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.