A tiny fossil discovered in Scotland a hundred years ago has prompted scientists to reconsider the evolution of flying insects. New research led by scientists from the Natural History Museum in London suggests that flying insects may have evolved as much as eighty million years later than previously thought. The findings challenge a long-established interpretation of one of the world’s oldest arthropod fossils and demonstrate how modern scientific techniques can transform our understanding of prehistoric life.

Rhynie Chert fragment with inset Rhyniognatha highlighted and confocal microscopy models. Picture credit: Emma Long.

Picture credit: Emma Long

The fossil, named Rhyniognatha hirsti, was discovered in 1926 in the famous Rhynie Chert deposits of northern Scotland. These remarkable deposits preserve evidence of a Devonian wetland ecosystem dating back approximately 408 million years. The exceptional preservation of fossils from this location has provided palaeontologists with invaluable information about some of the earliest terrestrial ecosystems.

To read an article from earlier this year highlighting the significance of the Rhynie Chert deposits: Fossils Provide a Remarkable Insight into Devonian Ecosystems.

A Tiny Fossil with Enormous Scientific Significance

The fossil of Rhyniognatha hirsti consists of part of the head of a tiny arthropod. Measuring less than one millimetre in length, this extraordinary specimen was largely overlooked for decades as researchers concentrated on other fossils recovered from the Rhynie Chert.

However, a scientific study published in 2004 dramatically changed the importance of this tiny fossil. Researchers identified similarities between its mouthparts and those of modern winged insects. Consequently, Rhyniognatha was interpreted as the oldest known representative of the winged insect lineage.

This identification had profound implications for understanding insect evolution. If Rhyniognatha belonged to the winged insect lineage, the evolutionary origins of flying insects must have extended back to at least the Early Devonian, approximately 400 million years ago.

Rhyniognatha fossil chip viewed under light microscope. Picture credit: Emma Long.

Picture credit: Emma Long

The fossil subsequently became an important reference point for researchers attempting to reconstruct the evolutionary relationships of insects, including the ancestors of modern dragonflies, bees and crickets.

Advanced Microscopy Challenges an Established Theory

Despite its scientific significance, questions remained about the true identity of Rhyniognatha hirsti. Some researchers suggested that the fossil might represent an ancient relative of centipedes rather than an insect. To investigate these competing interpretations, scientists led by the Natural History Museum undertook a detailed re-examination of the specimen using advanced confocal microscopy.

This technique uses precisely focused laser light to examine structures within a specimen. It allows scientists to produce detailed digital reconstructions and distinguish anatomical features that can be extremely difficult to interpret using conventional light microscopy.

The research team concentrated on the fossil’s jaws, particularly the arrangement of their joints. These structures are important because differences in mouthpart anatomy can help palaeontologists distinguish between major arthropod groups.

Their investigation revealed that the jaw joints of Rhyniognatha do not correspond precisely with those found in modern flying insects or centipedes.

Rhyniognatha confocal microscopy models. Picture credit: Emma Long.

Picture credit: Emma Long

As a result, the researchers concluded that there is insufficient evidence to confidently assign this ancient arthropod to either group.

Rethinking the Evolution of Flying Insects

The implications of this discovery extend far beyond the identification of a single fossil.

For more than two decades, Rhyniognatha hirsti has been used as a calibration point in evolutionary studies. By combining fossil evidence with genetic information from living organisms, scientists can estimate when different groups shared their last common ancestors.

However, these calculations depend upon fossils being correctly identified and placed within the appropriate evolutionary lineages. If Rhyniognatha cannot reliably be classified as an insect, it should no longer be used to establish a minimum age for the evolution of winged insects.

Dr Emma Long, the study’s lead author, explained that the re-examination suggests Rhyniognatha is probably not an insect at all. Removing this fossil from evolutionary calculations could shift estimates for the origins of flying insects forward by as much as eighty million years.

Importantly, this does not establish an exact date for the first appearance of insect flight. Instead, it removes a previously influential piece of evidence supporting a much earlier evolutionary origin.

The findings therefore encourage scientists to reconsider when insects acquired wings and how the development of flight influenced the diversification of terrestrial ecosystems.

Museum Fossils Continue to Reveal New Secrets

This remarkable discovery also highlights the enduring scientific value of museum collections. Although Rhyniognatha hirsti was collected in 1926, modern microscopy has enabled scientists to examine its anatomy in ways that would have been impossible when the fossil was first discovered.

Dr Greg Edgecombe, a co-author of the study and Merit Researcher at the Natural History Museum, emphasised the importance of applying new analytical techniques to historical specimens.

Dr Edgecombe stated:

“Revisiting old fossils with new technology allow us to see them in a new light, and Rhyniognatha is no exception. By using advanced microscopy techniques, we were able to digitally separate the fossil to see its key features in greater detail than ever before.”

Museum collections preserve an enormous wealth of scientific information. As technology advances, fossils collected many decades ago can provide fresh evidence and challenge established interpretations. For instance, this new research has changed our understanding with regards to the evolution of flying insects.

The re-examination of Rhyniognatha demonstrates that even the smallest fossils can have an enormous influence on our understanding of evolutionary history.

For palaeontologists, the research is also an important reminder that scientific interpretations are continually tested and refined as new evidence becomes available.

The multi-award-winning Everything Dinosaur website: Prehistoric Animal Replicas.

Why did crocodiles survive the extinction event that wiped out the non-avian dinosaurs? New research led by University College London (UCL) suggests that their preference for warm climates played an important role. Throughout their long evolutionary history, crocodiles and their relatives generally followed suitable climatic conditions rather than adapting to new ones. This new study provides important insights into how crocodiles survived dinosaur extinction event conditions approximately 66 million years ago.

The study, published in the journal “Science Advances”, examined more than 7,000 fossils and records representing over 400 living and extinct species. Researchers combined this information with computer reconstructions of Earth’s ancient climates and geography. Their findings suggest that warm regions near the equator provided important refuges following the Chicxulub asteroid impact approximately 66 million years ago.

Keeping to warm climates throughout their 250-million-year history may have helped crocodiles and their relatives survive the asteroid that killed the dinosaurs, finds a new study led by University College London researchers. Picture credit: Davide Bonadonna.

Picture credit: Davide Bonadonna

Crocodiles Followed Warm Climates

The crocodile evolutionary lineage belongs to a group of archosaurs called pseudosuchians. These reptiles first appeared around the same time as the dinosaurs, approximately 250 million years ago. Although modern crocodilians share broadly similar body plans, their prehistoric relatives were remarkably diverse. Some were heavily armoured herbivores, whilst others evolved into formidable terrestrial predators.

For example, Postosuchus was a large, terrestrial predator of the Late Triassic.

A model of Postosuchus from Safari Ltd.

The picture (above) helps to illustrate the diversity of the pseudosuchians.  Two species of Postosuchus  have been named, and its fossils have been found in several locations in North America.  The picture shows a Postosuchus model introduced by the American company Safari Ltd.

To view the range of Safari Ltd prehistoric animal models: Safari Ltd. Wild Safari Prehistoric World Models.

The company continues to make replicas of pseudosuchians.  For example, the latest release is a model of the fearsome, Late Cretaceous Deinosuchus.

The new Wild Safari Prehistoric World Deinosuchus model.

Despite this extraordinary diversity, the researchers identified a consistent relationship between crocodile-line archosaurs and climate. Rather than evolving to tolerate substantially different climatic conditions, most lineages moved into regions where temperatures remained suitable.

During warmer geological intervals, their geographical ranges expanded. Conversely, cooling climates forced populations to retreat towards tropical regions.

Prehistoric Crocodiles Even Lived in Antarctica

During the early Eocene, approximately fifty million years ago, global temperatures were considerably higher than today. The polar regions were largely ice-free, and warm conditions extended into high latitudes. Consequently, crocodile relatives inhabited regions of North America, Europe and even Antarctica.

However, as global temperatures declined over subsequent millions of years, suitable habitats contracted. Crocodile populations increasingly became restricted to warmer latitudes.

The researchers identified two notable exceptions to this general pattern.

During the Cretaceous Thermal Maximum, approximately ninety-four million years ago, one lineage evolved adaptations permitting it to tolerate exceptionally high temperatures.

Furthermore, an extinct group of Australian crocodiles adapted to increasingly dry conditions around thirty-four million years ago.

Nevertheless, these exceptions emphasise how strongly climate influenced the distribution and evolution of crocodile-line archosaurs.

How Crocodiles Survived Dinosaur Extinction Event

The research team also investigated climatic conditions following the asteroid impact that marked the end of the Cretaceous Period. The impact triggered enormous environmental disruption. Dust and other particles entering the atmosphere reduced incoming sunlight, causing temperatures to fall and disrupting ecosystems. Scientists modelled several scenarios involving reduced sunlight and increased atmospheric carbon dioxide.

Under simulations involving a five or ten per cent reduction in sunlight, tropical and subtropical regions remained climatically suitable for crocodile relatives. Only the most extreme scenario, involving a fifteen per cent reduction, eliminated these suitable climatic refuges. However, the researchers considered this scenario unlikely.

Dr Alfio Alessandro Chiarenza of UCL Earth Sciences commented:

“The asteroid did not make the whole planet equally hostile to every group. Crocodiles’ long-standing preference for warm environments may have placed survivors exactly where suitable climates held up best, like around the equator. These refuges could have sheltered populations that later recovered and radiated out.”

Crocodile relatives already inhabiting warmer regions may have been particularly well positioned to survive the environmental crisis. These populations could subsequently have recovered and expanded into other suitable habitats.

Changing Climate Was Not the Only Factor

Importantly, the researchers stressed that climatic preferences alone cannot explain crocodilian survival. Several additional biological characteristics probably contributed to their resilience.

Their relatively low metabolic requirements meant that crocodiles could survive with less food than similarly sized warm-blooded animals. In addition, flexible diets may have helped them exploit different food resources. Semi-aquatic lifestyles could also have provided advantages during periods of environmental instability.

Furthermore, smaller body size among surviving lineages may have reduced their energy requirements. Together, these characteristics probably increased the likelihood that some crocodile-line archosaurs survived the end-Cretaceous mass extinction.

Important Lessons for Modern Crocodile Conservation

The findings also have significant implications for living crocodilians. Professor Philip Mannion of UCL Earth Sciences highlighted the importance of allowing species to move into suitable habitats as environmental conditions change. Historically, crocodiles could respond to changing climates by shifting their geographical distributions.

Professor Mannion stated:

“These findings have implications for species today. If crocodiles mostly coped with past climate change by moving towards suitable habitats, today’s species will need room to move as the planet warms, and the loss of suitable areas to roads, farms and cities is making that harder.”

As global temperatures rise, protecting suitable habitats and maintaining connections between populations could become increasingly important.

An anterior view of the skull of an estuarine crocodile photographed in the Grant Museum, London. The largest reptile on Earth, the estuarine crocodile (Crocodylus porosus) from south-east Asia is also known as the saltwater crocodile or saltie. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The research demonstrates how studying the fossil record can help scientists understand evolutionary responses to environmental change. This new research provides important insights into how crocodiles survived dinosaur extinction event conditions marking the end of the Cretaceous.

It also provides another fascinating example of how palaeontology contributes to modern conservation biology.

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

The scientific paper: “Climatic niche conservatism shapes the macroevolution, extinction, and survivorship of crocodile-line archosaurs” by Alfio Alessandro Chiarenza, Alexandra F. C. Howard, Grace L. Varnham, Alex Farnsworth, Paul J. Valdes, and Philip D. Mannion published in Science Advances.

The Everything Dinosaur website: Models of Crocodile and Prehistoric Animals.

A remarkable new dinosaur species has been identified from a fossil discovered on the Isle of Wight. The dinosaur, named Invictibellatrix amberina, was a formidable predator that lived approximately 120 million years ago (Early Cretaceous). Researchers from University College London (UCL) led the study, which has been published in the scientific journal “Royal Society Open Science”. This new Isle of Wight dinosaur belonged to a mysterious group of carnivorous theropods called the Megaraptora. Significantly, it represents the first evidence of these theropod dinosaurs in Europe.

The new theropod dinosaur, Invictibellatrix amberina (centre of the image), in its ecosystem on the Isle of Wight, United Kingdom in the Early Cretaceous (around 120 million years ago). It lived in what was likely a seasonally wet-to-dry floodplain environment and is surrounded by other dinosaurs including large, long-necked rebbachisaurid sauropods (directly behind Invictibellatrix, centre) and relatives of Iguanodon (right). A spinosaurid theropod, potentially the apex predator of the time, fishes (left). Invictibellatrix has just caught and is consuming two small mammals. Gymnosperms dominate the environment as flowering plants (angiosperms) were not common at this time. Other reptiles including relatives to modern lizards, crocodiles and turtles enjoy the warm Early Cretaceous weather of the UK. Picture credit: Sergey Krasovskiy and Pedro Salas.

Picture credit: Sergey Krasovskiy and Pedro Salas

Invictibellatrix amberina – A Fearsome Cretaceous Predator

The newly described dinosaur was approximately three to four metres long. It stood around 1.5 metres tall and was roughly comparable in size to a large tiger. Although relatively small compared to later megaraptorans, it would have been a dangerous predator.

Megaraptorans were predominantly two-legged carnivorous dinosaurs. Unlike tyrannosaurids, which evolved massive skulls and powerful jaws, megaraptorans possessed relatively slender heads. Their forelimbs were equipped with enormous, curved claws that probably played an important role in capturing and subduing prey.

A typical Late Cretaceous megaraptoran theropod.  This is a model of Megaraptor (M. namunhuaiquii) from Argentina.  Note the slender jaws and the long, forelimbs with powerful, grasping claws. This is the red/brown coloured Megaraptor model from Haolonggood (Duan Jing Zhu).

To view the range of Haolonggood prehistoric animal models in stock: Haolonggood Prehistoric Animal Models.

The researchers suggest that Invictibellatrix may have possessed feathers. Furthermore, its hand claws could have measured between ten and twenty centimetres in length. It probably hunted smaller dinosaurs, lizards and mammals. However, the precise diet of this Early Cretaceous predator remains unknown.

Lead author Dr Cassius Morrison (UCL Earth Sciences) compared its ecological role to that of a modern hyena. Although formidable, Invictibellatrix was probably not the apex predator within its ecosystem.

A New Isle of Wight Dinosaur Fossil Overlooked for a Century

Remarkably, the fossil was discovered more than a hundred years ago. Amateur palaeontologist Reginald Walter Hooley collected the specimen from the south-western coast of the Isle of Wight. Following Hooley’s death, the Natural History Museum acquired more than a thousand specimens from his collection in 1924. Among them was a fragment of the rear portion of a dinosaur skull.

For decades, this scientifically important fossil remained largely overlooked.

Anterior (left) and posterior (right) views of the newly identified megaraptoran theropod dinosaur fossil leading to the erection of a new species – Invictibellatrix amberina. The oval hole is where the brain would have been. The fossil was acquired by the Natural History Museum in 1924. Note, scale bar equals 5 cm. Picture credit: The Trustees of the Natural History Museum, London.

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

The scientists used computed tomography (CT) scanning to examine the fossil. This technique enabled them to create three-dimensional digital reconstructions of the preserved skull bones and the internal braincase cavity. Subsequently, the research team compared these structures with those of other predatory dinosaurs. These included tyrannosaurs, spinosaurids and various other theropods.

Several distinctive anatomical features were identified. For example, the opening through which the spinal cord entered the braincase was oval-shaped. In addition, the fossil possessed an unusual hourglass-shaped crest.

These characteristics, together with the results of computational evolutionary analyses, supported the identification of a new megaraptoran species.

The First Megaraptoran Dinosaur Discovered in Europe

The discovery of Invictibellatrix amberina (pronounced In-vik-tee-bel-ah-tricks am-ber-ree-nah) could help resolve a long-standing mystery concerning megaraptoran evolution. Previously, scientists had identified megaraptoran fossils in regions including Asia, South America and Australia. However, definitive evidence of their presence in Europe had remained elusive. Researchers have proposed that megaraptorans originated in Asia before dispersing through Europe into the southern supercontinent of Gondwana.

The Isle of Wight fossil provides important evidence supporting this hypothesis.

Dr Cassius Morrison (University College London) with the braincase fossil. Picture credit: The Trustees of the Natural History Museum, London.

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

The scientists also used mathematical modelling to investigate the geographical distribution of megaraptorans through geological time. Their results suggest that these dinosaurs were widespread during the Early Cretaceous. However, their distribution subsequently changed. By the Late Cretaceous, megaraptorans appear to have disappeared from the northern landmass of Laurasia. Meanwhile, some lineages evolved into gigantic apex predators across Gondwana. For example, Megaraptor namunhuaiquii from the Late Cretaceous of Argentina.

Some of the largest megaraptorans possessed formidable hand claws measuring approximately thirty-five centimetres long.  In addition, megaraptorans such as Maip macrothorax may have grown to nine to ten metres in length, matching some tyrannosaurs and the largest allosaurs in size.

A 1:40 scale replica of the giant, South American megaraptor Maip macrothorax. The CollectA Deluxe Maip macrothorax model measures 26 cm in length.

The image above shows the CollectA Deluxe 1:40 scale replica of M. macrothorax. It was introduced in 2025.

To view the CollectA Deluxe range: CollectA Deluxe Prehistoric Animal Models.

An article providing information on Maip macrothorax: A New, Giant Megaraptorid Theropod is Described from Argentina.

The reasons for their apparent disappearance from northern continents remain uncertain. Environmental changes, climatic shifts and competition with other large theropods may have contributed.

Invictibellatrix amberina – What’s in a Name?

The genus name Invictibellatrix translates as “unconquered female warrior”. It acknowledges the evolutionary success of megaraptorans, some of which eventually became enormous apex predators. The researchers also intended the name to convey a positive message of resilience and hope to people experiencing discrimination, bullying or oppression.

The species name amberina refers partly to amber associated with the geological deposits from which the fossil originated (Wessex Formation). It also references a feminine personal name.

Everything Dinosaur applauds the research team for naming a new dinosaur species that gives hope and strength to all those who are bullied, discriminated, victimised and oppressed. That tomorrow will be theirs and not to give up in the face of such odds.

Together, these names give the dinosaur a distinctive identity that reflects both its evolutionary history and the researchers’ wider message.

Dr Cassius Morrison (University College London) with co-author PhD student Charlie Scherer (University College London) holding the fossil of the new Isle of Wight dinosaur. Picture credit: The Trustees of the Natural History Museum, London.

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

More Dinosaur Discoveries Await in Museum Collections

The identification of Invictibellatrix amberina highlights the importance of revisiting historical fossil collections. Although palaeontologists have studied the Isle of Wight for more than two centuries, new dinosaur species continue to be recognised.

Professor Paul Barrett of the Natural History Museum, the study’s senior author, emphasised the scientific importance of historical museum collections. Specimens collected many decades ago can yield extraordinary discoveries when examined using modern techniques.

The Isle of Wight has already provided scientists with an exceptional record of Early Cretaceous dinosaurs. The identification of this European megaraptoran adds another important chapter to a remarkable prehistoric story.

Two new, spinosaurids described: New Spinosaurids from the Isle of Wight Described.

A new Isle of Wight dinosaur (an iguanodontian – Comptonatus chasei) from the Isle of Wight: A New Iguanodontian Dinosaur from the Isle of Wight.

Furthermore, the discovery raises an intriguing possibility. Other overlooked fossils housed in museum collections might contain evidence of previously unknown dinosaurs.

Everything Dinosaur acknowledges the assistance of University College London and the Natural History Museum in the compilation of this article.

The scientific paper: “A new megaraptoran dinosaur from the Lower Cretaceous Wessex Formation, UK, and its implications for theropod evolution and biogeography” by Cassius D. Morrison, Charlie R. Scherer, Philip Mannion, Laura B. Porro, Brett Clark, Daniel D. Folkes and Paul M. Barrett published in Royal Society Open Science.

The award-winning Everything Dinosaur website: Everything Dinosaur.