A fossilised trilobite track has been recreated for an exhibit highlighting Palaeozoic life. The trace fossil with an accompanying trilobite model can be seen at the Liverpool World Museum.
A model of a trilobite track reconstructed for a museum display. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Trilobite Fossils
Trilobite fossils are ubiquitous. Tens of thousands of specimens can be viewed in museums and museum collections. However, trilobite trace fossils are rare. The Liverpool World Museum exhibit depicts a trilobite walking across the sea floor. A distinctive set of parallel tracks are shown. Trace fossils preserve evidence of the activity of an organism. Most trace fossils provide direct “in situ” evidence of the environment of the prehistoric creature that produced the trace.
A selection of our trilobite fossils from Wales. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Commenting Upon the Trilobite Track
A spokesperson from Everything Dinosaur commented:
“The track exhibit provides an opportunity for museum staff to recreate the environment in which some types of trilobite lived. Whilst some trilobites may have been active swimmers (nektonic), others were happy to wander along the sea floor, searching for food. The trace fossil exhibit also gives visitors the opportunity to view models of various trilobites.”
Everything Dinosaur team members have prepared some images of CollectA invertebrate models including the CollectA Age of Dinosaurs Popular trilobite model (Redlichia rex). Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The model shown above is a replica of Redlichia rex a large trilobite known from Cambrian strata. The R. rex figure is part of the invertebrate series produced by CollectA.
A selection of Calymene trilobite fossils on display. Some of the specimens show that these trilobites could roll into a ball to protect themselves. Picture credit: Everything Dinosaur.
Trilobite Body Fossils
Fossils are used by scientists to identify the relative age of rock strata. Rocks can be correlated through the examination of the fossils that they contain. Trilobites are important zonal fossils. The trilobite fossils shown (above), are from the Silurian (Wenlock Group, Shropshire). They represent examples of the Calymene genus. Some of the specimens are rolled up into a ball, presumably a defensive behaviour.
The spokesperson from Everything Dinosaur added:
“A trilobite fossil might be one of the first fossils that a young person is given as a gift. It can ignite a passion for nature within them and lead to a lifetime of fossil collecting and learning about prehistoric animals.”
The enormous Patagotitan arm bones are on display at the London Natural History Museum. These immense fossils are part of the “Titanosaur: Life as the Biggest Dinosaur” exhibition. This popular exhibition is open until January 2024. Team members at Everything Dinosaur have been fortunate to have visited the museum earlier in the year. This helped them to avoid the inevitable congestion at the peak of the summer tourist season.
The fossilised bones from the right arm of Patagotitan in approximate anatomical position. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Patagotitan Arm Bones
The display shows the right arm bones of Patagotitan in approximate anatomical position. The enormous scapula leads to the immense humerus with the ulna (left) and the radius (right) directly underneath it. The exhibition organisers have provided a helpful information panel to explain the layout of the arm bones.
A diagram showing the position of the fossilised bones on the skeleton of Patagotitan. The position of the scapula, the humerus and the lower arm bones (ulna and radius). Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Visit the Everything Dinosaur website for models and replicas of titanosaurs and other prehistoric creatures: Everything Dinosaur.
Patagotitan mayorum
Patagotitan was formally named and scientifically described in 2017 (Carballido et al). However, the huge fossil bones had attracted considerable media interest since the discovery of a giant portion of thigh bone in 2010. Numerous news reports occurred in 2014 and in January 2016 the BBC broadcast a special programme that tracked the fossil excavation and preservation. The programme was presented by Sir David Attenborough, and it was entitled “Attenborough and the Giant Dinosaur”.
In 2022, Safari Ltd added a replica of Patagotitan to their product range.
The Wild Safari Prehistoric World Patagotitan model has arrived at Everything Dinosaur. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
A spokesperson from Everything Dinosaur commented:
“Several other titanosaur models have been introduced since the naming of Patagotitan. With the interest in titanosaurs fuelled by the giant arm bones on display, collectors can expect more titanosaur figures to be introduced.”
Team members at Everything Dinosaur took the opportunity to photograph a cast of a Baryonyx fossil jaw on display at the London Natural History Museum. The cast is a replica of the original specimen number BMNH R9951. The holotype material was re-catalogued as NHMUK VP R9951. The British Museum was renamed the Natural History Museum in 1992. The fossils represent one of the most complete dinosaur skeletons found in the UK.
A cast showing the premaxilla and maxilla of Baryonyx based on the fossil specimen number BMNH R9951. The holotype fossil material was later re-catalogued as NHMUK VP R9951. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Fossils of this famous theropod dinosaur were excavated from a clay pit near Ockley in Surrey in 1983. The field team was led by palaeontologists from the British Museum (Natural History Museum). There is a cast of the Baryonyx skeleton on display in the dinosaur gallery at the museum.
Baryonyx walkeri
Named and formally described in 1986, Baryonyx changed perceptions regarding spinosaurids. The scientific paper was published in “Nature”. It was entitled “Baryonyx, a remarkable new theropod dinosaur”. The authors of the paper were Alan Charig and Angela Milner. Both palaeontologists had distinguished careers. Alan Charig helped to popularise the science of vertebrate palaeontology when he wrote and presented the BBC television series “Before the Ark”. However, it is probably for their work on Baryonyx walkeri that they will be best remembered.
Taking its turn on the Everything Dinosaur turntable. The new for 2020 Mojo Fun Baryonyx with an articulated jaw. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The picture (above) shows a typical Baryonyx dinosaur model. The figure is from the Mojo Fun Prehistoric and Extinct collection.
The Baryonyx fossil jaw cast shows the premaxilla and the anterior portion of the maxilla. The holotype specimen includes a significant amount of skull and jaw material including both dentaries. Thanks to the skull and jaw fossils, scientists were able to reconstruct the skull of other spinosaurids such as Spinosaurus aegyptiacus.
A spokesperson from Everything Dinosaur commented.
“When we visit the London Natural History Museum, we like to view the Baryonyx exhibit. The fossils helped improve our understanding regarding theropod dinosaurs. The Baryonyx material representing about 65% of the entire skeleton still represents one of the most complete large theropod skeletons found in Europe.”
An enormous prehistoric whale named Perucetus colossus might be the heaviest vertebrate to have ever lived. Previously, the heaviest animal known to science was the blue whale (Balaenoptera musculus). These whales can weigh up to 190 tonnes. The newly described P. colossus is estimated to have weighed between 85 and 340 tonnes. Researchers writing in the academic journal “Nature” postulate that this animal pushes extreme size in cetaceans to a much earlier phase in their evolutionary development.
Reconstruction of Perucetus colossus in its coastal habitat. Estimated body length: 20 meters. Picture credit: Alberto Gennari.
Perucetus colossus
Fossils of this leviathan were discovered in the desert on the southern coast of Peru. Palaeontologist Mario Urbina spent decades painstakingly looking for fossils. In 2010, he made an exceptional discovery. Other field team members were puzzled when photographs of the unusual objects jutting out of the 39-million-year-old sediments were examined.
Location of the Perucetus colossus fossil discovery (Ica Province, southern Peru). Picture credit: Giovanni Bianucci.
These huge and odd-shaped objects were vertebrae from an immense skeleton. Each bone weighed over a hundred kilograms and four ribs found in association with the thirteen vertebrae measured approximately 1.4 metres in length. Several expeditions had to be organised to excavate and remove the colossal fossils from the remote location.
Part of the excavation team at the Perucetus dig site. Individuals on the picture, from left to right: Olivier Lambert, Walter Aguirre, Alberto Collareta, Walter Landini, Klaas Post, Giovanni Bianucci & Mario Urbina (bottom). Picture credit: Giovanni Bianucci.
A New Species of Basilosaurid Whale
The remarkable fossils are now part of the vertebrate collection housed at the Museo de Historia Natural, Universidad Nacional Mayor San Marcos in Peru. Perucetus has been assigned to Basilosauridae family. These whales were the earliest cetaceans to fully transition to an aquatic lifestyle. Basilosaurids are known from the early Eocene to the late Eocene and were geographically widespread.
Perhaps the most famous of all these ancient whales is Basilosaurus. It was an apex predator and some species could have reached lengths of twenty metres or so, approximately the same length as Perucetus colossus, but Basilosaurus was much lighter.
The CollectA Basilosaurus model. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The picture above depicts a Basilosaurus. Fossils indicate that Basilosaurus was much more slender and serpent-like when compared to the newly described Perucetus. The drawing is based on the CollectA Basilosaurus replica.
No other known basilosaurid had such massive bones. An international team of scientists including Olivier Lambert, a palaeontologist at the Royal Belgian Institute of Natural Sciences surface-scanned the preserved bones to measure their volume. Cores were taken from one dorsal vertebra and a rib to permit an assessment of bone density and structure. Comparisons with extant whales and other extinct basilosaurids were then made.
Palaeontologist and whale evolution expert Olivier Lambert (RBINS) in front of two ancient whales in the Gallery of Evolution of the Museum of Natural Sciences in Brussels. Picture credit: Thierry Hubin.
The twenty-metre-long skeleton of the Perucetus was estimated to be two to three times heavier than the blue whale skeleton called Hope exhibited in the Hintze Hall of the London Natural History Museum. To reconstruct the body mass of Perucetus, the authors used the ratio of soft tissue to skeleton mass known in living marine mammals. With estimates ranging from 85 to 340 tonnes, the mass of Perucetus colossus falls in or exceeds the distribution of the blue whale.
Preserved bones of the new whale species. Picture credit: Giovanni Bianucci, Marco Merella, Rebecca Bennion.
Adapted to a Shallow Water Marine Environment
The scientists postulate that Perucetus was adapted to a shallow water marine environment. The tremendous weight of this cetacean, perhaps as heavy as fifty African elephants, was partly due to modifications observed in the fossil bones. The outer portions of the bones were packed out with additional bone mass, giving them a bloated appearance (pachyostosis). The internal cavities were filled with compact bone (osteosclerosis). These two anatomical traits increased the weight of the skeleton.
Skeletal mass versus body mass. A range of total body mass and skeletal mass calculations across amniotes (mammals and reptiles, including birds). Picture credit: Giovanni Bianucci and Eli Amson.
Co-author of the study Olivier Lambert commented:
“These modifications are not pathological, but well known in many aquatic mammals (such as manatees) and extinct reptiles who mostly lived in shallow coastal waters. The extra weight helps these animals regulate their buoyancy and trim underwater. A stable position in the water may have been useful when foraging for crustaceans, demersal fish and molluscs along the seafloor. Such a large and heavy animal may also have been able to counteract waves in high-energy waters.”
In extant cetaceans, who can dive at much greater depth and live far offshore, the bone structure is much lighter.
Evidence of Early Gigantism
It had been thought that gigantism in baleen whales was a relatively recent development in cetacean evolution. The first huge filter-feeding whales were thought to have evolved around 5 million years ago (early Pliocene Epoch). However, the discovery of Perucetus colossus pushes back the evolution of gigantism in prehistoric whales to the Eocene.
Olivier Lambert added:
“Discovering a truly giant species such as Perucetus who is affected by strong bone mass increase changes our understanding of whale evolution. Gigantic body masses have been reached 30 million years before previously assumed, and in a coastal context.”
Everything Dinosaur acknowledges the assistance of a media release from the Royal Belgian Institute of Natural Sciences in the compilation of this article.
The scientific paper: “A heavyweight early whale pushes the boundaries of vertebrate morphology” by Giovanni Bianucci, Olivier Lambert, Mario Urbina, Marco Merella, Alberto Collareta, Rebecca Bennion, Rodolfo Salas-Gismondi, Aldo Benites-Palomino, Klaas Post, Christian de Muizon, Giulia Bosio, Claudio Di Celma, Elisa Malinverno, Pietro Paolo Pierantoni, Igor Maria Villa and Eli Amson published in Nature.
In Europe during the Pleistocene Epoch, brown bears (Ursus arctos) and the now extinct cave bear (Ursus spelaeus) co-existed. Did these large mammals compete for food? A recently published study that examined the jaw mechanics of each bear suggests that they had different diets.
A lower jaw from a cave bear which is around 40,000 years old. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Fossils from the Goyet Caves in Belgium
Three-dimensional analysis of jawbone fossils excavated from the caves of Goyet in Belgium show clear differences in jaw and dentition configuration. This suggests that brown bears and cave bears had different diets. The study also demonstrates that the diet of brown bears from 30,000 years ago differs only slightly from that of their North American relatives still living today.
Extant brown bears are the closest living relative to the extinct cave bear. Cave bears (U. spelaeus), are thought to have died out around 25,000 years ago.
Lateral view of the Papo Cave Bear model. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The picture (above) shows a model of a cave bear (Ursus spelaeus) from the Papo model range.
Scientists estimate that brown bears and cave bears co-existed from about 1.3 million years ago up until the extinction of the cave bear. They lived in the same habitats and probably competed for plant food. The caves of Goyet and Trou des Nutons in Belgium contain the remains of both bear species, which are about 30,000 years old.
Writing in the journal “Boreas”, Anneke van Heteren, mammal curator at the Zoologische Staatssammlung München (SNSB-ZSM), and Mietje Germonpré of the Royal Belgian Institute of Natural Sciences (RBINS) showed that the two contemporaries fed differently.
The cave bear was probably entirely vegetarian, whilst the brown bear was an omnivore even then, just like it is today. The shape and biomechanics of the jaws of the two bear species differ significantly. In addition, the scientists were also able to identify small differences in the jaws of the fossil brown bears compared to their conspecifics still living today.
Anneke van Heteren commented:
“Presumably, the fossil brown bears from Belgium ate slightly more plant food than the brown bears from North America today.”
Studying the Fossils of Cubs
The researchers also examined the fossilised jaws of cave bear cubs from the cave network. Their jaws were less well suited to chewing solid food than those of the adults.
Dr Anneke van Heteren added:
“The young bears were also still being fed milk by their mothers. Their jaws first had to adapt to the later development of their permanent dentition.”
The biomechanical differences in the jaws are particularly evident in their gape angles when chewing their food. The study team used geometric morphometrics to assess these physical differences. This is the measurement of skeletal parts with the help of measuring points, so-called landmarks. The method allowed the researchers to visualise the jawbones of the bears in three dimensions. Once a three-dimensional model has been created, the function of the jaw and the teeth can be assessed using statistical methods.
Everything Dinosaur acknowledges the assistance of a media release from the Royal Belgian Institute of Natural Sciences in the compilation of this article.
The scientific paper: “Geometric morphometric assessment of the fossil bears of Namur, Belgium: Allometry and ecomorphology” by Anneke H. van Heteren and Mietje Germonpré published in the journal Boreas.
On a visit to the Manchester Museum a team member overheard a grandmother challenging her grandchildren. Her young charges were tasked with counting the fossils in a display cabinet. The cabinet contained various ichthyosaur fossil specimens. Part of the exhibit included marine reptile fossil dung (coprolite). The grandmother asked the children to have a go at counting ichthyosaur coprolites.
Counting ichthyosaur coprolites. A grandmother visiting the Manchester Museum played a counting came with her grandchildren. It involved counting ichthyosaur coprolites. Picture credit: Everything Dinosaur.
The children were enjoying their visit to the Manchester Museum. After the photographs in front of the Tyrannosaurus rex cast (Stan), the grandmother set the counting challenge. We are not sure whether she knew that the display cases contained fossils of marine reptile poo, but the children were undeterred. They eagerly accepted the counting challenge.
Counting games can help young children become more confident. Counting games can help them to develop confidence with numeracy.
The Tyrannosaurus rex cast on display at the Manchester Museum. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
A spokesperson from Everything Dinosaur commented:
“There is lots to see and lots to do at the Manchester Museum. Staff hand out worksheets and encourage children to take part in various activities themed around the exhibits. We have not come across an activity that involved counting ichthyosaur coprolites before. We congratulate the family for their innovation.”
A model of an ichthyosaur. The Ichthyosaurus model (Wild Safari Prehistoric World) ready to take its turn on the Everything Dinosaur turntable. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The image (above) shows a typical replica of an ichthyosaur. This is the Wild Safari Prehistoric World Ichthyosaurus model.
“There is an extensive display of ichthyosaur and other marine reptile fossil material on display. Several of the fossils of ichthyosaurs come from the Dorset coast. We have found some ichthyosaur fossils on the Dorset coast too. We do have ichthyosaur coprolite fossils in our collection. However, we have never played a counting coprolite game unlike the grandchildren.”
A joint Canadian and Chinese team of scientists have described a remarkable fossil that preserves a dramatic moment in time when a carnivorous mammal attacked a bigger herbivorous dinosaur. Repenomamus attacks Psittacosaurus, a stunning fossil specimen from the Lower Cretaceous from the Lujiatun fossil beds.
Entangled Psittacosaurus and Repenomamus skeletons showing details of their interaction. Scale bar equals 10 cm. Picture credit: Gang Han.
Mammal Attacks a Dinosaur
Dr Jordan Mallon (Canadian Museum of Nature), a co-author of the study published in the journal “Scientific Reports” commented:
“The two animals are locked in mortal combat, intimately intertwined, and it’s among the first evidence to show actual predatory behaviour by a mammal on a dinosaur.”
Life reconstruction showing Psittacosaurus being attacked by Repenomamus 125 million years ago. Picture credit: Michael W. Skrepnick/courtesy of Canadian Museum of Nature.
A Fossil from “China’s Dinosaur Pompeii”
The fossil’s discovery challenges the perception that dinosaurs had few threats from their mammal contemporaries during the Cretaceous. It is true to comment that in most terrestrial ecosystems the dinosaurs dominated. However, this exceptionally rare fossil demonstrates that some mammals may have attacked members of the Dinosauria.
The fossil was collected in China’s Liaoning Province in 2012, and both skeletons are nearly complete. Their completeness is due to the fact that they come from an area known as the Lujiatun fossil beds, which have been dubbed “China’s Dinosaur Pompeii”.
The fossil specimen is now in the collections of the Weihai Ziguang Shi Yan School Museum in China’s Shandong Province.
Entangled Psittacosaurus and Repenomamus skeletons showing details of their interaction. Scale bar equals 10 cm. Picture credit: Gang Han.
Repenomamus Attacks Psittacosaurus
The dinosaur victim has been identified as Psittacosaurus lujiatunensis. It was about the size of a large dog. It is being attacked by a Repenomamus robustus. Repenomamus is not closely related to placental mammals. It was a triconodont, larger and more powerfully built compared to most Mesozoic mammals. The taxonomic position of the Triconodonta within the stem mammals and the Mammalia remains controversial. With a body length of approximately one metre, R. robustus was smaller and lighter than Psittacosaurus lujiatunensis. However, this fossil provides evidence that this mammal attacked dinosaurs that were larger than itself.
Detail of fossil showing Repenomamus biting the ribs of Psittacosaurus. Picture credit: Gang Han.
Repenomamus Ate Psittacosaurus
It was already known that Repenomamus ate dinosaurs. A scientific paper was published in 2005 that documented the discovery of a large Repenomamus fossil specimen with the preserved remains of a juvenile Psittacosaurus in what would have been the animal’s digestive tract.
Dr Mallon explained:
“The co-existence of these two animals is not new, but what’s new to science through this amazing fossil is the predatory behaviour it shows.”
Detail of the fossil showing the left hand of Repenomamus wrapped around the lower jaw of Psittacosaurus. Picture credit: Gang Han.
The Lujiatun Member (Yixian Formation)
The Lujiatun Member of the Lower Cretaceous Yixian Formation of China is famous for its extensive vertebrate fossil remains. Animals were buried by mudslides and debris following volcanic eruptions. These pyroclastic flows entombed these unfortunate creatures preserving their last moments of life more than 125 million years ago.
Hillside where the fossil was collected from the Lujiatun Member of the Yixian Formation of north-eastern China in 2012. Picture credit: Gang Han.
The Psittacosaurus-Repenomamus fossil was in the care of study co-author Dr Gang Han in China, who brought it to the attention of Canadian Museum of Nature palaeobiologist Xiao-Chun Wu. Whilst fossil forgeries are known from the Jehol Group of China, the research team excavated more of the matrix and confirmed that this was an authentic specimen, most likely preserving predatory behaviour.
Repenomamus the Aggressor
A detailed examination of the fossil pair shows that the Psittacosaurus is lying prone, with its hindlimbs folded on either side of its body. The body of the Repenomamus coils to the right and sits atop its prey, with the mammal gripping the jaw of the larger dinosaur. The mammal is also biting into some of the ribs, and the back foot of Repenomamus is gripping onto the dino’s hind leg. These animals are locked in mortal combat.
Dr Mallon postulated that the weight of evidence suggested that an attack from the Repenomamus was underway when the pyroclastic flow killed both animals.
Detail of fossil showing the left hind foot of Repenomamus gripping the left lower leg of Psittacosaurus. Picture credit: Gang Han.
Not Scavenging a Carcase
The research team have ruled out the possibility that the Repenomamus was scavenging a Psittacosaurus corpse. Tooth marks on the dinosaur bones are absent, suggesting that this fossil represents evidence of a mammal attacking a dinosaur.
It is unlikely the two animals would have become so entangled if the dinosaur had been dead before the mammal encountered it. The position of the Repenomamus on top of the Psittacosaurus suggests it was also the aggressor.
Attacks on herbivores by smaller carnivores are seen today. Mallon and Wu note that some lone wolverines are known to hunt larger animals, including caribou and domestic sheep. On the African savanna, wild dogs, jackals and hyenas will attack prey that are still alive, with the prey collapsing, often in a state of shock.
Dr Mallon stated:
“This might be the case of what’s depicted in the fossil, with the Repenomamus actually eating the Psittacosaurus while it was still alive—before both were killed in the roily aftermath.”
Repenomamus robustus attacks Psittacosaurus lujiatunensis moments before a volcanic debris flow buries them both circa 125 million years ago. Picture credit: Michael W. Skrepnick/courtesy of Canadian Museum of Nature.
The research team speculates in their research paper that further amazing fossils await discovery. The volcanically derived deposits from the Lujiatun fossil beds will continue to yield new evidence of interactions among species.
Everything Dinosaur acknowledges the assistance of a media release from the Canadian Museum of Nature in the compilation of this article.
The scientific paper: “An extraordinary fossil captures the struggle for existence during the Mesozoic” by Gang Han, Jordan C. Mallon, Aaron J. Lussier, Xiao-Chun Wu, Robert Mitchell and Ling-Ji Li published in Scientific Reports.
The oldest spider ever found in Germany has been scientifically described. Named Arthrolycosa wolterbeeki this ancient creepy-crawly roamed northern Germany more than 300 million years ago (Carboniferous).
The fossils of this arachnid come from the Piesberg quarry near Osnabrück in Lower Saxony. They represent the first Palaeozoic spider found in Germany.
Arthrolycosa wolterbeeki fossils (top) and interpretative line drawing (bottom). Picture credit: Jason Dunlop, Museum für Naturkunde Berlin.
Arthrolycosa wolterbeeki
In a recent article published in the international journal Paläontologische Zeitschrift, Dr Jason Dunlop from the Museum für Naturkunde Berlin described this ancient arthropod. The spider is between 310 and 315 million years old and was named after its discoverer, Tim Wolterbeek, who generously donated the fossil to the Museum für Naturkunde Berlin.
The spider had a body length of about one centimetre and a leg span of about four centimetres. It was about the same size as a common Wolf spider (Lycosidae). It belonged to a primitive group of arachnids known as the mesotheles, which, in contrast to most spiders today, still have a segmented abdomen. Its living relatives are found only in eastern Asia.
The fossil reveals stunning details. The silk-producing spinnerets and even hair and claws on the legs have been identified.
An Arthrolycosa wolterbeeki life reconstruction. Picture credit: Jason Dunlop, Museum für Naturkunde Berlin.
One of Nature’s Big Success Stories
The Arachnida are one of nature’s great success stories. More than 50,000 species of spider have been described worldwide. About a thousand species live in Germany. Spiders are also preserved as fossils. More than 1,400 extinct species are known. It is thought the first spider-like, terrestrial arthropods evolved in the Devonian. These creatures rapidly diversified and thrived in the swamps of the Carboniferous. They became important predators of insects and other small invertebrates. Some giant forms evolved, although the classification of some specimens remains controversial. For example, Megarachne servinei from the Late Carboniferous of Argentina had a leg span in excess of fifty centimetres. Once thought to be a giant spider, it has been reclassified as a bizarre eurypterid.
To read an article from 2018 about the discovery of a Cretaceous-aged spider with a whip-like tail: A Tale of a Spider with a Tail.
The Piesberg quarry is an important fossil site and was declared a National Geotope in 2019. The location has yielded numerous fossils of plants, insects and other animals, including arachnids such as scorpions. This new fossil shows that Late Carboniferous spiders also lived in the Piesberg coal forests. Spiders of this age are still extremely rare. Only twelve Carboniferous species worldwide can be positively identified as spiders, with previous records coming from France, the Czech Republic, Poland and the United States (Mazon Creek).
Everything Dinosaur acknowledges the assistance of a media release from the Museum für Naturkunde Berlin in the compilation of this article.
The scientific paper: “The first Palaeozoic spider (Arachnida: Araneae) from Germany” by Jason A. Dunlop published in Paläontologische Zeitschrift.
A newly published study suggests that the Cambrian predator Anomalocaris canadensis had grasping appendages that were too weak to crack trilobite exoskeletons.
The research examined the mechanical properties of the claw-like appendages of the Late Cambrian predator Anomalocaris canadensis. The study concluded that this marine carnivore was built for speed but was not strong enough to crack the exoskeletons of trilobites.
An Anomalocaris life reconstruction. Picture credit: Katrina Kenny.
A Nektonic, Agile Hunter
Writing in the academic journal the Proceedings of the Royal Society Biology, the researchers led by Russell Bicknell (American Museum of Natural History), show that A. canadensis was weaker than previously thought. They postulate that Anomalocaris was a fast and agile swimmer. It was nektonic, catching soft prey such as jelly fish and early vertebrates in open water. The study further refutes the idea that this large predator hunted trilobites.
The fossilised head of an Anomalocaris canadensis showing a contracted grasping appendage. Picture credit: Greg Edgecombe.
This Study Supports the Conclusions of Earlier Research
Earlier research (Christopher Nedin, 1999) focused on the ring-shaped mouthparts of Anomalocaris (the oral cone). Anomalocaris mouthparts were at first misidentified. The oral cone was once thought to represent a jellyfish and named Peytoia. The lack of wear on the mouthparts was highlighted suggesting that they did not they did not come into regular contact with mineralised trilobite exoskeletons. It was proposed these radiodonts probably fed on soft-bodied organisms.
Revising the Behaviour of Anomalocaris canadensis
It had been thought that Anomalocaris was responsible for some of the scarred and crushed trilobite specimens preserved in the fossil record.
Postdoctoral researcher Russell Bicknell commented:
“That didn’t sit right with me because trilobites have a very strong exoskeleton, which they essentially make out of rock, while this animal would have been mostly soft and squishy.”
This study set out to investigate whether the pair of grasping appendages located on the head were capable of ripping apart a trilobite. Burgess Shale fossil material was used to create an accurate three-dimensional model of Anomalocaris canadensis.
Natural History Museum researcher and co-author of the paper, Greg Edgecombe explained:
“Having access to specimens with the entire body preserved in the fossils allowed us to understand the anatomy of the appendages in the context of the rest of the head and the trunk. We were able to get a better picture of Anomalocaris as a living organism.”
A new biomechanical study using techniques applied in engineering projects suggests that the spiked, grasping appendages of Anomalocaris canadensis were not strong enough to break the exoskeleton of a trilobite. Picture credit: Greg Edgecombe.
Compared to Extant Whip Scorpions and Whip Spiders
The scientists used modern predatory whip spiders and whip scorpions as analogues. The team demonstrated that the predator’s segmented appendages were able to grab prey and could both stretch and flex. Finite element analysis, a modelling technique used in engineering, was used to identify stresses and points where the appendage would have been under strain.
The team calculated that the appendages would have been damaged while grasping hard prey such as trilobites. The researchers also used computational fluid dynamics to place the three-dimensional model of Anomalocaris in a virtual current to predict the body position it would use while swimming.
Dr Imran Rahman (London Natural History Museum) stated:
“This study emphasises the great potential of modern computer modelling methods in palaeontology. By employing techniques more commonly used in other disciplines like engineering, we can test ideas about long-extinct animals like Anomalocaris.”
This is the first time this combination of biomechanical modelling techniques has been used together in a single study. A different view of Anomalocaris canadensis has emerged. The animal was probably nektonic. A speedy swimmer, chasing soft-bodied prey in the water column with its front appendages outstretched and forward-facing.
Bicknell remarked:
“Previous conceptions were that these animals would have seen the Burgess Shale fauna as a smorgasbord, going after anything they wanted to, but we are finding that the dynamics of the Cambrian food webs were probably much more complex that we once thought.”
Everything Dinosaur acknowledges the assistance of a media release from the London Natural History Museum in the compilation of this article.
The scientific paper: “Raptorial appendages of the Cambrian apex predator Anomalocaris canadensis are built for soft prey and speed” by Russell D. C. Bicknell, Michel Schmidt, Imran A. Rahman, Gregory D. Edgecombe, Susana Gutarra, Allison C. Daley, Roland R. Melzer, Stephen Wroe and John R. Paterson published in the Proceedings of the Royal Society B.
The oldest fossil “stomach stone” has been discovered at Kimmeridge Bay, Dorset on the famous “Jurassic Coast”. The baseball-sized fossil was found by the eminent palaeontologist Dr Steve Etches MBE. It is thought to be around 150 million years old. The fossil is at least 59 million years older than the previous oldest known fossilised stomach stone.
The world’s oldest fossil “stomach stone” also known as a calculus. This exceptionally rare fossil was found at Kimmeridge Bay. It is estimated to be approximately 150 million years old (Late Jurassic). Picture credit: Ivan Sansom.
Fossil “Stomach Stone” – A Calculus
Dr Etches sought the opinions of other palaeontologists to see if he could learn more about this mystery object. It was initially dismissed as not being organic in nature. The consensus was that it had formed through geological processes. The stone was passed on to experienced fossil preparator Nigel Larkin who compared it to material in the collections of the Royal College of Surgeons, England, and the University College London (UCL) pathology collections.
It soon became clear the stone was a “calculus”. A “calculus” is a concretion, a collection of minerals that form in the body. These objects are found in many parts of the body, the kidneys, the bladder, the stomach the urinary tract and they have a very specific internal structure.
Dr Steve Etches MBE holding the world’s oldest calculus. One of the UK’s rarest fossils. Found by Steve at Kimmeridge on the Jurassic Coast. Picture credit: The Etches Collection.
An Exceptional Fossil Discovery
Only a handful of calculi have been discovered in the fossil record. It is thought that more exist, but they have not been formally identified.
Nigel Larkin commented:
“I was fascinated by this very curious mystery object and was determined to discover what it was. Unless stomach stones are actually found preserved within a skeleton it is almost impossible to tell what sort of animal it might have formed inside.”
The size of the stomach stone and the location of its discovery (marine deposits) suggests that this object formed inside the body of a large marine reptile. The calculus could have come from a plesiosaur, an ichthyosaur, a pliosaur or perhaps a marine crocodile.
Dr Ivan Sansom, Senior Lecturer in Palaeobiology at the University of Birmingham, carried out microscopic analyses of the stone to determine the exact structure of the specimen and its mineral composition. Based on this analysis Dr Sansom concluded that this stone had formed in the gastro-intestinal tract. It was a fossil “stomach stone”.
The Only Calculus from the UK Fossil Record
The fossil “stomach stone” is estimated to be around 150 million years old (Late Jurassic). This discovery extends the range of known calculi in the fossil record by approximately 59 million years. It is the only fossil of its kind to have been found in the UK. It also confirms their occurrence in marine palaeoenvironments rather than just terrestrial deposits.
Everything Dinosaur acknowledges the assistance of a media release from the University of Reading in the compilation of this article.
The scientific paper: “The fossil record’s oldest known calculus (an enterolith of the gastrointestinal tract), from the Kimmeridge Clay Formation (Upper Jurassic), UK” by Nigel R. Larkin, Thomas Henton, Steve Etches, Adrian J. Wright, Tzu-Yu Chen, Laura L. Driscoll, Richard M. Shelton and Ivan J. Sansom published in the Proceedings of the Geologists’ Association.
