Geology - Part 5

26 02, 2021

Concentrated Levels of Iridium Found at Chicxulub Impact Site

By Mike|2024-05-19T12:06:38+01:00February 26th, 2021|Adobe CS5, Dinosaur Fans, Geology, Main Page, Palaeontological articles|0 Comments

High levels of the rare Earth element iridium have been found in drill cores taken from the peak-ring sequence of the Chicxulub impact site located on the Yucatan peninsula (Mexico). This evidence further supports the theory that the extra-terrestrial space object that smashed into our planet some 66 million years ago is linked to the Cretaceous-Palaeogene (K-Pg) mass extinction event.

*The day that everything changed. Scientists have found more evidence linking the Chicxulub impact event to the K-Pg mass extinction.*

Picture credit: Map from Nature Geoscience / illustration courtesy of NASA

In 2016, IODP-ICDP* Expedition 364 drilled into the Chicxulub crater’s peak ring, an irregular ring of hills that surrounds the crater’s centre bringing around 835 metres of rock to the surface for detailed laboratory analysis.

* IODP (International Ocean Discovery Program) and the ICDP (International Continental Scientific Drilling Program).

The Chicxulub Impact Site

Iridium is extremely rare on Earth. However, a spike in levels has been recorded at numerous sites around the world that represent deposits laid down around 66 million years ago. The researchers state that the iridium levels found in the drill cores are four times more concentrated than elsewhere. The scientists found iridium levels were highest across the transition into early Paleogene sediments (Danian faunal stage).

Geophysical Map of the Chicxulub Impact Crater — *A geophysical map of the impact crater and the Chicxulub crater peaks from which the drill cores were taken.*

Picture credit: NASA

A Vapourised Bolide

Writing in the academic journal “Science Advances” the researchers conclude that this evidence combined with the spike in worldwide iridium deposits at the time of the mass extinction event, constitutes indisputable evidence that the suspected dinosaur-killing bolide that created the Chicxulub crater was indeed the culprit.

Commenting on the significance of this research, co-author Professor Joanna Morgan (Imperial College London) stated:

“This asteroid was vaporised and ejected from the impact site at high speed. Iridium, and other asteroidal material, then circled the Earth above the stratosphere within a fast-moving dust cloud and may have taken up to two decades to settle through the atmosphere and ocean before being deposited at the impact site.”

Lead author of the study, Professor Steven Goderis of the Free University of Brussels-VUB added:

“It’s quite remarkable that we found concentrations this high within the impact structure itself. In the first hours to months after the impact, the crater was a highly turbulent environment affected by tsunamis and earthquakes. Luckily, the iridium layer was preserved. This unquestionably ties the formation of the crater to the mass extinction event that marked the end of the Cretaceous and confirms that the asteroid impact and dinosaur extinction are indisputably linked.”

Identifying the K-T Boundary (Iridium Clay Layer) — Identifying concentrations of the rare Earth element iridium in a clay layer. At various locations around the world geologists have identified an iridium rich clay layer that marks the end of the Cretaceous and the beginning of the Palaeogene (K-T boundary).

Picture credit: The Open University/Everything Dinosaur

Everything Dinosaur acknowledges the contribution of a media release from Imperial College London in the compilation of this article.

To read a related article looking at how palaeontologists interpret fossil evidence of a global impact event: Quarry Site Might Reveal Evidence of Cretaceous Mass Extinction Event.

The scientific paper: “Globally distributed iridium layer preserved within the Chicxulub impact structure” by Steven Goderis, Honami Sato, Ludovic Ferrière, Birger Schmitz, David Burney, Pim Kaskes, Johan Vellekoop, Axel Wittmann, Toni Schulz, Stepan M. Chernonozhkin, Philippe Claeys, Sietze J. de Graaff, Thomas Déhais, Niels J. de Winter, Mikael Elfman, Jean-Guillaume Feignon, Akira Ishikawa, Christian Koeberl, Per Kristiansson, Clive R. Neal, Jeremy D. Owens, Martin Schmieder, Matthias Sinnesael, Frank Vanhaecke, Stijn J. M. Van Malderen, Timothy J. Bralower, Sean P. S. Gulick, David A. Kring, Christopher M. Lowery, Joanna V. Morgan, Jan Smit, Michael T. Whalen and the IODP-ICDP Expedition 364 Scientists published in Science Advances.

Visit the Everything Dinosaur website: Everything Dinosaur.

28 12, 2020

Favourite and Popular Blog Posts of 2020 (Part 2)

By Mike|2024-01-02T06:54:20+00:00December 28th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos, Photos/Pictures of Fossils, Press Releases|0 Comments

Favourite Blog Posts of 2020 (Part 2)

Everything Dinosaur team members conclude their review of their favourite blog articles of 2020 by looking at articles and news stories that were posted up between July and December. With the best part of 180 posts to choose from selecting our favourite six for this period was quite tricky. The ones we have selected demonstrate the broad range of topics we cover on the Everything Dinosaur weblog.

To view our earlier article about our favourite posts in the first half of the year: Favourite Blog Posts of 2020 (Part 1).

July – “Lizard Born of Fire”

We might have been in the middle of a global pandemic but Everything Dinosaur team members kept up their blogging reporting upon tiny theropod eggs from Japan, a revision of Dilophosaurus and a number of new dinosaurs. Our favourite post of the month concerned the scientific description of Aratasaurus museunacionali, a basal member of the Coelurosauria from Brazil. The genus name translates as “lizard born of fire”, a reference to the terrible fire that ripped through the National Museum of Brazil where the fossil specimen was kept.

A Life Reconstruction of the Basal Member of the Coelurosauria Aratasaurus museunacionali

Aratasaurus museonacionali illustration.

Aratasaurus museonacionali life reconstruction.

Picture credit: Museu Nacional

To read more about A. museunacionali: Aratasaurus museunacionali A Lizard Born of Fire.

August – Oculudentavis khaungraae Not a Stem Bird

The controversy over the naming of the smallest dinosaur based on a skull preserved in amber from northern Myanmar rumbled on. In August, a paper was published that refuted claims that the tiny skull of the animal named Oculudentavis khaungraae was that of an archosaur. A month earlier (July 2020), the original scientific paper describing this remarkable fossil was retracted.

The Tiny Fossil Skull Preserved in Amber from Myanmar – But is it a Dinosaur?

Oculudentavis khaungraae skull in amber.

Tiny fossil skull preserved in amber (Oculudentavis khaungraae).

Picture credit: Lida Xing et al (Nature)

To read more about O. khaungraae: Smallest Dinosaur Preserved in Amber a Lizard.

September: Doctor Who Meets a Trilobite

The Oxford University Museum of Natural History celebrated its 160th birthday, the Monsters of the Deep exhibition opened in the midst of the chaos caused by COVID-19 and Euparkeria got a makeover. Our favourite post of September concerned a new species of trilobite (Gravicalymene bakeri) from Tasmanian that was named after Doctor Who actor Tom Baker.

A Photograph of a Gravicalymene bakeri Trilobite Fossil with Line Drawing

Gravicalymene bakeri trilobite fossil with line drawing.

Picture credit: Australian Museum

To read more about “Doctor Who and the Trilobites”: Newly Described Species of Trilobite Named after Doctor Who Actor.

October – It’s a Dog’s Life

In October we reported on the mapping of the genome of the Scimitar-toothed cat Homotherium latidens, discussed a new species of mosasaur from Morocco and the diet of pterosaurs, but our favourite article concerned the research into ancient dog DNA. The study suggested that the diversity observed between dogs in different parts of the world today originated when all of mankind were hunters and gatherers.

Mapping Ancient Doggy DNA

Mesolithic dog skull (left) compared to wolf skull (right).

Picture credit: E. E. Antipina (Institute of Archaeology of the Russian Academy of Sciences)

To read the article: DNA Study Highlights Ancient Relationship Between Humans and Dogs.

November – Dinosaurs from the Emerald Isle

In November, Everything Dinosaur celebrated publishing its 5,000 blog post, discussed Kholumolumo a dinosaur from an African rubbish dump, looked at seal evolution and got to grips with the earliest Paranthropus robustus skull described to date.

Our favourite post concerned the first dinosaur remains reported from Ireland, not just one dinosaur but two!

First Evidence of Dinosaurs from Ireland

Dr Mike Simms holds the two precious fossils.

Dr Mike Simms (National Museums Northern Ireland) holds the theropod tibia on the left and the thyreophoran femur on the right.

Picture credit: The University of Portsmouth

To learn more about the Irish dinosaurs: The First Dinosaur Remains from Ireland.

For dinosaur and prehistoric animal models: Dinosaur Figures and Prehistoric Animal Models.

December – Thalassodraco etchesi Swims into View

As the year closed, in the final month of 2020 we looked at how interactive “I-books” were helping to explain archaeology, examined a very flashy new dinosaur (U. jubatus), the first sauropod dinosaur from Switzerland (Amanzia greppini) and studied Parasaurolophus pathology.

Our favourite post concerned the establishment of a new species of Late Jurassic ichthyosaur after the discovery of fossil bones by the wonderful Dr Steve Etches MBE, the founder of the amazing Etches Collection museum in Dorset.

A Life Reconstruction of the Newly Described Thalassodraco etchesi

Thalassodraco etchesi life reconstruction.

A life reconstruction of the newly described Late Jurassic ichthyosaur Thalassodraco etchesi.

Picture credit: Megan Jacobs/University of Portsmouth

To read more about Thalassodraco etchesi: A New Taxon of Late Jurassic Ichthyosaur is Described.

This concludes our review of the blog posts that we have researched and written up over the last twelve months. Which one is your favourite?

Hopefully, this is your favourite dinosaur website: Everything Dinosaur.

27 12, 2020

Favourite and Popular Blog Posts of 2020 (Part 1)

By Mike|2024-01-02T06:54:49+00:00December 27th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos, Photos/Pictures of Fossils, Press Releases|0 Comments

Favourite Blog Posts of 2020 (Part 1)

At Everything Dinosaur, we try and post up an article on this blog site every single day. This can be quite a challenge considering all our other activities and projects. However, as a result of our work on this weblog we have managed to compile a huge amount of information, articles and features chronicling (for the most part), advances in the Earth sciences and new fossil discoveries along with research into the Dinosauria.

This year, Everything Dinosaur’s blog has passed the 5,000 articles benchmark. Here is a selection of our own favourite news stories that we have covered in the first six months of 2020 (January to June).

January – A New Allosaurus Taxon

In January, a new species of North American Allosaurus was added to the pantheon of dinosaurs known from the famous Morrison Formation of the western United States. Allosaurus jimmadseni honours the sadly departed James H. Madsen Jr. Utah’s inaugural state palaeontologist. The famous Allosaurus specimen MOR 693 “Big Al” was reassigned to this new species.

A Pack of Allosaurus (A. jimmadseni) Attack a Luckless Juvenile Sauropod

Allosaurus jimmadseni a new Allosaurus taxon is described.

A pack of allosaurs (A. jimmadseni) attacking a juvenile sauropod.

Picture credit: Todd Marshall

The January Allosaurus article: A New Species of Allosaurus.

February – The “Father of Argentinian Palaeontology” – José Bonaparte

On the 18th February José Bonaparte, regarded by many as the most influential vertebrate palaeontologist of the 20th century passed away. Respected and admired, José helped to develop and train a whole new generation of Earth scientists. He was also responsible for naming and describing a large number of new dinosaurs including Abelisaurus, hence our illustration of that South American theropod (below).

José Bonaparte and a Drawing of One of the Many Dinosaurs He Named and Described (Abelisaurus comahuensis)

Lamenting the death of José Bonaparte (February 2020).

José Bonaparte (inset) and a drawing of one of the dinosaurs he named in his long and distinguished career Abelisaurus (A. comahuensis).

Picture credit: Télam/Everything Dinosaur

To read more about José Bonaparte: José Bonaparte – The Founding Father of Palaeontology in Argentina.

March – Telling the Time Back in the Cretaceous

As the COVID-19 pandemic took hold, team members at Everything Dinosaur were distracted by some remarkable research undertaken by scientists from the University of Ghent and the Vrije Universiteit Brussel.

A study of the growth rings preserved on the fossilised shells of Cretaceous bivalves permitted the researchers to calculate that 70 million years ago, the day length was approximately thirty minutes shorter and a year on Earth was around a week longer than it is today.

To read this article: Telling the Time Back in the Cretaceous.

April – Homo erectus at Home in Africa

The remarkable Drimolen fossil hominin site in South Africa, provided palaeoanthropologists with likely confirmation that the hominin H. erectus did indeed evolve in Africa and not Asia. A carefully and painstakingly reconstructed fossil skull (DNH 134), found in this area – regarded as the “Cradle of Humankind”, suggests that Homo erectus existed some 100,000 to 200,000 years earlier than previously realised.

We still have a lot to learn about our own evolution.

Homo erectus Evolved in Africa

The partial H. erectus cranium from the Drimolen Fossil Hominin site.

Picture credit: La Trobe University (Australia)

To learn more about the origins of Homo erectus: H. erectus Originated in Africa.

May – Lots of Pterosaurs

A jawbone found on the Isle of Wight was identified as a new species of tapejarid pterosaur. The flying reptile, named Wightia declivirostris which translates as “slanting beak from the Isle of Wight” was one of several new pterosaur species described in 2020.

A Life Reconstruction of the Early Cretaceous Pterosaur Wightia declivirostris

Wightia declivirostris from the Isle of Wight

A life reconstruction of the newly described tapejarid from the Lower Cretaceous of the Isle of Wight (Wightia declivirostris).

Picture credit: Megan Jacobs (University of Portsmouth)

To read more about Wightia declivirostris: A New Terrific Tapejarid.

We have a lot more to learn about the Pterosauria too.

For models and replicas of pterosaurs and other prehistoric animals: Wild Safari Prehistoric World Figures.

June – Fossilised Stick – Provides a Surprise

A fossil discovered more than fifty years ago and regarded as little more than a “fossilised stick” has proved to be a new species of Late Devonian plant and it will help scientists to better understand the flora of the ancient landmass of Gondwana.

The specimen was found by amateur geologist John Irving whilst exploring the banks of the Manilla River in Barraba (New South Wales, Australia). A study in the open-access journal PeerJ identifies the newly named Keraphyton mawsoniae and proposes that it has a similar structure to primitive horsetails and ferns. The fossil which looks so unremarkable on the outside, once studied in cross-section, has provided a unique window into the plant life on Earth around 360 million years ago.

Not Much to Look at on the Outside but Inside a Treasure Trove of Information for Palaeobotanists

The newly described Keraphyton mawsoniae a fern-like land plant from the Late Devonian of Australia.

Picture credit: Champreux et al (PeerJ)

To read more about K. mawsoniae: Fossil Stick Proves to be New Species of Ancient Plant.

This selection represents some of our favourite blog posts from the first six months of 2020, which one is your favourite post?

We will conclude this review of the news stories we have covered on this blog in part 2.

In the meantime, visit the Everything Dinosaur website: Everything Dinosaur.

1 12, 2020

The First Sauropod from Switzerland

By Mike|2023-10-30T13:36:02+00:00December 1st, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Amanzia greppini – The First Sauropod Described From Switzerland

Badly distorted and disarticulated dinosaur bones found in the 1860s in north-western Switzerland have led to the establishment of a new genus of European sauropod. Amanzia greppini, described from an assortment of fragmentary fossil material, representing four individuals is the first sauropod to be described from fossil remains found in Switzerland. The fossils come from Upper Jurassic strata which form part of the Reuchenette Formation, they were discovered in a limestone quarry in the Basse Montagne, near the city of Moutier.

Limb Bones of Amazia greppini from the Late Jurassic of Switzerland

Forelimb bones associated with Amanzia greppini and interpretative drawings. Right humerus in (a) posterior and (b) anterior view with line drawings showing preserved cartilage outlined in grey. Left radius in (c) anterior and (d) posterior view. Left ulna in anterior view (e) and posterior view (f). Right ulna in anterior view (g) and anterior view (h). Views of an ungual phalanx. Note scale bar = 5 cm.

Picture credit: Schwarz et al (Swiss Journal of Geosciences)

The bones had been sold to a private collector, but the Swiss geologist Jean-Baptiste Greppin was notified of the find and identified the assortment of distorted and crushed bones as the remains of dinosaurs. In the early 20th century these remains were associated with the English sauropod Cetiosauriscus stewarti known from fossils found in Cambridgeshire. However, an extensive review of the Swiss fossil material conducted by Daniela Schwarz (Museum für Naturkunde, Berlin) and co-workers resulted in a new genus being erected earlier this year.

Kimmeridgian versus Callovian

The researchers who re-visited the Swiss sauropod remains identified a number of unique autapomorphies (distinctive traits) to distinguish their fossils from those of C. stewarti. In addition, the Swiss dinosaur was much smaller, with an estimated maximum length of around ten metres compared to the proposed fifteen metres for Cetiosauriscus. The scientists, which included Philip Mannion (University College London), Oliver Wings (University Halle-Wittenberg in Germany) and Christian Meyer (University of Basel), found differences in the caudal vertebrae (tail bones) as well as difference in the shape and proportions of the femur, humerus and coracoid.

A discrepancy in the geological age between C. stewarti and the Swiss fossil material was also noted. Fossils of Cetiosauriscus stewarti come from strata associated with the Callovian faunal of the Middle Jurassic, whilst the fossils of Amanzia greppini come from geologically younger deposits laid down during the Kimmeridgian faunal stage (Late Jurassic).

Skeletal Reconstruction of Amanzia greppini and Size Comparison with the Geologically Older Cetiosauriscus stewarti

Amanzia skeletal drawing and size comparison with Cetiosauriscus stewarti. — Skeletal reconstruction of A. greppini. Known fossil elements shown in blue. As much information is missing from the incomplete skeletal material, the dorsal vertebrae, the proportions and morphology of the cervical vertebrae and the skull were modified from Camarasaurus. Scaled silhouette drawings (b) of Cetiosauriscus stewarti (in black) and A. greppini (in grey) demonstrating the significant size difference between the two taxa. Note scale bar = 1 metre.

Picture credit: Schwarz et al (Swiss Journal of Geosciences)

Honouring a Famous Swiss Scientist

The genus is named in honour of the well-known Swiss geologist Amanz Gressly (1814–1865) who introduced the term “facies” to describe rock types with different characteristics and discovered the first dinosaur fossil from Switzerland in 1856. The trivial or specific name pays tribute to Jean-Baptiste Greppin, who was the first person to identify the jumbled remains from the quarry as coming from a member of the Dinosauria.

In addition, to the sauropod bones, a single, worn tooth from a sauropod was discovered. This tooth (specimen number NMB M.H. 451), has been assigned to A. greppini. Bones from an ancient marine crocodylomorph and a broken theropod tooth were also found in association with the sauropod remains. Based on the matrix material and the study of ostracod fossils found at the quarry, the scientists concluded that the carcass of Amanzia, was buried in a shallow, temporary lake close to the sea.

Middle and Posterior Caudal Vertebrae with Accompanying Line Drawing (A. greppini)

Middle and posterior caudal vertebrae of A. greppini. — Middle and posterior caudal vertebrae of A. greppini with interpretative line drawing. Note scale bar = 5 cm. Differences in the length : height ratios between these bones and those tail bones associated with Cetiosauriscus stewarti helped to identify the Swiss fossil material as that of a new genus.

Picture credit: Schwarz et al (Swiss Journal of Geosciences)

More European Sauropods to Come

When this research was published in the Swiss Journal of Geosciences earlier this year (February 2020), the researchers concluded that the first Swiss sauropod taxon helped to demonstrate the diversity of the sauropods known from the Late Jurassic of Europe. The exact placement of Amanzia greppini within the Sauropoda remains controversial, the authors speculated that it might be a sister taxon to the Neosauropoda or a member of the Turiasauria, a geographically and temporally widespread group of sauropods with a number of European genera such as Cardiodon, Losillasaurus, Zby and Turiasaurus.

They concluded that more fossil discoveries and the reassessment of sauropod fossils held in museum collections would lead to the naming of many more European sauropod genera.

The scientific paper: “Re-description of the sauropod dinosaur Amanzia (“Ornithopsis/Cetiosauriscus”) greppini n. gen. and other vertebrate remains from the Kimmeridgian (Late Jurassic) Reuchenette Formation of Moutier, Switzerland” by Daniela Schwarz, Philip D. Mannion, Oliver Wings and Christian A. Meyer published in the Swiss Journal of Geosciences.

Visit the award-winning Everything Dinosaur website: Everything Dinosaur.

17 09, 2020

New Research Published on the Carnian Pluvial Episode – Late Triassic Mass Extinction

By Mike|2024-03-15T16:52:17+00:00September 17th, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles|0 Comments

Getting to Grips with a Mass Extinction Event – Carnian Pluvial Episode

The fossil record of the Phanerozoic (the Eon of visible life), indicates that there were five major mass extinction events. The fossil record marks huge and very rapid (at least in geological terms anyway), reductions in the diversity of life on a world-wide scale. Our planet might well be going through a mass extinction event at the moment, but for one team of scientists their attention has been on the Late Triassic (Carnian faunal stage), plotting a time of extensive terrestrial and marine faunal turnover.

Examining the Impact of the Carnian Pluvial Episode

The researchers, which include scientists from Bristol University, the University of Ferrara (Italy), the University of Vienna and the China University of Geosciences in Wuhan Province, conclude that around 233 million years ago about a third of all marine genera disappeared.

Terrestrial Fauna in the Late Triassic – Did a Major Extinction Event Help to Trigger the Rise of the Dinosaurs

Late Triassic terrestrial fauna. — *Life in the Late Triassic, an explosion in dinosaur diversity. Did the Crocodylomorpha and the Dinosauria benefit from the Late Triassic Carnian Pluvial Episode?*

Picture credit: Davide Bonadonna

Many types of land-living animal did no better. The herbivorous rhynchosaurs and dicynodonts were greatly reduced in diversity during the Carnian, but intriguingly crocodylomorphs and those other archosaurs, the Dinosauria seem to have benefitted from the extinction of other types of tetrapod, with both the Crocodylomorpha and dinosaurs diversifying towards the end of the Carnian. The scientists postulate that the rise of the dinosaurs to dominance might have been a direct consequence of the Carnian Pluvial Episode (CPE).

To read an earlier blog article that links the CPE with dinosaur diversification: Out with a Bang! In with a Bang! The story of the Dinosauria.

A Time of Immense Global Environmental Change

The Carnian Pluvial Episode took place from around 234 to 232 million years ago. There was a marked rise in rainfall (at least four episodes of increased rainfall have been deduced from sedimentary and palaeontological data). The Earth got warmer and more humid. This led to extensive environmental changes and the subsequent demise and then collapse of many ecological systems.

Writing in the academic journal “Science Advances”, the scientists throw their collective weight behind the theory that enormous volcanic eruptions in the Wrangellia Province of western Canada, that resulted in the deposition of vast amounts of basalt, were probably the cause of the global environmental changes.

Co-author of the paper Jacopo Dal Corso (China University of Geosciences), explained:

“The eruptions peaked in the Carnian. I was studying the geochemical signature of the eruptions a few years ago and identified some massive effects on the atmosphere worldwide. The eruptions were so huge, they pumped vast amounts of greenhouse gases like carbon dioxide and there were spikes of global warming”.

This warming resulted in the increased humidity and higher levels of rainfall, a phenomenon first detected by geologists Mike Simms and Alastair Ruffell in the 1980s. The climate change caused major biodiversity loss in the ocean and on land, but just after the extinction event new groups took over, forming more modern-like ecosystems.

Environmental and Geochemical Changes of the CPE

Environmental and geochemical changes associated with the Carnian Pluvial Event. — (A) Calculating the age of the CPE based on geochemical indicators and (B) Palaeogeography during the Carnian, the map showing where sedimentary and palaeontological data has been obtained documenting changes in environmental conditions.

Picture credit: Jacopo Dal Corso et al/Science Advances

A Provide Effect on Planet Earth

The environmental changes had a profound effect on life on our planet. As well as a diversification of the dinosaurs, many other modern groups of animals and plants appeared at this time, including lizards and the first mammals. When mapping the losses of marine fauna at the genus level, the team concluded that whilst the CPE was not as devastating as the either the end-Triassic or end-Cretaceous extinction events, some 33% of all marine genera died out.

A Comparison of Marine Faunal Turnover During Major Extinction Events

Plotting marine extinctions and faunal turnover over the Carnian Pluvial Event. — *(A) Comparison of extinction rates of all marine genera during the CPE with those of major Phanerozoic mass extinction events.*

Picture credit: Jacopo Dal Corso et al/Science Advances

The Effect on Plant Life

The shifts in climate encouraged substantial changes in global flora too. Many new types of plants emerged that were more suited to the humid climate. Several modern fern families emerged and the Bennettitales (cycad-like plants), diversified. Extensive coal deposits formed once again, the first substantial coal seams being produced since the Permian. Conifers seem to have benefitted and the researchers, which include Professor Mike Benton (Bristol University), remark that the CPE provides the first major finds of amber in the fossil record. As tree resin is usually produced when plants are under stress, this suggests that terrestrial ecosystems were in a state of flux during this period in Earth’s history.

Professor Benton stated:

“The new floras probably provided slim pickings for the surviving herbivorous reptiles. I had noted a floral switch and ecological catastrophe among the herbivores back in 1983 when I completed my PhD. We now know that dinosaurs originated some 20 million years before this event, but they remained quite rare and unimportant until the Carnian Pluvial Episode hit. It was the sudden arid conditions after the humid episode that gave dinosaurs their chance.”

Terrestrial Extinctions and Originations During the Carnian (Late Triassic)

Mapping the major biological changes amongst plants, insects and vertebrates during the Carnian. — Plotting the major biological changes amongst plants, insects and vertebrates during the Carnian. Trackmaker assemblages from the Southern Alps suggest a faunal turnover within the Archosauria with the dinosaurs replacing the crocodylomorphs as a significant component of terrestrial ecosystems.

Picture credit: Jacopo Dal Corso et al/Science Advances

The Impact of the Carnian Pluvial Episode

The researchers conclude that the CPE may not have been as significant as the big five Phanerozoic mass extinctions but it did have a dramatic impact on terrestrial and marine environments and helped to bring in a variety of new types of plants and animals, marking an important step towards the origins of the types of ecosystems we see around us today.

The scientific paper: “Extinction and dawn of the modern world in the Carnian (Late Triassic)” by Jacopo Dal Corso et al published in Science Advances.

The Everything Dinosaur website: Everything Dinosaur.

9 09, 2020

What was Panthalassa? Helping Customers with their Queries

By Mike|2024-03-14T17:02:38+00:00September 9th, 2020|Dinosaur Fans, Educational Activities, Geology, Main Page|0 Comments

What was Panthalassa? Where was it?

At Everything Dinosaur, we get lots of enquiries and questions emailed to us. For example, we recently received an query about Panthalassa, the sender had heard the name but was not sure what this referred to, other than that it had something to do with ancient life. Panthalassa is the name of the huge, super-ocean that was created with the convergence of the world’s landmasses into a single block, known as Pangaea (sometimes also referred to as Pangea).

The Panthalassa Ocean

Panthalassa was formed in the Late Palaeozoic Era it persisted for much of the Mesozoic. It was sub-divided in the Late Triassic into Pacific and Atlantic regions as the geological process of rifting led to the formation of the Atlantic Ocean Basin.

A Map Showing the Approximate Location of Pangaea and the Surrounding Panthalassa Ocean (circa 200 mya)

The super-ocean Panthalassa. — *The location of the super-ocean Panthalassa around 200 million years ago.* *Picture credit: Everything Dinosaur.*

Picture credit: Everything Dinosaur

An Enormous Body of Water

The Panthalassa Ocean at its largest size covered more than 70% of the entire planet’s surface. The term “Panthalassa” is derived from the Greek and means “all sea”. This enormous body of water was so vast, that if you had observed our planet from certain viewpoints in outer space, no trace of any land on planet “Earth” could be observed.

A spokesperson from Everything Dinosaur commented:

” We get contacted by all sorts of people asking all kinds of questions, students at university, pupils at school, parents contacting us on behalf of a curious child who has asked a question which they themselves have been unable to answer and we do our best to respond to all the queries that we receive. It might take a while for our team members to reply, but we do genuinely, try to help as many people as we can.”

Hopefully, the information we provided on Panthalassa will permit smooth sailing for the emailer when it comes to looking at prehistoric oceans from now on.

The Everything Dinosaur website: Everything Dinosaur.

31 08, 2020

Hunting Ammonites A Wonderful Fossil Collecting Trip

By Mike|2024-03-14T09:21:22+00:00August 31st, 2020|Educational Activities, Geology, Photos, Photos/Pictures of Fossils|0 Comments

Hunting Ammonites

For a few hours team members at Everything Dinosaur were able to take a break from their duties and to visit the Yorkshire coast on a hunt for ammonites and other fossil remains. It was an early start to take advantage of collecting on a low tide and to make the best of the fine weather that had been forecast. For many fossil hunters, the hunt is almost as rewarding as the finds. With all the problems with travel at the moment due to the COVID-19 pandemic, it made a pleasant change to be able to participate in a fossil hunting expedition, albeit only for a few hours.

The Spectacular and Very Beautiful Yorkshire Coast

A trip to the coast to collect fossils. — A visit to the North Yorkshire coast on fossil collecting expedition. The beginning of the day, fine weather is forecast and the early start permitted the team to collect fossils on a falling tide. Picture credit: Everything Dinosaur,

Picture credit: Everything Dinosaur

Avoiding the Cliffs Whilst Fossil Hunting

The recent heavy rains had saturated the cliffs, making the risk of rockfalls even greater. During the team’s visit to the beach, several small rockfalls were observed, however, team members stayed away from the cliffs and were content to scour the foreshore looking for fossils. As this location on the North Yorkshire coast is a SSSI (site of special scientific interest), hammering rocks out of the cliffs is not permitted. There were plenty of ammonites to see, including quite large ones, preserved at numerous locations at beach level.

Large Ammonite Fossils Could be Observed on the Beach

Fossil ammonite (geological hammer provides scale). — *Large ammonites preserved on the beach. The geology hammer provides a scale.*

Picture credit: Everything Dinosaur

The cliffs at this location are very dangerous and there is a steep and hazardous descent to the beach from the cliff top, this location is not for the faint hearted and not suitable for family groups.

Searching for Fossils on the Foreshore – Some Interesting Finds

Fossil hunting on the foreshore. — *A Dactylioceras ammonite negative exposed in a broken “cannonball” and some brachiopod pieces collected from the foreshore.*

Picture credit: Everything Dinosaur

The Everything Dinosaur website: Everything Dinosaur.

Lower Jurassic Fossils

The strata dates from the Lower Jurassic and there were plenty of small fragments of ammonites to collect in addition to the occasional gryphaea fossil along with various bivalves and brachiopods. Some of the large specimens were kept as when we visit schools or conduct outreach science activities, we like to give away fossils to help provide resources to the teaching team and to encourage young people to take up fossil collecting as a hobby.

An Ammonite Fossil Found on the Beach

An ammonite fossil find. — *An ammonite partially eroded out of a nodule. We think this is an example of Dactylioceras commune.* *A wonderful discovery whilst fossil hunting.*

Picture credit: Everything Dinosaur

An Ammonite Model

When we visited schools we liked to take an ammonite model with us as well as ammonite fossils. The model helped the children to understand what the creature looked like in real life.

A Model of an Ammonite

CollectA Pleuroceras ammonite model. — *CollectA Age of Dinosaurs Popular Size Pleuroceras ammonite model.*

The picture (above) shows a CollectA ammonite figure. To view this range of prehistoric animal models: CollectA Prehistoric Life Figures.

26 08, 2020

Stegosaurus Fossil Bone Found on Scottish Island

By Mike|2024-03-13T17:04:41+00:00August 26th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Confirmation of Scottish Stegosaurs

The Jurassic-aged strata found on the coastline of the Isle of Skye in Scotland’s Inner Hebrides is recognised as one of the most globally significant locations in the world for dinosaur fossils from the Middle Jurassic. Recently, the fossil sites on Skye received greater legal protection: Legal Protection for Isle of Skye Fossil Locations. The vertebrate body and trace fossils confirm the presence of a rich biota of different dinosaurs and early mammals. Footprints on Skye had hinted at the presence of stegosaurs in Scotland. It is ironic therefore, that further evidence for the existence of armoured dinosaurs in the Middle Jurassic of Scotland has not come from Skye but from its island neighbour, the Isle of Eigg that lies to the south.

Stegosaur Limb Bone Found on a Beach on the Isle of Eigg

Stegosaur limb bone found on Scottish beach. — *The stegosaur limb bone exposed on the beach (Isle of Eigg).*

Picture credit: Dr Elsa Panciroli (National Museums Scotland)

A Stegosaurus Fossil Bone – A Serendipitous Discovery

The contemporaneous Jurassic strata that outcrops on the small island of Eigg, it covers an area of just 30² kilometres (11² miles), has been well explored. It is renowned for its fossils of marine fauna including ammonites, prehistoric sharks and marine reptiles. This is the first time that a dinosaur bone has been found on the Isle of Eigg. The 166 million-year-old limb bone (Bathonian faunal stage of the Jurassic), was discovered by chance by Dr Elsa Panciroli (National Museums Scotland).

Dr Panciroli explained:

“I was running along the shore on my way back to meet the rest of the team and I ran right over it. It wasn’t clear exactly what kind of animal it belonged to at the time, but there was no doubt it was a dinosaur bone.”

The bone is highly eroded, it having been exposed on the face of a boulder for some time, it measures a little over fifty centimetres in length. It represents a bone from the hind limb.

The Stegosaurus Fossil Bone Specimen Removed from the Boulder

Eroded stegosaur limb bone. — *The eroded stegosaur limb bone is now in the collection of the National Museums of Scotland.*

Picture credit: N. Larkin

A Hugely Significant Find

The scientists comment that this single fossil bone represents a “hugely significant find”, albeit one found fortuitously thanks to a sharp-eyed field team member. Dinosaur fossils from the Middle Jurassic are particularly rare and this fossil has a global significance for palaeontologists.

Palaeontologist Dr Steve Brusatte (University of Edinburgh), who has co-authored a paper on the fossil bone stated:

“This fossil is additional evidence that plate-backed stegosaurs used to roam Scotland, which corroborates footprints from the Isle of Skye that we identified as being made by a stegosaur”.

The bone now resides in the collections of National Museums Scotland (Edinburgh), the fieldwork on the Isle of Eigg was funded by the National Geographic Society with the permission of The Isle of Eigg Heritage Trust.

A paper on the fossil specimen will be published in the Earth And Environmental Transactions Of The Royal Society Of Edinburgh.

Mesozoic Strata Associated with Skye, Eigg and Rùm (Inner Hebrides)

Mesozoic strata on the Isle of Skye and the Isle of Eigg. — *The Isle of Eigg in relation to the Isle of Skye (Inner Hebrides), the location of Mesozoic-aged strata is highlighted in dark green.*

Picture credit: Google Maps with additional annotation by Everything Dinosaur

The British Isles and Stegosaurs

The oldest fossils of a stegosaur described to date, also come from the British Isles, but from a location very much to the south and east of the Inner Hebrides. The coast of North Yorkshire, notably the Saltwick Formation has yielded at least two stegosaur tracks, attributed to the ichnospecies Deltapodus brodricki. These are the oldest fossils attributed to a stegosaur known to science (we think). The Saltwick Formation was laid down around 175-171 million years ago (Aalenian faunal stage of the Middle Jurassic) and are therefore at least five million years older than the stegosaur body and trace fossils associated with the Inner Hebrides.

Natural Casts of Stegosaur Tracks (Deltapodus brodricki) from the North Yorkshire Coast

Stegosaur tracks (north Yorkshire coast). — *Natural casts of stegosaur tracks Deltapodus brodricki from the Aalenian aged Saltwick Formation.*

Picture credit: Martin Whyte and Mike Romano

Isle Skye Middle Jurassic Fossils: Isle of Skye Steps into the Jurassic Spotlight.

The Everything Dinosaur website: Everything Dinosaur.

23 08, 2020

Dramatic Rock Fall Reveals Ancient Fossilised Trackways in Arizona

By Mike|2024-03-13T16:34:53+00:00August 23rd, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Two Ancient Trackways Discovered in Arizona

A fortuitous rock fall on the Bright Angel Trail in the Grand Canyon National Park (Arizona), has revealed two ancient trace fossils that have been interpreted as the trackways created by small vertebrates as they climbed a steep sand dune. The sandstone blocks containing the fossilised trackways from the Manakacha Formation, a sub-unit of the extensive Supai Group, are the subject of a scientific paper published in the academic, on-line, open-access journal PLOS One.

Estimated to be around 313 million years old (Moscovian Age of the Pennsylvanian Epoch – Late Carboniferous), the fossilised trackways are thought to have been made by either basal diapsid reptile or a basal synapsid and are the first tetrapod tracks reported from the Manakacha Formation and the oldest known from the Grand Canyon region.

An Artist’s Reconstruction of the Tetrapod Ascending the Sand Dune

Basal amniote moves up a sand dune. — *Crossing a sand dune. A life reconstruction of a basal amniote moving diagonally up a dune creating a trackway similar to the one described in the scientific paper.*

Picture credit: Emily Waldman

Ascending Sand Dunes

The rocks in this region are aeolian sandstones and the discovery of the two trackways document the earliest known occurrence of dunefield-dwelling amniotes. Lead author of the scientific paper, Steve Rowland (professor emeritus of geology at the University of Nevada), commented that these fossils demonstrate that by the Late Carboniferous, the first vertebrates capable of laying eggs out of water had adapted to desert habitats.

The Main Trackway, Line Drawing, Site of Rock Fall and Counterpart Slab

Trackway evidence at the Grand Canyon. — Main trackway block adjacent to Bright Angel Trail (Grand Canyon), with tracks in concave epirelief (impressions) at (A). Scale is calibrated in decimeters. Sketch of main trackway surface (B). Note occurrence of Trackway 2 (alignments of small black spots) above Trackway 1. The rocks (C) next to the Bright Angel Trail, including at least two rocks with amniote tracks. Counterpart block (D) with tracks in convex hyporelief (natural casts).

Picture credit: Rowland et al (PLOS One)

Side-stepping Ascent of a Steep Dune Revealed by Fossilised Trackways

The rock fall occurred close to a popular hiking trail and they were first spotted during a geology field trip to the Grand Canyon in 2016. The leader of that trip, professor Allan Krill sent a photograph of the tracks to the Department of Geology at the University of Nevada and Professor Rowland decided to investigate further. The tracks have been interpreted as showing the ascent of a dune slope at an angle of approximately 20 degrees, thus reducing the steepness of the climb.

The second trackway, a series of small rounded depressions in the rock suggest claw marks. It has been postulated that these marks are a deeper undertrackway, made some hours or days after the first track was produced, possibly by an animal of the same species as the first trackmaker.

Line Drawing of Main Trackway (1) with a Plotted Three-dimensional Track Interpretation

Line drawing of main trackway surface and coloured digital elevation model. — Studying the fossilised trackways. *Sketch of main trackway surface (A). Detail of a portion of the trackway, with scale (B). Coloured digital elevation model with explanation of colours (C). Contour interval is 1 cm.*

Picture credit: Rowland et al (PLOS One)

The scientists conclude that to traverse over the steep slope the little animal was moving, laterally one step at a time so that it always had its three other legs to support its body and to grip the surface. The transition across the dune may not have been particularly elegant but the 28 impressions that have been preserved may help to shed further light on the evolution of early amniotes, which are scarce in the Carboniferous/Early Permian fossil record of North America.

A Controversial Interpretation

Not everyone is convinced of the interpretation of the fossils by the research team which included Mario Caputo (Society for Sedimentary Geology) and Zachary Jensen (College of Southern Nevada).

A spokesperson representing the palaeontology programme at the Grand Canyon commented that there was a lot of disagreement amongst the scientific community when it came to interpreting fossil tracks and inferring animal behaviours from them. During the Late Carboniferous, this part of Arizona was a coastal-plain on the western edge of the super-continent of Pangaea. There were extensive dunefields in close proximity, the dunes being formed by the action of the wind (aeolian), occasionally exceptional tidal conditions, storms or other flooding events interrupted the aeolian deposition burying parts of the dunefield in fine mud.

The scientific paper: “Early adaptation to eolian sand dunes by basal amniotes is documented in two Pennsylvanian Grand Canyon trackways” by Stephen M. Rowland, Mario V. Caputo and Zachary A. Jensen published in the open-access, on-line journal PLOS One.

The Everything Dinosaur website: Everything Dinosaur.

12 08, 2020

Vectaerovenator inopinatus – “Unexpected Air Filled Hunter”

By Mike|2024-03-12T14:45:38+00:00August 12th, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Photos/Pictures of Fossils|0 Comments

Vectaerovenator inopinatus – “Unexpected Air Filled Hunter from the Isle of Wight”

This week has seen the announcement of the discovery of four fossil bones from the foreshore near Knock Cliff, south of the town of Shanklin on the Isle of Wight that led to the naming of a new species of carnivorous dinosaur. The new theropod has been named Vectaerovenator inopinatus (pronounced: Vec-tare-row-ve-nay-tor in-op-pin-ar-tus). Most of the media outlets that have covered this story have focused on the dedicated people who found the fossils and the research team responsible for describing them. The fossils were found over a period of several weeks in 2019 in three separate discoveries, two by individuals and one by a family group, who all handed in their finds to the nearby Dinosaur Isle Museum (Sandown).

The Carcass of Vectaerovenator inopinatus Floats Out to Sea

The Vectaerovenator inopinatus floats out to sea. — *Vectaerovenator inopinatus – carcass floating out to sea. The fossil bones come from the marine Ferruginous Sandstone Formation of the Lower Greensand Group.*

Picture credit: Trudie Wilson

A Vital Contribution to the Earth Sciences

The contribution from amateur fossil hunters cannot be underestimated, such enthusiastic and knowledgeable fossil hunters continue to make a hugely significant contribution to the Earth sciences. The fossil material, consisting of four vertebrae (one cervical, two dorsal and one caudal), are, with the exception of some isolated teeth, the youngest non-avian theropod remains reported from Mesozoic strata from the British Isles.

The fossils come from the Aptian (Early Cretaceous), Ferruginous Sandstone Formation of the Lower Greensand Group and as these are marine deposits, it is likely that the carcass was washed out to sea and floated for some time before eventually settling on the seabed. Most Early Cretaceous dinosaur fossil material known from the British Isles come from the Wealden Group or the older Purbeck Limestone Group.

Exposures of the generally younger Ferruginous Sandstone Formation can be found in Dorset as well as the southern part of the Isle of Wight. These sediments were laid down during a period of rising sea levels. The rising seas engulfed the lower lying coastal swamps, floodplains and deltas that had been home to many different types of dinosaur. Dinosaur fossils are exceptionally rare in these strata. For example, a single, isolated theropod tooth found at Punfield Cove, Dorset represents the very first record of a dinosaur from the Lower Greensand of Dorset.

As the four fossil bones ascribed to V. inopinatus are consistent in size and have the same adhering matrix, it is very likely the all four bones came from a single, individual dinosaur.

Silhouette of Vectaerovenator inopinatus with the Fossil Bones in Approximate Life Position

Vectaerovenator inopinatus silhouette showing placement of fossil bones. — *A silhouette of V. inopinatus showing the placement of the four fossil bones. Although the material was collected on separate occasions, it is thought that they all come from a single skeleton.*

Picture credit: Darren Naish

Vectaerovenator inopinatus – One of the Few Valid British Greensand Taxa

What fossils that are associated with the Lower Greensand Group, are often highly fragmentary, substantially eroded and often the result of re-deposition from older strata. The four vertebrae represent the youngest non-avian theropod remains reported from the British Mesozoic. Described as a mid-sized tetanuran, the Vectaerovenator specimen is estimated to represent a four-metre-long animal, one that roamed Europe approximately 115 million years ago. It is the first diagnosable theropod taxon to be named from Aptian deposits associated with Europe.

“Unexpected Air-filled Hunter from the Isle of Wight”

The scientific name translates as unexpected, air-filled hunter from the Isle of Wight. The neck and back bones are chambered (camerate) and full of air pockets (highly pneumatic). These are adaptations to help lighten the skeleton and extensions to the lungs, part of an extremely efficient respiratory system seen today in living birds.

The shape of the cervical vertebra, along with the evidence of highly pneumatised bones indicate that Vectaerovenator was a member of the Tetanurae, a clade of theropod dinosaurs defined as all theropods more closely related to birds than they are to the genus Ceratosaurus. As such, this is by far the largest clade of theropods known, it includes the tyrannosaurs, Maniraptora, megalosaurs, allosaurs, ornithomimosaurs and the Aves. It is not possible to classify these bones any further, down to the family or the genus name for example.

Formal Scientific Paper Expected Soon

The formal scientific paper is expected to be published next month in the journal Papers in Palaeontology.

The continuing transgression of the sea led to much of the land in this region becoming fully submerged. Deposition from deltas stopped, land-derived sediments to this part of the world ceased and for millions of years the only material to accumulate on the seabed were the microscopic remains of eukaryotic phytoplankton (coccolithophoroids). Many coccolithophorids are covered in overlapping scales made of calcium carbonate. Their remains formed the beautiful white cliffs, (which gave the Isle of Wight its name) and formed the stunning white cliffs associated with the coast of south-eastern England and elsewhere in Europe.

Everything Dinosaur acknowledges the assistance of a media release from the University of Southampton in the compilation of this article.

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