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Fossil finds, new dinosaur discoveries, news and views from the world of palaeontology and other Earth sciences.

22 03, 2017

Newly Described Silurian Fossil Honours Sir David Attenborough

By | March 22nd, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Fossil Discovery Named in Honour of Sir David Attenborough’s 90th Birthday

Sir David Attenborough has been honoured by an international team of scientists who have named a newly described Silurian Arthropod after the veteran broadcaster and naturalist.  Sir David has had a number of new species named in his honour, this 430 million-year-old, distant relative of today’s crabs and lobsters joins a long list of flora and fauna that includes wild flowers and a Jurassic Pliosaur (Attenborosaurus conybeari).

To read an article about a kitten-sized marsupial lion named after Sir David: Attenborough’s New Kitty”

Honouring Sir David Attenborough – Cascolus ravitis

An image (computer generated) of the Silurian Arthropod Cascolus ravitis.

A computer generated image of the newly described Silurian Arthropod Cascolus ravitis.

Picture Credit: Professor David Siveter et al

Sir David grew up in Leicestershire, he and his family lived on the campus of the former University College Leicester, where his father was the principal.  As a boy, Sir David often explored the exposed Jurassic outcrops, near to his Leicester home hunting for fossils.  His love of the local countryside and the animals and plants that surrounded his home, fuelled his passion to become a scientist.

Three-Dimensional Arthropod Fossil

The fossil specimen, which measures less than ten millimetres long, is described as “exceptionally well-preserved in three-dimensions”.  The researchers, which include scientists from Imperial College (London), Oxford University and Yale (United States), as well as Leicester University, have been able to identify the exoskeleton and other parts of the animal, such as the delicate antennae, legs and the compound eyes.  It has been assigned to the Crustacea sub-phylum and joins a remarkable fossil assemblage representing a marine biota preserved when ash from a volcano covered an ancient underwater ecosystem.  The actual location of the fossil site is a closely guarded secret, the site can be found in the county of Herefordshire, close to the Welsh border.  At this location, the limestone rock sequence is interrupted by a fine-grained bedding plane that represents ash from a volcanic eruption that smothered the seabed.  The ash buried all the creatures in and around the seafloor at the time, creating a unique opportunity for palaeontologists to study this ancient habitat.

Professor David Siveter (Department of Geology, Leicester University), commented:

“Such a well-preserved fossil is exciting, and this particular one is a unique example of its kind in the fossil record, and so we can establish it as a new species of a new genus.”

Cascolus ravitis

The genus name is derived from “castrum” meaning stronghold and “colus” which translates from the Old English as “dwelling in”, terms from which the surname Attenborough is derived.  The species name is a combination of “Ratae”, the Roman name for Leicester, “vita” which means life and “commeatis” a messenger.

Sir David Attenborough Receiving a High-Resolution Image of the Fossil Named in His Honour

Sir David Attenborough receiving a copy of the high resolution image of Cascolus ravitis

Sir David Attenborough receiving a high-resolution image of the newly described Silurian fossil.

Picture Credit: Leicester University

Left to right: Derek Siveter, (University of Oxford), Sir David Attenborough, Professor Paul Boyle, President and Vice-Chancellor of University of Leicester and David Siveter, University of Leicester.

Speaking about his latest honour, the nonagenarian, who will be celebrating his 91st birthday in a few weeks’ time, stated:

“The biggest compliment that a biologist or palaeontologist can pay to another one is to name a fossil in his honour and I take this as a very great compliment.  I was once a scientist so I’m very honoured and flattered that the Professor should say such nice things about me now.”

To read about other fossil discoveries from the Herefordshire site: The Kite Runner from the Silurian of England

Prehistoric marine parasites: Prehistoric Parasites from the Silurian

Sir David Attenborough has had a Genus of Jurassic Pliosaur Named in His Honour

Attenborosaurus conybeari

Named in honour of Sir David Attenborough – Attenborosaurus

Picture Credit: Everything Dinosaur

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

The research is published in the journal Proceedings of the Royal Society B (Biology).

19 03, 2017

Dinosaurs Learn to Stand on Their Two Feet

By | March 19th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

New Theory as to Why Bipedalism Evolved in the Dinosauria

Iconic dinosaurs such as Tyrannosaurus rex, Velociraptor, Coelophysis and Carnotaurus were all bipeds.  That is, they evolved the ability to walk on their hind legs.  Bipedalism is a trait that seems to have evolved early in history of the Dinosauria and it is a characteristic that is widespread amongst both lizard-hipped and bird-hipped forms.  It had been suggested that bipedalism arose in the ancestors of dinosaurs, to allow the forelimbs to be freed from a locomotive role, allowing them to have other uses, primarily to seize and grasp prey.  However, a team of scientists from the Department of Biological Sciences at the University of Alberta (Canada), have put forward a new theory to explain why some dinosaurs stood on two feet instead of four.  The ancestors of the dinosaurs had a “need for speed”!

The Basal Dinosauriform Marasuchus (M. lilloensis) is Typical of a Bipedal Ancestor of the Dinosauria

The basal dinosauriform Marasuchus from the Late Triassic of Argentina

The basal dinosauriform archosaur Marasuchus of the Middle Triassic. A potential ancestor of the Dinosauria.

 

Picture Credit: Pterosauriablog (author Taylor Reints)

The picture above shows the crow-sized Marasuchus, fossils of which come from the La Rioja Province (north-eastern Argentina), specifically from the Chañares Formation.  This fast running, bipedal reptile lived some 242 – 235 million years ago and the University of Alberta researchers argue that the presence of big muscles (the caudofemoralis), associated with the back of the legs and tail were central to driving the evolution of bipedalism amongst the archosaurs that were to eventually lead to the evolution of the dinosaurs.

From All Fours to Just Two Legs

Publishing in the academic periodical “The Journal of Theoretical Biology” lead author, Scott Persons and is co-worker Professor Phil Currie, argue that basal dinosauriforms were essentially quadrupeds but they evolved to stand upright, a characteristic that was passed onto their descendants the dinosaurs.

The scientists challenge the idea that bipedalism came about in order to help with the seizing of prey.

Persons stated:

“While that works for some of the very, very early dinosaurs, which were certainly carnivorous, you see a bunch of herbivorous dinosaurs evolve later on and a good many of those groups actually keep their bipedal stance, which is a little strange.”

Big Muscles in the Tail

The researchers argue, that strong muscles at the base of the tail helped to power the hind legs of these prototype dinosaurs.  This allowed them to run faster and for longer.  Hind legs evolved to become longer, whilst the forelimbs became shorter to reduce body weight and to improve balance and agility.  Some of these proto-dinosaurs gave up quadrupedalism entirely.   However, as all young dinosaur fans will happily tell you, there were lots of four-legged dinosaurs, examples being Triceratops, Stegosaurus and Diplodocus.  These dinosaurs were herbivores, they evolved heavy defensive weapons, horns and armour which meant that a faster, cursorial lifestyle was sacrificed.  As plant-eaters, they evolved ever larger stomachs and digestive tracts to help them process the tough plant material they ate, bigger guts also led to a reversion back to being a quadruped.

Palaeontologist Scott Persons added:

“In the groups where speed was no longer a concern, they often went back to being a quadruped”

A Rearing Diplodocus – A Four-Legged Dinosaur

CollectA Rearing Diplodocus.

A rearing Diplodocus!

Picture Credit: Everything Dinosaur

If you take the lizard-hipped, Sauropoda for instance, these herbivores evolved into a myriad of forms, but they all had the same basic body plan and there was a trend towards gigantism within this infraorder.  However, it has been suggested that those strong, muscular tails and powerful back legs enabled these dinosaurs to rear up to feed higher up in the vegetative canopy.  It has been suggested that baby Sauropods may have retained the ability to run on their hind legs, probably to help them escape predators.

To read an article about proposed bipedalism in juvenile Sauropods: Facultative Bipedalism in Young Sauropods

The powerful caudofemoralis muscle provides a greater source of propulsion to the back legs and it is the presence of this tail muscle that may have given the impetus to developing a two-legged stance.

Modern Lizards Provide a Clue

Modern facultatively bipedal lizards offer an analog for the first stages in the evolution of dinosaurian bipedalism.   In biology, the term facultative refers to the ability of many organisms to do things by choice rather than by obligation.  Facultatively bipedal lizards may spend most of the time on all fours, but when the need arises, such as to escape danger, these reptiles can revert to a bipedal stance.  An example of a living facultative biped lizard is the Australian frilled lizard (Chlamydosaurus kingii).

The Australian Frilled Lizard – An Example of a Living Reptilian Facultative Biped

Australian Frilled Lizard

The Australian frilled lizard – a facultative biped.

Why Don’t Fast Running Mammals Run on Two Legs?

Biomechanically, running on four legs is more efficient than running on two legs.  However, the University of Alberta researchers concluded that the behaviour of synapsid reptiles, distant ancestors of today’s fast running horses, cats, camels, and grey hounds, during the Permian, may explain the lack of bipeds amongst the Mammalia.

In the Permian geological period, it seems some animals started losing the reptilian trait of a strong leg-powering tail muscle.  Around that time, many creatures were becoming burrowers, (adapting to a fossorial lifestyle), so they needed strong front limbs for digging.  Big back legs and a long, powerful tail would have made it tough to manoeuvre in the confines of a burrow, as well as making it easier for a pursuing predator to snatch them by their tail.  The scientists postulate that living underground may have helped those proto-mammals survive the Permian mass extinction.  Their descendants would have evolved to run fast, but without the tail muscles that would have caused them to stand upright.

Commenting on the biological merits of Tetrapods evolving to favour one set of legs for running Scott Persons stated:

“That’s a really funny and strange adaptation.  Why would you choose to use just one set of limbs to help you run away when you’re most desperate?  And the answer has to do with that great big tail muscle [caudofemoralis].  It effectively sort of overpowers the back legs relative to the front legs.  What the lizards are effectively doing is popping a wheelie as they speed off.”

That cursorial advantage explains the relative abundance of cursorial facultative bipeds and obligate bipeds among fossil diapsids and the relative scarcity of either amongst the Mammalia and their close relatives.  Having lost their caudofemoralis in the Permian, perhaps in the context of adapting to a fossorial lifestyle, the mammalian line has been disinclined towards bipedalism, but, having never lost the caudofemoralis of their ancestors, the basal dinosauriforms and their relatives were more inclined to adopting a bipedal stance.

A Tale in a Tail!  Researchers Explain the Presence of Bipedalism within the Dinosauria

 

Gorgosaurus libratus illustrated.

A tale in the tail – the caudofemoralis provides propulsion leading to an evolutionary bias towards a bipedal stance.

Picture Credit: Everything Dinosaur

18 03, 2017

T. rex Has the Monopoly on Dinosaur Public Relations

By | March 18th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

T. rex Game Piece Destined for Monopoly

The makers of the family favourite board game “Monopoly” have announced that a Tyrannosaurus rex playing piece will be added to the game later this year.  The game “Monopoly” first went on sale in 1935, by the mid 1930’s, T. rex was already established as a “super star” amongst the Dinosauria.  This iconic dinosaur, famous for its tiny arms and huge jaws was one of the figures selected for new versions of the game, following a public vote.

The New T. rex Monopoly Game Piece

Tyrannosaurus rex added to board game (Monopoly).

T. rex game piece being added to Monopoly board game.

Picture Credit: BBC News

Palaeontologists, now know that Tyrannosaurus rex was not the largest carnivorous dinosaur.  However, it was one of the very last of huge Theropod dinosaurs to evolve and the Tyrannosaurs seem to have been a very long lived group of meat-eating dinosaurs.  The first Tyrannosaurs evolved during the Jurassic and one of the earliest was the tyrannosauroid Guanlong (G. wucaii), known from the Shishugou Formation of China.  Guanlong was formally described in 2006 and it is believed to have lived some 160 million years ago (Oxfordian faunal stage of the Late Jurassic).

Despite the huge increase in different types of dinosaur, T. rex seems to dominate still.  This Late Cretaceous meat-eater has a special place in the public’s affection.  No dinosaur movie seems complete without an appearance of Tyrannosaurus rex, here at Everything Dinosaur, T. rex models out sell all the other dinosaur models by a ratio of 4 :1.  Tyrannosaurus rex certainly seems to have cornered the market when it comes to dinosaur public relations.

Tyrannosaurus rex is as popular as ever, now Monopoly fans can play with a T. rex game piece.  We are not sure how a fully-grown Tyrannosaurus rex would have coped with Bond Street, the Waterworks or even the Old Kent Road, but we are sure this new addition to the family board game will be most welcome.

Theropods in London!  Does T. rex Have a Monopoly?

Theropods in London.

Dinosaurs in London?

Picture Credit: Dinosaurs Unleashed

17 03, 2017

Primitive Neornithischian Dinosaurs and Seed Dispersal

By | March 17th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Plant-Eating Dinosaurs Probably Played an Important Role in Seed Dispersal

Time to catch up on our reading and first on the list of papers is this fascinating insight into the relationship between plant-eating dinosaurs and seed dispersal.  An international team of scientists from Portugal, Spain and Argentina have described a new species of primitive, bird-hipped dinosaur and an assessment of the body cavity led to the discovery of the dinosaur’s last meal.  Permineralised seeds, most of which having been identified as coming from cycads (Cycadales), suggest that herbivorous dinosaurs played an important role in seed dispersal, just as many plant-eating mammals do today.

The New Argentinian Dinosaur Isaberrysaura mollensis is Related to Kulindadromeus from Siberia

A scale model of the feathered dinosaur Kulindadromeus.

A 1:1 scale model of Kulindadromeus, closely related to Isaberrysaura.

Picture Credit: T. Hubin/RBINS

The researchers which include lead author, Leonardo Salgado (CONICET – Universidad Nacional de Río Negro), conducted a phylogenetic analysis and assigned this new dinosaur species to the basal Ornithopoda, suggesting that it is closely related to Kulindadromeus (K. zabaikalicus), fossils of which are known from geologically younger strata found in Siberia.  However, this new dinosaur, named Isaberrysaura was much larger, with an estimated body length of approximately six metres.

The Feeding Habits of Herbivorous Dinosaurs

Despite some two-thirds of all the dinosaurs described to date being plant-eaters, there is little direct evidence of the feeding habits of herbivorous dinosaurs that matches the stomach contents preserved within a carcase.  Most unaltered gut content that has been found is associated with much later dinosaurs -hadrosaurids and ornithopods.  This is the first time that gut contents have been identified in association with the remains of a basal neornithischian.

The specimen, representing a single individual, consists of an almost complete skull, vertebrae, part of the left shoulder blade (scapula), along with ribs and elements from the pelvic girdle.  It was excavated from the Los Molles Formation (Neuquén Basin, Argentina), from sediments that suggest a coastal-delta environment, the presence of the zone ammonite Sonninia altecostata in the same fossil bed, indicate that Isaberrysaura lived some 170 million years ago (Early Bajocian faunal stage of the Middle Jurassic).  These are the first dinosaur remains found in this geological unit and the one of the oldest dinosaurs known from the Neuquén Basin.  In addition, this is the first neornithischian dinosaur known from the Jurassic of South America.  The skull and the teeth show some affinity with basal stegosaurids which suggests that both the Thyreophora and neornithischian dinosaurs shared a lot of similar features (potential evidence of convergent evolution amongst plant-eating dinosaurs).

Isaberrysaura mollensis – Views of the Skull and Teeth

Isaberrysaura mollensis - views of the skull and teeth.

The skull in (a) dorsal and left lateral view (c) with corresponding line drawings (b and d).  Premaxillary tooth (e) and maxillary teeth (e and f).

Picture Credit: Scientific Reports

 Why Isaberrysaura?

This month, we have once again been celebrating International Women’s Day (March 8th), it is pleasing to note that the female form of “saurus” has been chosen when it came to naming this new dinosaur, as the genus has been erected to honour Isabel Valdivia Berry, who reported the finding of the holotype material.  In the body cavity, the researchers were able to identify a mass of permineralised seeds.  These were identified as belonging mostly to the Cycadales group of plants.  These tough seeds would have passed through the dinosaur’s gut and would have been deposited in the dung.  This fossil discovery suggests a possible and unexpected role of bird-hipped dinosaurs, that of Jurassic seed-dispersal agents.

An Analysis of the Gut Contents of Isaberrysaura 

The gut contents of Isaberrysaura mollensis.

Permineralised seeds identified in the gut cavity of Isaberrysaura mollensis.

The photograph above shows images of the body cavity showing evidence of the seed fossils.

Some of the fossils show that their fleshy seed-coats are still intact (sc = sarcotesta), this indicates that these seeds were swallowed whole with little or no chewing action in the mouth.

The scientific paper: “A New Primitive Neornithischian Dinosaur from the Jurassic of Patagonia with Gut Contents”, published in the journal “Scientific Reports”

15 03, 2017

Not All Mesozoic Crocodiles Were Giants

By | March 15th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Knoetschkesuchus – Living on an Island

Last month, scientists published in the on line academic journal “PLOS ONE” a paper that provided details of the discovery of a new species of Late Jurassic terrestrial crocodile, but this animal was no ground-shaking giant, like most of its kind (atoposaurids), it probably had a maximum length of under a metre and it would have weighed a couple of kilogrammes or so.

Lead author of the research paper, Daniela Schwarz (Leibniz Institute for Evolutionary and Biodiversity Research, Germany), in collaboration with colleagues, re-examined fossils including skull material (an adult and a juvenile specimen), that had previously been assigned to the atoposaurid Theriosuchus – a genus of crocodile-like reptile that is known from a large number of fossils dating from the Late Jurassic and into the Early Cretaceous from places as far apart as Thailand and southern England.  However, when the beautifully preserved fossils were studied using CT scans and three-dimensional images of the fossil material created, a number of autapomorphies were identified to allow the erection of a new genus.

A View of the Larger Specimen of Knoetschkesuchus langenbergensis

Knoetschkesuchus langenbergensis fossil material (larger specimen).

Knoetschkesuchus langenbergensis fossil material.

Picture Credit: PLOS ONE

The little crocodile has been named Knoetschkesuchus langenbergensis, the fossils come from the famous Langenberg Quarry, located near the town of Goslar, Lower Saxony, northern Germany.  The limestones and marls that form the quarry site, were laid down in shallow inlets associated with an island archipelago.  The Knoetschkesuchus material comes from Bed 83, the same location as the fossils of the dwarf Sauropod Europasaurus (E. holgeri).

Lots of Terrestrial Crocodiles in the Mesozoic

Knoetschkesuchus langenbergensis fossil material has been dated to the Upper Kimmeridgian stage of the Jurassic, approximately 154 million years ago, like most members of the Atoposauridae it had large eyes and it may have been a fast runner.  The researchers conclude that the Langenberg Quarry fossils represent a new species because of unique features of the skull, such as openings in the jaw bone and in front of the eye, as well as the shape and placement of the animal’s tiny teeth.  The teeth are heterodont in nature (different shapes), at the tip of the snout they are pointy and needle-like, very typical of a small crocodilian, but towards the back of the jaws they are broader and more rounded, particularly in the lower jaw.  It has been suggested that these teeth were adapted for crushing hard-shelled prey, such as snails, which are known from abundant gastropod fossils associated with Bed 83.

Line Drawings Showing Various Views of Both the Adult and Juvenile Skull Specimens

Knoetschkesuchus skull illustrations

Knoetschkesuchus skull drawings.

Picture Credit: PLOS ONE with additional annotation by Everything Dinosaur

Note

Elements of the adult skull fossil have been drawn based on scaled-up material from the juvenile specimen.

Dr Schwarz commented:

“The study describes a new diminutive crocodile Knoetschkesuchus langenbergensis that lived around 154 Million years ago in north-western Germany.  Knoetschkesuchus belongs to the evolutionary lineage that leads to modern crocodiles and preserves for the first time in this group two skulls in 3-D, allowing us detailed anatomical studies via micro-CT images.  Our research is part of the Europasaurus-Project which studies the remains of a unique Jurassic island ecosystem in northern Germany.”

A Unique Island Ecosystem

The Langenberg Quarry preserves the remains of a unique Late Jurassic European ecosystem.  The islands were relatively small and this led to a divergence between residents of these islands and their ancestors which lived on the larger landmasses to the east.  For example, in response to limited food resources and space, the Sauropod Europasaurus became a dwarf form.  The atoposaurid crocodiles probably filled a number of ecological niches within the food chain, including that of arboreal predators.  These distant ancestors of today’s crocodiles were in turn preyed upon by a variety of Theropod dinosaurs, the majority of which are only known from fragmentary teeth.  What is quite remarkable, is the diversity of the Theropod teeth found in Upper Jurassic deposits of northern Germany.  Studies have suggested that representatives of the Tyrannosauroidea, as well as Allosauroidea, Megalosauroidea and probably Ceratosauria roamed this part of the world some 155 to 150 million years ago.

The genus name (Knoetschkesuchus) is a combination of the family name of Nils Knötschke, and suchus (from the Greek meaning crocodile).  The genus name honours of Nils Knötschke (Dinosaurier-Freilichtmuseum Münchehagen), who collected, prepared, and curated several important fossil specimens from the Langenberg Quarry.

14 03, 2017

Pushing Back the Origins of Complex Life

By | March 14th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|0 Comments

Scientists Uncover Evidence of the Earliest Plants

One of the most significant steps in the history of life on Earth may have occurred earlier than previously thought, according to a new study published by Scandinavian scientists in the on line academic journal “PLOS Biology”.  The evolution of simple, non-nucleated cells (prokaryotes) to large, more complex and specialist cells (eukaryotes) may have taken place some 400 million years earlier.  The team might have uncovered evidence of the oldest plants known to science.

Red Algae – Look Out for the Stacked Plates

The researchers which include Therese Sallstedt (Swedish Museum of Natural History), examined exquisitely preserved, three-dimensional fossils, found in very ancient sedimentary rocks from central India (Vindhyan basin).  These rocks are known for their abundance of micro-fossils, and the researchers analysed the minute fossil remains that represent a biota that once existed in a shallow sea.  The team identified structures within the micro-fossils that correspond to chloroplasts, which are found within plant cells today.  The strata has been dated to approximately 1.6 billion years ago, the photosynthetic biomats amidst extensive cyanobacterial micro-fossils, had filaments and other features such as plate-like discs that represent stacked cells that are very reminiscent of red algae (Rhodophyta).  Prior to this discovery, experts believed that the earliest eukaryotes evolved some 1.2 billion years ago, as demonstrated by the oldest known multicellular organism Bangiomorpha pubescens, found in Canadian rocks around 1.2 billion years old.  Bangiomorpha is related to today’s red algae, it seems, from this new evidence, that the multicellular Rhodophyta, complete with their complex cells containing a nucleus, have been on Earth for far longer than previously thought.

Two Forms of Red Algae

The fossils appear to show two distinct types of red algae: Rafatazmia chitrakootensis, characterised as filamentous in shape and containing large plate-like, stacked discs that the researchers think may be parts of algal chloroplasts and Ramathallus lobatus, which would have been more rounded in shape and fatter.

Digital Images of Rafatazmia chitrakootensis

Evidence of the oldest plants uncovered.

Rafatazmia chitrakootensis digital images of the ancient eukaryote (chloroplast structures highlighted green).

Picture Credit: PLOS Biology

The picture above shows (A–L) Holotype, NRM X4258.  (A) Surface rendering.  (B) Volume rendering with rhomboidal disks coloured for visibility.  (C) Virtual slice. (D) Surface.  (E) Volume. (F–L) Transverse slices (positions indicated in B).  (M–O) NRM X5620, surface, volume, slice.  (P–R) NRM X5574, surface, volume, slice.  Scale bars 50 μm.

Most scientists already believed that red algae (Rhodophyta) to be some of the earliest eukaryotic organisms to evolve.  Pushing the date back by some 400 million years or so, has implications for our understanding of evolution as a whole and may help clear questions about the rates at which mutations occur in the genome over time.

The scientific paper: “Three-dimensional Preservation of Cellular and Subcellular Structures Suggests 1.6 billion-year-old Crown-group Red Algae”, published in “PLOS Biology.”

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

9 03, 2017

Neanderthals and Aspirin

By | March 9th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page|0 Comments

A Reappraisal of our Closest Cousin

The Neanderthal (Homo neanderthalensis) is our closest relative on the hominin family tree.  As our own genome has become better understood, geneticists and anthropologists have been able to appreciate just how closely related we are to Neanderthals.  However, since the first description of the Neanderthal (based on fossil remains from the Neander Valley in Germany), back in 1863, H. neanderthalensis has had quite a bad press.  For most of the last 150 years or so, since we have known about this hominin species, the Neanderthals have been depicted as dim-witted, brutal ape-men.  We now live in more enlightened times, our perception of the Neanderthal has changed.  There is considerable evidence to indicate that this species of human, one that died out around 28,000 years ago, just a blink in geological time, was smart, strong and had a sophisticated culture.

Many 20th Century Artists Depicted Neanderthals as “Ape-men”

Ancient hominins by Zdenek Burian.

Neanderthals depicted a quite primitive “ape-men”.

Picture Credit: Zdenek Burian

Neanderthals May Have Used Plants as Medicine

In a new study, published this week in the journal “Nature”, researchers from the University of Liverpool in collaboration with colleagues from the University of Adelaide’s Australian Centre for Ancient DNA (ACAD) and Dental School suggest that Neanderthals may have had quite a remarkable knowledge of medicine, even using penicillin, some 40,000 years before Sir Alexander Fleming.  An analysis of ancient DNA found in the dental plaque of Neanderthals has provided further evidence that this species of hominin was intelligent and resourceful, using plant-based medicines and moulds to treat a variety of complaints.

The research also reveals dietary differences between different Neanderthal populations.

Commenting on the study, lead author Dr Laura Weyrich (ACAD) stated:

“Dental plaque traps micro-organisms that lived in the mouth and pathogens found in the respiratory and gastrointestinal tract, as well as bits of food stuck in the teeth, preserving the DNA for thousands of years.  Genetic analysis of that DNA ‘locked-up’ in plaque, represents a unique window into Neanderthal lifestyle, revealing new details of what they ate, what their health was like and how the environment impacted their behaviour.”

Partial Neanderthal Skull Showing Jaw Bones

Neanderthals were smarter than we thought.

DNA from ancient dental plaque provides new insights into the Neanderthals.

Picture Credit: University of Liverpool

The scientists analysed and evaluated dental plaque samples from four Neanderthals found at the cave sites of Spy (Belgium) and El Sidrón (Spain).  The four samples range in date from 50,000 years ago to 42,000 years ago approximately.  The samples represent the oldest dental plaque to be genetically analysed.

The Spy Cave Neanderthals were found to have a largely carnivorous diet, consuming Coelodonta (Woolly Rhinoceros), wild sheep and foraged mushrooms.  In contrast, the Neanderthals from the El Sidrón Cave site, showed no evidence of meat consumption, appearing to have had a largely vegetarian diet, consisting of moss, tree bark, mushrooms and pine nuts.

A spokesperson from Everything Dinosaur commented:

“Based on this dietary information, it can be assumed that these two groups of Neanderthals had very different lifestyles.  One group seem to have been active hunters, trapping, ambushing and killing animals, whilst the other group seem to have been foragers within a forest environment.  The dental plaque analysis leads to the inference that different groups of Neanderthals had different behaviours and ultimately, different strategies for survival.”

Surprising Self-Medication

Evidence for self-medication was detected in an El Sidrón Neanderthal with a dental abscess (identified from scarring left on the jaw), this individual (most likely a male), also suffered from a chronic gastrointestinal pathogen (Enterocytozoon bieneusi).  He would have been suffering from a severe bought of diarrhoea.  The intestinal parasite was identified through studying DNA in the ancient dental plaque.  However, further analysis revealed that he had been chewing the bark of the Poplar tree, which contains the natural pain killer salicylic acid (the active ingredient in modern aspirin).  The scientists could also detect a natural antibiotic mould (Penicillium) not found in the other Neanderthals examined within this study.

From this, the team concluded that Neanderthals may have possessed a substantial knowledge of medicinal plants and their various anti-inflammatory and pain-reliving properties.

One of the researchers stated:

“Our findings contrast markedly with the rather simplistic view of our ancient relatives in popular imagination.”

The El Sidrón Neanderthal provided another intriguing insight into our Neanderthal evolutionary relationship.  It seems that we shared several disease-causing microbes, including the bacteria that cause gum disease and dental caries.  The scientists were able to identify the oldest microbial genome yet sequenced, a gum rotting bacteria called Methanobrevibacter oralis.  The microbial genome is estimated to be around 48,000 years old.

The researchers also noted how rapidly the oral microbial community has altered in recent history.  The composition of the oral bacterial population in Neanderthals and both ancient and modern humans correlated closely with the amount of meat consumed in the diet, with the Spanish Neanderthals grouping more closely with chimpanzees and our forager ancestors in Africa.  The Belgian Neanderthal bacteria, in contrast, were similar to early hunter gatherers, and quite close to modern humans and early farmers.

Dental plaque and its microbial treasures are providing an extraordinary window on the past, giving geneticists and anthropologists new ways to explore and understand our evolutionary history through the micro-organisms that lived in us.

8 03, 2017

Unravelling a Fishy Tale

By | March 8th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|1 Comment

Reassessment of Ichthyosaur Material Solves Century Old Mystery

Ichthyosaurs were a very successful group of marine reptiles. They originated during the Triassic and thrived in the seas of the Mesozoic and had a global distribution, but towards the end of the Cretaceous, these dolphin-shaped animals, that seemed so perfectly adapted to their environment, became extinct.  They were the first, large extinct reptiles brought to the attention of the scientific world.  It is difficult to avoid mention of the Ichthyosaurs when looking at information that outlines the history of palaeontology, however, despite first having been described nearly 200 years ago, (1821), there is still a lot we don’t know about these iconic “fish lizards”.

The Iconic Ichthyosaurus

An Ichthyosaur illustration.

An Ichthyosaur (courtesy of Robert Richardson).

Picture Credit: Robert Richardson

The Long History of Ichthyosaur Research

It is the long history of scientific study and research into the Ichthyosaurs that has proved to be a bit of a headache for today’s palaeontologists.   Dean Lomax, a palaeontologist and Honorary Scientist at The University of Manchester, working with Professor Judy Massare of Brockport College, New York, have studied thousands of Ichthyosaur specimens and have delved through hundreds of years of records to solve an ancient mystery, a mystery that dates back to the early 1820’2, when the English geologist William Conybeare, described the first species of Ichthyosaurus.

Many Ichthyosaur fossils were found in England during the early 19th century, but it was not until 1821 that the first Ichthyosaur species was described called Ichthyosaurus communis.  This species has become one of the most well-known and iconic of all the British fossil reptiles, after all, an Ichthyosaurus even featured on a set of specially commissioned Royal Mail stamps to celebrate 150 years of British palaeontology!

To read article about the Royal Mail commemorative stamps: Royal Mail Issues New Prehistoric Animal Stamps

In 1822, three other species of Ichthyosaurus were described, based on differences in the shape and structure of their teeth.  Two of the species were later re-identified as other types of Ichthyosaur, whereas one of these species, called Ichthyosaurus intermedius, was still considered closely related to I. communis.

In the years that followed, many eminent scientists, including Sir Richard Owen (the man who coined the word dinosaur), studied “fish lizard” fossils collected from Dorset, Somerset, Yorkshire and other locations in England.  Their studies and observations of Ichthyosaurus communis and I. intermedius resulted in confusion with the species, with many skeletons identified on unreliable grounds.

Commenting on this palaeontological puzzle, Dean Lomax stated:

“The early accounts of Ichthyosaurs were based on very scrappy, often isolated, remains.  This resulted in a very poor understanding of the differences between species and thus how to identify them.  To complicate matters further, the original specimen of Ichthyosaurus communis is lost and was never illustrated.  Similarly, the original specimen of I. intermedius is also lost, but an illustration does exist.  This has caused a big headache for palaeontologists trying to understand the differences between the species.”

Hunting for Clues to Help Solve a “Fish Lizard” Mystery

Dean Lomax and Judy Massare examining Ichthyosaur specimens.

Dean Lomax and Judy Massare examining Ichthyosaur specimens in the marine reptile gallery at the Natural History Museum (London).

Picture Credit: Dean Lomax

In the mid-1970’s, palaeontologist, Dr Chris McGowan was the first to suggest that Ichthyosaurus communis and I. intermedius may represent the same species.  He could not find reliable evidence to separate the two species.  Subsequent studies argued for and against the separation of the species.

In this new research, Dean and Judy have reviewed all of the research for and against the separation of the two species.  This is the most extensive scientific study ever published comparing the two Jurassic-aged marine reptiles.   The pair of scientists have confirmed that the species are the same and that features of Ichthyosaurus intermedius can be found in other Ichthyosaur species, including I. communis.

It seems that the fossil material ascribed to the species Ichthyosaurus intermedius lack any autapomorphies – distinctive features or derived characteristics and traits that are unique to that taxon.

Thanks to the efforts of these two researchers, a fishy tale that is over a hundred years may have been resolved.

In recent years, the duo have described three new species and have provided a reassessment of historical species.  Their work has provided a far superior understanding of the species than has ever been produced.

The research has been published in Journal of Systematic Palaeontology: http://dx.doi.org/10.1080/14772019.2017.1291116.

4 03, 2017

Woolly Mammoth Genome Meltdown

By | March 4th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Mammoth Mutational Meltdown As Species Headed for Extinction

Woolly Mammoths experienced a mutational meltdown in their genome prior to their extinction according to a study published this week by researchers at the University of California (Berkeley).  The Woolly Mammoth genome has been mapped (2015), scientists have been able to make comparisons between the extinct species (Mammuthus primigenius) and its closest living relative, the Indian Elephant (Elephas maximus).  A great deal of information has been gained from these genetic studies, but the mystery of why this animal which roamed across Europe, Siberia, North America and the land mass which once joined Asia to the Americas (Beringia), died out remains.  In this new research, scientists from the University of California (Berkeley) compared the genetic makeup of one of the last surviving mammoths, with the genome of a mammoth that had lived when these iconic creatures of the Pleistocene were still thriving.

Study into the Last Population of Woolly Mammoths Reveals Genetic Defects

Woolly Mammoths.

DNA clues as to why the last Mammoths became extinct.

Picture Credit: Everything Dinosaur

To read an article on the mapping of the Woolly Mammoth genome: Woolly Mammoth Genome is Sequenced

Comparing the Genome of a Mammoth from 45,000 Years Ago to One of the Last Mammoths

The comparison gave researchers the rare opportunity to see what happens to the genome as a population dwindles, the conclusions drawn support existing theories of genome deterioration stemming from small population sizes.  The study also provides a stark warning to conservationists and environmentalists.  Preserving a small group of isolated animals is not sufficient to stop negative effects of inbreeding and genomic meltdown.

Corresponding author, Rebekah Rogers, who led the work as a postdoctoral scholar at Berkeley and is now an assistant professor at the University of North Carolina stated:

“There is a long history of theoretical work about how genomes might change in small populations.  Here we got a rare chance to look at snapshots of genomes “before” and “after” a population decline in a single species.  The results we found were consistent with this theory that had been discussed for decades.”

The researchers, which included Professor Monty Slatkin, looked at the genome from a Woolly Mammoth that had lived on Wrangel Island, the last known refuge of the Woolly Mammoth.  The DNA was extracted from a specimen that lived some six hundred years before the elephant species finally died out.  The genetic material from the 4,300-year-old individual was compared to the DNA from a mammoth that had lived in Siberia some 40,000 years earlier when the Woolly Mammoth population was still large and relatively robust.

Reporting in the journal “PLOS Genetics”, the researchers found a lot of mutations in the Wrangel Island specimen’s genome.  The comparative analysis with the mainland mammoth remains showed that the Wrangel Island specimen had accumulated multiple harmful mutations in its genome, which interfered with gene functions.  The animals had lost many olfactory receptors, which detect odours, as well as urinary proteins, which can impact upon social status and mate choice.  The genome also revealed that the Wrangel Island mammoth had specific mutations that likely created an unusual translucent satin coat.

Rebekah Rogers said mathematical models developed by Slatkin of how genomes change as population conditions change were key to analysing and comparing the two genomes.

She stated:

“With only two specimens to look at, these mathematical models were important to show that the differences between the two mammoths are too extreme to be explained by other factors.”

Wrangel Island – The Last Refuge of the Woolly Mammoth

Rising sea levels cut off the land that is now known as Wrangel Island around 10,000 years ago.  A population of Woolly Mammoths were then isolated from the mainland and this population persisted for several thousand years, before the last of the Mammoths became extinct around 2000 B.C.

The Location of Wrangel Island in the Arctic Ocean

Wrangel Island.

The last refuge of the Woolly Mammoth.

Picture Credit: Google Maps

The isolated and small population of Wrangel Island mammoths probably exhibited an accumulation of detrimental mutations consistent with genomic meltdown in response to low effective population sizes in the dwindling population.  With Mountain Gorilla (Gorilla beringei beringei), Snow Leopard (Panthera uncia) and the Sumatran Rhinoceros (Dicerorhinus sumatrensis) populations at or below the assumed population of Wrangel Island mammoths (around 300 individuals), this research provides conservationists with sobering evidence which suggests attempting to preserve a small group of individuals may not be enough to stop degradation of the genetic material that the viability of the species depends on.

To read an article that suggests dwindling supplies for freshwater speeded up the demise of isolated Woolly Mammoth populations: Last of the Mammoths Died of Thirst

Genetic Studies are Helping to Solve the Riddle of the Woolly Mammoth Extinction

Mammoth vertebrae.

Genetic studies are now telling us more about Woolly Mammoths than their bones ever could.

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