Yesterday, Everything Dinosaur team members posted up an article that provided information on the evolutionary history of burrowing vertebrates. The first vertebrates to dig burrows were probably lungfish. These animals were similar to extant lungfish, animals such as Neoceratodus forsteri, the Australian lungfish. This taxon is also referred to as the Queensland lungfish.
Ironically, it is thought that this species of lungfish does not enter a dormant state (aestivation), by producing a mucous cocoon and burying itself in mud. Neoceratodus forsteri inhabits slow-moving rivers and reservoirs, primarily in south-eastern Queensland. In contrast, the African genus Protopterus does dig burrows. Protopterus is distantly related to the Australian lungfish. During the dry season when lakes tend to dry up, this fish excavates a burrow and buries itself in the mud. It enters a state of dormancy (aestivation), enabling it to survive whilst it waits for the water to return. During aestivation Protopterus is able to reduce its metabolism to 1/60th of its active state.
A stuffed specimen of an Australian lungfish (Neoceratodus forsteri) on display at the London Natural History Museum. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
A team of researchers, including scientists from the Museum für Naturkunde Berlin examined the origins and early evolution of vertebrate burrowing behaviour. Their paper was published in Earth-Science Reviews.
The scientific paper comprises a short overview of convergent morphological and behavioural adaptations seen in modern fossorial taxa. The researchers also document the diversity of extant vertebrate burrows. In addition, the team reviews the fossil record of inferred vertebrate burrows and fossorial vertebrates from the Devonian to the Triassic. Results highlight a probable Devonian earliest occurrence of fossoriality in continental vertebrates (Dipnoi – lungfishes).
The earliest lungfish taxa were mostly marine animals. However, after the Carboniferous, lung fish fossils are confined to deposits laid down in freshwater environments.
The Australian lungfish specimen at the London Natural History Museum is displayed next to a model of a Protopterus burrow. This can confuse visitors, it was stated earlier in this article that not all lungfish exhibit this burrowing behaviour.
A newly published scientific paper documents the evolutionary history of burrowing vertebrates. Many animals alive today are able to live underground. Burrows are used for a variety of purposes. They are used for shelter, protection and for breeding. Understanding the origin and early evolution of fossorial vertebrates and the architecture and function of the burrows they excavate is an important component of the history of life on Earth. However, little research has been done into this area of vertebrate behaviour. A newly published scientific paper reviews the fossil record of vertebrate burrows and fossorial vertebrates.
Two new species of Early Cretaceous mammals were described from fossils found in north-eastern China. Fossiomanus sinensis (upper right) and Jueconodon cheni in their burrows. A newly published scientific paper reviews the fossil record of burrowing vertebrates. Picture credit: Zhao Chuang.
Picture credit: Zhao Chuang
The Evolution of Burrowing Vertebrates
Scientists including Dr Lorenzo Marchetti and colleagues from the Museum für Naturkunde Berlin analysed both body and trace fossils. The fossil material covered a large interval of geological time, from the Devonian to the Triassic. The research revealed an older appearance of several features related to burrowing behaviour and their relationship with global warming and mass extinctions.
During the Devonian-Carboniferous, burrows were probably used primarily for aestivation or temporary shelter and evidence of fossoriality is restricted so far to European and North American localities. During the Permian, fossoriality became geographically widespread and developed in new, distantly related vertebrate lineages. This is evidence of convergent evolution. Adaptations for burrowing and living underground being identified in both synapsids and diapsids.
The research highlights that lungfish (Dipnoi) were probably the first vertebrates to use burrows. Lungfish excavate burrows so that they have a protected environment in which they can spend long periods in a state of dormancy (aestivation). This behaviour probably first evolved in the Devonian.
Burrows Became Bigger and More Complex
The paper, published in “Earth-Science Reviews” outlines a trend for bigger and more complex burrows during the Palaeozoic and into the Mesozoic. Burrows became permanent shelters and breeding locations. The researchers link these developments to climate crises such as the Cisuralian aridification (Early Permian) and the end-Permian extinction event.
After the end-Permian mass extinction, vertebrate fossoriality became more common and widespread. This behaviour became a feature of continental environments and in more distal floodplain areas, probably as a consequence of changing fluvial regimes. In the Triassic, fossoriality is recorded in even more groups, such as the Temnospondyli and the Procolophonidae. In addition, evidence of burrow sharing by unrelated vertebrates appears. This indicates that burrowers were playing an increasing role as ecosystem engineers.
Everything Dinosaur acknowledges the assistance of a media release from the Museum für Naturkunde Berlin in the compilation of this article.
The scientific paper: “Origin and early evolution of vertebrate burrowing behaviour” by Lorenzo Marchetti, Mark J. MacDougall, Michael Buchwitz, Aurore Canoville, Max Herde, Christian F. Kammerer and Jörg Fröbisch published in Earth-Science Reviews.
The Wild Safari Prehistoric World Utahraptor dinosaur model is now in stock. This extremely colourful and detailed dromaeosaur model is available from Everything Dinosaur. Team members got the opportunity to photograph the figure whilst visiting a trade show in Europe.
The Wild Safari Prehistoric World Utahraptor model spotted at a trade show. The soon to be available colourful Kentrosaurus figure can be seen to the left of the Utahraptor. Picture credit: Everything Dinosaur.
This hand-painted Utahraptor replica measures twenty-three centimetres in length. It stands around eleven and a half centimetres tall. It is an extremely colourful dinosaur model. The vivid blue colouration reminds us of a budgerigar. Dromaeosaurids like Utahraptor are, after all, distantly related to modern birds. The Wild Safari Prehistoric World Utahraptor dinosaur model is supplied with an Everything Dinosaur Utahraptor fact sheet.
A Wild Safari Prehistoric World Utahraptor dinosaur model.
A spokesperson from Everything Dinosaur welcomed the arrival of the Utahraptor dinosaur model. Other new figures from Safari Ltd will be available later in the year.
Unpacking the new Wild Safari Prehistoric World Utahraptor dinosaur figure. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
To view the extensive range of prehistoric animal figures and dinosaur toys available from Everything Dinosaur’s award-winning website: Visit Everything Dinosaur.
Eurypterids (Eurypterida) are often referred to as sea scorpions. Like scorpions these extinct invertebrates are members of the Arthropoda Phylum. They are distantly related to extant scorpions and spiders. It is thought that the first eurypterids evolved during the Ordovician. They thrived in the Silurian and Devonian. Giant forms evolved, animals like Jaekeklopterus, Acutiramus and Pterygotus. However, the number of taxa was severely depleted during the end-Devonian extinction event and although they survived for at least another 100 million years or so, during the Carboniferous and Permian they only made up a very small percentage of the taxa described from fossil deposits.
Examples of the Pterygotioidea eurypterid lineage. Note the flattened, blade-like telson that probably helped with propulsion or acted like a rudder helping to steer the animal through the water. The fossils represent Pterygotus anglicus. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The picture (above) shows two Pterygotus anglicus fossil specimens on display at the London Natural History Museum. These Early Devonian fossils come from Arbroath (Scotland).
The Shape of the Telson
Note the broad, flattened, blade-like final segment of the animal. This is the telson and in the Pterygotioidea lineage (as well as in some other Superfamilies), the telson evolved into an organ to help with propulsion and steering. In other eurypterids, the telson is shaped very differently. For example, in the sea scorpion fossil (below), the telson is long and pointed.
A fossil of a sea scorpion (eurypterid) on display at the Manchester Museum. Note the pointed end segment (telson). Probably an example of the Silurian eurypterid Eurypterus. Picture credit: Everything Dinosaur.
The Giant Claws (Chelicerae) Seen in Some Sea Scorpion Fossils
The segmented body of eurypterids consisted of the frontal prosoma (head) and the posterior opisthosoma (abdomen). The prosoma contained the mouth and six pairs of appendages which are usually referred to as appendage pairs I to VI using Roman numerals. The segments that make up the opisthosoma are usually numbered using Arabic numerals 1, 2, 3 etc. The opisthosoma comprised twelve segments in total plus the telson.
The first pair of appendages, the only pair located in front of the mouth opening, is called the chelicerae (pronounced kel-iss-ser-ray). This pair of appendages evolved into a myriad of forms in the Chelicerata (pronounced kel-iss-ser-rat-ah), the Subphylum containing the eurypterids, spiders, mites, scorpions and horseshoe crabs. This pair of appendages form the fangs seen in spiders and form the feeding limbs of horseshoe crabs.
An Atlantic horseshoe crab in ventral view with the six pairs of appendages and the telson labelled. The first pair of appendages (chelicerae) help to push food into the mouth opening. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Powerful Pincers Adapted for Grasping Prey
Some of these appendages, such as the chelicerae of giant pterygotids evolved into powerful pincers armed with strong claws analogous to those seen in crabs and lobsters. These chelicerae seem to be adapted for grasping and subduing prey. This suggests that many eurypterids were predatory.
A stunning fossil of a sea scorpion (eurypterid) claw housed at the National Museum Cardiff (Wales) photographed in 2019 when team members at Everything Dinosaur visited.The image shows a single chelicera ramus. Picture credit: Everything Dinosaur.
Note
A single appendage is referred to as a chelicera (pronounced kel-iss-ser-rah). Whereas a pair or more are referred to as chelicerae (kel-iss-ser-ray).
A spokesperson from Everything Dinosaur commented that these arthropods were remarkable animals.
“Some 250 different taxa have been described and some of these sea scorpions show adaptations that indicate they may have been partially terrestrial. Venturing out onto land is supported by trace fossils potentially preserving tracks of eurypterids walking across mud close to bodies of water.”
In 2020, CollectA introduced a Horseshoe crab model. These animals are members of the Limulidae family. This model of an ancient invertebrate is extremely detailed. The Horseshoe crab lineage has a fossil record that dates back to the Ordovician. Team members were asked to take some photographs of the figure for a palaeontology related project.
CollectA Horseshoe crab in lateral view. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The CollectA Horseshoe Crab Model
The model is very detailed, and the paint scheme makes this replica look extremely realistic. However, it is on the underside where the care and dedication of the design team really shows.
The CollectA Horseshoe crab model in ventral view (view of the underside). Picture credit: Everything Dinosaur.
The small chelicerae (modified claws) are bent towards the mouth. These appendages pass food into the mouth. The walking legs show the bifurcated end segments, and the rear “pusher” leg is clearly visible. The design team have included a vent at the base of the long, pointed telson.
An Atlantic Horseshoe crab in ventral view (view of the underside). Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The picture (above) shows an Atlantic Horseshoe crab (Limulus polyphemus) in ventral view. It is on display at the London Natural History Museum.
CollectA Age of Dinosaurs Popular Size Horseshoe crab figure. The model measures 15 centimetres in length and the width of the carapace is 7.7 cm approximately.
In horseshoe crabs, the head and thorax are fused. This structure is called the prosoma. It is also sometimes referred to as the cephalothorax. The cephalothorax is covered in a hard, protective carapace.
Our thanks to Mojo Fun for sending Everything Dinosaur some new images of the Mojo Fun prehistoric life dinosaur models. The images we received includes a clever illustration of a Mojo Fun Tyrannosaurus rex model.
We think this T. rex dinosaur model was introduced into the Mojo Fun prehistoric and extinct range in 2020. It has certainly proved to be popular with dinosaur fans and model collectors. The manufacturer has paid tribute to dinosaurs in films by mimicking a famous scene from the “Jurassic Park/Jurassic World” franchise.
Mojo Fun pays tribute to the “Jurassic Park/Jurassic World” franchise with this clever piece of artwork featuring a Mojo Fun T. rex model.
Mojo Fun Tyrannosaurus rex
The Mojo Fun T. rex figure is escaping from captivity. The image parodies scenes from the famous Universal Studio’s film franchise.
The Mojo Fun Tyrannosaurus rex Deluxe figure measures around 30 cm in length. Team members at Everything Dinosaur estimate its head height to be approximately 11 cm.
A spokesperson from Everything Dinosaur commented:
“Every dinosaur fan will get the connection between the Mojo Fun T. rex image and the movies. There are rumours circulating that a new film in the “Jurassic Park/Jurassic World” franchise will be released in 2025. Mojo Fun’s timing of the release of this new image is apposite.”
With the publication of the scientific paper announcing the discovery of Eoneophron infernalis, we at Everything Dinosaur thought we would take a closer look at the Caenagnathidae. The Caenagnathidae family (pronounced seen-nag-nay-thid-ay), are part of the Oviraptorosauria clade of maniraptoran theropod dinosaurs. They are closely related to the oviraptorids (Oviraptoridae family).
A scale drawing of a dinosaur (Anzu wyliei). This dinosaur is a member of the Caenagnathidae family, and its fossils come from the Hell Creek Formation (Maastrichtian faunal stage of the Late Cretaceous). Picture credit: Everything Dinosaur.
The Maniraptora clade consists of coelurosaurian dinosaurs and is defined as including the birds and the non-avian dinosaurs more closely related to them than to Ornithomimus velox. As well as containing the Oviraptorosauria, this clade also includes several other groups such as the dromaeosaurids, the Troodontidae family and the therizinosaurs.
The Oviraptorosauria clade* is comprised of the Caudipteridae family and two closely related dinosaur families the Caenagnathidae and the Oviraptoridae that together are classified as the Caenagnathoidea. The Oviraptorosauria are united by having very bird-like skeletons, with highly pneumatised bones. In addition, the rostrum is very short, and these dinosaurs have beaks. The beak is often, but not always edentulous (no teeth). These dinosaurs were all probably feathered.
An Oviraptor dinosaur model (CollectA Age of Dinosaurs).
The image (above) depicts an Oviraptor model from the CollectA Age of Dinosaurs range.
The Caenagnathidae Family and Eoneophron infernalis
The family Caenagnathidae, together with its closely related sister family the Oviraptoridae, comprises the superfamily Caenagnathoidea. Virtually all known members of this superfamily are confined to the Late Cretaceous. Taxonomically the Caenagnathidae is defined as Chirostenotes pergracilis and all other theropods more closely related to it than they are to Oviraptor philoceratops.
Most of these dinosaurs tend to be quite small. As a result, they are probably underrepresented in the fossil record. For example, Anzu wyliei was thought until recently to be the only caenagnathid from the Hell Creek Formation. However, there are probably at least three caenagnathids present in Hell Creek strata, including the recently named Eoneophron infernalis.
The femur (left) and right tibia (right) of Eoneophron. Picture credit: Kyle Atkins-Weldman.
Caenagnathids Not Closely Related to Ostriches
The Caenagnathidae family was originally erected by Raymond Martin Sternberg (1940), the son of the pioneering palaeontologist Charles Mortram Sternberg. Raymond Martin Sternberg thought that these dinosaurs were flightless birds. He erected the Caenagnathidae family which translates as “recent jaws”. It was mistakenly thought that these theropods were closely related to the Palaeognathae “old jaws” bird family. Extant palaeognath birds include the flightless Kiwi, the Ostrich and the Rhea as well as volant forms such as Tinamou birds. It is now known that the Caenagnathidae family of non-avian dinosaurs are not closely related to palaeognaths.
Caenagnathids are confined to the Late Cretaceous of Asia and North America. They tend to have small heads, long necks and short tails.
Time-calibrated Oviraptorosauria clade consensus tree showing the position of Eoneophron infernalis. Picture credit: Atkins-Weltman et al.
Challenging Phylogenetic Assessment
Whilst the fragmentary nature of most caenagnathid specimens makes phylogenetic assessment challenging, in the recent Eoneophron infernalis paper the researchers undertook a time-calibrated phylogenetic analysis of the Oviraptorosauria. Eoneophron was placed as a sister taxon to Citipes elegans and Elmisaurus rarus.
The difficulties involved in classifying oviraptorosaurs is exemplified by this placement. Although skeletal similarities between these three dinosaurs exist, there is a lack of comparable fossil material to study. Citipes elegans is geologically older. Its fossils come from the Dinosaur Provincial Park Formation of Alberta (Campanian faunal stage of the Late Cretaceous). In contrast, Elmisaurus rarus probably predates Eoneophron infernalis by a couple of million years. It too is from the Maastrichtian faunal stage of the Cretaceous. However, E. rarus fossils come from the Nemegt Formation of Mongolia.
A revision of already described specimens coupled with improved fossil sampling should help palaeontologists to gain a better understanding of the taxonomy of the Oviraptorosauria and specifically the enigmatic Caenagnathidae.
The Oviraptorosauria clade* also includes some other theropods regarded as basal members of this clade. For example, Incisivosaurus gauthieri from the Early Cretaceous of China.
Team members at Everything Dinosaur took the opportunity to photograph the life-size Deinonychus replicas on display at the London Natural History Museum. These animated figures can be found in the Blue Zone of the Museum.
Visiting Deinonychus
Team members are not sure when the duo were installed in the Dinosaurs Gallery, but we estimate that these life-size replicas have been at the Museum for more than a decade.
Life-size Deinonychus replicas on display at the London Natural History Museum. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Animated Deinonychus Dinosaur Models
The robotic armature permits these figures to move. The models can lift their heads, open their jaws and make a bow-like gesture to visitors. There is audio too. The Deinonychus replicas make a hissing sound. It reminds us of the sound a cat makes when it is frightened or being threatened.
New for 2020 the Wild Safari Prehistoric World Deinonychus dinosaur model. A replica of this large dromaeosaurid.
The picture (above) illustrates Deinonychus. This model is from the Wild Safari Prehistoric World range of replicas.
A spokesperson from Everything Dinosaur commented:
“There are lots of amazing exhibits at the London Natural History Museum. However, we always like to say hello to the pair of Deinonychus figures. A visit is not complete until we have spent a little time in their company.”
On the subject of a visit, take a look at the award-winning Everything Dinosaur website.
An award-winning and user-friendly dinosaur themed website: Everything Dinosaur.
Everything Dinosaur team members had the opportunity to view the five new Mojo Fun repaints for 2024 at the recent Spielwarenmesse trade fair in Germany. The repainted dinosaur models will be in stock at Everything Dinosaur soon. The five figures include the Parasaurolophus (biped and quadruped stance), the Baryonyx, Troodon and a Stegosaurus.
The five repainted Mojo Fun dinosaur models for 2024. The standing Parasaurolophus (left) and the Parasaurolophus in the quadrupedal pose (mid left). The repainted Baryonyx is at the back and the Stegosaurus repaint is also at the back (back right). A pair of Troodon repaints can be seen (right). Picture credit: Everything Dinosaur.
Whilst there are new dinosaur models scheduled for 2025, the 2024 offering consists of five repainted figures. The Mojo Fun repaints for 2024 are listed below:
Standing Parasaurolophus.
Quadrupedal Parasaurolophus.
Stegosaurus.
Troodon with an articulated jaw.
Baryonyx with an articulated jaw.
The repainted Mojo Fun Baryonyx figure for 2024. This figure has a muted colour scheme compared to the original Mojo Fun Baryonyx. The articulated jaw has been retained. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
A spokesperson from Everything Dinosaur commented:
“We had the opportunity to see the new Mojo Fun repaints at the recent Spielwarenmesse in Germany. We were particularly impressed with the paint schemes. The Baryonyx and the Troodon figures are our personal favourites.”
Newly published research examining dinosaur locomotion and comparing it with other archosaurs suggests that the way in which dinosaurs moved could have given them a competitive advantage.
The research was undertaken by a team from the University of Bristol. It has been published today in Royal Society Open Science. The team’s findings indicate that the earliest dinosaurs were simply faster and more dynamic than their competitors. Perhaps the greater locomotor plasticity of dinosaurs gave them a distinctive advantage over other terrestrial animals. This may help to explain why the dinosaur/pterosaur/bird branch of the archosaurs, the Avemetatarsalia eventually outcompeted the archosaur crocodilian lineage (Pseudosuchia).
Studying Dinosaur Locomotion
The researchers compared the limb proportions of an extensive range of archosaurs that lived during the Triassic. In total, the limb proportions of 208 taxa were studied. The research team identified which of these tetrapods was quadrupedal (four-footed) or bipedal (two-footed). The cursoriality index of each animal was also examined. The cursoriality index is essentially a measure of running ability.
The results demonstrated that the earliest dinosaurs and their close relatives were bipedal and cursorial – they had limbs adapted for running. These animals, members of the Avemetatarsalia subgroup of the archosaurs had a much wider range of running styles compared to the other archosaur lineage, the Pseudosuchia.
Evolutionary tree showing how dinosaur limb adaptation expanded through the Triassic period until it was greater overall than the spread of locomotion types in their competitors, including pseudosuchians, other avemetatarsalians, and other archosaurs. These changes also included many early dinosaurs with strong adaptations to cursoriality (running). Mass extinctions are marked along the time scale: PTME, Permian-Triassic mass extinction; CPE, Carnian pluvial episode; ETME, end-Triassic mass extinction). Picture credit: Amy Shipley.
A Higher Range of Locomotory Modes by the Avemetatarsalia
The Pseudosuchia include the ancestors of extant crocodilians. Some were small, bipedal insectivores, but most were medium-to-large-sized carnivores and herbivores, and they were very successful throughout the Triassic. The research team calculated that the Dinosauria and other members of the Avemetatarsalia, maintained a higher range of locomotory modes throughout this period.
Lead author of the study Amy Shipley commented:
“When the crunch came, 233 million years ago, dinosaurs won out”.
The MSc Palaeobiology student at the University of Bristol added:
“At that time, climates went from wet to dry, and there was severe pressure for food. Somehow the dinosaurs, which had been around in low numbers already for twenty million years, took off and the pseudosuchians did not. It’s likely the early dinosaurs were good at water conservation, as many modern reptiles and birds are today. But our evidence shows that their greater adaptability in walking and running played a key part.”
Evolution of the thigh bone (femur) through the Triassic, starting with a very limited array of shapes, and ending with a broad array of shapes for the dinosaur femur (high disparity), indicating a wide range of locomotion modes. Picture credit: Amy Shipley.
The End Triassic Mass Extinction Event (ETME)
Co-author of the paper, Professor Mike Benton explained that at the end of the Triassic there was a mass extinction event. Most of the pseudosuchians died out, except for the ancestors of today’s crocodilians. The surviving dinosaurs expanded their range of locomotion again, taking over many of the empty niches in food webs.
Co-author Dr Armin Elsler added:
“When we looked at evolutionary rates, we found that in fact dinosaurs were not evolving particularly fast. This was a surprise because we expected to see fast evolution in avemetatarsalians and slower evolution in pseudosuchians. What this means is that the locomotion style of dinosaurs was advantageous to them, but it was not an engine of intense evolutionary selection. In other words, when crises happened, they were well placed to take advantage of opportunities after the crisis.”
An illustration of the early dinosaur Eoraptor lunensis from the Upper Triassic Ischigualasto Formation of Argentina. Picture credit: Nobu Tamura.
Could Dinosaur Locomotion be Key to Their Evolutionary Success?
Fellow collaborator Dr Tom Stubbs stated that the word “dinosaur” conjures up in the public’s imagination a slow-moving, large and lumbering animal. The first dinosaurs, animals such as Eoraptor lunensis were very different. The first members of the Dinosauria were small and agile.
Dr Stubbs said:
“The first dinosaurs were only a metre long, up high on their legs, and bipedal. Their leg posture meant they could move fast and catch their prey while escaping larger predators.”
Co-author Dr Suresh Singh concluded:
“And of course, their diversity of posture and focus on fast running meant that dinosaurs could diversify when they had the chance. After the end-Triassic mass extinction, we get truly huge dinosaurs, over ten metres long, some with armour, many quadrupedal, but many still bipedal like their ancestors. The diversity of their posture and gait meant they were immensely adaptable, and this ensured strong success on Earth for so long.”
Everything Dinosaur acknowledges the assistance of a media release from Bristol University in the compilation of this article.
The scientific paper: “Locomotion and the early Mesozoic success of Archosauromorpha” by Amy E. Shipley, Armin Elsler, Suresh A. Singh, Thomas L. Stubbs and Michael J. Benton published in Royal Society Open Science.
