Longest sauropod dinosaur trackway discovery


This video says about itself:

3 September 2012

Huge sauropods’ footprints from the late Jurassic plus tridactyls’ trackways – Plagne, French Jura…150 millions years ago!

From CNRS in France:

World’s longest sauropod dinosaur trackway brought to light

November 13, 2017

In 2009, the world’s largest dinosaur tracks were discovered in the French village of Plagne, in the Jura Mountains. Since then, a series of excavations at the site has uncovered other tracks, sprawling over more than 150 meters. They form the longest sauropod trackway ever to be found. Having compiled and analyzed the collected data, which is published in Geobios, scientists from the Laboratoire de Géologie de Lyon (CNRS / ENS de Lyon / Claude Bernard Lyon 1 University), the Laboratoire Magmas et Volcans (CNRS / Université Clermont Auvergne / Université Jean Monnet / IRD), and the Pterosaur Beach Museum conclude these tracks were left 150 million years ago by a dinosaur at least 35 m long and weighing no less than 35 t.

In 2009, when sauropod tracks were discovered in the French village of Plagne — near Lyon — the news went round the world. After two members of the Oyonnax Naturalists’ Society spotted them, scientists from the Paléoenvironnements et Paléobiosphère research unit (CNRS / Claude Bernard Lyon 1 University) confirmed these tracks were the longest in the world. Between 2010 and 2012, researchers from the Laboratoire de Géologie de Lyon supervised digs at the site, a meadow covering three hectares. Their work unearthed many more dinosaur footprints and trackways. It turns out the prints found in 2009 are part of a 110-step trackway that extends over 155 m — a world record for sauropods, which were the largest of the dinosaurs.

Dating of the limestone layers reveals that the trackway was formed 150 million years ago, during the Early Tithonian Age of the Jurassic Period. At that time, the Plagne site lay on a vast carbonate platform bathed in a warm, shallow sea. The presence of large dinosaurs indicates the region must have been studded with many islands that offered enough vegetation to sustain the animals. Land bridges emerged when the sea level lowered, connecting the islands and allowing the giant vertebrates to migrate from dry land in the Rhenish Massif.

Additional excavations conducted as late as 2015 enabled closer study of the tracks. Those left by the sauropod’s feet span 94 to 103 cm and the total length can reach up to 3 meters when including the mud ring displaced by each step. The footprints reveal five elliptical toe marks, while the handprints are characterized by five circular finger marks arranged in an arc. Biometric analyses suggest the dinosaur was at least 35 m long, weighted between 35 and 40 t, had an average stride of 2.80 m, and traveled at a speed of 4 km/h. It has been assigned to a new ichnospecies1: Brontopodus plagnensis. Other dinosaur trackways can be found at the Plagne site, including a series of 18 tracks extending over 38 m, left by a carnivore of the ichnogenus Megalosauripus. The researchers have since covered these tracks to protect them from the elements. But many more remain to be found and studied in Plagne.

1 The prefix ichno- indicates that a taxon (e.g., a genus or species) has been defined on the basis of tracks or other marks left behind, rather than anatomical remains like bones.

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Big carnivorous dinosaur discovery in Lesotho


This 25 October 2017 video says about itself:

A dinosaur as big as a bus roamed southern Africa 200 million years ago, scientists have revealed thanks to the discovery of several huge three-toed footprints.

From the University of Manchester in England:

‘Mega-carnivore’ dinosaur roamed southern Africa 200 million years ago

October 25, 2017

An international team of scientists has discovered the first evidence that a huge carnivorous dinosaur roamed southern Africa 200 million year ago.

The team, which includes researchers from The University of Manchester, University of Cape Town, South Africa, and Universidade de São Paulo, Brazil, have found several three-toed footprints measuring 57cm long and 50cm wide.

This means the dinosaur would have an estimated body length of around nine metres (30 feet) and be a little less than three metres tall at the hip. That’s four times the size of a lion, which is currently the largest carnivore in southern Africa.

The footprints belong to a new species, named Kayentapus ambrokholohali, which is part of the group of dinosaurs called “megatheropod.” The term “Megatheropods” describes the giant two-legged carnivorous dinosaurs, such as the iconic Tyrannosaurus rex (T. rex) which fossil evidence shows was around 12 metres long.

This study, which is published in PLOS ONE, also reveals that these footprints make up the largest theropod tracks in Africa.

The tracks were found on an ancient land surface, known as a palaeosurface, in the Maseru District of Lesotho, a small country in southern Africa. The surface is covered in 200 million years old ‘current-ripple marks’ and ‘desiccation cracks’ which are signs of a prehistoric watering hole or river bank.

Dr Fabien Knoll, Senior Research Fellow at The University of Manchester, said: ‘The latest discovery is very exciting and sheds new light on the kind of carnivore that roamed what is now southern Africa.

‘That’s because it is the first evidence of an extremely large meat-eating animal roaming a landscape otherwise dominated by a variety of herbivorous, omnivorous and much smaller carnivorous dinosaurs. It really would have been top of the food chain.’

What makes the discovery even more important is that these footprints date back to the Early Jurassic epoch, when it was thought the size of most theropod dinosaurs was considerably smaller. On average they were previously thought to be around three to five metres in body length, with some records showing they may have reached seven metres at the very most. It is only much later in the Jurassic and during the Cretaceous, which starts 145 million years ago, that truly large forms of theropods, such as T. rex, appear in body and trace fossil records.

Dr Lara Sciscio, postdoctoral Research Fellow at the University of Cape Town, said: ‘This discovery marks the first occurrence of very large carnivorous dinosaurs in the Early Jurassic of southern Gondwana — the prehistoric continent which would later break up and become Africa and other landmasses. This makes it a significant find. Globally, these large tracks are very rare. There is only one other known site similar in age and sized tracks, which is in Poland.’

The ancient surface where these footprints were found is also covered with the tracks of much smaller theropod dinosaurs.

Dr Knoll added: ‘In South Africa, Lesotho, Zimbabwe and Namibia, there is good record of theropod footprints from the Late Triassic and Early Jurassic epochs. In fact, there are numerous palaeosurfaces where footprints and even tail and body impressions of these, and other animals, can be found. But now we have evidence this region of Africa was also home to a mega-carnivore.’

T. rex’s silly-looking arms were built for slashing. Robust bones and bearlike claws suggest the dino’s ridiculously small limbs were far from useless. By Carolyn Gramling. 3:30pm, October 25, 2017.

First Jurassic ichthyosaur discovery in India


This video about ichthyosaurs is called Sea Reptile Birth – Walking with Dinosaurs in HQ – BBC.

From PLOS ONE:

First Jurassic ichthyosaur fossil found in India

The fish-like reptile was over five-meter long, likely ate ammonites and other crunchy prey

October 25, 2017

A new near-complete fossilized skeleton is thought to represent the first Jurassic ichthyosaur found in India, according to a study published October 25, 2017 in the open-access journal PLOS ONE by Guntupalli Prasad from the University of Delhi, India, and colleagues.

Ichthyosaurs, literally ‘fish lizards’ in Greek, were large marine reptiles which lived alongside dinosaurs in the Mesozoic Era. While many ichthyosaur fossils have been found in North American and Europe, in the Southern Hemisphere, their fossil record has mostly been limited to South America and Australia.

Now, the authors of the present study report what they believe to be the first Jurassic ichthyosaur found in India, from the Kachchh area in Gujarat. The near-complete skeleton, nearly 5.5m long, is thought to belong to the Ophthalmosauridae family, which likely lived between around 165 and 90 million years ago. It was found among fossils of ammonites and squid-like belemnites, and its tooth wear patterns suggest it predated such hard, abrasive animals.

While the authors have not yet been able to pinpoint the ichthyosaur‘s species, they believe that a full identification could inform on possible ophthalmosaurid dispersal between India and South America. They hope that unearthing more Jurassic vertebrates in this region could provide further insights into the evolution of marine reptiles in this part of the globe.

Lead author Guntupalli Prasad notes: “This is a remarkable discovery not only because it is the first Jurassic ichthyosaur record from India, but also it throws light on the evolution and diversity of ichthyosaurs in the Indo-Madagascan region of the former Gondwanaland and India’s biological connectivity with other continents in the Jurassic.”

New ichthyosaur species discovery in England


This video from Britain says about itself:

10 October 2017

A new species of a marine [reptile] has been discovered from a fossil which has been stored in the University of Nottingham’s engineering collection for more than 50 years. The fossil was of a type of ichthyosaur, a [group of] sea-dwelling animals which grew to up to 16 metres in length and survived until around 90 million years ago.

It has today been announced as Protoichthyosaurus applebyi, a holotype, or original specimen that describes a new species. It is the first known fossil of its kind anywhere in the world. The specimen has previously been used for teaching and outreach work while visiting primary schools to encourage children to explore science and engineering by Dr David Large, a geologist and Head of the Department of Chemical and Environmental Engineering at the university. The fossil was a hit with children but was forgotten about for years, and until recently had been sitting on a shelf in a storeroom.

Dean Lomax, a palaeontologist and Visiting Scientist at The University of Manchester, contacted Dr Large in 2014 while searching for another ichthyosaur fossil, and was unaware that the newlyfound specimen even existed as it had not been scientifically examined before. Eventually it was determined that this specimen is of a species new to science.

It has been hailed as a major step in uncovering Britain’s early fossil past and understanding ichthyosaur evolution. He said “This ichthyosaur is an essential part of Nottingham’s scientific collection and I’d like to thank David for bringing it to my attention. As part of our study we have identified over 20 specimens of Protoichthyosaurus, but only one example of P. applebyi, making this the only known specimen recorded so far. I’m confident that there will be more out there.”

From the University of Manchester in England:

‘Fake fin’ discovery reveals new ichthyosaur species

October 10, 2017

An ichthyosaur first discovered in the 1970s but then dismissed and consigned to museum storerooms across the country has been re-examined and found to be a new species.

In 1979, after inspecting several ichthyosaurs from the UK, palaeontologist Dr Robert Appleby announced a new type of ichthyosaur called Protoichthyosaurus. He also named two species, P. prostaxalis and P. prosostealis. Other scientists, however, dismissed the discovery of Protoichthyosaurus and suggested that it was identical with Ichthyosaurus, a very common UK ichthyosaur.

Now a detailed study led by palaeontologists Dean Lomax (The University of Manchester) and Professor Judy Massare (State University of New York), has re-examined and compared Protoichthyosaurus and Ichthyosaurus. It found major differences in the number of bones in the front fin, or forefin, of both species. This fundamental difference probably reflects the way both species used them to manoeuvre whilst swimming. Differences were also found in the skulls. But it was another discovery about the fins that also got the team’s attention.

Lomax explains: “This unusual forefin structure was originally identified by Robert Appleby in 1979, but some of the historic specimens he examined had been ‘faked’, and this fakery had been missed until now. In some instances, an isolated fin of an Ichthyosaurus had been added to a Protoichthyosaurus skeleton to make it appear more complete, which led to the genuine differences being missed. This has been a major problem because it stopped science from progressing. We also found some pathological fins, including Ichthyosaurus fins with pathologies that mimic the Protoichthyosaurus forefin structure.”

Lomax and Massare also teamed up with former undergraduate student Rashmi Mistry (University of Reading), who had been studying an unusual ichthyosaur in the collections of the Cole Museum of Zoology, University of Reading, for her undergraduate dissertation.

“Whilst doing my dissertation in 2016, I studied several ichthyosaurs in the collections, including a very small skeleton. It had an unusual forefin that matched Protoichthyosaurus, which I understood to be a widely unrecognised genus. However, when I contacted Dean, he was very excited. He told me that this little skeleton is the only known small juvenile Protoichthyosaurus,” added Rashmi.

Over 20 specimens of Protoichthyosaurus were identified as part of this study. This is significant as each specimen (with a forefin) has the same structure. The specimens are from the Jurassic Period, between 200 — 190 million years old, and come from Somerset, Dorset, Leicestershire, Warwickshire, Nottinghamshire, England, and Glamorgan, Wales.

Whilst searching through collections, Dean also came across a skeleton at The University of Nottingham. This specimen is different to all other known examples of Protoichthyosaurus in the skull and humerus and it has been identified as a new species, which the team have called Protoichthyosaurus applebyi, in honour of Robert Appleby. It is currently on display as part of the ‘Dinosaurs of China’ exhibition at Lakeside Arts, University of Nottingham.

Big Jurassic crocodile discovery in Britain


This video says about itself:

2 October 2017

British waters are reassuringly free of deadly reptiles today – but 163 million years ago a sea crocodile dubbed the ‘Melksham monster’ lurked on our shores.

Scientists have established that the 10-foot long creature, named after the town in Wiltshire where its fossil was unearthed, lived in the warm, shallow seas that covered much of what is now Europe.

The heavily damaged fossil had been sitting in the archives of London’s Natural History Museum since 1875.

Its identification reveals that an extinct group of aquatic reptiles evolved millions of years earlier than was previously thought.

The creature’s powerful jaws and large, serrated teeth allowed it to feed on large prey including prehistoric squid, and it was one of the most fearsome predators of its day.

Modern crocodiles are largely found in tropical regions of Africa, Asia, the Americas and Australia. Their ancient ancestor is named Ieldraan melkshamensis after the Wiltshire town of Melksham where it was found preserved in clay.

Its name also means ‘older one’ because it was thought until now that the sub-family of prehistoric crocodiles to which it belongs – known as Geosaurini – originated in the Late Jurassic period, between 152 and 157 million years ago.

In fact, the latest discovery – together with detailed re-analysis of existing fossil evidence – suggests the group arose millions of years earlier, in the Middle Jurassic.

It was identified as a new species based on distinctive features of its skull, lower jaw and, in particular, its teeth.

Dr Steve Brusatte, of the University of Edinburgh’s School of GeoSciences, who was involved in the study, said: ‘The Melksham Monster would have been one of the top predators in the oceans of Jurassic Britain, at the same time that dinosaurs were thundering across the land.’

From the University of Edinburgh in Scotland:

Monstrous crocodile fossil points to early rise of ancient reptiles

October 2, 2017

A newly identified prehistoric marine predator has shed light on the origins of the distant relatives of modern crocodiles.

The discovery reveals that an extinct group of aquatic reptiles evolved millions of years earlier than was previously thought, researchers say.

Palaeontologists at the University of Edinburgh discovered the new species — which dates back 163 million years — by studying a heavily damaged fossil which was held in the Natural History Museum‘s archives for almost 150 years.

The ancient reptile — called Ieldraan melkshamensis — has been nicknamed the Melksham Monster after the town in England where it was unearthed.

Until now, it was thought that the sub-family of prehistoric crocodiles to which the new species belongs — known as Geosaurini — originated in the Late Jurassic period, between 152 and 157 million years ago.

However, the latest discovery — together with detailed re-analysis of existing fossil evidence — suggests that the group arose millions of years earlier, in the Middle Jurassic, the team says.

The little-studied specimen — acquired by the museum in 1875 — was identified as a new species based on distinctive features of its skull, lower jaw and, in particular, its teeth.

The study, published in the Journal of Systematic Palaeontology, was carried out in collaboration with the Natural History Museum, London. The research was funded by Marie Sklodowska-Curie Actions.

Davide Foffa, a PhD student in the University of Edinburgh’s School of GeoSciences, who led the study, said: “It’s not the prettiest fossil in the world, but the Melksham Monster tells us a very important story about the evolution of these ancient crocodiles and how they became the apex predators in their ecosystem. Without the amazing preparation work done by our collaborators at the Natural History Museum, it would not have been possible to work out the anatomy of this challenging specimen.”

Mark Graham, Senior Fossil Preparator at the Natural History Museum, said: “The specimen was completely enclosed in a super-hard rock nodule with veins of calcite running through, which had formed around it during the process of fossilisation. This unyielding matrix had to be removed by force, using carbon steel tipped chisels and grinding wheels encrusted with industrial diamonds. The work took many hours over a period of weeks, and great care had to be taken to avoid damaging the skull and teeth as they became exposed. This was one tough old croc in life and death!”

What baby ichthyosaurs ate


This video is called Sea Reptile Birth – Walking with Dinosaurs in HQ – BBC.

By Helen Thompson, 2:00am, October 3, 2017:

A baby ichthyosaur’s last meal revealed

As far as last meals go, squid isn’t a bad choice. Cephalopod remains appear to dominate the stomach contents of a newly analyzed ichthyosaur fossil from nearly 200 million years ago.

The ancient marine reptiles once roamed Jurassic seas and commonly pop up in England’s fossil-rich coast near Lyme Regis. But a lot of ichthyosaur museum specimens lack records of where they came from, making their age difficult to place.

Dean Lomax of the University of Manchester and his colleagues reexamined one such fossil. Based on its skull, they identified the creature as a newborn Ichthyosaurus communis. Microfossils of shrimp and amoeba species around the ichthyosaur put the specimen at 199 to 196 million years old, the researchers estimate.

Tiny hook structures stand out in the newborn’s ribs — most likely the remnants of prehistoric black squid arms. Another baby ichthyosaur fossil that lived more recently had a stomach full of fish scales. So the new find suggests a shift in the menu for young ichthyosaurs at some point in their evolutionary history, the researchers write October 3 in Historical Biology.

See also here. And here.

Dinosaur discovery in Chile, missing link?


This video says about itself:

4 September 2015

“Chilesaurus” is an extinct genus of herbivorous theropod dinosaur. The genus is monotypic, represented by the type species “Chilesaurus diegosuarezi“. “Chilesaurus” lived approximately 145 million years ago in the Late Jurassic period of Chile.

Fossils of “Chilesaurus”, a vertebra and a rib, were first discovered on 4 February 2004 by the seven-year-old Diego Suárez who, together with his parents, geologists Manuel Suárez and Rita de la Cruz, was searching for decorative stones in the Aysén Region. More specimens were present that in 2008 were reported as representing several dinosaurian species. Only later was it realised that these belonged to a single species with a bizarre combination of traits.

In 2015, the type species “Chilesaurus diegosuarezi” was named and described by Fernando Emilio Novas, Leonardo Salgado, Manuel Suárez, Federico Lisandro Agnolín, Martín Dário Ezcurra, Nicolás Chimento, Rita de la Cruz, Marcelo Pablo Isasi, Alexander Omar Vargas and David Rubilar-Rogers. The generic name refers to Chile. The specific name honours Diego Suárez.

The holotype, “SNGM-1935”, was found in a layer of the Toqui Formation dating from the late Tithonian. It consists of an articulated rather complete skeleton with skull of a juvenile individual, lacking the feet and most of the tail. Four other partial skeletons and several single bones are the paratypes. They represent juvenile and adult individuals.

“Chilesaurus” measures 3.2 m from nose to tail. The holotype is a smaller individual of half that length.

That was in 2015. But now …

From Biology Letters:

A dinosaur missing-link? Chilesaurus and the early evolution of ornithischian dinosaurs

Matthew G. Baron, Paul M. Barrett

16 August 2017

Abstract

The enigmatic dinosaur taxon Chilesaurus diegosuarezi was originally described as a tetanuran theropod, but this species possesses a highly unusual combination of features that could provide evidence of alternative phylogenetic positions within the clade.

In order to test the relationships of Chilesaurus, we added it to a new dataset of early dinosaurs and other dinosauromorphs. Our analyses recover Chilesaurus in a novel position, as the earliest diverging member of Ornithischia, rather than a tetanuran theropod. The basal position of Chilesaurus within the clade and its suite of anatomical characters suggest that it might represent a ‘transitional’ taxon, bridging the morphological gap between Theropoda and Ornithischia, thereby offering potential insights into the earliest stages of ornithischian evolution, which were previously obscure. For example, our results suggest that pubic retroversion occurred prior to some of the craniodental and postcranial modifications that previously diagnosed the clade (e.g. the presence of a predentary bone and ossified tendons).

1. Introduction

Chilesaurus diegosuarezi is from the Late Jurassic (Tithonian; ca 150 Ma) Toqui Formation of Chile and possesses a bizarre suite of anatomical features that, if considered individually, are usually thought to characterize distantly related dinosaur clades.