The Sedgwick Museum in Cambridge has an exhibit that tells the remarkable story of the eurypterid Megarachne servinei. It was once thought to be a giant spider. However, it has been assigned to the Mycteroptidae family within the Euryptreida Order. In a recent blog post we looked at the eurypterid display at the Museum.  In particular we commented upon the enormous Jaekelopterus rhenaniae, which is regarded as being one of the largest invertebrates known to science.

To view our earlier post about the giant Jaekelopterus rhenaniae and the eurypterid exhibit: A Colourful Eurypterid Size Chart.

In the exhibit highlighting giant invertebrates, a series of posters provide visitors with information how the palaeo-reconstruction artist Bob Nicholls worked with the researchers to create an interpretation of the fossil material. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Megarachne servinei

The genus name translates as “giant spider”.  If the original scientific assessment had proved to be correct, then M. servinei would be the biggest spider known to science.

Part of this display explains how renowned palaeo-reconstruction artist Bob Nicholls worked with researchers to produce an accurate life reconstruction of this ancient South American invertebrate.

The life reconstruction of Megarachne servinei on display at the Sedgwick Museum (Cambridge). This illustration was created by talented palaeoartist Bob Nicholls. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Mike from Everything Dinosaur commented:

“Palaeoart brings long-extinct creatures back to life. The Megarachne servinei is a fine example. By combining science with illustration, it helps people visualise how these animals looked and lived. As a result, complex fossil evidence, which is often fragmentary becomes easier to understand.”

The Everything Dinosaur website: Dinosaur Models and Prehistoric Animal Figures.

Mike and Sue from Everything Dinosaur recently visited the Sedgwick Museum in Cambridge. During their trip, they spotted a colourful eurypterid size chart on display. It immediately caught their attention.

A largest eurypterid size chart on display at the Sedgwick Museum (Cambridge). The Devonian freshwater eurypterid Jaekelopterus rhenaniae is the largest discovered to date and perhaps the biggest invertebrate of all time. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The Eurypterid Size Chart

The size chart shows seven different eurypterids.  The smallest is Megarachne servinei which is known from the Late Carboniferous of Argentina.  When it was described, it was thought to be a spider. As such, it would have been the largest spider known to science. However, several eurypterids were much bigger.  For example, the largest eurypterid in the diagram, indeed possibly the largest invertebrate of all time is Jaekelopterus rhenaniae.

The stunning 1:20 scale CollectA Deluxe Jaekelopterus rhenaniae model. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The picture (above) shows the CollectA Deluxe 1:20 scale Jaekelopterus rhenaniae figure. It is a spectacular model.

To view the range of CollectA Deluxe figures in stock: CollectA Deluxe Scale Models.

“Sea Scorpions”

Eurypterids, also known as sea scorpions, are fascinating creatures. Scientists have described around 250 different species. They were active predators. Using their chelicerae, they hunted invertebrates and even primitive fish.

At first, all eurypterids lived in the sea. They were entirely marine. However, things began to change over time. By the Late Devonian and Carboniferous, freshwater species had evolved.

The story of their discovery is also remarkable. In 1818, the very first eurypterid fossil came to light in New York State. At the time, it was thought that this fossil represented an early fish.

Mike from Everything Dinosaur commented:

“The Sedgwick Museum offers a fantastic experience. Its collection includes extremely important fossil discoveries. In addition, visitors find it far less crowded than the London Natural History Museum.”

The Everything Dinosaur website: Dinosaur Toys and Models.

Two remarkable juvenile Pterodactylus fossils have helped researchers to solve a puzzle concerning the Upper Jurassic deposits at Solnhofen. The Upper Jurassic Solnhofen archipelago of Germany has yielded a pterosaur assemblage that has long underpinned and continues to dominate much of our understanding of these Mesozoic flying reptiles.  Pterosaur fossils from this location broadly fit into two categories.  Firstly, there are the highly fragmentary fossils of adult, or sub-adults.  Often a specimen is represented by a single bone.  Secondly, there are the numerous very young pterosaurs* that are preserved almost intact and articulated.

A detailed analysis of two remarkable hatchling Pterodactylus fossils has helped scientists to put forward a plausible theory as to why these two types of fossil preservation, driven by ontogeny occurred.  They postulate that these two baby pterosaurs perished in a violent storm.  Young pterosaurs were caught in powerful tropical storms. Ironically, these powerful storms also created the ideal conditions to preserve their remains and hundreds more.

A hatchling Pterodactylus caught in a storm. Picture credit: Rudolf Hima.

Picture credit: Rudolf Hima

The Mystery of the Hatchling and Juvenile Pterodactylus Specimens

The researchers, including scientists from the University of Leicester discovered broken humeri in the fossilised remains of two hatchling pterosaurs.  These very young flying reptiles suffered broken wings.  The cause of death for these pterosaurs nicknamed “Lucky I” and “Lucky II” by the researchers, has been revealed.  Consider this a post-mortem on events that took place in the Late Jurassic around 150 million years ago.

Writing in the academic journal “Current Biology”, the team highlight that the preservation bias for large, more robust specimens was turned on its head in the waters of the Solnhofen lagoon.  Small delicate animals such as a juvenile Pterodactylus would rarely make it into the fossil record.  However, occasionally nature conspires to produce the conditions that permit the preservation of diminutive pterosaurs.

Lead author of the paper, Rab Smyth (University of Leicester) explained:

“Pterosaurs had incredibly lightweight skeletons. Hollow, thin-walled bones are ideal for flight but terrible for fossilisation. The odds of preserving one are already slim and finding a fossil that tells you how the animal died is even rarer.”

Examining the Tiny Fossils Under UV Light

Examination of the tiny fossils under UV light revealed the presence of broken upper arm bones (humeri) in the two specimens.  These details, easily overlooked, provided the evidence that their wings were subjected to a strong twisting force.  This was probably caused by a strong gust of wind rather than a collision against a hard surface.

Broken bones offer clues to the perils of pterosaur flight. Skeletal reconstructions of the two Pterodactylus hatchlings are shown in flight position, with broken bones marked in red. UV images reveal clear breaks in the upper arm bones. A silhouette of a house mouse (Mus musculus) is included for scale. Picture credit: Smyth et al (University of Leicester).

Picture credit: Smyth et al (University of Leicester)

The picture (above) shows fossil specimen MBH 250624-07 (Lucky I) as (A) part and (B) counterpart.  They are photographed under UV light.  The broken left humerus is in a predominantly ventral view, with the skull exposed in lateral view. Images C and D show the part and counterpart of Lucky II (SNSB-BSPG 1993 XVIII 1508 a/b), photographed in ventral view.  The fossil has a fractured right humerus.

Skeletal reconstructions of Lucky I (E) and Lucky II (F) along with a silhouette of a house mouse (Mus musculus) to provide scale.

Highlighting how Local Environmental Conditions can Distort the Fossil Record

The skeletons are virtually complete and articulated. Except for one small detail. Both specimens show the same unusual injury – a clean, slanted fracture to the humerus. Lucky’s left wing and Lucky II’s right wing were both broken in a way that suggests a powerful twisting force.  The researchers postulate that these unfortunate flying reptiles were caught up in a storm.

Pterosaur fossil preservation in the Solnhofen deposits. (A) Most of the time, pterosaurs stood little chance of becoming fossils. Decaying larger individuals sometimes left behind scattered bones that reached the lagoon floor, but smaller pterosaurs were usually lost without trace. (B) Storms, however, created very different conditions. Powerful winds and waves dragged the bodies of small and young pterosaurs into deeper waters. At the same time, these storms stirred up salty water from the lagoon floor. This water contained almost no oxygen, and when it mixed with the surface waters, it triggered sudden die-offs of marine life. These toxic waters acted as a barrier to scavengers and decay, allowing pterosaur bodies to sink largely untouched. The final step came when lime-rich mud, carried by the storm, rapidly buried the remains. This quick covering not only protected soft tissues from decay but also preserved fragments of larger pterosaurs that had been deposited earlier. Together, these rare conditions explain why fossils from Solnhofen are so well preserved. Picture credit: Smyth et al (University of Leicester).

Picture credit: Smyth et al (University of Leicester)

Catastrophically injured, the pterosaurs plunged into the surface of the lagoon, drowning in the storm driven waves and quickly sinking to the seabed where they were rapidly buried by very fine limy muds stirred up by the violent storm events. This rapid burial allowed for the remarkable preservation seen in their fossils.  The researchers have highlighted how local environmental conditions can lead to distortions in the fossil record.

Ironic Names for Juvenile Pterodactylus Fossils

Lucky I and Lucky II are ironic nicknames for these pterosaur fossils.  These animals may only have been a few days or weeks old when they perished.  There are many other small pterosaurs preserved in the Solnhofen limestone deposits.  These too, might present very young flying reptiles.  They may not demonstrate obvious signs of skeletal trauma but they could have met a similar fate as Lucky I and Lucky II. Unable to resist the strength of storms these young pterosaurs were also flung into the lagoon. This discovery may explain why smaller fossils are so well preserved – they were a direct result of storms – a common cause of death for pterosaurs that lived in the region.

Larger, stronger individuals, it seems, were able to weather the storms and rarely followed the Luckies stormy road to death. They did eventually die though but likely floated for days or weeks on the now calm surfaces of the Solnhofen lagoon, occasionally dropping parts of their carcasses into the abyss as their bodies slowly decomposed.

Rab Smyth added:

“For centuries, scientists believed that the Solnhofen lagoon ecosystems were dominated by small pterosaurs. But we now know this view is deeply biased. Many of these pterosaurs weren’t native to the lagoon at all. Most are inexperienced juveniles that were likely living on nearby islands that were unfortunately caught up in powerful storms.”

The researchers conclude that catastrophic storm sampling explains the high numbers of small, potentially juvenile pterosaurs preserved in the Solnhofen deposits.  This study also has implications for the perceived flight abilities of very young flying reptiles.  Wing injuries in neonatal pterosaurs were likely caused by violent storm events and this research supports precocial flight ability.

A “Lucky” Break

Co-author of the paper, Dr David Unwin (University of Leicester) commented:

“When Rab spotted Lucky we were very excited but realised that it was a one-off. Was it representative in any way? A year later, when Rab noticed Lucky II we knew that it was no longer a freak find but evidence of how these animals were dying. Later still, when we had a chance to light-up Lucky II with our UV torches, it literally leapt out of the rock at us – and our hearts stopped. Neither of us will ever forget that moment.”

*very young pterosaurs – there is some debate over whether the fossils all represent hatchlings or very young animals.  In addition, describing these two specimens as representatives of the taxon Pterodactylus has drawn criticism.  It has been suggested that this study could have included a detailed phylogenetic analysis rather than assign the two fossil specimens to what has been referred to as a “taxonomic wastebasket”.

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

The scientific paper: “Fatal accidents in neonatal pterosaurs and selective sampling in the Solnhofen fossil assemblage” by Robert S.H. Smyth, Rachel Belben, Richard Thomas and David M. Unwin published in Current Biology.

The award-winning Everything Dinosaur website: Everything Dinosaur.

Scientists including researchers from the Museum für Naturkunde (Berlin) have identified the oldest leaf mines in the fossil record. In addition, evidence of insect egg deposits has been found in association with these ancient trace fossils. Insect trace fossils in the studied fossil materials are so abundant that the researchers state that this is the oldest evidence of an insect infestation known to science.  The plant fossils examined in this ground-breaking research come from several museum collections.  The trace fossils record the highly specialised behaviour of insect larvae that lived approximately 295 million years ago.

The research, published in the journal “Scientific Reports” indicates that this specialised feeding behaviour had evolved at least forty million years earlier than previously thought.

The oldest leaf mines (Asteronomus maeandriformis) known to science. A plant fossil from the Permian period collected in Thuringia (left). Leaf mines of the leaf miner fly Liriomyza on a sow thistle (right). Picture credit: Laaß et al (Museum für Naturkunde Berlin).

Picture credit: Laaß et al (Museum für Naturkunde Berlin)

The Advantages of Being a Leaf Miner

In the late spring and summer evidence of the activity of insect larvae feeding inside the leaves of plants is easy to find. The insects produce distinctive channels in the surface of the leaf. Living inside plant tissue has many advantages. For example, the larvae are protected from predators, and they are less prone to harmful infections. In addition, they avoid dehydration, and the larvae have an almost inexhaustible supply of food all around them.

Today, leaf mines are produced exclusively by insects such as beetles, dipterans (flies), wasps and butterflies.  They undergo complete transformation (metamorphosis) and are therefore referred to as holometabolous insects. Holometabolous insects have four stages:

• Egg
• Larva
• Pupa
• Adult

Holometabolous insects are highly adaptable and extremely numerous. They have evolved slender, maggot-like larvae without body appendages that are optimally adapted to life inside plant tissue.

Until now, it was unclear when this sophisticated and highly successful strategy emerged in the Insecta. Previously, the oldest reliable evidence of leaf mines came from plant fossils from the Triassic.  This new study identifies for the first time leaf mining in Palaeozoic fossils.  These oldest leaf mines highlight the importance of conserving museum collections.

The Oldest Leaf Mines

The researchers from the natural history museums in Berlin, Chemnitz, Münster and Osnabrück, the TU Bergakademie Freiberg and Martin Luther University Halle-Wittenberg have been able to prove, leaf mining behaviour occurred more than forty million years earlier than previously thought. The extensive plant fossil collections from the natural history museums in Schleusingen, Berlin and from the Freiberg University collection were examined. These collections contained numerous exceptionally well-preserved specimens of the feeding traces of Asteronomus maeandriformis on leaves of the seed fern Autunia conferta.

The plant fossils come from the coal fields in Crock, Thuringia. These deposits, representing ancient swamps, were laid down in the Early Permian. Close scrutiny of the specimens permitted the team to conclusively prove leaf mining behaviour. In addition, the team identified many of the egg deposits associated with the feeding tunnels, which in some cases even contained the remains of insect eggs.

Numerous types of plants today have extremely ancient lineages.  For example, horsetails (Equisetum) continue to thrive as they are able to grow in areas where other plants would find it difficult to get a foothold. Often regarded as weeds, these tough little plants are essentially living fossils as the earliest examples of the genus Equisetum date from the Early Jurassic of South America. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Over Eighty Percent of the Fossil Autunia Plants Infested

Evidence of leaf mining was found in more than eighty percent of all the fossilised Autunia plants from Thuringia studied.

Palaeobotanist Ludwig Luthardt, one of the co-authors of the paper stated:

“Why exactly the Autunia plants in Crock were infested en masse remains largely a mystery. However, the phenomenon occurred at a time of global change, during which tropical terrestrial ecosystems gradually became drier. This shows how important it is to look to the past in times of current global climate change.”

Everything Dinosaur acknowledges the assistance of a media release from the Museum für Naturkunde Berlin in the compilation of this article.

The scientific paper: “Host-specific leaf-mining behaviour of holometabolous insect larvae in the early Permian” by Michael Laaß, Ludwig Luthardt, Steffen Trümper, Angelika Leipner, Norbert Hauschke and Ronny Rößler published in Scientific Reports.

The Everything Dinosaur website: Prehistoric Animal Models and Figures.

One of the world’s most unusual dinosaurs is even stranger than first thought.  Newly published research in the journal “Nature” confirms that the Moroccan armoured dinosaur Spicomellus afer is definitely an ankylosaur.  In addition, to the extremely spiky appearance, it probably had a tail weapon.  The evolution of a tail weapon predates this feature in any other known ankylosaur by more than thirty million years.  Furthermore, Spicomellus had a unique bony collar ringed with metre-long spikes sticking out from either side of its neck.

It has been nicknamed the “punk rock dinosaur”.

A Spicomellus life reconstruction in anterior view. Picture credit: Matthew Dempsey.

Picture credit: Matthew Dempsey

This dinosaur was formally named and described in 2021 (Maidment et al).  The initial description was made based on a single rib bone. The rib had spikes fused to it, a unique feature, not seen in any other animal.  However, the “T-shaped” cross section of the rib permitted the scientists to confidently assign this fossil to an ankylosaur.  Named Spicomellus afer, it represents Africa’s first known ankylosaur and the earliest representative of this iconic dinosaur clade (Ankylosauria).

To read Everything Dinosaur’s blog post from 2021 announcing the discovery of Africa’s first ankylosaur: The Earliest Ankylosaur and Africa’s First – Spicomellus.

The Remarkable Early Ankylosaur Spicomellus afer

The fossils are more than 165 million years old. This armoured dinosaur lived during the Middle Jurassic, near what is now the Moroccan town of Boulemane.  Further fossil discoveries have enabled the research team to learn more about this remarkable armoured dinosaur.  For example, they now know that Spicomellus had bony spikes fused onto and projecting from all of its ribs, a feature not seen in any other vertebrate species living or extinct. It had long spikes, measuring eighty-seven centimetres in length, which the researchers believe would have been even longer in real life.  These spikes emerged from a bony collar that sat around the reptile’s neck.

A fossil rib showing the spikes fused to it, a unique feature not seen in any other animal. Picture credit: The Trustees of the Natural History Museum, London.

Picture credit: The Trustees of the Natural History Museum, London

Professor Susannah Maidment of Natural History Museum, London, and the University of Birmingham, who co-led the team of researchers commented:

“To find such elaborate armour in an early ankylosaur changes our understanding of how these dinosaurs evolved. It shows just how significant Africa’s dinosaurs are, and how important it is to improve our understanding of them.”

Elaborate Dermal Armour

Ankylosaurs are best known from Late Cretaceous Northern Hemisphere ecosystems.  For instance, Ankylosaurus and Euoplocephalus are known from Upper Cretaceous rocks in the northern United States and Canada.  Ziapelta is known from fossils found in New Mexico, whereas Saichania, Pinacosaurus and Tarchia are known from Upper Cretaceous rocks in Asia.

“Sede” the Ankylosaurus dinosaur model.  The authors of the Spicomellus study postulate that with the emergence of larger predators this could have resulted in ankylosaur armour becoming simpler and more defensive.  Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The picture (above) shows a model of the Late Cretaceous ankylosaur Ankylosaurus magniventris.  The figure is from the Chinese manufacturer PNSO.

To view the range of PNSO models and figures in stock: PNSO Age of Dinosaurs Models.

The researchers postulate that the unique, elaborate spines and spikes of Spicomellus may have functioned for display as well as defence.  Later ankylosaurs had simpler armour with less extravagant osteoderms.  This might indicate a shift towards a primarily defensive function, perhaps in response to increased predation pressures or a switch to combative courtship displays.

Professor Maidment added:

“Spicomellus had a diversity of plates and spikes extending from all over its body, including metre-long neck spikes, huge upwards-projecting spikes over the hips, and a whole range of long, blade-like spikes, pieces of armour made up of two long spikes, and plates down the shoulder. We’ve never seen anything like this in any animal before. It’s particularly strange as this is the oldest known ankylosaur, so we might expect that a later species might have inherited similar features, but they haven’t.”

Professor Susannah Maidment of the Natural History Museum holding a rib with fused spikes. Picture credit: The Trustees of the Natural History Museum, London.

Picture credit: The Trustees of the Natural History Museum, London

Was There a Large Theropod in the Ecosystem?

There is another potential explanation for the remarkable armour associated with Spicomellus afer.  Could it have shared its environment with a large predator such as a theropod dinosaur?  There is certainly evidence to suggest that by the Middle Jurassic formidable tetanuran theropods were present in many ecosystems.

Co-author of the study, Professor Richard Butler (University of Birmingham) stated:

“Seeing and studying the Spicomellus fossils for the first time was spine-tingling. We just couldn’t believe how weird it was and how unlike any other dinosaur, or indeed any other animal we know of alive or extinct. It turns much of what we thought we knew about ankylosaurs and their evolution on its head and demonstrates just how much there still is to learn about dinosaurs”.

Professor Susannah Maidment of the London Natural History Museum and Professor Richard Butler (University of Birmingham) examine the fossil remains along with fellow researchers. Picture credit: The Trustees of the Natural History Museum, London.

Picture credit: The Trustees of the Natural History Museum, London

Did Spicomellus afer Have a Tail Club?

One feature of early ankylosaurs that may have survived, however, is their tail weaponry. While the end of Spicomellus’ tail has not be found, the caudal vertebrae that do survive suggest that it had a club or a similar tail weapon. Some of these tail vertebrae are fused together.  They form a structure referred to as a “handle”.  This feature has only been found in ankylosaurs that possessed a tail club.  If Spicomellus did have a tail club, it overturns current understanding regarding tail club evolution in the Ankylosauria.  These structures were previously thought to have first evolved in the Early Cretaceous.

The authors believe that the combination of a tail weapon and an armoured shield that protected the hips suggest that many of the ankylosaurs’ key adaptations already existed by the time of Spicomellus.

Spicomellus fossil material. This dinosaur was originally described in 2021, however, more fossils were excavated in 2023 providing the research team with further information about the bizarre anatomy of Spicomellus. Picture credit: The Trustees of the Natural History Museum, London.

Picture credit: The Trustees of the Natural History Museum, London

Improving Our Understanding of the Geographic Distribution of Armoured Dinosaurs

Finding more fossils of Spicomellus confirms its ankylosaurian affinities.  In addition, it helps to deepen our understanding of the geographic distribution of armoured dinosaurs. It also helps to spark public imagination in the Dinosauria as we learn more about the baffling characteristics of species like Spicomellus.

Professor Driss Ouarhache, lead of the Moroccan team from the Université Sidi Mohamed Ben Abdellah who co-developed the research, commented:

“This study is helping to drive forward Moroccan science. We’ve never seen dinosaurs like this before, and there’s still a lot more this region has to offer.”

The Spicomellus afer fossils that form the basis of this study were cleaned and prepared at the Department of Geology of the Dhar El Mahraz Faculty of Sciences in Fez, Morocco, using scientific equipment provided by the University of Birmingham’s Research England International Strategy and Partnership Fund. The fossils are now catalogued and stored on this site.  Perhaps, they will be put on display so that the public will have the opportunity to view these amazing fossils.

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

In addition, Everything Dinosaur acknowledges the assistance of the London Natural History Museum for the use of their images.

The scientific paper: “Extreme armour in the world’s oldest ankylosaur” by Susannah C. R. Maidment, Driss Ouarhache, Kawtar Ech-charay, Ahmed Oussou, Khadija Boumir, Abdessalam El Khanchoufi, Alison Park, Luke E. Meade, D. Cary Woodruff, Simon Wills, Mike Smith, Paul M. Barrett and Richard J. Butler published in the journal Nature.

The award-winning Everything Dinosaur website: Everything Dinosaur.

The Queensland-based Age of Dinosaurs Natural History Museum has announced a remarkable Australian ichthyosaur discovery. The specimen, probably representing Platypterygius australis is perhaps the most complete ichthyosaur ever found “Down Under”.  It was unearthed some sixty miles south of McKinlay (Queensland).  Preparation will soon commence at the Australian Age of Dinosaurs Museum of Natural History.  The fossil find highlights the rich palaeontological heritage of this part of western Queensland.

An aerial view of the ichthyosaur quarry. Picture credit: Australian Age of Dinosaurs Museum.

Picture credit: Australian Age of Dinosaurs Museum of Natural History

A Remarkable Australian Ichthyosaur Discovery

The skeleton measures an impressive 7.1 metres in length.  It was discovered on Toolebuc Station by neighbouring property owner and fossil enthusiast Cassandra Prince two years ago.  The specimen was carefully excavated the following year by Cassandra and her family. Remarkably well-preserved, the skeleton includes a complete vertebral column, intact left flipper, partial right flipper, rare hind flippers, partial caudal vertebrae and a nearly complete skull and torso.  Palaeontologists have described this find as one of the most scientifically valuable marine reptile fossils from Australia.

Cassandra Prince with her ichthyosaur discovery. Picture credit: Australian Age of Dinosaurs Museum.

Picture credit: Australian Age of Dinosaurs Museum of Natural History

Platypterygius australis

The Platypterygius genus is a geographically and temporally widespread genus.  Numerous species have been named.  Although, their taxonomic affinity is controversial all the specimens assigned to this genus are robust, macropredators with robust teeth.  It is likely that Platypterygius australis was a formidable predator in the inland sea (Eromanga Sea) that covered much of Australian in the late Early Cretaceous.

Museum Founders David and Judy Elliott assisted Cassandra and her family with collecting the specimen, which was subsequently transported to the Museum so that its preparation can start.  The fossil specimen has been generously donated to the Museum by the Toolebuc Station owners.  Once cleaned and prepared, the ichthyosaur specimen will be mounted in a special exhibition at the Museum.

David Elliott stated:

“This find is a huge win for science and public exhibitions in Australia. Its discovery is testament to the dedication and expertise of Cassandra and her fossil-hunting family and the unique geological heritage of the region. We look forward to sharing this incredible piece of Australia’s prehistory with visitors for generations to come.”

The Toolebuc fossil ichthyosaur specimen uncovered. This 7.1 metre specimen represents a remarkable Australian ichthyosaur discovery. Picture credit: Australian Age of Dinosaurs Museum.

Picture credit: Australian Age of Dinosaurs Museum of Natural History

Everything Dinosaur acknowledges the assistance of a media release from the Australian Age of Dinosaurs Museum in the compilation of this article.

The award-winning Everything Dinosaur website: Prehistoric Animal Models and Toys.

Researchers have described a new dinosaur species from the Wessex Formation of the Isle of Wight.  The dinosaur, an iguanodontian, has been named Istiorachis macarthurae.  The extended neural spines associated with the dorsal and caudal vertebrae suggest that it possessed a sail structure.

Possible explanations for neural spine elongation in the Ankylopollexia include biomechanical advantage, perhaps related to increasing body size and a move towards quadrupedalism. In addition, such structures could have evolved as aids to visual signalling or to deter rivals. Perhaps these changes in body shape were driven by sexual selection, species recognition or both

Hyperelongation of neural spines is known in a number of dinosaur taxa. Most recorded incidences occur during the Barremian and early Aptian faunal stages of the Early Cretaceous. The evolution of elongated neural spines probably took place due to a variety of evolutionary pressures. The drivers for this body shape probably differed in different taxa. Furthermore, it is likely that no single explanation fully supports the variation seen throughout the Cretaceous.

A life reconstruction of Istiorachis macarthurae. Picture credit: James Brown (University of Portsmouth).

Picture credit: James Brown (University of Portsmouth)

Istiorachis macarthurae

This new iguanodontian dinosaur was identified by Jeremy Lockwood, a retired GP, as part of his PhD studies at the University of Portsmouth and the Natural History Museum, London.  Detailed analysis of fossil bones held in the collection of the Dinosaur Isle museum, Isle of Wight led to the identification of several autapomorphies which resulted in the establishment of this new taxon.

The genus name is derived from the Ancient Greek words ἱστίον (istion), meaning a sail, and ῥάχις (rachis), the spine or backbone. It refers to the probable sail-back appearance of the dinosaur.

Pronounced Is-tree-oh-rak-is mack-ar-four-eye, the species name honours the Isle of Wight resident Dame Ellen MacArthur. Dame Ellen MacArthur is a famous sailor.  Therefore, it seemed appropriate to honour her by naming a possible sail-backed dinosaur after her. In 2005, she set a world record for the fastest solo non-stop voyage around the world on her first attempt and Dame Ellen MacArthur has also founded the Ellen MacArthur Cancer Trust for young people on the Isle of Wight.

Dr Jeremy Lockwood with the spinal column of Istiorachis macarthurae with some of the pelvic elements (pubis and head of the ischium). Note the elongated neural spines. Picture credit: University of Portsmouth.

Picture credit: University of Portsmouth

Smaller Iguanodontians Including Istiorachis macarthurae

Dr Lockwood has played a significant role in helping palaeontologists to better understand the smaller iguanodontians from the Isle of Wight.  This is the third iguanodontian named from fossils found on the island in recent years.  For example, last year (2024), Comptonatus chasei was described.  Moreover, in 2021, an iguanodontian with an unusual bulbous snout was described (Brighstoneus simmondsi).

To read Everything Dinosaur’s blog post about the discovery of Comptonatus chasei: A New Dinosaur From the Isle of Wight.

To learn more about B. simmondsi: A New Iguanodontid from the Isle of Wight.

A Highly Diverse Early Cretaceous Ecosystem

The fossil material is estimated to be around 125 million years old.  It came from Wessex Formation exposures from the southwestern part of the island.  This discovery further demonstrates the remarkable dinosaur diversity during the Early Cretaceous.  In addition, it helps to cement the Isle of Wight as a globally significant location for dinosaur fossils.

Commenting on how the new taxon was established, Dr Lockwood explained:

“While the skeleton wasn’t as complete as some of the others that have been found, no one had really taken a close look at these bones before. It was thought to be just another specimen of one of the existing species, but this one had particularly long neural spines, which was very unusual.”

The findings have been published this week in the academic journal “Papers in Palaeontology”.

Dr Lockwood holding the single cervical vertebra (neck bone) known from Istiorachis macarthurae. Picture credit: University of Portsmouth.

Picture credit: University of Portsmouth

Dr Lockwood added:

“Evolution sometimes seems to favour the extravagant over the practical. While the exact purpose of such features has long been debated – with theories ranging from body heat regulation to fat storage – researchers believe that the most likely explanation in this case is visual signalling, possibly as part of a sexual display and this usually is because of sexual selection. In modern reptiles, sail structures often show up more prominently in males, suggesting that these attributes evolved to impress mates or intimidate rivals. We think Istiorachis may have been doing much the same.”

A Detailed Analysis of Neural Spines in Iguanodontids and Their Relatives

A large database was constructed consisting of data on the neural spines of iguanodontids and their close relatives.  The database was created using observations, photographs, scientific illustrations and reconstructions of vertebrae.  The data enabled the researchers to trace the evolutionary history of elongated neural spines within the Iguanodontia.  This analysis permitted the team to identify broad trends in the evolution of sail-like structures.

Dr Lockwood stated:

“These methods let us move beyond simply describing the fossil and actually test hypotheses about its function. We showed that Istiorachis’s spines weren’t just tall – they were more exaggerated than is usual in Iguanodon-like dinosaurs, which is exactly the kind of trait you’d expect to evolve through sexual selection.”

Co-author of the study, Professor Susannah Maidment (London Natural History Museum), added:

“Jeremy’s careful study of fossils that have been in museum collections for several years has brought to life the iguanodontian dinosaurs of the Isle of Wight. His work highlights the importance of collections like those at Dinosaur Isle, where fossil specimens are preserved in perpetuity and can be studied and revised in the light of new data and new ideas about evolution. Over the past five years, Jeremy has single-handedly quadrupled the known diversity of the smaller iguanodontians on the Isle of Wight, and Istiorachis demonstrates we still have much to learn about Early Cretaceous ecosystems in the UK.”

A silhouette of Istiorachis macarthurae showing known fossil material and providing a size estimate. Note scale bar = 50 cm. Picture credit: James Brown (University of Portsmouth) with additional annotation by Everything Dinosaur.

Picture credit: James Brown (University of Portsmouth) with additional annotation by Everything Dinosaur

Highlighting a Broader Evolutionary Trend

Importantly, Istiorachis macarthurae appears to highlight a broader evolutionary trend.  The database suggests that elongation of neural spines in iguanodontians began in the Late Jurassic.  It becomes an increasingly common feature during the Early Cretaceous. However, true hyper-elongation, where neural spines reach heights in excess of four times the height of the vertebral body remain rare.

Similar elongated spines are seen in living reptiles.  For example, many species of extant lizards sport elaborate crests and sail-like structures.  These play a role in visual communication as well as signalling the health and vitality of the animal.

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

The scientific paper: “The origins of neural spine elongation in iguanodontian dinosaurs and the osteology of a new sail-back styracosternan (Dinosauria, Ornithischia) from the Lower Cretaceous Wealden Group of England” by Jeremy A. F. Lockwood, David M. Martill, Susannah C. R. Maidment published in Papers in Palaeontology.

The award-winning Everything Dinosaur website: Prehistoric Animal Models and Toys.

Locomotion in the Sauropoda is hotly debated by palaeontologists.  Some of these leviathans grew to enormous sizes. Once thought to have been semi-aquatic, scientists have a better understanding of their anatomy, and most academics concur that these reptiles were well-adapted to a terrestrial existence. How these animals moved their enormous bulk has been the subject of numerous scientific papers.  In a new study, researchers have examined the caudal vertebrae of the giant Giraffatitan brancai to gain a better understanding of tail mobility.  This research, published in the journal “Royal Society Open Science” provides fresh insights into the biomechanical properties of one of the largest dinosaurs known to science.

The study analysed eighteen preserved tail vertebrae from a nearly complete tail of Giraffatitan brancai.  Excavated from Upper Jurassic deposits in Tanzania, these fossils are in the collection at the Museum für Naturkunde Berlin.

A model of Giraffatitan brancai. The W-Dragon Giraffatitan Compared to a Papo standing T. rex dinosaur model. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The tails of archosaurs are important.  They have a biomechanical function and assist with movement.  In addition, they function as behavioural tools helping animals to communicate and interact with their environment. Until recently, tails have been neglected in biomechanical analyses and were considered as a stiff (sometimes independent) unit. However, the tail’s role in movement is now increasingly being appreciated.

Testing the Movement of Individual Giraffatitan brancai Caudal Vertebrae

New kinematic programmes were used to test the movement of the individual caudal vertebra in relation to each other. The scientists wanted to explain the impact of forces on the muscles.  Furthermore, they wanted to pinpoint areas of muscle attachment on the tail bones.  From this, they set out to determine the mobility and movement of the dinosaur.

Corresponding author, Dr. Verónica Díez Díaz (Museum für Naturkunde Berlin), explained:

“Our analyses show that the tail of Giraffatitan was much more mobile and functionally versatile than previously assumed.”

A detailed analysis of the so-called haemal arches was undertaken.  These haemal arches are bony structures on the underside of the tail vertebrae. They were often overlooked in earlier studies.  In this new study, the researchers conclude that these elements had a significant influence on the mobility of the tail.

Diagram of specimen number MB.R.2921 caudal series of G. brancai, left, with (green) intervertebral discs between vertebrae. Colour coded computer model (right) testing the flexibility of the caudal vertebrae. Picture credit: Díez Díaz et al.

Picture credit: Díez Díaz et al

Employing Sophisticated Computer Models

The use of sophisticated computer models confirm that the Giraffatitan exhibit at the Berlin Natural History Museum is accurate.  Sauropods did not drag their tails behind them like crocodilians.  Instead, the carried their tails raised off the ground. Furthermore, Giraffatitan could move its tail flexibly in several directions.

This study provides new information on the posture, movement and possibly the social interactions of these massive dinosaurs. The study not only offers new perspectives on the anatomy of macronarian sauropods, it also provides valuable impetus for future reconstructions and palaeobiological interpretations.

Everything Dinosaur acknowledges the assistance of a media release from the Museum für Naturkunde Berlin in the compilation of this article.

The scientific paper: “Centres of rotation and osteological constraints on caudal ranges of motion in the sauropod dinosaur Giraffatitan brancai” by Verónica Díez Díaz, Pasha A. van Bijlert, William Irvin Sellers, Mathew J. Wedel and Daniela Schwarz published in Royal Society Open Science.

The award-winning Everything Dinosaur website: Dinosaur Models and Figures.

A new species of Early Jurassic plesiosaur has been named based on a detailed examination of an almost complete fossil specimen discovered nearly fifty years ago.  The articulated specimen represents a skeletally immature individual, and it has been named Plesionectes longicollum.  Writing in the open-access journal PeerJ, the researchers identified several unique anatomical features of the fossil that permitted the erection of a new taxon. For instance, this plesiosaur had an exceptionally long neck.  At least forty-three cervical vertebrae have been identified.  The count hampered by the poor state of preservation of the skull.

The fossil material had been studied previously. For example, evidence of soft tissue preservation had been identified on the neck, tail and rear limbs. In addition, V-shaped neurocentral sutures have been identified.  Furthermore, this animal had between twenty and twenty-one dorsal vertebrae, one of the highest counts known among Lower Jurassic plesiosaurs.

Moreover, the fossil was excavated from a different horizon from the famous oil shales exposed near to Holzmaden. It is much older than other plesiosaurs known from the Posidonia Shale (Posidonienschiefer Formation). The remains of this marine reptile are thought to be around 183 million years old.

Plesionectes longicollum life reconstruction. Picture credit: Peter Nickolaus.

Picture credit: Peter Nickolaus

Plesionectes longicollum

Researcher Sven Sachs (Naturkunde-Museum Bielefeld, Germany) in collaboration with his colleague Daniel Madzia from the Polish Academy of Sciences, conducted the first detailed osteological examination of the fossil material.  This fossil is surprisingly large compared to other plesiosaurs known from the Posidonia Shale. It measures approximately 2.95 metres long, but when the head is included, this marine reptile would have measured around 3.2 metres in length.

The genus name derives from the Greek for “close” or “near”, referring to its plesiosaur affinities, and the Greek word for “swimmer” a common suffix in plesiosaur taxon nomenclature. The species name derives from the Latin and means “long neck”.

To read a recent blog post about examination of soft tissue preservation in a plesiosaur from the Posidonia Shale: Lower Jurassic Plesiosaur Soft Tissue is Examined.

The Plesionectes longicollum holotype (SMNS 51945). Patches of soft tissue have been preserved around the neck, tail, and hindlimb. This marine reptile is thought to have measured around 3.2 metres in length. Picture credit: Sven Sachs.

Picture credit: Sven Sachs

Discovered in 1978

The fossil material was found in 1978. It was discovered by Gotthilf Fischer in his own quarry in Holzmaden. The specimen was prepared by its discoverer and in 1979 it was acquired by the Staatliches Museum für Naturkunde (Stuttgart).

In personal correspondence with Everything Dinosaur, researcher Sven Sachs outlined the direction of his future studies. He intends to commence a reassessment of the famous genus Plesiosaurus.

Sven commented:

“It will surely take a few years to visit all the collections where Plesiosaurus material is housed, to analyse the data, and to write it all up, but this will be a fun project as it is such an iconic taxon.”

A close view of the posterior cervical vertebrae of Plesionectes longicollum. This early-diverging plesiosauroid from the Lower Jurassic Posidonia Shale of Holzmaden, Germany had at least 43 neck bones. Picture credit: Sven Sachs.

Picture credit: Sven Sachs

In summary, this newly described species helps to define the remarkable diversity of Lower Jurassic plesiosauroids known from Germany.  In addition, it invites renewed examination of specimens in museum collections.

Everything Dinosaur acknowledges the assistance of one of the study’s authors in the compilation of this article.

The scientific paper: “An unusual early-diverging plesiosauroid from the Lower Jurassic Posidonia Shale of Holzmaden, Germany” by Sven Sachs and Daniel Madzia published in PeerJ.

A team of international researchers have named a new species of Permian archosauromorph based on a single neck bone.  The animal has been named Manistropheus kulicki.  It provides new insights into the early evolution of archosauromorphs, a clade that includes the crocodiles, birds, pterosaurs and dinosaurs.  The cervical vertebra was discovered last century, but it has only just been scientifically described.  It was found at the famous Korbacher Spalte site in central Germany.  A fissure preserves the fragmentary and isolated remains of many Late Permian vertebrates.  The sediments are believed to around 255 million years old.

The Korbacher Spalte locality is important because it preserves evidence of tetrapods prior to the mass extinction event at the Permian-Triassic boundary.

The holotype of Manistropheus kulicki (SMNK-PAL 76022) shown in left lateral view. Picture credit: Carola Radke.

Picture credit: Carola Radke

Korbacher Spalte

The Korbacher locality is particularly well known for its many finds of the early mammal ancestor, a cynodont called Procynosuchus.  This synapsis is also jokingly referred to as the “Korbach dachshund” because of its appearance. However, scientists have now described a previously unknown species of archosauromorph reptile based on a single, well-preserved cervical vertebra. Distinctive characteristics of the fossil bone enabled the team to erect a new genus and species – Manistropheus kulicki.

Manistropheus kulicki Cervical Vertebra

The vertebra is characterised by an elongated, diamond-shaped centre and a crescent-shaped indentation on the side of the front edge of the vertebra. This gives the new genus its name – from the Old Norse Máni, the personification of the moon in Germanic mythology, and the Greek “stropheus,” meaning vertebra. Overall, the specimen shows similarities to early archosauromorphs but also shows features that are absent in other reptiles of that time. A comprehensive study of the phylogenetic relationships suggests that M. kulicki stands at the base of this important reptile lineage.  It is thought to be a basal archosauromorph.

The study also used an analysis of morphological diversity to investigate how cervical vertebrae have changed over the course of Earth’s history. The results suggest that archosauromorphs were already morphologically diverse before their extinction and that their cervical anatomy diversified rapidly in the Early Triassic.  Cervical vertebrae anatomy changed faster than other parts of the skeleton.

Lead author of the study, Dr Martín Ezcurra (CONICET) stated:

“This discovery is particularly significant because Permian archosauromorphs are extremely rare, with only five fossil species from this period known to date. Thanks to Manistropheus kulicki, we can see how diverse this group already was before the mass extinction.”

Co-author Professor Hans-Dieter Sues (Smithsonian Institute), added:

“This fossil not only proves the existence of a new species, but also supports the assumption that there was already a previously hidden diversity of archosauromorphs in the Permian period.”

Diverse Archosauromorphs Present in Equatorial Regions During the Late Permian

Professor Jörg Fröbisch (Museum für Naturkunde Berlin), another co-author of the study, highlighted the significance of the Korbach Spalte site.

He commented:

“The Korbach fissure site is proving to be a key location for better understanding life on land in the tropical regions of the supercontinent Pangaea shortly before the largest mass extinction in Earth’s history. “

The naming of this basal archosauromorph from Germany highlights the importance of continuing to explore lesser-known fossil sites.  It is especially important to explore fossil sites that provide insights into ancient ecosystems threatened with extinction.

Everything Dinosaur acknowledges the assistance of a media release from the Museum für Naturkunde Berlin in the compilation of this article.

The scientific paper: “A new late Permian archosauromorph reptile from Germany enhances our understanding of the early diversity of the clade” by Martín D. Ezcurra, Hans-Dieter Sues and Jörg Fröbisch published in the Journal of Systematic Palaeontology.

The Everything Dinosaur website: Prehistoric Animal Models.