have also been attributed to ctenochasmids it is likely that such pterosaurs produced both the droppings and the footprints.

The modern Chilean flamingo, which is a filter feeder, can produce droppings full of foraminifera when feeding in coastal wetlands.

“The similar contents of the droppings of these flamingos and the pterosaur coprolites could be explained by similar feeding environments and mesh sizes of the filter-feeding apparatus. It appears therefore that the pterosaurs which produced the footprints and droppings found in Poland were indeed the flamingos of the Late Jurassic,” says Martin Qvarnström.

New dinosaur discovery in South African university


This July 2015 video says about itself:

Massospondylus” is a genus of sauropodomorph dinosaur from the Early Jurassic Period. It was described by Sir Richard Owen in 1854 from remains discovered in South Africa, and is thus one of the first dinosaurs to have been named. Fossils have since been found at other locations in South Africa, Lesotho, and Zimbabwe. Material from Arizona’s Kayenta Formation, India, and Argentina has been assigned to this genus at various times, but the Arizonan and Argentinian material are now assigned to other genera.

The type species is “M. carinatus”; seven other species have been named during the past 150 years, but only “M. kaalae” among these is still considered valid. Early sauropodomorphs systematics have undergone numerous revisions during the last several years, and many scientists disagree where exactly “Massospondylus” lies on the dinosaur evolutionary tree. The family name Massospondylidae was once coined for the genus, but because knowledge of early sauropodomorph relationships is in a state of flux, it is unclear which other dinosaurs—if any—belong in a natural grouping of massospondylids; several 2007 papers support the family’s validity.

Although “Massospondylus” was long depicted as quadrupedal, a 2007 study found it to be bipedal. It was probably a plant-eater, although it is speculated that the early sauropodomorphs may have been omnivorous. This animal, which was 4 meters long, had a long neck and tail, with a small head and slender body. On each of its forefeet, it bore a sharp thumb claw that was used in defense or feeding. Recent studies indicate that “Massospondylus” grew steadily throughout its lifespan, possessed air sacs similar to those of birds, and may have cared for its young.

From the University of the Witwatersrand in South Africa:

New species of dinosaur discovered after lying misidentified in fossil vaults for 30 years

August 6, 2019

A PhD student of the University of the Witwatersrand, South Africa, has discovered a new dinosaur species in the University’s vaults, after it has been laying misidentified in a collection for 30 years.

The team of scientists, led by PhD Student Kimberley Chapelle, recognised that the dinosaur was not only a new species of sauropodomorph, but an entirely new genus. The specimen has now been named Ngwevu intloko which means “grey skull” in the Xhosa language, chosen to honour South Africa’s heritage. She was joined in the research by her PhD supervisors: Prof Jonah Choiniere (Wits), Dr Jennifer Botha (National Museum Bloemfontein), and Professor Paul Barrett (Natural History Museum, London). Together, Kimberley and these world-leading researchers have been improving knowledge of South African palaeontology for the last six years. The dinosaur has been described in the academic journal, PeerJ.

Professor Paul Barrett, Chapelle’s PhS supervisor and researcher at the Natural History Museum in the UK explains, “This is a new dinosaur that has been hiding in plain sight.” “The specimen has been in the collections in Johannesburg for about 30 years, and lots of other scientists have already looked at it. But they all thought that it was simply an odd example of Massospondylus.”

Massospondylus was one of the first dinosaurs to reign at the start of the Jurassic period. Regularly found throughout southern Africa, these animals belonged to a group called the sauropodomorphs and eventually gave rise to the sauropods, a group containing the [London] Natural History Museum’s iconic dinosaur cast Dippy. Researchers are now starting to look closer at many of the supposed Massospondylus specimens, believing there to be much more variation than first thought.

Kimberley Chapelle explains why the team were able to confirm that this specimen was a new species, “In order to be certain that a fossil belongs to a new species, it is crucial to rule out the possibility that it is a younger or older version of an already existing species. This is a difficult task to accomplish with fossils because it is rare to have a complete age series of fossils from a single species. Luckily, the most common South African dinosaur Massospondylus has specimens ranging from embryo to adult. Based on this, we were able to rule out age as a possible explanation for the differences we observed in the specimen now named Ngwevu intloko.”

The new dinosaur has been described from a single fairly complete specimen with a remarkably well-preserved skull. The new dinosaur was bipedal with a fairly chunky body, a long slender neck and a small, boxy head. It would have measured three metres from the tip of its snout to the end of its tail and was likely an omnivore, feeding on both plants and small animals.

The findings will help scientists better understand the transition between the Triassic and Jurassic period, around 200 million years ago. Known as a time of mass extinction it now seems that more complex ecosystems were flourishing in the earliest Jurassic than previously thought.

“This new species is interesting,” says Prof Barrett, “because we thought previously that there was really only one type of sauropodomorph living in South Africa at this time. We now know there were actually six or seven of these dinosaurs in this area, as well as variety of other dinosaurs from less common groups. It means that their ecology was much more complex than we used to think. Some of these other sauropodomorphs were like Massospondylus, but a few were close to the origins of true sauropods, if not true sauropods themselves.”

This work shows the value of revisiting specimens in museum collections, as many new species are probably sitting unnoticed in cabinets around the world.

Big Jurassic dinosaur bone discovery in France


This 26 July 2019 video says about itself:

The thigh bone of a giant dinosaur was recently found at the Angeac-Charente excavation site in southwestern France. The two-meter-long femur is thought to have belonged to a sauropod, a herbivorous dinosaur that was widespread in the late Jurassic era, over 140 million years ago.

According to Dutch NOS TV today, the thigh bone weighs 500 kilogram. Sice 2010, when the excavations in this area of France began, 7500 bones of 40 different dinosaur species have been found.

How dinosaur age mammals ate


This 2016 video is called Top 7 Prehistoric Mesozoic Mammals.

From the University of Chicago Medical Center in the USA:

Jurassic fossil shows how early mammals could swallow like their modern descendants

July 18, 2019

The 165-million-year-old fossil of Microdocodon gracilis, a tiny, shrew-like animal, shows the earliest example of modern hyoid bones in mammal evolution.

The hyoid bones link the back of the mouth, or pharynx, to the openings of the esophagus and the larynx. The hyoids of modern mammals, including humans, are arranged in a “U” shape, similar to the saddle seat of children’s swing, suspended by jointed segments from the skull. It helps us transport and swallow chewed food and liquid — a crucial function on which our livelihood depends.

Mammals as a whole are far more sophisticated than other living vertebrates in chewing up food and swallowing it one small lump at a time, instead of gulping down huge bites or whole prey like an alligator.

“Mammals have become so diverse today through the evolution of diverse ways to chew their food, weather it is insects, worms, meat, or plants. But no matter how differently mammals can chew, they all have to swallow in the same way,” said Zhe-Xi Luo, PhD, a professor of organismal biology and anatomy at the University of Chicago and the senior author of a new study of the fossil, published this week in Science.

“Essentially, the specialized way for mammals to chew and then swallow is all made possible by the agile hyoid bones at the back of the throat,” Luo said.

‘A pristine, beautiful fossil’

This modern hyoid apparatus is mobile and allows the throat muscles to control the intricate functions to transport and swallow chewed food or drink fluids. Other vertebrates also have hyoid bones, but their hyoids are simple and rod-like, without mobile joints between segments. They can only swallow food whole or in large chunks

When and how this unique hyoid structure first appeared in mammals, however, has long been in question among paleontologists. In 2014, Chang-Fu Zhou, PhD, from the Paleontological Museum of Liaoning in China, the lead author of the new study, found a new fossil of Microdocodon preserved with delicate hyoid bones in the famous Jurassic Daohugou site of northeastern China. Soon afterwards, Luo and Thomas Martin from the University of Bonn, Germany, met up with Zhou in China to study the fossil.

“It is a pristine, beautiful fossil. I was amazed by the exquisite preservation of this tiny fossil at the first sight. We got a sense that it was unusual, but we were puzzled about what was unusual about it,” Luo said. “After taking detailed photographs and examining the fossil under a microscope, it dawned on us that this Jurassic animal has tiny hyoid bones much like those of modern mammals.”

This new insight gave Luo and his colleagues added context on how to study the new fossil. Microdocodon is a docodont, from an extinct lineage of near relatives of mammals from the Mesozoic Era called mammaliaforms. Previously, paleontologists anticipated that hyoids like this had to be there in all of these early mammals, but it was difficult to identify the delicate bones. After finding them in Microdocodon, Luo and his collaborators have since found similar fossilized hyoid structures in other Mesozoic mammals.

“Now we are able for the first time to address how the crucial function for swallowing evolved among early mammals from the fossil record,” Luo said. “The tiny hyoids of Microdocodon are a big milestone for interpreting the evolution of mammalian feeding function.”

New insights on mammal evolution as a whole

Luo also worked with postdoctoral scholar Bhart-Anjan Bhullar, PhD, now on the faculty at Yale University, and April Neander, a scientific artist and expert on CT visualization of fossils at UChicago, to study casts of Microdocodon and reconstruct how it lived.

The jaw and middle ear of modern mammals are developed from (or around) the first pharyngeal arch, structures in a vertebrate embryo that develop into other recognizable bones and tissues. Meanwhile, the hyoids are developed separately from the second and the third pharyngeal arches. Microdocodon has a primitive middle ear still attached to the jaw like that of other early mammals like cynodonts, which is unlike the ear of modern mammals. Yet its hyoids are already like those of modern mammals.

“Hyoids and ear bones are all derivatives of the primordial vertebrate mouth and gill skeleton, with which
our earliest fishlike ancestors fed and respired,” Bhullar said. “The jointed, mobile hyoid of Microdocodon coexists with an archaic middle ear — still attached to the lower jaw. Therefore, the building of the modern mammal entailed serial repurposing of a truly ancient system.”

The tiny, shrew-like creature likely weighed only 5 to 9 grams, with a slender body, and an exceptionally long tail. The dimensions of its limb bones match up with those of modern tree-dwellers.

“Its limb bones are as thin as matchsticks, and yet this tiny Mesozoic mammal still lived an active life in trees,” Neander said.

The fossil beds that yielded Microdocodon are dated 164 to 166 million years old. Microdocodon co-existed with other docodonts like the semiaquatic Castorocauda, the subterranean Docofossor, the tree-dwelling Agilodocodon, as well as some mammaliaform gliders.

Jurassic sauropod dinosaur, from quadrupedal to bipedal


GROWING UP As Mussaurus patagonicus grew, the long-necked dinosaur’s center of mass shifted back toward its hips and tail, letting it go from a four-legged to two-legged gait even as it ballooned from the size of a chick to that of a rhinoceros. A. Otero et al./Scientific Reports 2019

By John Pickrell, 5:00am, May 20, 2019:

This early sauropod went from walking on four legs to two as it grew

Center of mass shifts led to a rare change in walking style for a long-necked dinosaur relative

Most long-necked sauropods lumbered on four legs all their lives to support their titanic bulk. But an early relative of such behemoths as Brachiosaurus made the unusual transition from walking on four legs to two as it grew, a new study shows.

Diminutive at hatching, Mussaurus patagonicus (which means “mouse lizard”) began life walking on all fours. But by the time the 200-million-year-old plant eater reached its 6-meter-long adult size, it roamed what’s now Argentina on two legs.

The changing length of M. patagonicus’s arm bones relative to its body and its inward facing-palms as an adult had hinted at the transition. But for the first time, computer simulations based on a rich fossil record show how a shift in the creature’s center of gravity as it grew enabled a change to bipedal walking, researchers report May 20 in Scientific Reports.

Researchers took CT scans of fossil bones from six individual M. patagonicus — covering different stages of the species’ development, from 60-gram hatchlings the size of baby chickens to 1.5 metric ton adults the size of rhinoceroses. The researchers added virtual flesh to digitized bones to create 3-D models that allowed them to estimate both the weight and center of gravity of M. patagonicus at many different stages of its life.

Reconstructions of the hatchlings showed that the creature’s center of mass was so far forward that the dinosaurs could move around only by walking on all four legs, says Andrew Cuff, a paleontologist of the Structure and Motion Laboratory of the Royal Veterinary College in Hatfield, England.

As the dinos grew, their center of mass moved back toward their hips, allowing them to walk upright on two legs, Cuff and colleagues found. The transition “is incredibly rare,” he says. “We have struggled to find any other animals aside from humans that go through that transition…. Finding it in the fossil record is pretty exceptional.”

The results suggest these adult dinosaurs turned bipedal because their tail muscles became bulkier and heavier as they grew, moving their center of gravity backward, says Stephen Poropat, a paleontologist at Swinburne University of Technology in Melbourne, Australia, who was not involved in the research. “It is not the changing proportions of Mussaurus’s front legs that is necessitating this change from walking on four legs to walking on two legs as an adult,” he says.

As later long-necked dinos bulked up in size (SN Online: 9/4/14), going to two legs may no longer have been an option. Massive sauropods instead probably started on four legs like M. patagonicus and stayed that way, developing trunklike front legs to bear their weight. “What we gain from this [study] is that there may be a size limit of how big you can get being a biped in this group,” Cuff says.

Jurassic bird species discovery, second ever


Alcmonavis fossil

From the Ludwig-Maximilians-Universität München in Germany:

First birds: Archaeopteryx gets company

May 14, 2019

Summary: Researchers describe a hitherto unknown bird from the late Jurassic period. It is the second bird capable of flight, after the famous Archaeopteryx, to be identified from this era.

Archaeopteryx’s throne is tottering. Since the discovery of the first fossil of the primal bird in 1861, it had been considered the only bird from the Jurassic geological period. Today’s birds are thought to be direct descendants of carnivorous dinosaurs, with Archaeopteryx representing the oldest known flying representative of this lineage. All of the specimens that have been found up to now come from the region of the Solnhofen Archipelago, which during the Jurassic era spanned across what is today the Altmühl Valley, in the area between Pappenheim and Regensburg. Archaeopteryx lived here in a landscape of reef islands about 150 million years ago.

A team led by Professor Oliver Rauhut has taxonomically identified a bird unknown until now: Alcmonavis poeschli, the second bird from the era identified as capable of flight. “This suggests that the diversity of birds in the late Jurassic era was greater than previously thought,” says Rauhut, paleontologist at the Department of Earth and Environmental Sciences as well as the Bavarian State Collection of Paleontology and Geology.

Only a wing of Alcmonavis poeschli was discovered. “At first, we assumed that this was another specimen of Archaeopteryx. There are similarities, but after detailed comparisons with Archaeopteryx and other, geologically younger birds, its fossil remains suggested that we were dealing with a somewhat more derived bird,” says Rauhut. According to the team’s taxonomic studies, which are currently featured in the scientific journal eLife, Alcmonavis poeschli was not merely somewhat larger than Archaeopteryx; apparently it could also fly better. “The wing muscles indicate a greater capacity for flying,” says Rauhut. Alcmonavis poeschli exhibits numerous traits lacking in Archaeopteryx but present in more recent birds. This suggests that it was adapted better to active, flapping flight.

The discovery of Alcmonavis poeschli has implications for the debate over whether active flapping birds arose from gliding birds. “Its adaptation shows that the evolution of flight must have progressed relatively quickly,” says Dr. Christian Foth from the University of Fribourg (Switzerland), one of the co-authors of the study.

The bird now being described for the first time derives its name from the old Celtic word for the river Altmühl, Alcmona, and its discoverer Roland Pöschl, who leads the excavation at the Schaudiberg quarry close to Mörnsheim. A fossil of Archaeopteryx was also discovered in the same unit of limestones. The two primal birds thus apparently lived at the same time in what was then a subtropical lagoon landscape in southern Germany.