A new species of Late Cretaceous South American mammal has been named and described. The omnivorous Orretherium tzen is only the second mammal from the Mesozoic known from Chile. The newly described O. tzen joins Magallanodon baikashkenke which was named in 2020. Orretherium has been described from a partial lower jawbone, which had 5 teeth in situ and a single isolated tooth found just a few metres away from the jaw fragment. It is thought to have been about the size of a modern skunk, although it was only distantly related to modern mammals.
The Mammal Quarry
The fossils were found in exposures of the Dorotea Formation (late Campanian to early Maastrichtian faunal stages of the Late Cretaceous), on a small hill nicknamed “the mammal quarry”, reflecting the significance of the site in terms of Late Cretaceous mammalian fossil finds. Although the isolated tooth that helped describe this species was found close to the jaw fragment, the researchers cannot unambiguously refer this tooth to the same individual animal although it is highly probable taking in account their compatible size, wear and close proximity.
Classified as a member of the Meridiolestida
Orretherium has been classified as a member of the Meridiolestida, an extinct group of mammals known from South America and Antarctica.
Co-author of the research paper published in the journal Scientific Reports, Sergio Soto-Acuña (University of Chile), commented:
“This mammal is a primitive lineage of the group of meridiolestids, very successful at the end of the Age of dinosaurs in South America. The jaw found has five teeth in place that indicate omnivorous habits, it probably fed on plants and insects”.
The scientific paper: “New cladotherian mammal from southern Chile and the evolution of mesungulatid meridiolestidans at the dusk of the Mesozoic era” by Agustín G. Martinelli, Sergio Soto-Acuña, Francisco J. Goin, Jonatan Kaluza, J. Enrique Bostelmann, Pedro H. M. Fonseca, Marcelo A. Reguero, Marcelo Leppe and Alexander O. Vargas published in Scientific Reports.
Customers of Everything Dinosaur who have purchased the recently introduced PNSO A-Shu the Qianzhousaurus dinosaur model have been keen to sing the model’s praises.
The A-Shu tyrannosaur replica is one of a series of dinosaur models in PNSO’s mid-size model range that was introduced recently. For example, this range also includes Domingo the Carnotaurus.
Customers Review the Qianzhousaurus Figure
Customers who purchased this dinosaur from Everything Dinosaur have been keen to praise this PNSO figure.
Kevin reviewed the model stating that it was a:
“Beautiful model, at this moment the most accurate depiction of Qianzhousaurus.”
“This one was love at first sight and I’m so happy I’ve bought it! The attention in the details, such as the eyes, teeth and claws. The marking was also a great choice imo. Another must have by PNSO”.
A spokesperson from Everything Dinosaur commented:
“PNSO have introduced several carnivorous dinosaurs into their not to scale, mid-size model range and they have plans to introduce even more in 2021. We are pleased that dinosaur model collectors have been so delighted with their acquisitions.”
Qianzhousaurus (Q. sinensis), may have only be scientifically described in 2014 but this long snouted tyrannosaurid, closely related to Alioramus has certainly made a big impression amongst dinosaur fans and model collectors.
Researchers have published a description of a new species of anurognathid pterosaur from the Tiaojishan Formation in Hebei Province China. The diminutive flying reptile has been named Sinomacrops bondei and is the third anurognathid species to have been described from Jurassic-aged rocks found in China. Although the specimen is badly crushed, it represents the near complete skeleton of a single individual and as such it has helped palaeontologists to better understand the phylogeny of these enigmatic, but poorly known, wide-mouthed pterosaurs.
The Amazing Anurognathidae
Palaeontologists that focus on the Pterosauria have long speculated as to where in the flying reptile family tree the Anurognathidae fit. Very few fossils are known and those that have been made available to study demonstrate a mix of basal as well as more derived traits. All the anurognathids described to date are estimated to have had wingspans less than 90 cm. Their fossils are associated with terrestrial environments and it has been suggested that these little flying reptiles lived in forests and ate insects, perhaps capturing them on the wing.
The genus name translates from the Greek for Chinese, large eyes/face. The specimen (number JZMP-2107500095) is the first record of an anurognathid pterosaur skull preserved in a mostly lateral view. The species epithet honours the Danish palaeontologist Niels Bonde in recognition of his many years contributing to vertebrate palaeontology.
A Crushed Skeleton
Although the skeleton is badly crushed, the fossilised remains which herald from the Daohugou Beds of the Tiaojishan Formation and are therefore between 164 – 158 million years old (Callovian to the Oxfordian stage of the Middle to Late Jurassic), have provided a new insight into the variation of jaw shape in these wide-mouthed pterosaurs. In addition, the Sinomacrops discovery permitted the researchers to undertake a revision of anurognathid phylogeny and the researchers propose that these strange flying reptiles are a sister group of the Darwinoptera and basal members of the Monofenestrata.
The Monofenestrata comprises a wide range of pterosaur families, broadly grouped together as they had long tails, a lengthy fifth toe and the possession of a single large opening on each side of the skull in front of the eyes. Hence the name Monofenestrata (Latin for “one window”), the merging of the nasal and antorbital openings into a single feature.
The scientific paper: “Sinomacrops bondei, a new anurognathid pterosaur from the Jurassic of China and comments on the group” by Xuefang Wei, Rodrigo Vargas Pêgas, Caizhi Shen, Yanfang Guo, Waisum Ma, Deyu Sun, Xuanyu Zhou published in PeerJ.
Newly published research has provided palaeontologists with remarkable new evidence shedding light on the evolution of gill structures in the Arthropoda. Writing in the academic journal “Science Advances”, researchers from the University of California Riverside in conjunction with colleagues from the Indian Statistical Institute (Kolkata) and the American Museum of Natural History (New York), have demonstrated that some species of trilobite had gills on their upper limbs.
Exquisitely Preserved Fossils
Many thousands of species of trilobite have been named and described. However, very few fossils of these enigmatic, extinct members of the Arthropoda preserve soft parts of the animal’s bodies.
Fossils Preserved as Fool’s Gold Reveal New Information
The segmented limbs of trilobites were biramous, that is the limb was spilt into two branches. The function of the upper element of this limb has long been debated. It had been thought by some scientists that is served a respiratory function, but the evidence to support this hypothesis was lacking.
Remarkably detailed fossil specimens preserved in iron pyrite were subjected to scans using computerised tomography (CT scans). The computer generated images revealed dumbbell-shaped filaments in the upper limb branch that are morphologically comparable with gill structures in crustaceans.
The Beecher’s Trilobite Bed
The beautifully preserved specimens with their soft parts replaced by pyrite come from the famous Beecher’s trilobite bed which is a Late Ordovician Lagerstätte with over 85% of the fossils found at the site representing the trilobite Triarthrus eatoni.
Lead author of the paper PhD student Jin-bo Hou (University of California Riverside) commented:
“Up until now, scientists have compared the upper branch of the trilobite leg to the non-respiratory upper branch in crustaceans, but our paper shows, for the first time, that the upper branch functioned as a gill”.
The research team mapped how blood would have filtered through chambers in these delicate structures, absorbing oxygen as it progressed through the tiny structures which measure around 30 microns across, that’s three times smaller than the diameter of a human hair.
These structures appear much the same as gills in modern marine arthropods like lobsters and crabs, but crucial anatomical differences were identified, helping scientists to better understand the phylogeny of the Trilobita within the arthropod phylum. Comparing the specimens in pyrite to another trilobite species (Olenoides serratus), gave the team additional information about how the filaments were arranged relative to one another and to the legs.
The researchers concluded that the upper limb’s partial articulation to the body via an extended membrane is morphologically comparable to the junction of the respiratory book gills of extant horseshoe crabs (Limulus). Furthermore, this morphology differentiates it from the typically robust junctions associated with crustaceans and the extinct sea scorpions.
The scientific paper: “The trilobite upper limb branch is a well-developed gill” by Jin-bo Hou, Nigel C. Hughes and Melanie J. Hopkins published in Science Advances.
Everything Dinosaur team members have been asked to provide some scientific information on the “Styx Demon”, the pachycephalosaur known as Stygimoloch. The profile of this animal was raised recently due to its appearance in the last “Jurassic World – Fallen Kingdom” film to be released and with the introduction of a Stygimoloch model in the Papo “Les Dinosaures” range.
Preparing Stygimoloch Information for a Dinosaur Exhibit
A paper presented at the 2007 annual meeting of the Society of Vertebrate Paleontology suggested that the spiky Stygimoloch was not a valid species of dinosaur, but its fossils represented juveniles of the already described and much larger, bone-headed dinosaur Pachycephalosaurus. With the validity of this genus in question, this makes preparing scientific information for a dinosaur exhibit featuring Stygimoloch a bit of a challenge for our dedicated team members.
Summarising the Story of Stygimoloch
In 1973, scientists from the University of California Berkeley, whilst exploring Hell Creek Formation exposures in McCone County, Montana, found a single, robust skull fragment with the remains of three distinct, prominent horns projecting out of the back of it.
Although classified as a bone from a pachycephalosaur, no further work on the bone was carried out until palaeontologists Hans-Dieter Sues and Peter Galton published a comprehensive review of North American pachycephalosaur fossils in 1983. They named Stygimoloch (S. spinifer), based on this unusual skull bone and other fragmentary material that had once been thought to represent part of the neck frill from a Triceratops.
Rising to the Challenge
Our team members are not ones to shy away from a challenge. As well as providing information on Stygimoloch for the exhibition, they also prepared some additional information featuring Pachycephalosaurus wyomingensis so that visitors could learn more about how perceptions regarding Hell Creek Formation pachycephalosaurs have changed.
That talented team at Rebor have introduced two limited edition hatchling Deinosuchus polystone replicas. Two fantastic replicas of a hatching Deinosuchus, a fearsome crocodile that lived in the southern United States during the Late Cretaceous.
Fans of the Rebor range have two colour variants to choose from. There is the Rebor Club Selection: Meta the hatchling Deinosuchus (estuary variant) as shown above. Alternatively, collectors could select the Rebor Club Selection: Meta the hatchling Deinosuchus (swamp variant) shown below.
Digitally Designed Models
These two polystone replicas are the first models in the extensive Rebor Club Selection portfolio to have been digitally sculpted. Fans of the Rebor range can expect even more detailed and lifelike figures.
Only 500 of Each Have Been Made
Announcing these figures over the Easter Holiday weekend, Rebor have stipulated that only 500 of each of the Deinosuchus models (swamp variant and the estuary variant) will be produced. These are limited edition models, likely to rise in value over time as collectors, not able to pick one up when first introduced, desperately try to complete their Rebor model collections.
Aware of the Rebor range’s popularity a spokesperson from Everything Dinosaur commented:
“These stunning Rebor Club Selection replicas are bound to be very popular. The two polystone figures combine the excellence of Rebor with the fact that there are very few Deinosuchus figures in production. These two factors plus their limited production run are going to make both “swamp” and “estuary” highly collectable.”
Available from Pre-order from Everything Dinosaur
The Rebor Club Selection: Meta the hatchling Deinosuchus “swamp variant” and the Rebor Club Selection: Meta the hatchling Deinosuchus “estuary variant” are available to pre-order from Everything Dinosaur.
The company spokesperson advised that customers did not delay in placing their pre-orders. Demand is going to far exceed supply and very soon both “swamp” and “estuary” will be as extinct as Deinosuchus hatcheri, the giant prehistoric crocodile upon which these polystone replicas are based.
Both the Rebor Club Selection Meta the hatchling Deinosuchus models are available to order from Everything Dinosaur (whilst stocks last).
The Amazon rainforest is an extremely important low latitude habitat with a huge diversity of animals, fungi and plant species. Described as the “lungs of the planet”, this tropical rainforest is at the very centre of many global conservation efforts. New research suggests that it was the extra-terrestrial impact event some 66 million years ago that led to the rise of this angiosperm dominated ecosystem.
K/Pg Extinction Event
Approximately 66 million years ago a rock from space smashed into our planet. This triggered a sudden mass extinction event devastating around 75% of all the animal and plant terrestrial species, many of which subsequently became extinct. At this time the dinosaurs, their cousins the pterosaurs and the majority of marine reptiles died out.
Analysis of Fossil Pollen and Study of Fossil Leaves
Writing in the journal “Science”, researchers from the Southern Methodist University (Texas) and the University of Wyoming report on the study of tens of thousands of fossil pollen specimens along with thousands of leaf fossils from Cretaceous-aged strata and deposits laid down after the K/Pg extinction event. The scientists, which include co-author Dr Ellen Currano (Department of Botany, University of Wyoming), found that the types of plant creating tropical forests were very different pre and post the extra-terrestrial impact. In the Late Cretaceous tropical forests were dominated by conifers and they were much more open than the dense, angiosperm forests that came about during the Palaeocene.
A Thick Forest Canopy Denying Access to Light
The scientists discovered that the fossil pollen and leaves show a marked transition in tropical forest flora. After the extra-terrestrial impact forests developed a thick canopy blocking much of the light from reaching the ground and angiosperms became more dominant.
How Did These Changes Come About?
As well as the documenting the turnover in flora and the transition from one tropical forest environment to a different type of rainforest in the Palaeocene, the researchers propose three possible explanations for this change:
The absence of large megaherbivores, specifically dinosaurs allowed plant densities in forests to increase. The extinction of giant plant-eating dinosaurs such as the Ceratopsia, hadrosaurs, armoured dinosaurs and the titanosaurs allowed plants to grow at lower levels as they were not being trampled or consumed by herbivorous dinosaurs.
Several types of fern and conifer became extinct during the K/Pg transition permitting new types of angiosperm (flowering plants) to evolve and exploit the vacated niches.
Falling ash from the impact enriched soils throughout the tropics, provided an advantage to faster-growing angiosperms.
The scientists conclude that the three hypotheses are not mutually exclusive and that a combination of factors could have led to the change in the flora as recorded in the fossil record.
A Significant Lesson for Today
Today, a rapidly changing climate, largely caused by the actions of our own species is having a dramatic effect on the world’s forests. The researchers note that the fossil record demonstrates that rainforests do not simply “bounce back”, after a catastrophe. They can take millions of years to recover and a very different type of ecosystem is likely to emerge.
The scientific paper: “The impactful origin of neotropical rainforests” by Bonnie F. Jacobs and Ellen D. Currano published in the journal Science.
Long-time fan of dinosaurs and prehistoric animals, Marc, who is also a long-time customer of Everything Dinosaur offered to write a short testimonial about his experiences purchasing from us.
What a kind thought especially in these difficult and challenging times.
“I’ve been an Everything Dinosaur customer for a number of years, and they’ve never once let me down. They’ve always had an excellent range of models, which has only improved with time with the addition of lines from Creative Beast (Beasts of the Mesozoic) and PNSO, among others. Service has always been personable and friendly but professional, and every package has arrived on time. I also (as a dinosaur nerd) really appreciate the effort they put into the educational side. Overall, ED is a business well worth supporting, and I hope they’re around for a long while yet.”
A spokesperson from Everything Dinosaur thanked Marc for their kind gesture and stated:
“Our thanks to Marc and to every single one of our customers who support our company. These are exceptionally difficult times and we are doing all we can to maintain our high standards of customer service and to offer an even wider range of prehistoric animal models and figures.”
The spokesperson from Everything Dinosaur continued:
“We remain committed to bringing into stock even more models of prehistoric animals as we support our customers and fans of dinosaurs and other extinct creatures.”
Once again, our thanks to Marc for writing a testimonial for Everything Dinosaur.
A team of international researchers have named and described a new species of fearsome, meat-eating dinosaur based on a partial skull found in 2015 in Neuquén Province (northern Patagonia). The dinosaur is a member of the Abelisauridae family and it has been named Llukalkan aliocranianus. The genus name is from the local Mapuche dialect and translates as “one who causes fear”. Not only was Llukalkan a likely apex predator, its discovery helps to confirm that the abelisaurs were one of the most important and significant predators in South America during the Late Cretaceous.
Found in Close Proximity to Viavenator exxoni
The well-preserved skull was found in outcrops of the Bajo De La Carpa Formation at the La Invernada fossil site. The strata at this location were laid down approximately 85 million years ago (Santonian faunal stage of the Late Cretaceous) and the bones were found close to the location of an earlier abelisaurid discovery (Viavenator exxoni), which had been found by some of the scientists that also participated in the Llukalkan study.
Assessment of the lacrimal bone suggest that this skull material represents a sub-adult animal and comparison with other abelisaurids such as Carnotaurus indicates that Llukalkan may have been around five metres in length, making it slightly smaller than Viavenator which is estimated to have been around six metres long.
Writing in the peer reviewed academic publication the “Journal of Vertebrate Paleontology”, the researchers which included Federico A. Gianechini, Leonardo S. Filippi and Ariana Paulina-Carabajal identified a number of autapomorphies within the skull material that led them to confidently assign a new species. The trivial name is derived from the Latin for “different skull”.
Abelisaurids “Top Dogs”
Something like ten different genera of abelisaurid dinosaur have been discovered in Patagonia to date. The scientists state that Llukalkan and Viavenator were probably contemporaneous and they help to demonstrate the dominance of this type of theropod dinosaur in the Late Cretaceous of Argentina. Both Viavenator and the newly described Llukalkan were closely related, both have been assigned to the Abelisauridae clade – the Furileusauria which includes the geologically much younger and much larger Pycnonemosaurus (P. nevesi), fossils of which come from Brazil.
Megaraptors for Company
It is likely that these two furileusaurian abelisaurids probably shared their environment with another type of large theropod hypercarnivore. Fossils of the megaraptor Tratayenia rosalesi, which was described in 2018, are also associated with the Santonian-aged strata of the Bajo de la Carpa Formation, albeit the Tratayenia material was found at a different location.
At around eight metres in length (possibly even bigger), T. rosalesi was a formidable predator. Whether the abelisaurids were the “top dogs” when it came to the food chain remains uncertain. However, with the discovery of Llukalkan so close to the fossils of Viavenator, it does suggest that these types of theropods were extremely successful predators.
The scientific paper: “A New Furileusaurian Abelisaurid from La Invernada (Upper Cretaceous, Santonian, Bajo De La Carpa Formation), Northern Patagonia, Argentina” by Federico A. Gianechini, Ariel H. Méndez, Leonardo S. Filippi, Ariana Paulina-Carabajal, Rubén D. Juárez-Valieri and Alberto C. Garrido published in the Journal of Vertebrate Paleontology.
Australia boasts a weird and wonderful flora and fauna. Millions of years of isolation has led to the land “down under” evolving a very unique biota, perhaps most marked by the abundance of marsupial mammals. Today’s fauna, remarkable as it might be, is overshadowed somewhat by the incredible megafauna that once existed on the continent. For example, giant, flightless birds thrived and evolved into a myriad of different sized forms as climates and habitats changed. Some of these birds, members of the extinct family the Dromornithidae, were giants and have been nicknamed “Thunderbirds” or even “Devil Ducks”. A newly published study examines the evolutionary development of “bird brains” in a bid to settle the phylogeny of these giant birds.
Mapping the Brains of “Mihirungs”
Scientists had puzzled over the phylogeny of these extinct birds for some time. Earlier studies suggested that they were related to waterfowl – hence one of their nicknames “Devil Ducks”. Researchers from Flinders University (Adelaide, South Australia), reconstructed the brains of a number of dromornithid genera in a bid to better understand the family’s origins and to learn more about their place in the Australian megafauna dominated prehistoric ecosystems.
One of the birds studied was the enormous Dromornis stirtoni, the largest of the “mihirungs” (the Aboriginal word for “giant bird”).
Plant-eater or Meat-eater?
Heavier than a polar bear (Ursus maritimus) Dromornis stirtoni is known from Upper Miocene deposits from Australia’s Northern Territory. It had a huge skull, more than half a metre long, but its brain was squeezed for space.
It possessed a big, powerful beak, but its diet along with the diets of other dromornithids remains a mystery. It could have fed on leaves, nuts and fruit, or perhaps it was a predator. The lack of a “hook” and the absence of talons in this and other species suggests that these flightless birds were probably not hypercarnivores.
Examining Bird Brains
Writing in the academic journal “Diversity”, the researchers examined the craniums of giant “Thunderbirds” looking at a variety of genera including the earliest Dromornis murrayi from the Late Oligocene to Dromornis planei and Ilbandornis woodburnei from the mid Miocene Epoch and Dromornis stirtoni, that roamed northern Australia around 7 million years ago (Messinian, the last stage of the Miocene).
Related to Gamefowl (Galliformes)
The researchers conclude that these birds were probably more closely related to gamefowl (Galliformes) than they were to waterfowl (Anseriformes).
Commenting on the research, one of the authors Dr Warren Handley (Flinders University) stated:
“Together with their large, forward-facing eyes and very large bills, the shape of their brains and nerves suggested these birds likely had well-developed stereoscopic vision, or depth perception, and fed on a diet of soft leaves and fruit. The shape of their brains and nerves have told us a lot about their sensory capabilities, and something about their possible lifestyle which enabled these remarkable birds to live in the forests around river channels and lakes across Australia for an extremely long time.”
An Evolutionary Experiment
The researchers suggest that the Dromornithidae were the result of birds distantly related to chickens getting a free reign in evolutionary terms on the isolated continent. They took a very different evolutionary path when compared to their relatives the megapodes which still exist in Australasia.
The researchers postulate that the range in body sizes exhibited by dromornithids were due to climate change and the availability of food within the ecosystem. The Late Miocene was a period of dramatic climate change with the continent becoming more arid and cooler. Rainforests retreated and were replaced by more open woodlands, these changes may have played a role in the evolution of giant forms such as D. stirtoni.
Everything Dinosaur acknowledges the assistance of a media release from Flinders University in the compilation of this article.
The scientific paper: “Endocranial Anatomy of the Giant Extinct Australian Mihirung Birds (Aves, Dromornithidae)” by W. D. Handley and T. H. Worthy published in Diversity.