All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
//April
6 04, 2019

Book Celebrates “Golden Age of Dinosaurs”

By | April 6th, 2019|Book Reviews, Dinosaur Fans, Main Page|0 Comments

The Dinosaurs Rediscovered

The official press release to accompany the recently published “The Dinosaurs Rediscovered” by Professor Michael Benton (University of Bristol), states that we are “living in a golden age of dinosaur science“.  With so many new dinosaurs being named and described, the last one we blogged about was the small, Australian Ornithischian dinosaur Galleonosaurus dorisae, named just a few weeks ago, it is hard to disagree.

To read about Galleonosaurus: New Australian Ornithopod Described

The Front Cover of the Recently Published “The Dinosaurs Rediscovered”

"The Dinosaurs Rediscovered".

The jacket cover of the new book about dinosaurs “The Dinosaurs Rediscovered”.

Picture Credit: Thames and Hudson

The Press Release

The official press release states that over the past twenty years, the study of dinosaurs has changed from natural history to a true scientific discipline.  The utilisation of advanced technologies has revolutionised the study of prehistoric animals and life in the past.  This book, written by eminent palaeontologist Professor Mike Benton, combines first-hand accounts and anecdotes from a lifetime of fossil collecting with an updated review of Dinosauria research.

To read Everything Dinosaur’s review of the book: The Dinosaurs Rediscovered – a brief review

The press release goes on to state that “The Dinosaurs Rediscovered” presents all the latest palaeontological evidence which has transformed the study of dinosaurs.  Team members were asked the other day to select our favourite chapter.  This was not an easy task as all the chapters are beautifully compiled, but when pressed, we opted for chapter 9.  Chapter 9 outlines the reasons for the mass extinction event and explains in terms that the general reader can easily follow, the research into the Chicxulub impact crater.  This chapter also informs the reader that the extra-terrestrial bolide crashed into Earth probably in June – how can scientists make such an assertion; we suggest you read the book to find out!

Tale of the Tape

Title: “The Dinosaurs Rediscovered”

Author: Michael J. Benton

Publication: April 2019

Pages/Extent: 336

Illustrations: 163

Size: 23. 4 centimetres by 15.3 centimetres

ISBN: 978 0 500 052006

Published by: Thames & Hudson.

For further information visit the website of the publisherThe Dinosaurs Rediscovered can be found here

5 04, 2019

Four-Legged Whale Ancestor from the Eocene of Peru

By | April 5th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Peregocetus pacificus – The Travelling Whale that Reached the Pacific

A team of international researchers including scientists from Peru, France, Belgium, Italy and Holland have announced the discovery of an ancient four-legged whale from Peru.  The fossil discovery suggests that early whales crossed the South Atlantic more than 42.6 million years ago (Lutetian faunal stage of the Eocene).  The fossil material comes from the Playa Media Luna, in Peru’s desert-like Pisco Basin.  It is the oldest fossil of a whale found to date in the New World.

A Life Reconstruction of the Newly Described Early Cetacean – Peregocetus pacificus

Peregocetus pacificus life reconstruction.

Life reconstruction Peregocetus pacificus.  Note: the tail fluke is speculative.

Picture Credit: A Gennari/Royal Belgian Institute of Natural Sciences

In 2011, an international team of palaeontologists excavated a well-preserved skeleton of a four-legged whale ancestor.  Writing in the academic journal, “Current Biology”, the scientists conclude that P. pacificus illustrates a key phase in the evolution and dispersal of early whales.  It represents the first record of an amphibious whale for the whole Pacific Ocean and its discovery supports the hypothesis for an early dispersal of primitive cetaceans to the New World across the South Atlantic.

Field Team Members Working on a Block of Fossil Bones

Peregocetus pacificus fossil excavation.

Field team members working on a block of bones (Peregocetus pacificus).

Picture Credit: Christian de Muizon (Natural History Museum – Paris)

A Quadruped with a Powerful Tail to Assist with Swimming

The first whales are believed to have evolved around fifty million years ago, from terrestrial, hoofed, quadrupeds such as Indohyus from Kashmir.  To read an article about Indohyus: Deer-like Fossil Confuses Whale Evolution.  The discovery of  Peregocetus pacificus will help to fill in some of the gaps in the fossil record of early members of the Cetacea.  Dr Olivier Lambert of the Royal Belgian Institute of Natural Sciences and a co-author of the scientific paper stated:

“This is the most complete specimen ever found for a four-legged whale outside of India and Pakistan.”

A View of a Fossilised Rib of Peregocetus pacificus

Peregocetus pacificus rib bone (in situ).

Peregocetus pacificus rib bone partially excavated at the dig site.

Picture Credit: G. Bianucci (University of Pisa)

The Oldest Four-Legged Whale of the New World

Peregocetus combines terrestrial locomotion abilities and use of the tail for swimming, although the presence of a partial tail fluke as seen in the above illustration is speculative.  Measuring between 3.4 to 4 metres in length, it probably resembled a large otter and like extant otters, it most likely hunted in the water and preyed on fish.  The scientific name translates as “the travelling whale that reached the Pacific Ocean”, a reflection of this being the oldest New World whale fossil discovered to date.  Although, not a complete skeleton, the fossil material represents the most complete skeleton of a four-legged whale outside India and Pakistan.

Olivier Lambert added:

“The animal could carry its own weight and crawl about on land.  We can see this, among other things, because the pelvis is firmly attached to the sacrum and the front and hind legs are very similar to those of Peregocetus’s ancestors from India and Pakistan.  You can even see marks of small hooves on the toes and fingers.”

Line Drawings Illustrating the Known Skeletal Material of Peregocetus in Swimming and Terrestrial Positions

Peregocetus pacificus line drawings (swimming and on land).

Preserved parts of the skeleton showing proposed terrestrial and swimming positions.

Picture Credit: Olivier Lambert (Royal Belgian Institute of Natural Sciences)

The picture (above), shows schematic drawings of the skeleton of Peregocetus in a swimming (top) and a walking stance (bottom), showing the main preserved bones.  Stippled lines indicate reconstructed parts.

Like a Giant Otter

The researchers are confident that Peregocetus was an accomplished swimmer, perfectly at home in the water.  The last few tail bones (caudal vertebrae), have not been found, so it is not possible to state whether this early whale had a tail fluke, but Lambert observed:

“The anatomy of the first vertebrae of the tail resembles that of amphibious mammals such as otters and beavers.  So, we think the animal propelled itself through the water by wave-like movements of the posterior part of the body, including the tail, and by moving its large feet and long toes that were most likely webbed.”

Cranial and Postcranial Material (Peregocetus pacificus)

The lower jaw and postcranial fossil bones of Peregocetus pacificus.

Mandible and postcranial bones of Peregocetus pacificus.

Picture Credit: G. Bianucci (University of Pisa)

A Very Long Journey

The scientists suggest that the ancestors of Peregocetus crossed the Atlantic Ocean between North Africa and the northernmost portion of South America.  During the Eocene, the Atlantic Ocean was only half as wide as it is today and the prevailing surface currents from Africa to South America would have helped the ancestors of Peregocetus to reach the other side.  Once on the eastern coast of South America, the population gradually moved further northwards and populations were eventually established on the western (Peruvian) coast of South America.  Later, relatives of Peregocetus would spread further north, to the east coast of North America.

The Prepared Lower Jaw of P. pacificus

Peregocetus pacificus lower jaw.

The left mandible (lower jaw) of Peregocetus pacificus.

Picture Credit: Olivier Lambert (Royal Belgian Institute of Natural Sciences)

The Pisco Basin in Peru is proving to be hot-spot for whale fossils.  In 2017, the international team with Olivier Lambert found, 200 metres away from the spot where Peregocetus pacificus was excavated, a 36.4 million-year-old descendant of the basilosaurids, identified as the oldest known member of the mysticete group – Mystacodon selenensis.  Basilosaurids were fully aquatic and mainly used their tail fluke to propel themselves.  Their front limbs had evolved into paddles and the rear legs were much reduced and vestigial.

There are two main types of whale alive today.  Firstly, there is the Odontoceti (toothed whales), such as sperm whales, dolphins and porpoises.   Secondly, there is the Mysticeti, the baleen whales such as the blue, humpback and gray whale.

Everything Dinosaur acknowledges the assistance of a press release from the Royal Belgian Institute of Natural Sciences in the compilation of this article.

4 04, 2019

Spring Prehistoric Times Magazine (Issue 129)

By | April 4th, 2019|Dinosaur Fans, Magazine Reviews, Main Page|2 Comments

The Next Issue of Prehistoric Times Magazine is at the Printers

Spring is in the air, the frogspawn in our office pond has turned from black dots to commas and with the arrival of British Summer Time (BST), the days seem longer.  The next issue of “Prehistoric Times” magazine must be coming out soon and sure enough we received an email from the editor informing us that issue 129 (spring 2019), is at the printers.  This issue will commemorate the publication of one of the most important and influential papers on the Dinosauria ever produced.  It is fifty years since John Ostrom’s seminal paper on Deinonychus antirrhopus appeared in the scientific literature.

The Front Cover of “Prehistoric Times” Magazine (Spring 2019)

Prehistoric Times magazine (spring 2019).

Prehistoric Times magazine (issue 129).

Picture Credit: Mike Fredericks

Bulletin of the Peabody Museum

The front cover features a stunning illustration of D. antirrhopus.  Mike Fredericks (editor) wrote to us saying:

“The Deinonychus cover is by Kurt Miller, a super talented CG artist who did the Carnotaurus cover on issue #117.”

Inside the magazine, the excellent and most informative Phil Hore will discuss the anniversary of the ground-breaking paper.  Ostrom’s paper entitled “Osteology of Deinonychus antirrhopus, an unusual Theropod from the Lower Cretaceous of Montana”, was published in the Bulletin of the Peabody Museum of Natural History in July 1969.  The entire paper can be downloaded  (all 165 plus pages), as a pdf from the Museum’s archive.  It was this paper that defined Deinonychus as a fast-moving, agile predator and that demonstrated that birds evolved from members of the Dinosauria.

The 1969 paper features an illustration of Deinonychus, one that helped to redefine the way academics and the public view dinosaurs.  It was regarded as a “dinosaur renaissance”.

The Original “Dinosaur Renaissance”

The Dinosaur Renaissance - Deinonychus

The original “Dinosaur Renaissance” inspired by Bakker (Deinonychus).

Picture Credit: Robert T. Bakker (1969)

The Spring Issue of Prehistoric Times

The spring issue of “Prehistoric Times” includes an article on the enigmatic chalicotheres and it features the illustrations of the British artist and author Dougal Dixon.  The head of Edgar Rice Burroughs Inc, from Tarzana, California, writes an informative piece about Burroughs and the book that inspired numerous writers “The Land That Time Forgot”.   Philip J Currie returns for the second part of his feature on the dinosaurs of “The Land That Time Forgot” and Stephen Brusatte provides a review of the top palaeontology related news stories of the last twelve months.

The front cover of the magazine with its splendid Deinonychus artwork is certainly very eye-catching, as it that fuscia-coloured font.

Mike Fredericks confessed:

“A favourite magazine of mine as a kid, Famous Monsters of Filmland used neon colours like this pink for their cover login in the 1970’s and this logo is a bit of a tribute to it.”

We are looking forward to receiving our copy of “Prehistoric Times”, it should be with us very soon.

Want to subscribe to “Prehistoric Times”?   Click this link for more details: Subscribe to Prehistoric Times

3 04, 2019

How Big is the PNSO Ceratosaurus Dinosaur Model “Nick”?

By | April 3rd, 2019|Adobe CS5, Dinosaur Fans, Everything Dinosaur Products, Everything Dinosaur videos, Main Page, Photos of Everything Dinosaur Products, Product Reviews|0 Comments

How Big is the PNSO Ceratosaurus Dinosaur Model?

The new for 2019 PNSO Ceratosaurus dinosaur model “Nick” is certainly making waves amongst dinosaur fans and model collectors.  Staff at Everything Dinosaur are not sure why our chums at PNSO chose to call their Ceratosaurus figure “Nick”, but all of us have been very impressed with the quality and craftsmanship demonstrated in this exceptionally large dinosaur model.  How big is the PNSO Ceratosaurus?   We could get out one of our tape measures or geological rulers to show just how huge this model is, but, instead we have created a short video that compares the PNSO Ceratosaurus with the recently introduced CollectA Deluxe Ceratosaurus.  After all, a picture (or in this case a short video), is worth more than a thousand words, or so the saying goes.

The New for 2019 PNSO Ceratosaurus “Nick” Compared to the CollectA Deluxe Ceratosaurus Figure

Video Credit: Everything Dinosaur

Comparing the PNSO Ceratosaurus to the CollectA Deluxe Ceratosaurus

In this short video (it lasts a little over thirty seconds), we compare the PNSO Ceratosaurus dinosaur model with the CollectA Deluxe 1:40 scale Ceratosaurus, which itself is a sizeable dinosaur replica.  The CollectA Deluxe Ceratosaurus is a recently introduced model, it only came out last year.

To read about all the new for 2018 CollectA Deluxe prehistoric animal models: CollectA Deluxe Figures Introduced in 2018

However, the CollectA figure is dwarfed by the impressive and enormous PNSO Ceratosaurus.   The PNSO replica is one of the largest Theropod figures that we have ever stocked.

The PNSO Ceratosaurus Dinosaur Model “Nick”

The PNSO Ceratosaurus dinosaur model.

The PNSO Ceratosaurus dinosaur model “Nick”.

Picture Credit: Everything Dinosaur

Tale of the Tape – Ceratosaurus Dinosaur Models

The CollectA Deluxe Ceratosaurus is not a small dinosaur model by any means, but in our video, it looks tiny compared to the colossal PNSO Ceratosaurus.  For the statisticians amongst us here are the model measurements:

  • CollectA Ceratosaurus – length 27 cm approximately with a head height of 12 cm.
  • PNSO Ceratosaurus “Nick” – length around 58 cm approximately, with a head height of about 26 cm.

Remarkably, the base for the PNSO figure is around ten times the size of the base associated with the CollectA Deluxe Ceratosaurus.

Ceratosaurus But Which Species?

A number of species have been assigned to the Ceratosaurus genus and it is difficult to decide which species these replicas represent.  For example, do they represent C. nasicornis or perhaps C. dentisulcatus?  Whatever the species epithet, both these models are most impressive, but the PNSO Ceratosaurus is going to need a lot more shelf space.

In terms of calculating a scale for the PNSO model, this is challenging.  The maximum size for Ceratosaurus is unknown with estimated lengths ranging from about 4.5 metres to excess of 6 metres depending on the fossil specimen and the species.  If we take the upper figure (six metres) and we estimate the length of the PNSO Ceratosaurus to be about sixty centimetres, then, based on this crude assessment, the PNSO figure is in approximately 1:10 scale.

The CollectA Deluxe 1:40 Scale Ceratosaurus Compared to the PNSO Ceratosaurus Dinosaur Model

Comparing Ceratosaurus figures.

Comparing the PNSO Ceratosaurus dinosaur model with the CollectA Deluxe Ceratosaurus.

Picture Credit: Everything Dinosaur

To view the range of PNSO prehistoric animal figures available from Everything Dinosaur including “Nick” the Ceratosaurus: PNSO Age of Dinosaurs

To view the range of CollectA Deluxe prehistoric animal figures including the 1:40 scale Ceratosaurus: CollectA Deluxe Prehistoric Life

2 04, 2019

A New Species of Mastodon Hinding in Plain Sight

By | April 2nd, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Mammut pacificus – A Newly Recognised Species of Mastodon

A new species of the iconic North American Ice Age prehistoric elephant (Mastodon) has been recognised.  Writing in the academic journal PeerJ, scientists including researchers from the Western Science Centre, California State University, the U.S. Geological Survey and the Department of Earth and Environmental Sciences (Vanderbilt University), in collaboration with other institutions have named Mammut pacificus based on Californian fossil material and specimens from southern Idaho.  This is the first new North American Mastodon species to have been reported in fifty years, ironically, this new Ice Age giant was hiding in plain sight for several decades.

The Holotype Skull and Tusks (M. pacificus)

M. pacificus cranial fossil material and tusks (holotype).

Mammut pacificus cranial fossil material.  Cranium in: (A) dorsal, (B) ventral, (C) left lateral, (D) right lateral, (E) posterior, (F) distal end of left tusk (I1), lateral, and (G) right tusk (I1), lateral view.  Scale equals 10 cm.

Picture Credit: PeerJ/Western Science Centre

Diamond Valley Lake Fossil Finds

The Californian fossil material was excavated from the Diamond Valley Lake site in the 1990’s.  A huge reservoir was being constructed and during the building work in Riverside County, more than 700 Mastodon fossil bones, representing over 100 individuals were discovered.  In total, more than 100,000 skeletal fossils were unearthed during the reservoir project, providing palaeontologists with an insight into the Pleistocene fauna of the western United States.  This material, in conjunction with further Mastodon fossil finds from the construction of the Ziegler Reservoir in Snowmass Village (Colorado), have enabled scientists to build up a much bigger dataset of western North American Mastodon fossils.

For an article that outlines the fossil excavation work carried out during the Ziegler Reservoir project: North American Ice Age Fossil Finds

Concluding the Snowmass dig: Fossil Excavations at Snowmass Village Come to an End

With more Mastodon fossils to study, palaeontologists have been able to identify subtle differences in bone and tooth morphology that cannot be put down to individual variation within a species.

An Illustration of a Typical Mastodon (Scale Drawing of M. americanum)

Scale Drawing American Mastodon.

American Mastodon scale drawing – (Mammut americanum).

Picture Credit: Everything Dinosaur

Different from Mammut americanum

In the scientific paper, the scientists note a number of physical differences between their proposed new taxon and Mammut americanumM. pacificus is described as having more vertebrae within the pelvic region (six sacral vertebrae), a lack of any lower tusk in the jaw and a different shaped femur (thigh bone).  The mid-shaft diameter of the femur is proportionately greater in the Californian specimens.  In addition, the molars are smaller and narrower, even when ontogenetic characters are accounted for.

The Holotype Pelvis (M. pacificus)

Holotype pelvis of M. pacificus (dorsal view).

WSC 18743, M. pacificus holotype pelvis.  Pelvis in dorsal view.  Orthographic view of photogrammetric model.  Scale = 10 cm.

Picture Credit: PeerJ/Western Science Centre with additional annotation by Everything Dinosaur

The researchers claim that the cumulative evidence strongly points to the discovery of a new species.  Furthermore, all known Pleistocene Mammut remains from California are consistent with their diagnosis of M. pacificus.  This suggests that M. americanum was not present in California.  The Californian population may have been isolated from the rest of the Mastodon population for thousands of years, giving rise to a new species.

The scientific paper: “Mammut pacificus sp. nov.  A Newly Recognised Species of Mastodon from the Pleistocene of Western North America” by Alton C. Dooley Jr​, Eric Scott, Jeremy Green, Kathleen B. Springer, Brett S. Dooley and Gregory James Smith published in PeerJ.

2 04, 2019

Mei long – The Sleeping Dragon

By | April 2nd, 2019|General Teaching|Comments Off on Mei long – The Sleeping Dragon

Mei long – The Sleeping Chinese Dragon

The beautifully preserved fossils of a small, Chinese dinosaur have provided scientists with an insight into how some types of dinosaur might have slept.  Fossils of the little Chinese Theropod dinosaur known as Mei long reveal that it coiled up in a sleeping posture with its head tucked under its arm and its tail wrapped around its body.  This sleeping posture preserved in a number of M. long specimens is very similar to the sleeping postures of many living birds.

A Life Reconstruction of the Little Chinese Feathered Dinosaur Mei long

Did feathered dinosaurs preen their feathery coats?

A life reconstruction of the sleeping posture of the Chinese Theropod dinosaur Mei long.

The fossils of Mei long come from north-eastern China.  These unfortunate dinosaurs were buried by hot volcanic ash as they slept.  Their fossils have been preserved in three-dimensions, helping palaeontologists to learn more about the resting and sleeping postures of Theropod dinosaurs.

1 04, 2019

Amazing Fossils Depict End Cretaceous Mass Extinction Event

By | April 1st, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Fossil Discovery Offers Detailed View Minutes After Chicxulub Impact

A paper published in the PNAS (Proceedings of the National Academy of Sciences – USA), provides a detailed snapshot of a terrible natural disaster linked to the Chicxulub bolide impact event.  A site (Tanis), in North Dakota’s Upper Cretaceous Hell Creek Formation, records the devastation caused by a massive surge of water which occurred as seismic shockwaves reverberated around the Earth as a result of the huge extra-terrestrial impact in what is now the Gulf of Mexico.

Examining Rock Layers Looking for Evidence

Exploring sediments, looking for fossils.

Identifying the K-T boundary at the margins of  Upper Cretaceous sediments.

Picture Credit: Robert DePalma (University of Kansas)

A team of palaeontologists, including researchers from the University of Kansas, the Black Hills Institute and Manchester University, in collaboration with a number of other academic institutions report on what has been described as a “motherlode of exquisitely-preserved plant, animal and fish fossils”, the remains of a river ecosystem which flowed into the Western Interior Seaway, which was wrecked within minutes of the extra-terrestrial impact event.

The site is described as a “rapidly emplaced high-energy onshore surge deposit” along the KT boundary that contains associated ejecta and iridium impactite associated with the End Cretaceous extinction event that resulted in the loss of many groups of terrestrial vertebrates including the pterosaurs and the dinosaurs as well as the extinction of a wide variety of marine organisms.

Lead author of the scientific paper, Robert DePalma (University of Kansas), described the site as:

“A tangle mass of freshwater fish, terrestrial vertebrates, trees, branches, logs, marine ammonites and other marine creatures was all packed into this layer by the inland-directed surge”.

One of the Plaster Jackets from the Site Reveals the Devastation

The Tanis Konservat-Lagerstätte

The Tanis Konservat-Lagerstätte.  Plaster field jacket  (A) with partially prepared (freshwater) Acipenseriform fish next to a fragment from an ammonite shell (inset).

Picture Credit: PNAS

The doctoral student went onto add:

“Timing of the incoming ejecta spherules matched the calculated arrival times of seismic waves from the impact, suggesting that the impact could very well have triggered the surge.”

Devastation Occurred Within Minutes of the Impact

The researchers conclude that the fossil site does not record a tsunami.  Tanis is more than 2,000 miles from the bolide impact site in the Gulf of Mexico, a tsunami would have taken at least seventeen hours to reach North Dakota, but seismic waves and a subsequent water surge would have occurred within minutes of the collision.

DePalma and his colleagues describe the rushing wave that shattered the Tanis site as a “seiche.”

What is a Seiche?

A seiche (pronounced “saysh”), relates to a standing wave in an enclosed or part-enclosed body of water.  This term was first used widely by the Swiss scientist François-Alphonse Forel (1841-1912), who pioneered the study of inland water ecosystems.  It is believed the etymology derives from the Swiss/French dialect meaning “swaying back and forth”, a reference to observations of water level changes in alpine lakes.  This phenomenon can have many causes, but seismic activity is known to lead to water surges.

DePalma explained:

“As the 2011 Tohoku earthquake in Japan showed us, seismic shaking can cause surges far from the epicentre.  In the Tohoku example, surges were triggered nearly 5,000 miles away in Norway just 30 minutes after impact.  So, the KT impact could have caused similar surges in the right-sized bodies of water worldwide, giving the first rapid “bloody nose” to those areas before any other form of aftermath could have reached them.”

According to Kansas University researchers, even before the surge arrived, Acipenseriform fish (sturgeon) found at the site already had inhaled tiny spherules ejected from the Chicxulub impact.

Fish Fossils Show Evidence of Microtektites Embedded in Their Gills

Microtektites from the Chicxulub impact recorded in fossil fish.

Fish Fossils show evidence of microtektites embedded in their gills.

Picture Credit: PNAS

The picture above shows Acipenseriform fish with ejecta clustered in the gill region.  Image (A) an X-ray of a fossil sturgeon head (outlined, pointing left; FAU.DGS.ND.161.115.T).  Magnified image (B) of the X-ray in (A) showing numerous ejecta spherules clustered within the gill region (arrows).  Images C and D are micro-CT images of another fish specimen (paddlefish), with microtektites embedded between the gill rakers in the same fashion.

Co-author David Burnham (Kansas University) stated:

“The fish were buried quickly, but not so quickly they didn’t have time to breathe the ejecta that was raining down to the river.  These fish weren’t bottom feeders, they breathed these in while swimming in the water column.  We’re finding little pieces of ejecta in the gill rakers of these fish, the bony supports for the gills.  We don’t know if some were killed by breathing this ejecta, too.”

One of the co-authors of the paper is Californian geologist Walter Alvarez, who, along with is his father Luis, postulated the theory of an impact event playing a role in the End Cretaceous extinction (1980).  They identified a layer of sediment in the strata marking the Cretaceous/Palaeogene boundary (KPg), that was enriched with the rare Earth element iridium and they concluded that an extra-terrestrial object must have collided with the Earth.

The Approaching Bolide About to Strike Planet Earth

Asteroid strikes the Earth.

An extra-terrestrial impact event.  Moments before the impact event, now scientists have fossil evidence providing data on what happened minutes after the collision.

Picture Credit: Deposit Photos/Paul Paladin

Described as a Lagerstätte of the KT Event

The number and quality of preservation of the fossils at Tanis are such that Burnham dubs it the “lagerstätte” of the KT event.  A lagerstätte, comes from the German “storage place”, it describes a sedimentary deposit that contains a large number of very well preserved fossils.  For example, the Tanis site preserves numerous Acipenseriform fish, which are cartilaginous and not bony and therefore less likely to become fossils.

David Burnham added:

“The sedimentation happened so quickly everything is preserved in three dimensions, they’re not crushed.  It’s like an avalanche that collapses almost like a liquid, then sets like concrete.  They were killed pretty suddenly because of the violence of that water.  We have one fish that hit a tree and was broken in half.”

Indeed, the Tanis location contains many hundreds of articulated ancient fossil fish killed by the Chicxulub impact’s consequences and is remarkable for the biodiversity it reveals alone.

Mapping the Direction of the Surge and Examining the Fish Fossils

Carcasses orientated by flow and mass mortality deposit.

A site map (left) showing the flow of water indicated by the orientation of the material and a mass deposit of fish from the site.

Picture Credit: PNAS

Several New Species

The scientists conclude that there are likely to be several new species of fish named as a result of this discovery.  In addition, some specimens are the best known examples of their genus found to date.  It was quickly realised that the surrounding matrix was deposited by a sudden, violent rush of water, a surge that was directed inland away from the Western Interior Seaway.  Impact debris including shocked minerals and ejecta spherules were found in the sediment and a compact layer of KT boundary clay overlies the deposit.

Tanis provides a post impact “snapshot,” including ejecta accretion and faunal mass death, advancing our understanding of the immediate effects of the Chicxulub impact.

According to Burnham, this site will advance our understanding of the Chicxulub impact significantly, describing Tanis as “smoking-gun evidence” of the aftermath.

Everything Dinosaur acknowledges the assistance of a press release from the University of Kansas in the compilation of this article.

The scientific paper: “A Seismically Induced Onshore Surge Deposit at the KPg Boundary, North Dakota” by Robert A. DePalma, Jan Smit, David A. Burnham, Klaudia Kuiper, Phillip L. Manning, Anton Oleinik, Peter Larson, Florentin J. Maurrasse, Johan Vellekoop, Mark A. Richards, Loren Gurche, and Walter Alvarez published in the PNAS.

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