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21 04, 2017

New Species of Hyaenodont from Egypt Described

By | April 21st, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Masrasector nananubis – From the Late Eocene of Egypt

If people are asked to name a meat-eating mammal, you can expect to get answers such as tiger, bear or lion.  Those of us with more of a domestic outlook on life might mention cats and dogs, but for a significant portion of the Cenozoic, sometimes referred to as the “Age of Mammals”, the Carnivora, the Order to which bears, cats and dogs belong, did not get a look in.  Prior to the evolution of many types of recognisable carnivorous mammal alive today, other types of mammals filled the role of hypercarnivores*.

One such group was the Hyaenodonta.  A diverse clade of carnivorous mammals that filled a variety of roles in terrestrial ecosystems in both the New and the Old World.  Writing in the on-line academic journal PLOS One, scientists from Ohio University and the University of Southern California have published details of a new species of Yorkshire terrier-sized hyaenodont, the beautifully preserved skull and jaws are helping palaeontologists to understand more about the evolution and phylogeny of this extinct group, a group that has no close relatives alive today.

The Skull and Jaws of a Newly Identified Species of Hyaenodont

Skull and jaws of Masrasector nananubis.

Computer generated image showing the skull and jaws of Masrasector nananubis (right lateral view).

Picture Credit: PLOS One

Masrasector nananubis – Named after a God of Ancient Egypt

The Late Eocene deposits of the Fayum Depression (Egypt), have provided scientists with a substantial number of mammal fossils, including a number of hyaenodonts, the latest to be added to this list is Masrasector nananubis.  It has been classified as member of the Hyaenodontidae, specifically part of the Teratodontine clade, a poorly known group which are distinguished from other hyaenodonts by subtle differences in the shape of their skulls, jaws and teeth.  Masrasector translates as “the Egyptian slicer”, a reference to the large molars (carnassials).  The species or trivial name honours Anubis, the jackal-faced Egyptian god of mummification.  The premolars and molars of Masrasector have larger grinding surfaces when compared to other hyaenodonts.  The researchers have speculated that Masrasector nananubis may have supplemented its diet of small mammals, amphibians, reptiles and insects by feeding on fruit and nuts.  This suggests that, like other members of the Teratodontinae clade, it may not have relied on meat consumption as much as other hyaenodonts that were hypercarnivorous.  It has been suggested that M. nananubis may have been mesocarnivorous*.

Views of the Skull of Masrasector nananubis

Cranium material of Masrasector.

Views of the skull of Masrasector (Hyaenodont).

Picture Credit: PLOS One

It may be true that hyaenodont fossils are known from Africa, North America, Asia and Europe and that the genus Hyaenodon survived for around twenty-six million years, the longest temporal spam known for a fossil mammal, but the discovery of these Masrasector fossils is still very significant.  The fossils comprise largely complete skulls, jaws, and parts of the skeleton, making them one of the most complete known African hyaenodonts from the Paleogene found to date.  Previously, researchers only had isolated bones and teeth fragments to work with, frustrating palaeontologists as they attempt to piece together the family tree representing the Hyaenodontidae.

The fossils come from a dig site (locality 41) in the Fayum Depression, the well-consolidated clays have been dated to the Late Priabonian of the Eocene (approximately 34 million years ago).  The Masrasector material represents some of the oldest fossils known for this type of hyaenodont.

Commenting on the importance of the fossils, corresponding author for the study, Matthew R. Borths (Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University), stated:

“These fossils might be the oldest and most complete ever discovered, but there is still much that remains to be discovered as the fossils of other members of this group are fragmentary.  Masrasector can be used as a cornerstone of character development for exploring the evolution and diversity of other hyaenodontids.”

 

An Illustration of the Giant Hyaenodont (H. gigas)

Hyaenodon gigas scale drawing.

A scale drawing of the giant Hyaenodon gigas.

Picture Credit: Everything Dinosaur

Matthew went onto add:

“Hyaenodonts were the top predators in Africa after the extinction of the dinosaurs.  This new species is associated with a dozen specimens, including skulls and arm bones, which means we can explore what it ate, how it moved, and consider why these carnivorous mammals died off as the relatives of dogs, cats, and hyenas moved into Africa.”

Hypercarnivore* an animal which has at least 70% of its diet made up of meat.

Mesocarnivore* an animal which has around 50% to 70% of its diet made up of meat.

The scientific paper: “Craniodental and Humeral Morphology of a New Species of Masrasector (Teratodontinae, Hyaenodonta, Placentalia) from the Late Eocene of Egypt and Locomotor Diversity in Hyaenodonts” by Matthew R. Borths and Erik R Seiffert published in PLOS One.

18 04, 2017

New Species of Arowana Fish from the Eocene of China

By | April 18th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

The Origins of the Dragon Fish (Scleropages)

Scientists from the Institute of Vertebrate Palaeontology and Palaeoanthropology (IVPP) have published details of the discovery of beautifully preserved fish fossils from China that have helped map the origins of one of the most valuable and sought after aquarium fishes in the world.  Scleropages formosus, the Asian Arowana, otherwise known as the Dragon Fish from south-eastern Asia, quite rare in the wild these days, but it is highly regarded amongst freshwater aquarium owners, who can splash out thousands of dollars to acquire particularly colourful specimens.

In a scientific paper published in the journal “Vertebrata PalAsiatica”, Dr Zhang Jiangyong (IVPP) in collaboration with Dr Mark Wilson (University of Alberta), report on the discovery of a new species of osteoglossid fish from the Early Eocene Xiwanpu Formation in Hunan and the Yangxi Formation in Hubei, (China).  The prehistoric fish is remarkable similar to the extant species and it has been named Scleropages sinensis (the name translates as “hard scaled leaves from China”, a reference to the robust tough body scales that characterises these fish).

The Holotype Fossil Material of Scleropages sinensis

The holotype fossil material of S. sinensis.

Holotype of Scleropages sinensis.

Picture Credit: Zhang Jiangyong (IVPP)

The picture above shows the beautifully preserved holotype specimen of S. sinensis.  The fins are labelled (df) = dorsal fin, (cf) = caudal fin, (af) = anal fin, (pf and pec f) = pectoral fins, scale bar 1 centimetre.

This is the first time a nearly complete body fossil of this genus has been described.  Previously, the fossil record only consisted of individual scales, otoliths (calcified structures from the inner ear) and isolated fragmentary bones.  The discovery of Scleropages sinensis dates the divergence of Scleropages from the closely related Osteoglossum to at least as far back as the Early Eocene.  The fish fossils represent a number of different ontogenetic (growth stages). The largest specimens are 17.5 centimetres in length, the smallest under 8 centimetres long.

Fossil Scleropages are known from the Maastrichtian of India, the Maastrichtian/Late Palaeocene of Africa, the Palaeocene of Europe, the Eocene of Sumatra, and the Oligocene of Australia.   All of these earlier records are scales, otoliths and isolated bone fragments. Therefore, these newly described Chinese fossils are the first skeletons of fossil Scleropages ever unearthed in the world.

Views of the Scleropages Fossil Material

Views of Scleropages sinensis fossil material.

Scleropages sinensis fossil material (various views).

Picture Credit: Zhang Jiangyong (IVPP)

Dr Zhang stated:

“This new fish resembles Scleropages in skull bones, caudal skeleton, the shape and position of fins, and reticulate scales.  Therefore, it must belong to the genus.”

The extant species of Scleropages inhabits lakes, swamps and flooded forests as well as slowly meandering rivers. It is a carnivorous fish preying on insects, worms, small amphibians, other fish, small mammals and even birds.  The fish is renowned for its jumping, the researchers propose that Scleropages sinensis may have filled a similar niche in the Eocene ecosystem, but being smaller it probably had a more restricted diet than its extant relative.  Analysis of the fossil material suggests that sexual dimorphism may have existed in S. sinensis.

Comparing the Extinct Species with Living Species

Living species of Scleropages compared to the fossil material.

Comparison between Scleropages sinensis (A) and the living species S. formosus (B), S. leichardti.

Picture Credit: Zhang Jiangyong (IVPP)

13 04, 2017

The Dinosaurian Body Plan Alan Charig Remembered

By | April 13th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Teleocrater rhadinus and Dr Alan Charig

There’s a book on our office shelves, its dust jacket is faded and torn and the pages are yellowed with age, not surprising really as it was printed in 1973.  Although many of the passages, diagrams and ideas contained within it, have long since been superseded, it is treated with great reverence as it is one of the first dinosaur books I ever owned.  Entitled “Before the Ark” it accompanied a ten-part television series on vertebrate palaeontology produced by the BBC.  Written by Alan Charig and Brenda Horsfield, (Dr Charig wrote and presented the television series too), it remains a treasured possession and today, with the publication of a scientific paper in the journal “Nature”, we remember Dr Charig, a man who is still having an influence on science, even though he passed away some twenty years ago.

“Before the Ark” and Teleocrater – Tribute to Dr Alan Charig

"Before the Ark" and Teleocrater.

“Before the Ark” and Teleocrater (before the dinosaurs).

Picture Credit: BBC with T. rhadinus artwork by Gabriel Lio (Museo Argentino de Ciencias Naturales)

Early Dinosaur Cousin with “Crocodile-like Appearance”

Writing in the journal “Nature”, the researchers which include Sterling Nesbitt, assistant professor of geosciences at Virginia Tech, Roger Smith (University of Witwatersrand) and Paul Barrett of the Natural History Museum (London), describe more complete fossil material relating to Teleocrater rhadinus and formally establish this genus which helps to fill a critical gap in the fossil record leading to the evolution of the dinosaurs.

Teleocrater (the name means “slender complete basin” in reference to the reptile’s light build and the fully closed hip socket), was first proposed by Alan Charig back in the 1950’s.  He was a PhD student at Cambridge University writing a doctoral thesis on Triassic reptiles of Tanganyika (now Tanzania).  Alan was being supervised by Francis Rex Parrington, a vertebrate palaeontologist who had uncovered the very first fossils of what we now refer to as Teleocrater rhadinus, during fieldwork in Tanganyika in 1933.

Fieldwork undertaken in 2015, led to the discovery of more fossil material and crucially limb elements and ankle bones which have helped determine where amongst the Archosaurs Teleocrater should be placed.

Fieldwork in Tanzania (2015)

Excavating the fossils of Teleocrater and other Triassic animals.

Excavating the remains of Teleocrater rhadinus and other animals in southern Tanzania in 2015.

Picture Credit: Roger Smith

The photograph above shows authors Christian Sidor (left), Sterling Nesbitt, Kenneth Angielczyk (in the purple top and white floppy hat), along with Michelle Stocker (right), looking for Triassic vertebrates in exposures of the Manda Beds (Anisian faunal stage of the Middle Triassic) of southern Tanzania.

All Fossil Material from the Manda Beds

Francis R. Parrington collected the first fossil specimens from the Manda Beds in the Ruhuhu Basin of southern Tanzania.  These fossils were studied by Alan Charig for his doctorate, but much of Alan’s work on Teleocrater was never published.  Dr Charig went to Tanzania to search for more fossils in 1963, but it was not until the expedition of 2015, that the crucially important limb and ankle bones were recovered that demonstrated where on the Archosauria family tree Teleocrater should sit.

The ankle bones and other skeletal elements demonstrate that Teleocrater is more closely related to dinosaurs and birds than it is to crocodiles. It sits on the family tree of the Archosaurs at the base of the Avemetatarsalian branch, the “bird-line Archosaurs”, sometimes also referred to as the Ornithodira.  The researchers conclude that Teleocrater and its near relatives split off from other Avemetatarsalians before the evolutionary split between the Pterosauria (flying reptiles) and the dinosaurs.

Establishing T. rhadinus on the Archosauria Family Tree

The phylogeny of Teleocrater.

Teleocrater is more closely related to the Pterosauria and the Dinosauria (including Aves) than to crocodilians.

Picture Credit: Sterling Nesbitt of Virginia Tech with additional annotation by Everything Dinosaur

The Big Two Branches of the Archosauria

The Archosauria clade consists of birds and crocodiles plus an array of extinct creatures which include the dinosaurs, silesaurids and the flying reptiles (pterosaurs).  This huge group of reptiles can be generally divided up into two distinct branches, based on the anatomy of the ankle bones.  On one branch, we have the crocodiles and their relatives (Crurotarsi), which tend to have a sprawling gait, whilst on the other branch we have the Avemetatarsalia, otherwise referred to as the Ornithodirans, which tend to have their limbs directly under their hips and have a more upright gait, similar to mammals.

Dr Charig never got the opportunity to study fossils of the ankle bone, he passed away in 1997, without being able to complete his assessment of this reptile.  The researchers have honoured the contribution made by Alan Charig by naming him as an author on the 2017 paper and formally recognising the name Teleocrater, that he was the first to use.

Excavating the Fossils of Teleocrater

Excavating the fossils of Teleocrater and other Triassic animals.

Sterling Nesbitt (left) and Christian Sidor (right) working on some fossil bones.

Picture Credit: Roger Smith

Uniting the Aphanosauria Clade – Dinosaur Ancestors on All Fours

Teleocrater helps to cement the establishment of the Aphanosauria clade, a group of long-necked, slender-limbed, carnivores that lived in the Middle Triassic and were geographically widespread across Pangaea.  The Crurotarsi Archosaurs, those crocodile-like creatures were thought to be highly diversified and geographically widespread across the super-continent Pangaea.  It now seems that the other branch of the Archosauria, the Avemetatarsalia, may have been equally as diverse and as widespread as their crocodile-like cousins.

Previously, palaeontologists have postulated that the earliest dinosaur relatives were chicken-sized and bipedal.  Thanks to the 2015 fossil discoveries and the work first undertaken by F. R. Parrington and Alan Charig, scientists have a different body plan to consider.  T. rhadinus which roamed the area that was to become Tanzania some 245 million-years-ago, was much larger at around three metres long and it was a quadruped.

An Illustration of the Early Avemetatarsalian Teleocrater rhadinus

T. rhadinus illustration.

A life reconstruction of Teleocrater rhadinus.

Picture Credit:  Gabriel Lio (Museo Argentino de Ciencias Naturales)

Alan Charig studied the fossils of what we now know as Teleocrater rhadinus.  Twenty years after his death, scientists can place this enigmatic reptile and its relatives within the Avemetatarsalian branch of the Archosauria, Teleocrater represents one of the earliest members of this sub-branch, a lineage that eventually led to the dinosaurs and the birds.

In addition, with a more complete picture of Teleocrater, palaeontologists have another puzzle to ponder.  If the early branch members of the Avemetatarsalia were more species-rich and more widely geographically distributed than previously thought, then several early Dinosauromorphs used to help scientists to understand how the body plan of the Dinosauria evolved, may represent specialised forms rather than the typical ancestral Avemetatarsalian body plan.

Today, we reflect on the work of Dr Alan Charig and his mentor Francis Rex Parrington.  The researchers writing in the journal “Nature” have helped to put flesh onto those bones first examined all those years ago.  For my part, my thanks to Alan Charig for helping to write such a beautiful book and for inspiring a generation of science writers and enthusiasts.

The scientific paper: “The Earliest Bird-line Archosaurs and he Assembly of the Dinosaur Body Plan” by Sterling J. Nesbitt, Richard J. Butler, Martín D. Ezcurra, Paul M. Barrett, Michelle R. Stocker, Kenneth D. Angielczyk, Roger M. H. Smith, Christian A. Sidor, Grzegorz Niedźwiedzki, Andrey G. Sennikov & Alan J. Charig published in the journal “Nature”.

Everything Dinosaur acknowledges the help of Virginia Tech in the compilation of this article.

12 04, 2017

Chinese Fossil Sites Under Threat

By | April 12th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Mining Operations Damage Famous Fossil Site

An article in the South China Morning Post highlights the growing concern expressed by the scientific community over damage to a globally important fossil site in Guizhou Province (south-western China).  Phosphorous mining operations are wiping away fossil evidence of some of the earliest organisms classified as animals known to science.  The tiny micro-fossils preserved in strata exposed in Weng’an county, represent the remains of multi-cellular organisms, marine sponges that once thrived in an ancient sea some 600 million years ago.

A False Colour Image Showing One of the Sponge-Like Micro-fossils (Doushantuo Formation)

Sponge-like Ediacaran micro-fossil.

A scanning electron microscope image of the 600 million-year-old sponge-like animal fossil (false colour image).

Picture Credit: NIGPAS (Chinese Academy of Sciences)

Professor Zhu Maoyan and his colleagues at the Nanjing Institute of Geology and Palaeontology have called for urgent measures to be taken to help protect the Weng’an biota.  The world-renowned fossil site, one of the few places that preserves traces of Ediacaran fauna, is threatened as hundreds of mining trucks are transporting rocks from the area every day.  Weng’an county has one of Asia’s largest phosphorus reserves.  The mining business contributes more than sixty per cent of the county government’s annual tax income.  Intensive mining in the area has led to cases of massive subsidence.

The professor, who has led a number of field teams to explore the fossiliferous sediments, that first came to the attention of palaeontologists less than twenty years ago, stated:

“Six hundred million years of life’s evolutionary history is being traded to help produce a bowl of rice.”

The demand for phosphorous to make fertiliser is increasing, unfortunately, the rocks that form the Doushantuo Formation of Guizhou Province are a rich source of this important element.  However, local officials in Weng’an county have promised action after a fossil site covering about three square kilometres was nearly destroyed and buried under huge heaps of debris caused by subsidence.

The micro-fossils preserved in the phosphorite rocks of the Doushantuo Formation, preserve the remains of 600 million-year-old, sponge-like organisms.  Professor Zhu commented that the Weng’an biota was remarkable because of the abundance of fossils and their fine state of preservation, with details shown down to a cellular level.

The professor added:

“There may not be another place like it in the whole world.”

Features of the Fossils are Similar to Extant Sponge Anatomy

Precambrian sponge-like fossils.

Views of the sponge-like fossils from south-western China.

Picture Credit: NIGPAS (Chinese Academy of Sciences)

The picture above shows various views of micro-fossils from the Weng’an county location including highly magnified views of what be a holdfast structure (c, d, e, f, g and h).

Professor Zhu stressed that both local government and the public had failed to realise that the exposures in Weng’an county are unique and very valuable to science.  It was suggested that a “core area” be chosen and then this site given protection.

To read an article featuring research by Virginia Tech College of Science and the Chinese Academy of Sciences which looks at the fossil evidence from the Doushantuo Formation: New Research Suggests Multicellular Life Started Earlier Than Previously Thought

9 04, 2017

Chicxulub Impact Event Not Responsible for Dinosaur Extinction

By | April 9th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Mexican Tracksites Indicate Decline of Dinosaurs Prior to Impact Event

A team of scientists based in Germany and Mexico have published a paper that challenges the commonly held belief that the extraterrestrial impact event marked by the Chicxulub crater resulted in the extinction of the dinosaurs and their flying cousins the pterosaurs.  In addition, studies of marine sediments indicate that at least one species of ammonite Sphenodiscus pleurisepta may have survived into the Palaeogene.

Chicxulub Extraterrestrial Impact Not the Cause of Global Mass Extinctions

Chicxulub impact event.

Did the extraterrestrial impact event wipe out the dinosaurs and pterosaurs?

Exploring the Fossil Assemblage of the Cretaceous/Palaeogene Boundary

Writing in the journal of the “Geological Society of America Bulletin”, the researchers which include lead author Professor Wolfgang Stinnesbeck of Heidelberg University, Professor Eberhard Frey (State Museum of Natural History, Karlsruhe) and scientists from the Museo del Desierto, Coahuila, (Mexico), postulate that the dinosaurs and the flying reptiles were in long-term decline before the Chicxulub impact and the global mass extinction that marked the end of the Mesozoic.  The scientists also postulate that Aves (birds), had spread and diversified at the same time as the Dinosauria was in decline.  Furthermore, based on fossil evidence, the team contend that at least one type of ammonite, Sphenodiscus pleurisepta persisted into the Cenozoic.

These conclusions were drawn from a comprehensive study of upper Cretaceous sedimentary sandstone rocks, laid down at the very end of the “Age of Dinosaurs”.  The tracks and body fossils found at two localities in the Mexican state of Coahuila, depict life on the shore and the surrounding waters of a shrinking inland sea.  Both sites represent sandstones within the Las Encinas Formation of north-eastern Mexico.

Remote Fossil Site in North-eastern Mexico (Las Encinas Formation)

Fossil site in north-eastern Mexico

One of the remote and isolated sites where the fossils were found.

Picture Credit: Professor Stinnesbeck/Heidelberg University

The trackway assemblages at Amargos and Rancho San Francisco respectively, were produced by at least six different types of birds, while trackways of azhdarchoid pterosaurs are rare.  Only a single footprint made by a dinosaur (Theropod) was recorded.

Professor Stinnesbeck commented:

“Dinosaur tracks, however, are rare.  Only a single footprint comes from a predatory dinosaur.”

Lack of Pterosaur Fossil Evidence

The scarcity of Pterosaur fossils was also noted.  The scientists state that azhdarchoid pterosaur fossils are rare.  Azhdarchids include some of the most famous and largest pterosaurs of all – Quetzalcoatlus Hatzegopteryx and Arambourgiania.  Most of the Pterosauria had become extinct by the Maastrichtian faunal stage of the Late Cretaceous.  From their heyday in the Early Cretaceous when at least ten pterosaur families existed, by the very end of the Cretaceous only two families of pterosaur are known in the fossil record.

Pterosaur Fossils Such as These Tracks are Very Rare

Pterosaur fossil tracks.

Pterosaur fossil tracks (north-eastern Mexico).

Picture Credit: Professor Stinnesbeck/Heidelberg University

The photograph above shows prints of Azhdharchidea pterosaurs in a sandstone of the Upper Cretaceous, location – Rancho San Francisco near Paredon, north-eastern Mexico.

Research into the two locations Amargos and Rancho San Francisco, indicate a gradual decline of the dinosaurs with a simultaneous increase in the diversity of birds even before the end of the Cretaceous.

Professor Stinnesbeck added:

“Until now, it was generally assumed that the dinosaurs died out first and bird species diversified afterwards.  Our data, however, substantiate the theory that birds ascended before dinosaurs became extinct.”

The team postulate that the extraterrestrial impact event was not the cause of the dinosaur and pterosaur extinction, these reptiles were already on their way out, long before that event took place.  This idea of only a few dinosaur species persisting until the very end of the Mesozoic has been proposed before.  A count of dinosaur fossils found in the famous Hell Creek Formation of Montana supported the theory that the Dinosauria were already in decline by the end of the Cretaceous, the fossil assemblage in the very youngest rocks was dominated by just a handful of species.

Ammonites Survived into the Cenozoic

In the scientific paper, the researchers comment that the ammonites were not wiped out by the asteroid/comet/meteor strike.  Professor Stinnesbeck and his colleagues suggest that the species Sphenodiscus pleurisepta, a type of ammonite known from the United States and Mexico, survived, albeit in a declining state into the Palaeogene.

The geology professor stated:

“The effects of the Chicxulub impact were therefore not the cause of a global mass extinction, which probably came about considerably less catastrophically than previously assumed.”

The power of the extraterrestrial impact is evidenced by the abundance of crystalline clay minerals that are rounded in shape (smectite spherules), within a two-and-a-half metre-thick layer of strata.

The Last Ammonite (Sphenodiscus pleurisepta)?

Sphenodiscus pleurisepta fossil ammonite.

Sphenodiscus pleurisepta ammonite fossil.

Picture Credit: Conrad

The picture above shows a typical fossil of S. pleurisepta (picture of the holotype fossil), scale bar equals 1 cm.

The fifty million year decline of the Dinosauria: Bayesian Analysis Sheds New Light on Dinosaur Decline

To read about other ammonites that may have persisted into the Cenozoic: Unravelling an Ammonite Mystery

10 03, 2017

Late Jurassic Crocodile Eggs and Meat-Eating Dinosaurs

By | March 10th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Crocodylomorph Ootaxa and the Theropod Connection

A number of media outlets have reported upon a paper published in the on line journal PLOS One which describes two new ootaxa (the name given to a species described just from egg fossils), of crocodilians from the Upper Jurassic rocks of western Portugal.  The focus on many of these reports has been on the age of the fossilised crocodile eggs.  Having been laid more than 150 million years ago, they are the oldest crocodilian eggs described to date.  However, the research paper itself, hints at a remarkable potential relationship between these ancient reptiles and their close cousins, Theropod dinosaurs.

A Clutch of Unhatched Late Jurassic Crocodylomorph Eggs (Lourinhã Formation)

Suchoolithus portucalensis fossil eggs.

The unhatched crocodylomorph eggs (Cambelas) ascribed to Suchoolithus portucalensis.

The Famous Lourinhã Formation

The first crocodylomorph eggs were found in 1987 and over the years a number of egg and egg shell fragment discoveries have been made.  The eggs are very similar to the eggs of extant crocodiles but the scientists have been able to identity distinctions between the fossil specimens (not least the size).  This has led to the erection of two new ootaxa.  The eggs of the smaller of the two crocodylomorphs – Suchoolithus portucalensis are shown in the photograph above.  The eggs are quite small and the researchers estimate that the adult female that laid these eggs would have been around seventy centimetres in length.  The second ootaxa to be named – Krokolithes dinophilus, which is known from a number of fossil specimens collected from four locations, is represented by larger but broken eggs and shell fragments.  The research team estimate that the female croc that laid these eggs would have been around the size of a female American Alligator (A. mississippiensis), probably more than two metres long.

Location of the Egg Fossil Finds Referred to in the New Study

Map showing the location of the fossil finds.

A map showing the location of the crocodylomorph egg fossil sites.

Picture Credit: PLOS One with additional annotation from Everything Dinosaur

Key

The picture above shows the five fossil locations that are covered in the scientific paper as well as indicating the position of the Lourinhã Formation in relation to the rest of Portugal.  A total of thirteen fossilised eggs collected at the Cambelas site have been ascribed to the ootaxa Suchoolithus portucalensis (the name translates from Latin as “egg stone crocodile from Portugal”), the fossils represent a clutch of unhatched eggs.  Eggs laid by a much larger crocodylomorph are associated with the other four locations, namely North and South Paimogo, Casal da Rola and Peralta.  These fossils comprise broken eggs and numerous shell fragments, they have been ascribed to the ootaxa Krokolithes dinophilus (which is from the Greek and means “crocodile eggs found in association with dinosaurs”).

Holotype of Krokolithes dinophilus (Specimen Number ML760 from Paimogo N, Praia da Amoreira-Porto Novo Member, Lourinhã Formation)

Krokolithes dinophilus fossil material.

Holotype of the oospecies Krokolithes dinophilus.

Found in Association with Theropod Dinosaur Nests

All the egg fossils (except for the Cambelas site fossils), were found in association with Theropod dinosaur nests and eggs.  So in essence, the palaeontologists, which included João Russo and Octávio Mateus (Museu da Lourinhã, Portugal), have identified four occurrences where the fossils of the large crocodylomorph K. dinophilus are found in the same place as the eggs and nests of large, meat-eating dinosaurs.  This could suggest some sort of biological relationship between the crocodiles and the Theropods.  This is certainly an intriguing thought and there are no parallels that can be drawn between this idea and the behaviour of modern crocodiles.  Extant crocodilians tend to lay eggs in relatively secluded places and a parent (usually the female), will stand guard helping to protect the nest and the subsequent hatchlings from predators.

It can be speculated that these prehistoric crocodiles preferred to nest in close proximity to large meat-eating dinosaurs as perhaps the presence of two different types of large predator helped to protect all the nests from potential danger.  With so many threats to eggs and recently hatched animals around in the Late Jurassic, it could be suggested that there was a degree of mutual benefit between various species – a symbiotic relationship with both the Theropods and the crocodilians gaining an advantage.

Some of the K. dinophilus egg fossils come from sites associated with the nests of Lourinhanosaurus (Lourinhanosaurus antunesi), a formidable Late Jurassic hunter, which may have reached lengths of eight metres or more.  The beautifully preserved Theropod embryos were the inspiration behind the limited edition “Baby Bonnie” 1:1 scale replicas created by Rebor.

The Rebor “Baby Bonnie” Scale Model of a Lourinhanosaurus antunesi Embryo

"Bony Bonnie" from Rebor.

The Rebor Club Selection Lourinhanosaurus replica.

Picture Credit: Everything Dinosaur

Other Krokolithes dinophilus fossils have been found in proximity to the nests and eggs of the ootaxon Preprismatoolithus coloradensis (which could represent the eggs of a large Allosaurus).  We expect palaeoartists to have a field day illustrating nesting site scenes featuring a mix of large predators together.

The Theory has Drawbacks

The absence of any modern parallels and the incomplete fossil record provides considerable drawbacks when it comes to the plausibility of crocodiles nesting alongside meat-eating dinosaurs.  Some of the fossil eggs shell fragments from the Paimogo locations might have been transported and deposited close to the Theropod nests, therefore their placement in the strata is not necessarily their original nesting context.  We at Everything Dinosaur have proposed that it is possible that crocodiles and Theropod dinosaurs preferred to use the same nesting locations, but they may not have bred at the same time.  After all, using an already dug out nest, one that had been used recently by a large, carnivorous dinosaur might prove advantageous for a wily crocodile.

The scientists conclude that this potential egg-laying symbiosis is a mystery and that going forward, further findings and studies are needed to ascertain if there was indeed some kind of reproductive relationship between crocodylomorphs and Theropods in the Late Jurassic of Portugal.

Views of the Lourinhã Formation

Views of the Lourinha Formation.

(A), location of Paimogo, Northern Lourinhã Formation, Praia da Amoreira-Porto Novo and Praia Azul Members. (B), location of Cambelas, Southern Lourinhã Formation, Assenta Member.

Picture Credit: PLOS One

24 02, 2017

Penguins Lived Alongside Dinosaurs (Probably)

By | February 24th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Giant Prehistoric Penguin 1.5 metres Tall

Ancient leg bones, found in Palaeocene-aged deposits located on the shoreline of Pegasus Bay near the city of Christchurch (New Zealand), has led scientists to propose that dinosaurs would have been familiar with penguins.  In addition, the leg bone fossils indicate that after the dinosaurs died out, some penguins became super-sized, standing around 1.5 metres tall.  The avian fossil material was excavated from sediments along the Waipara River, close to where this river meets the sea (Pegasus Bay).  It has been estimated that this giant, primitive penguin lived in a coastal environment some 61 million years ago.

Researchers from the Senckenberg Society for Natural Research (Frankfurt, Germany), have concluded that the penguin lineage is much older than previously thought, suggesting that these marine birds very probably evolved during the Late Cretaceous and the first kinds of penguins would have been very familiar to dinosaurs that wandered the remnants of the southern continent Gondwana.

A Super-sized Palaeocene Penguin

Penguin fossil comparison.

New specimen (left) compared to W. manneringi and an extant Emperor Penguin (Aptenodytes forsteri) on the right.

Picture Credit: Senckenberg Society for Natural Research

The picture above compares the fossil leg bones of the newly discovered penguin species, with that of another, smaller Palaeocene penguin found in the same area Waimanu manneringi, which was formally described in 2006.  The bones on the right are from the largest living species of penguin, the Emperor penguin (A. forsteri).   This fossil supports the theory that the ancestors of modern Aves rapidly diversified after the end Cretaceous extinction event occupying a number of niches that had previously been occupied by other types of bird and Theropod dinosaurs.

An Illustration of Waimanu manneringi

Waddling with dinosaurs.

Penguins probably waddled next to dinosaurs.

Picture Credit: Senckenberg Society for Natural Research

Although, Waimanu manneringi was a contemporary of the giant penguin, it had a different body plan, resembling a cormorant.  The two types of penguin were very different, this suggests that basal penguins probably evolved prior to the end of the Cretaceous.

Co-author of the scientific paper, Dr Paul Scofield (Canterbury Museum, New Zealand), explained:

“We believed up until this specimen was discovered that there was very little variation amongst these Palaeocene penguins.  We are now starting to understand that shortly after the extinction of the dinosaurs there were in fact two quite different groups of penguin.”

No Scientific Name as Yet

The lack of autapomorphies (distinctive features) and the fragmentary nature of the fossils has deterred the researchers from seeking to name their new prehistoric bird.

A spokesperson from Everything Dinosaur stated:

“The fossils probably represent a new species, however, with so few fossils to go on and with a lack of distinctive characteristics in the bones, it is not possible to erect a new species at the moment.  Should more fossil material be found, especially skull material, then a new prehistoric bird species could come about.”

The Prehistoric Penguin Compared in Size with a Modern Human

New Zealand giant penguin size comparison.

South Island giant penguin compared to modern human.

Picture Credit: Everything Dinosaur

The orientation of the leg bones suggests that, just like modern penguins, this ancient feathered friend probably waddled, walking in the same manner as its extant, smaller cousins.  The fossil discovery is highly significant as it will likely be used as an “anchor point” to determine how the penguin family evolved.  It is also very likely that other penguin species existed during the Palaeocene Epoch in this part of the world, but their fossilised remains have not yet been discovered.

The scientists are optimistic that the fossil site, just twenty miles north of the city of Christchurch, will yield further evidence of ancient sea birds.  Although, around twenty-five percent bigger than the largest penguin species around today (Emperor penguin), these fossils do not represent the largest penguin known to science.

To read more about one of the largest known penguin species: Picking up a Giant Prehistoric Penguin

Penguins were not the only creatures around today, that would have been familiar to the dinosaurs.  Everything Dinosaur wrote an article after research had been published back in 2008 that suggested the bizarre duck-billed platypus co-existed with duck-billed dinosaurs.

To read the article: Duck-billed Platypus and the Duck-billed Dinosaurs

13 02, 2017

Spiny, Armoured Slug Provides Best Evidence for the Ancestry of Molluscs

By | February 13th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Spiny but Slimy and with a Radula – Calvapilosa kroegeri

Scientists from the University of Bristol have uncovered a 480-million-year-old slug-like fossil in Morocco which sheds new light on the evolution of molluscs, a diverse group of invertebrates that includes clams, snails and cephalopods like squid and cuttlefish.

A Model of the Newly Described Calvapilosa kroegeri

Viewed from the top (left) and the bottom (right) - Calvapilosa kroegeri.

Calvapilosa kroegeri dorsal and ventral views.

Picture Credit: Dr Jakob Vinther

One of the defining characteristics of the molluscs is the possession of a radula, a kind of toothed-tongue which is used to rake up or rasp food.  The radula houses hundreds of teeth, the patterns of which can be used to determine diet and identify species.  Whilst not all molluscs have a radula, a radula cannot be found in any other group of animals.  It is a characteristic of the Mollusca Phylum.

Dr Jakob Vinther, from the Schools of Biological Sciences and Earth Sciences, is lead author of the study, which is published today in the academic journal Nature.

Dr Vinther stated:

“The molluscs are amongst the earliest animals identifiable in the fossil record, however determining what their ancestor looked like is difficult since many of the groups appear within a small window of time, making the sequence of evolutionary events difficult to piece together.”

The recent discovery of a new species of mollusc in the Anti-Atlas region in Morocco has enabled palaeontologists to revisit this problem and infer the appearance of the ancestor of all molluscs.  The new species discovered, Calvapilosa kroegeri, is part of the Fezouata Biota, a group of organisms from the early Ordovician period (485-470 million years ago), which are found in rocks in south-eastern Morocco.  The Fezouata Biota is famed for its exceptional preservation, allowing palaeontologists to identify details not preserved from any other fossil site.

Co-author of the scientific paper, Luke Parry, a PhD student at the University of Bristol, added:

“Calvapilosa kroegeri resembles a slug covered with short spines all over its upper body and with a large ‘fingernail-like shell’ over its head.  In the centre of the head of this species are two rows of teeth which we demonstrate is a radula.”

The discovery of this feeding structure firmly identifies Calvapilosa kroegeri as a mollusc.  Additionally, it suggests that similar fossil forms, such as Halkieria, a two-plated slug-like fossil, are also molluscs and possessed a radula.  Following an analysis to determine the family tree of molluscs, Calvapilosa kroegeri was revealed to be the most primitive member of the lineage leading to chitons.  Chitons can still be found today and are characterised by their possession of eight shell plates and spines around their margin, similar to what is seen covering the body of Calvapilosa.

Looking Like a Hairy Fingernail Calvapilosa kroegeri Fossil

Calvapilosa looks like a "hairy fingernail".

The fossil of Calvapilosa kroegeri, preserving the feeding apparatus (radula) and all the spines that covered the body.

Picture Credit: Peter Van Roy

Dr Vinther concluded:

“If we trace back the evolution of chitons, we can see that the number of their shells has increased with time.  It is therefore likely that the ancestor to all molluscs was single-shelled and covered in bristle-like spines, not dissimilar to Calvapilosa kroegeri.”

The Scientific Paper: “Ancestral Morphology of Crown-group Molluscs Revealed by a New Ordovician Stem Aculiferan” by J. Vinther, L. Parry, D. Briggs and P. Van Roy, published in Nature.

Everything Dinosaur acknowledges the help of a press release from Bristol University in the compilation of this article.

6 02, 2017

Fossil Hunting at Nuremberg Airport

By | February 6th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Educational Activities, Geology, Main Page, Photos/Pictures of Fossils|0 Comments

Fossil Hunting at the Airport

Waiting at an airport can be quite boring.  Once check in and the security searches have been completed, then there is not much more to do prior to boarding your flight.  However, for Everything Dinosaur team members returning from Germany, one airport provided them with the opportunity to go on an unexpected fossil hunt.  The polished limestone floors at Nuremberg Airport (southern Germany), are full of Jurassic marine invertebrate fossils.

A Fossil Spotted at the Airport (Nuremberg Airport)

The stone floors at Nuremberg airport are full of fossils.

A cephalopod fossil (ammonite) on the airport stone floor.

Picture Credit: Everything Dinosaur

The Jurassic of Germany

In southern Germany, particularly the state of Bavaria, in the region from Nuremberg in the north to Munich in the south, there are many limestone exposures and limestone quarries to be found.  Formed from carbonate rich muds that once existed at the bottom of salty lagoons and shallow coastal margins, the rocks are famous for their fine-grained structure and flat cleaving.  These properties help to make this limestone ideal building material and the stone in this part of Germany (known as Plattenkalk), has been quarried for thousands of years.

Most of the limestone represents sediments laid down in the Middle and Late Jurassic and large areas are highly fossiliferous.  Travellers at Nuremberg Airport were quite surprised to see members of Everything Dinosaur on their hands and knees, examining and photographing various floor tiles.

Jurassic Invertebrate Fossils in Abundance at Nuremberg Airport

Jurassic fossils at Nuremberg Airport.

An ammonite fossil with the cross section of a belemnite guard.

Picture Credit: Everything Dinosaur

In the picture above, the cross section of a belemnite guard can be clearly seen on one tile, abutted up against it is another tile that shows the cross-sectional outline of an ammonite.  There are also numerous bivalve and brachiopod fossils preserved in the stone floor.  Thousands of people visit Nuremberg Airport every week, but we wonder how many of them actually notice what they are walking on!

 Ten years ago, Everything Dinosaur blogged about an innovative fossil hunting tour that could be undertaken by travellers at John Lennon Airport (Liverpool).  The ancient remains of long extinct sea creatures can be seen in the stone of the walls and floors of the concourse.  John Lennon Airport introduced the “JLA Fossil Mystery Tour” in collaboration with the Liverpool Geological Society.

To read more about the John Lennon Airport Fossil Hunting Tour: Why Not go on a Fossil Hunt Whilst Waiting at the Airport?

Perhaps the Nuremberg Airport authorities have missed a trick, with such a wonderful stone floor, travellers could be encouraged to have a go at finding fossils for themselves.  There are certainly many hundreds of fossils to see, perhaps if a tour could not be organised, then it might be a good idea to put up some information boards and displays.  You never know, it might encourage more tourists to visit the museums in the area such as the Naturhistorisches Museum of Nuremberg.

Ancient Traces Preserved in the Limestone Floor

Two fossils in the airport.

Fossils at Nuremberg airport.

Picture Credit: Everything Dinosaur

The picture above shows two more ammonite fossils, although it is difficult to identify genera, the larger specimen (bottom left), still shows its fine, straight ribs that would have adorned the outside of the shell.  The smaller ammonite cross section (right), shows some preservation of internal structure, could those be suture lines we are seeing?

What an Ammonite Actually Looked Like

A model of an Ammonite.

A great ammonite model for use in schools, museums and for model collectors.

Picture Credit: Everything Dinosaur

The picture above shows the excellent Wild Safari Prehistoric World ammonite model.  If you look carefully at the stone floors at Nuremberg Airport you can spot the preserved remains of Jurassic ammonites and other extinct marine creatures.

To view the range of prehistoric animal models including the Wild Safari Prehistoric World ammonite available from Everything Dinosaur: Wild Safari Prehistoric World Models

27 01, 2017

The Oldest, Most Complete Iguanian of the Americas

By | January 27th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Magnuviator ovimonsensis from Egg Mountain

Palaeontologists picking through a bounty of fossils from Montana have discovered something very unexpected, a new species of lizard from that lived near to the end of the Age of Dinosaurs, whose closest relatives roamed in faraway Asia.

This ancient lizard, which lived 75 million-years-ago in a dinosaur nesting ground, is described in a paper published this week in the academic journal “The Proceedings of the Royal Society B”.  Named Magnuviator ovimonsensis, the new species fills in significant gaps in our understanding of how lizards evolved and spread during the Mesozoic, according to palaeontologists at the University of Washington and the Burke Museum of Natural History and Culture who led the research.

Postdoctoral research associate, David DeMar, lead author of the paper stated:

“It is incredibly rare to find one complete fossil skeleton from a relatively small creature like this lizard.  But, in fact, we had two specimens, both from the same site at Egg Mountain in Montana.”

Magnuviator is reshaping how scientists view lizards, their biodiversity and their role in complex ecosystems during the Cretaceous some seventy-five million-years-ago.

An Illustration of Magnuviator ovimonsensis

Magnuviator ovimonsensis illustrated.

An illustrated life reconstruction of Magnuviator ovimonsensis at the Egg Mountain site.

Picture Credit: Misaki Ouchida

The picture above shows a pair of Magnuviator lizards at the Egg Mountain fossil site.   One Magnuviator eats a wasp, on the ground is a tooth from the bird-like, Theropod dinosaur Troodon.  The arid-adapted plant is based on fossil pollen found near Egg Mountain.

An Ancient Lineage of Iguanian Lizards

Based on analyses of the nearly complete fossil skeletons, Magnuviator was an ancient offshoot of iguanian lizards.  The fossils are the oldest, most complete iguanian fossils from the Americas.  Today, iguanians include chameleons of the Old World, iguanas and anoles in the American tropics.  Based on its anatomy, Magnuviator was at best a distant relative of these modern lizard families, most of which did not arise until after the non-avian dinosaurs and quite a few lizards and other creatures became extinct some sixty-six million years ago.

The Holotype Fossil Material (M. ovimonsensis)

Magnuviator holotype fossil and line drawing.

Holotype fossil (A) with interpretative line drawing (B).

Picture Credit: David DeMar and Morgan Turner

The researchers came to these conclusions after a meticulous study of both Egg Mountain specimens over a period of four years.  This included a round of CT scans at Seattle Children’s Hospital to narrow down the fossil’s location within a larger section of rock and a second round at the American Museum of Natural History to digitally reconstruct the skull anatomy.  The fact that both skeletons were nearly complete allowed the team to determine not only that Magnuviator represented an entirely new species, but also that its closest kin weren’t other fossil lizards from the Americas.  Instead, it showed striking similarities to other Cretaceous Period iguanians from Mongolia.

The Second Magnuviator Fossil Specimen

Second Magnuviator ovimonsensis specimen.

The second Magnuviator ovimonsensis fossil specimen.

Picture Credit: Burke Museum of Natural History and Culture

DeMar commented:

“These ancient lineages are not the iguanian lizards which dominate parts of the Americas today, such as anoles and horned lizards.  So, discoveries like Magnuviator give us a rare glimpse into the types of ‘stem’ lizards that were present before the extinction of the dinosaurs.”

A Resident of Egg Mountain

But Magnuviator’s surprises don’t end with the Mongolian connection.  The site of its discovery is also astonishing.  Egg Mountain is already famous among fossil hunters.  Over thirty years ago, palaeontologists discovered the first fossil remains of dinosaur babies there, and it is also one of the first sites in North America where dinosaur eggs were discovered.

Senior author Greg Wilson (University of Washington, associate professor of biology), stated:

“We now recognise Egg Mountain as a unique site for understanding Cretaceous Period ecosystems in North America.  We believe both carnivorous and herbivorous dinosaurs came to this site repeatedly to nest, and in the process of excavating this site we are learning more and more about other creatures who lived and died there.”

The team even named their new find as homage to its famous home and its close lizard relatives in Asia.  Magnuviator ovimonsensis means “mighty traveller from Egg Mountain.”

A View of the Famous Fossil Location in Montana – Egg Mountain

The famous Egg Mountain fossil site.

A distant view of Egg Mountain and the basin in which it lies.

Picture Credit: David Varricchio

A distant view of Egg Mountain and the basin in which it lies.  Egg Mountain is in the centre-left of this image, within the basin.  Clearly visible at its top are black rectangular shapes, which are tarps erected near the excavation site

The Spectacular Egg Mountain Fossil Site

Through excavations at Egg Mountain led by co-author David Varricchio at Montana State University and meticulous analysis of fossils at partner institutions like the University Washington and the Burke Museum, scientists are piecing together the Egg Mountain ecosystem of around seventy-five million-years-ago.   In those days, Egg Mountain was a semi-arid environment, with little or no water at the surface. Dinosaurs like the duck-billed Hadrosaurs such as Maiasaura and the bird-like, carnivorous Troodon nested there.

To read about a study mapping the lives of a population of Maiasaura: Mapping the Lives of a Population of Plant-eating Dinosaurs

The Egg Mountain Ecosystem

Researchers have also unearthed fossilised mammals at Egg Mountain, which are being studied by Wilson’s group, as well as wasp pupae cases and pollen grains from plants adapted for dry environments.  Based on the structure of Magnuviator’s teeth, as well as the eating habits of some lizards today, the researchers believe that it could have feasted on wasps at the Egg Mountain site.  Though based on its relatively large size for a lizard, in excess of thirty centimetres long, Magnuviator could have also eaten something entirely different.  It might have been a herbivore.

Whatever its diet, Magnuviator and its relatives in Mongolia did not make it into the modern era.  DeMar and co-authors hypothesise that these stem lineages of lizards may have gone extinct along with the non-avian dinosaurs.  But given the spotty record for lizards in the fossil record, it will take more Magnuviator-level discoveries to resolve this debate, and, unfortunately, part of the excitement surrounding Magnuviator is that it is a very rare find.

Everything Dinosaur acknowledges the assistance of the University of Washington in the compilation of this article.

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