Jurassic dinosaurs footprints discovery in Scotland


This June 2018 CBS TV video is called Isle of Skye a hotbed of dinosaur discoveries.

From PLOS:

Dinosaur stomping ground in Scotland reveals thriving middle Jurassic ecosystem

Dozens of footprints expand the list of dinosaurs known to have lived in the region

March 11, 2020

During the Middle Jurassic Period, the Isle of Skye in Scotland was home to a thriving community of dinosaurs that stomped across the ancient coastline, according to a study published March 11, 2020 in the open-access journal PLOS ONE by Paige dePolo and Stephen Brusatte of the University of Edinburgh, Scotland and colleagues.

The Middle Jurassic Period is a time of major evolutionary diversification in many dinosaur groups, but dinosaur fossils from this time period are generally rare. The Isle of Skye in Scotland is an exception, yielding body and trace fossils of diverse Middle Jurassic ecosystems, serving as a valuable location for paleontological science as well as tourism.

In this paper, dePolo and colleagues describe two recently discovered fossil sites preserving around 50 dinosaur footprints on ancient coastal mudflats. These include the first record on the Isle of Skye of a track type called Deltapodus, most likely created by a stegosaurian (plate-backed) dinosaur. These are the oldest Deltapodus tracks known, and the first strong evidence that stegosaurian dinosaurs were part of the island’s Middle Jurassic fauna. Additionally, three-toed footprints represent multiple sizes of early carnivorous theropods and a series of other large tracks are tentatively identified as some of the oldest evidence of large-bodied herbivorous ornithopod dinosaurs.

All tracks considered, these two sites expand the known diversity of what was apparently a thriving ecosystem of Middle Jurassic dinosaurs in Scotland, including at least one type of dinosaur (stegosaurs) not previously known from the region. These findings reflect the importance of footprints as a source of information supplemental to body fossils. Furthermore, the authors stress the importance of revisiting previously explored sites; these new sites were found in an area that has long been popular for fossil prospecting, but the trackways were only recently revealed by storm activity.

Lead author dePolo says: “These new tracksites help us get a better sense of the variety of dinosaurs that lived near the coast of Skye during the Middle Jurassic than what we can glean from the island’s body fossil record. In particular, Deltapodus tracks give good evidence that stegosaurs lived on Skye at this time.”

Author Brusatte adds: “These new tracksites give us a much clearer picture of the dinosaurs that lived in Scotland 170 million years ago. We knew there were giant long-necked sauropods and jeep-sized carnivores, but we can now add plate-backed stegosaurs to that roster, and maybe even primitive cousins of the duck-billed dinosaurs too. These discoveries are making Skye one of the best places in the world for understanding dinosaur evolution in the Middle Jurassic.”

Belemnites and dinosaur age global warming


This 2006 video says about itself:

A short video introducing belemnites which were extinct cousins of the squid, octopus and cuttlefish.

From the University of Erlangen-Nuremberg in Germany:

Why organisms shrink in a warming world

March 9, 2020

Everyone is talking about global warming. A team of palaeontologists at GeoZentrum Nordbayern at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) has recently investigated how prehistoric organisms reacted to climate change, basing their research on belemnites.

These shrunk significantly when the water temperature rose as a result of volcanic activity approximately 183 million years ago, during the period known as the Toarcian. The FAU research team published their results in the online publication Royal Society Open Science.

‘Belemnites are particularly interesting, as they were very widespread for a long time and are closely related to the squid of today,’ explains palaeontologist Dr. Patricia Rita. ‘Their fossilised remains, for example the rostrum, can be used to make reliable observations.’ Within the context of the DFG-funded research project ‘Temperature-related stresses as a unifying principle in ancient extinctions,’ the hypothesis was confirmed that climate has a significant influence on the morphology of adult aquatic organisms. The body size of dominant species fell by an average of up to 40 percent.

The team of researchers believe that this Lilliput effect was a precursor to the later extinction of the animals. It is still unclear whether rises in temperature influenced the organisms’ metabolism directly or indirectly, for example due to a shortage of food sources.

Jurassic South African dinosaur, other footprints, discovery


This 13 August 2018 video says about itself:

Take a look at some of the most important and valuable archaeological treasures in the world that are to be found in South Africa’s Great Karoo. It was through the study of Karoo fossils in the early years of the 20th century that scientific thought was influenced in acknowledging that mammals arose from reptiles.

And, as every one of us is a living fossil – containing within our genes the secrets of our ancestors – a journey into the Karoo is in some respects a voyage of self-discovery.

World-famous palaeontologist, Dr Robert Broom, was greatly excited by seeing one specimen in particular, and that was the Milleretta.

The Milleretta was the first well-preserved skull ever discovered of the group of reptiles that may have had as one of its members the ancestor of all mammal-like reptiles. To Broom, this skull was “the seed of the mammal race.” These prehistoric mammal-like reptiles left their mark in other ways too – such as visible footprints, dating about 250 million years ago – found at Sante Sana, also in the Graaff-Reinet district.

From PLOS:

The ‘firewalkers’ of Karoo: Dinosaurs and other animals left tracks in a ‘land of fire’

Several groups of reptiles persisted in Jurassic Africa even as volcanism ruined their habitat

January 29, 2020

In southern Africa, dinosaurs and synapsids, a group of animals that includes mammals and
their closest fossil relatives, survived in a “land of fire” at the start of an Early Jurassic mass extinction, according to a study published January 29, 2020 in the open-access journal PLOS ONE by Emese M. Bordy of the University of Cape Town and colleagues.

The Karoo Basin of southern Africa is well-known for its massive deposits of igneous rocks left behind by extensive basaltic lava flows during the Early Jurassic. At this time, intense volcanic activity is thought to have had dramatic impacts on the local environment and global atmosphere, coincident with a worldwide mass extinction recorded in the fossil record. The fossils of the Karoo Basin thus have a lot to tell about how ecosystems responded to these environmental stresses.

In this study, Bordy and colleagues describe and identify footprints preserved in a sandstone layer deposited between lava flows, dated to 183 million years ago. In total, they report five trackways containing a total of 25 footprints, representing three types of animals: 1) potentially small synapsids, a group of animals that includes mammals and their forerunners; 2) large, bipedal, likely carnivorous dinosaurs; and 3) small, quadrupedal, likely herbivorous dinosaurs represented by a new ichnospecies (trace fossils like footprints receive their own taxonomic designations, known as ichnospecies).

These fossils represent some of the very last animals known to have inhabited the main Karoo Basin before it was overwhelmed by lava. Since the sandstone preserving these footprints was deposited between lava flows, this indicates that a variety of animals survived in the area even after volcanic activity had begun and the region was transformed into a “land of fire”. The authors suggest that further research to uncover more fossils and refine the dating of local rock layers has the potential to provide invaluable data on how local ecosystems responded to intense environmental stress at the onset of a global mass extinction.

Bordy adds: “The fossil footprints were discovered within a thick pile of ancient basaltic lava flows that are ~183 million years old. The fossil tracks tell a story from our deep past on how continental ecosystems could co-exist with truly giant volcanic events that can only be studied from the geological record, because they do not have modern equivalents, although they can occur in the future of the Earth.”

How Jurassic pterosaurs fed, new research


This video is called TRILOGY OF LIFE – Walking with Dinosaurs – “Ramphorhynchus“.

By John Pickrell, January 27, 2020 at 5:00 am:

A squid fossil offers a rare record of pterosaur feeding behavior

A tooth embedded in a squid fossil tells a story of a battle at sea with the flying reptile

A fossil of a squid with a pterosaur tooth embedded in it offers extraordinary evidence of a 150-million-year-old battle at sea. While many pterosaur fossils containing fish scales and bones in their stomachs have revealed that some of these flying reptiles included fish in their diet, the new find from Germany is the first proof that pterosaurs also hunted squid.

The fossil was excavated in 2012 in the Solnhofen Limestone, near Eichstätt in Bavaria, where many Jurassic Period fossils of pterosaurs, small dinosaurs and the earliest known bird, Archaeopteryx, have been found. The region’s environment at the time was something like the Bahamas today, with low-lying islands dotting shallow tropical seas.

The embedded tooth fits the right size and shape for the pterosaur Rhamphorhynchus, paleontologists report online January 27 in Scientific Reports. They argue that the tooth was left by a pterosaur that swooped to the ocean surface to snap up the 30-centimeter-long squid from the extinct Plesioteuthis genus, but was unsuccessful, possibly because the squid was too large or too far down in the water column for the predator to manage.

“The Plesioteuthis squid wrestled it off and escaped, breaking at least one tooth off the pterosaur, which became lodged in [the squid’s] mantle,” says Jordan Bestwick, a paleontologist at the University of Leicester in England. “This fossil is important in helping us understand the dietary range of Rhamphorhynchus, and tells us about its hunting behavior.”

The fossil itself is unique, according to pterosaur researcher Taíssa Rodrigues at the Federal University of Espírito Santo in Vitorio, Brazil, who was not involved in the study. “It is very rare to find predator-prey interactions that include pterosaurs,” she says. “In the few cases we do have, pterosaurs were the prey of large fish. So it is great to see this the other way around.”

Paleontologist Michael Habib of the University of Southern California in Los Angeles says he suspects the squid was far too large for the pterosaur to haul out of the water. “The pterosaur was lucky that the tooth broke off,” says Habib, who was not involved with the study. “A squid of that size could probably have pulled it under.”

New Jurassic carnivorous dinosaur discovery


This 2001 video is called When Dinosaurs Roamed America.

From the Ludwig-Maximilians-Universität München in Germany:

Paleontology: Experiments in evolution

December 11, 2019

A new find from Patagonia sheds light on the evolution of large predatory dinosaurs. Features of the 8-m long specimen from the Middle Jurassic suggest that it records a phase of rapid diversification and evolutionary experimentation.

In life, it must have been an intimidating sight. The dimensions of the newly discovered dinosaur fossil suggest that this individual was up to 8 meters long, and its skull alone measured 80 centimeters from front to back. The specimen was uncovered by the Munich paleontologist Oliver Rauhut in Patagonia, and can be assigned to the tetanurans — the most prominent group of bipedal dinosaurs, which includes such iconic representatives as Allosaurus, Tyrannosaurus and Velociraptor. This is also the group from which modern birds are derived. The new find is the most complete dinosaur skeleton yet discovered from the early phase of the Middle Jurassic, and is between 174 and 168 million years old. The specimen represents a previously unknown genus, and Rauhut and his Argentinian colleague Diego Pol have named it Asfaltoventor vialidadi. The genus name includes both Greek and Latin components (including the Latin term for hunter), while also referring to the nature of the deposits in which the fossil was found and the species name honours the road maintance of Chubut, who helped in the recovery of the specimen.

Almost the entire skull is preserved, together with the complete vertebral column including parts of the pelvis, all the bones of both anterior extremities and parts of the legs. “The fossil displays a very unusual combination of skeletal characters, which is difficult to reconcile with the currently accepted picture of the relationships between the three large groups that comprise the tetanurans — Megalosauria, Allosauria and Coelurosauria,” says Rauhut, who is Professor of Palaeontology in the Department of Earth and Environmental Sciences at Ludwig-Maximilians-Universitaet (LMU) in Munich and Senior Curator of the Bavarian State Collection for Paleontology and Geology. He and his co-author Diego Pol, who is based in the Museo Paleontológico Egidio Feruglio in Trelew (Argentina), describe the find in a paper that appears in the online journal Scientific Reports. According to the authors, A. vialidadi exhibits a diverse set of skeletal traits, which combines characters that have so far been found to be specific for various other species of dinosaurs.

The unusual mixture of morphological features displayed by A. vialidadi prompted the authors to carry out a comparative analysis with other tetanurans. They noted that around the period to which the new find can be assigned, the geographical range of this group was rapidly expanding, while the different species developed very similar sets of skeletal features.

Rauhut links the explosive evolution of the group with an episode of mass extinction that had occurred in the late stage of the Lower Jurassic, about 180 million years ago. The two researchers therefore interpret the parallel development of similar external traits in different species as an example of evolutionary experimentation during the subsequent rapid expansion and diversification of the tetanurans. The prior extinction of potential competitors will have opened up new ecological niches for the groups that survived, and the tetanurans were apparently among those that benefited.

“This is a pattern that we also observe in many other groups of animals in the aftermath of mass extinctions. It holds, for example, for the expansion and diversification of both mammals and birds following the extinction of the dinosaurs at the end of the Cretaceous 66 million years ago,” says Rauhut. It could also explain why it is so difficult to unravel the phylogenetic relationships close to the origin of many highly diversified animal groups.

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.