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/Dinosaur and Prehistoric Animal News Stories

Fossil finds, new dinosaur discoveries, news and views from the world of palaeontology and other Earth sciences.

6 12, 2017

Thornton Triceratops is Actually Torosaurus

By | December 6th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Triceratops Skeleton Turns Out to be Torosaurus

A partial, horned dinosaur skeleton, initially thought to represent a young adult Triceratops has been reassessed following a month of preparation and cleaning and identified as a Torosaurus (T. latus).  It was back in September that Everything Dinosaur first reported on the dinosaur fossil discovery in Thornton, Colorado (USA).  Sadly, the highly respected Denver Museum of Nature and Science palaeontologist, Mike Getty was taken ill at the dig site and passed away shortly afterwards.

Turns out, what was initially identified as a Triceratops has proved incorrect.  As the Denver Museum of Nature and Science preparators have worked on the fossil bones, they have uncovered enough material to confidently ascribe the fossils to the closely related, but much rarer Torosaurus latus.

An Illustration of the Horned Dinosaur Torosaurus latus

Torosaurus illustrated.

An illustration of Torosaurus latus (Sergey Krasovskiy).

Picture Credit: Sergey Krasovskiy

Triceratops and Torosaurus

Analysis of the large head shield that projects backwards from the skull has shown the frill of bone to be quite thin, with two distinct large holes (fenestrae), anatomical traits that are associated with Torosaurus and not Triceratops.  The new diagnosis was made after a careful comparative study using Triceratops specimens already within the Museum’s vertebrate fossil collection.  Torosaurus fossils are exceptionally scarce.  There are several thousand Triceratops (T. horridus and T. prorsus) fossils, representing something like 2,000 individuals.  In contrast, there are approximately 7 partial skulls of Torosaurus known.

A Skeletal Drawing Showing the Extent of the Fossil Material Found at the Thornton Site

Thornton Triceratops turns out to be a Torosaurus.

The yellow parts of the skeleton represent those elements of the Torosaurus found.

Picture Credit: Denver Museum of Nature and Science

A spokesperson for Everything Dinosaur commented:

“The fossil find at Thornton is highly significant.  The majority of the front-end of the individual has been excavated including an almost complete skull.  This specimen may provide palaeontologists with valuable information on how Torosaurus changed as it grew up.  In addition, these fossils could help to identify other Torosaurus specimens in museums that have been misidentified and labelled as Triceratops.”

Is Torosaurus Just a Very Old Triceratops?

The lack of Torosaurus fossil material compared to other horned dinosaurs from North America, led to speculation that Torosaurus was not a valid genus, that the fossil material ascribed to Torosaurus actually represented very old, very mature examples of Triceratops.  The Thornton specimen seems to represent a young adult animal, this may help to clarify the Torosaurus versus Triceratops debate.

To read an article published in 2010, that details an American study that suggested that Torosaurus fossils were actually Triceratops: The Extinction of Torosaurus – Second Time Around

Fossilised Bones Being Exposed at the Thornton Dig Site

The fossils of Torosaurus (T. latus).

Parts of the skeleton are exposed (Torosaurus latus).

Picture Credit: Denver Museum of Nature and Science

Joe Sertich (Curator of Dinosaurs at the Denver Museum of Nature and Science), stated:

“Not only is the fossil more complete and better preserved than I imagined, but it has also revealed itself to be something extremely rare.  The Thornton beast is by far the most complete, and best preserved, ever found.”

Nicknamed “Tiny”

The specimen has been nicknamed “Tiny”, but the work of preparing and studying these fossils is no small task.  The material was unearthed at a Saunders Construction site for a new Public Safety Facility.  Cleaning efforts have also revealed several more skull bones and a complete tibia (lower leg bone).  An estimated 95 percent of the skull and at least 20 percent of the skeleton have now been identified, making this the most complete Cretaceous-aged fossil discovered in Colorado.

Visitors to the Museum can observe the fossil preparation process in the Fossil Prep Laboratory, cleaning and preparing is estimated to take several more months.

Joe Sertich at the Dig Site Working on “Tiny” the Torosaurus

Excavating an Torosaurus.

Joe Sertich, curator of dinosaurs, (Denver Museum of Nature and Science) at the dig site (Thornton, Colorado).

Picture Credit: Denver Museum of Nature and Science

We wonder what Mike Getty would have made of it all?

To read more about the sad death of renowned scientist Mike Getty: Highly Respected Palaeontologist Dies at Dig Site

Everything Dinosaur acknowledges the assistance of the press team at the Denver Museum of Nature and Science in the compilation of this article.

5 12, 2017

The Archaeopteryx That Wasn’t

By | December 5th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Ostromia crassipes – The First European Member of the Anchiornithidae

The first fossil of Archaeopteryx to have been discovered, turns out not to represent the “Urvogel” at all.  In a reassessment of the fossil, known as the Haarlem specimen, as it is part of the vertebrate collection housed at the Teylers Museum in Haarlem (Holland), it has been re-described as a small predatory dinosaur belonging to the anchiornithid family.  The dinosaur has been named Ostromia crassipes, the genus name honours the late John Ostrom, who identified the Haarlem specimen as a Theropod and was instrumental in the work that led to the definition of dinosaurs as dynamic, active reptiles.

The Haarlem Specimen – the Holotype of Ostromia crassipes

Ostromia crassipes holotype fossil.

The holotype fossil of Ostromia crassipes, previously thought to represent Archaeopteryx.

Picture Credit: Oliver Rauhut/Ludwig-Maximilians-University (Munich, Germany)

The fossil studied, actually consists of two parts, the counterslab TM 6929 (left) and the main slab (right) TM 6928.

Archaeopteryx was named in 1861, however, the Haarlem specimen was found four years earlier.  To date, around a dozen specimens have been assigned to the Archaeopteryx genus, including a single, fossilised feather.  The discovery of Archaeopteryx supported the theory of natural selection proposed by Darwin and Wallace as it represented a transitional form between reptiles and birds.  Archaeopteryx fossils support the idea that modern birds are descendants of carnivorous dinosaurs.

Writing in the academic journal “BMC Evolutionary Biology”, palaeontologists Oliver Rauhut and Christian Foth from the Staatliches Museum für Naturkunde in Stuttgart have re-examined the Haarlem specimen.  They conclude that this fossil differs in several important respects from the other known representatives of the genus Archaeopteryx.  The researchers conclude that the fossil is not an Archaeopteryx at all, but a representative of the very bird-like maniraptoran dinosaurs known as anchiornithids.

These crow-sized, predatory dinosaurs possessed feathers on all four limbs, and they predate the appearance of Archaeopteryx by several million years.

Commenting on their study, Dr Oliver Rauhut stated:

“The Haarlem fossil is the first member of this group found outside China and together with Archaeopteryx, it is only the second species of bird-like dinosaur from the Jurassic discovered outside eastern Asia.  This makes it [the Haarlem specimen] even more of a rarity than the true specimens of Archaeopteryx.”

Subtle Anatomical Differences and Bone Osteology

The scientists looked at the relative proportions of limb, toe and finger bones and noted that the Haarlem material (TM 6929 and TM 6928), was different from other Archaeopteryx specimens.  In addition, it had affinities with the fossilised remains of Anchiornis from China.  Furthermore, differences in bone osteology were observed.  For example, the Haarlem fossil specimen has a regular, well-developed longitudinal furrow on the exposed medial side of the preserved manual phalanx, this furrow is not present on any of the finger bones ascribed to Archaeopteryx.

Comparing the Finger Bones (Manual Phalanges) of Various Theropods

Theropod manual phalanges comparison.

Comparison of Theropod finger bones in highly compacted sediments.  Scale bar in mm.

Picture Credit: BMC Evolutionary Biology

The photograph (above) shows close-up views of the finger bones (manual phalanges) of several Theropods, analysis of the shape of the bones, their features and their proportions led the researchers to conclude that the Haarlem specimen was not Archaeopteryx.

(a).  the right manus (hand) of the Thermopolis specimen of Archaeopteryx

(b). the right manus of the Solnhofen specimen of Archaeopteryx

(c). the left manus of the juvenile Theropod from Germany Sciurumimus albersdoerferi (image resolved under UV light)

(d). the second finger of the small Late Jurassic Theropod Compsognathus longipes

(e).  the impression from the first finger of the anchiornithid Anchiornis huxleyi

(f). the first finger of Caudipteryx, a feathered Theropod from the Early Cretaceous of China

Learning About Fauna of the Solnhofen Archipelago

Discovered in 1857, the Haarlem fossil specimen was found about 6 miles (10 kilometres), to the north-east of the closest Archaeopteryx locality known (Schamhaupten) which is near the town of Altmannstein in southern Bavaria.  The Jurassic-aged rocks in this area were laid down in a shallow sea, in which were scattered numerous small islands, an archipelago, that provided an environment, superficially similar to that of the Caribbean today.  These islands that once covered southern Bavaria, are known as the Solnhofen archipelago, the region from which all known specimens of the genus Archaeopteryx come from.  The taxonomic reassignment of the Haarlem specimen to the feathered Anchiornithidae has provided a fresh insight into the evolution of the Avialae and indicates that the first bird-like dinosaurs originated in Asia.  During the Middle to the Late Jurassic these creatures migrated westwards, reaching the Solnhofen archipelago of Western Europe some 150 million years ago.

The Haarlem fossil was originally recovered from what was then the eastern end of the archipelago, quite close to the mainland.  Unlike Archaeopteryx, anchiornithids were (most likely), unable to fly, and might not have been able to reach the more remote islands offshore.   All true fossils of Archaeopteryx found to date were recovered from the lithographic limestone strata further to the west, closer to the open sea.  This implies that dinosaurs like Ostromia may have been limited in their distribution, compared to the volant Archaeopteryx.

Faunal Distribution in the Solnhofen Archipelago (Late Jurassic)

The Solnhofen archipelago and Ostromia/Archaeopteryx distribution.

The researchers speculate that the flightless Ostromia could not have reached the islands furthermost from the mainland whilst Archaeopteryx with its powered flight capability was able to reach outlying islands.

Picture Credit: Everything Dinosaur

In the diagram above, Ostromia may have been unable to reach the more remote parts of the island chain whilst Archaeopteryx, which was capable of powered flight (its aerial abilities are still debated), would have been more able to “island hop”.

Based on these new findings, the researchers postulate that other known Archaeopteryx fossils may need reassessment.

Dr Rauhut suggests:

“Not every bird-like fossil that turns up in the fine-grained limestones around Solnhofen need necessarily be a specimen of Archaeopteryx,”

The scientific paper: “Re-evaluation of the Haarlem Archaeopteryx and the Radiation of Maniraptoran Theropod Dinosaurs” by Christian Foth and Oliver W. M. Rauhut published in BMC Evolutionary Biology.

An article on Archaeopteryx research: Archaeopteryx Had Feathered “Trousers”

The oldest Archaeopteryx fossil: The Oldest Archaeopteryx in Town?

2 12, 2017

Hamipterus Nesting Ground Discovery

By | December 2nd, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Pterosaurs Even More Like Birds

Pterosaurs like birds, were capable of powered flight.  It seems that command of the skies is not the only thing that these two types of vertebrate had in common.  Thanks to a remarkable series of discoveries from the remote Turpan-Hami Basin located in the Xinjiang Uygur Autonomous Region (north-western China), palaeontologists have learned that Pterosaurs, like many living birds nested in colonies, that they had preferred nesting sites and when young, Pterosaurs needed a degree of parental care, just like many species of birds today.

Pterosaur Nesting Colony (Hamipterus tianshanensis)

Hamipterus tianshanensis nesting ground.

Male (right) and female Hamipterus tianshanensis looking after their brood, whilst more Pterosaur chicks hatch in the foreground.

Picture Credit: Zhao Chuang

Hundreds of Pterosaur Eggs Discovered

Writing in the journal “Science”, researchers from the Chinese Academy of Sciences along with collaborators from a number of research institutions in Brazil have published a paper describing the discovery of 215 Pterosaur eggs, 16 of which contain the remains of embryos.  The eggs and the numerous fossil bones associated with the site have been attributed to Hamipterus tianshanensis, a flying reptile first named and described in 2014 whose exact taxonomic position in the Pterosaur family tree remains open to debate.

That point notwithstanding, H. tianshanensis has been propelled to super-stardom, like a Pteranodon taking to the air, representing one of the most significant Pterosauria discoveries made to date.

An Assemblage of Pterosaur Fossils

Hamipterus tianshanensis fossils including eggs and embryos.

Pterosaur fossil eggs and bones representing individuals of various ages.

Picture Credit: Xinhua/Wang Xiaolin

Pterosaur Nesting Grounds

Significantly, the number of eggs discovered are far too many to have been laid by a single female.  This suggests that these flying reptiles nested in colonies and furthermore, the overlaying of multiple clutches of eggs indicates that Pterosaurs, like many birds today, returned to the same nesting sites each year.  As the authors conclude, “the similarity between these groups goes beyond wings”.

The Remains of Numerous Individuals at the Site

Hamipterus fossil remains.

Hundreds of Pterosaur bones lying on the surface.  Note the tip of a geological hammer providing a scale.

Picture Credit: Xinhua/Alexander Kellner

Three-Dimensional Fossil Egg Preservation

The eggs were not laid at the location where they were discovered.  This exceptional Lagerstätte preserves a series of tragic events, it seems that periodically, the nesting area was subjected to flooding as a result of seasonal storms.  Many of the eggs have been preserved in three dimensions, caused by the encroachment of sediment.  Computed tomography scans have revealed minute details of some of the embryos preserved within the eggs.  For example, an almost complete skeleton of a hatchling shows that bones related to flight were less developed than bones of the hind limb, indicating that new-borns might have been able to walk but not fly.   The front limb bones lack ossification and had yet to fully form, whilst the leg bones such as the femora are well developed.  This suggests that the young Pterosaurs were unable to fly, but not completely helpless, their strong legs would have meant that they would not have been stuck in the nest but quite capable of locomotion.  However, these new insights have led the palaeontologists to conclude that, in the case of Hamipterus at least, the offspring were less precocious than previously assumed.

In short, mum and dad (coming to that bit next), had to take care of their young, bring food to them and protect them from predators.

Evidence Suggests that Pterosaurs Cared for their Young

Hamipterus feeding their young.

The male Hamipterus (background) stands guard whilst the female regurgitates food to her offspring (altricial behaviours in Pterosaurs).

Picture Credit: Zhao Chuang

The Significance of Dad

Hamipterus tianshanensis was named and described three years ago.  This fossil location had been discovered several years before, but the Pterosaur body fossils and the associated Pterosaur egg material (forty specimens and five eggs), were not scientifically described until 2014.  In the 2014 paper (Wang et al), which was written by many of the scientists involved in this latest study, it was postulated that differences in head crest shape or size helped to distinguish males from females.  It was proposed that specimens with larger skull crests were males.  This suggests sexual dimorphism in this species and, if this idea is taken a little further, it implies that the males may have played a role in helping to bring up the next generation. After all, fossilised remains of what might represent adult males have been swept together with the nest site fossils.  Many male birds share parental responsibilities and lots of extant Aves such as the Wandering Albatross (Diomedea exulans) for instance, pair for life.  Perhaps, adult Pterosaurs also had monogamous behaviour.

A Close-up View of the Preserved Leathery Egg of Hamipterus

Egg fossils (Pterosaur).

Pterosaur egg fossils (Hamipterus tianshanensis).

Picture Credit: Xinhua/Wang Xiaolin

Inferring Behaviours

To what degree the Pterosauria and Aves share behaviours remains a controversial area.  Further research into the remarkable Hamipterus Lagerstätte has greatly increased our knowledge about flying reptiles but we must be careful not to infer or imply too much from the fossil evidence.  The scientists conclude that the discovery of all these bones and fossilised eggs supports the idea that these Pterosaurs nested in colonies and that they returned to a favoured nesting site to breed.

Two of the Authors of the Scientific Paper Inspect Part of the Remote Dig Site

Collecting egg fossil specimens (Pterosaur).

Palaeontologists Wang Xiaolin (right) and Alexander Kellner collect specimens in a desert in Hami, northwest China’s Xinjiang Uygur Autonomous Region.

Picture Credit: Xinhua

The scientific paper: “Egg Accumulation with 3D Embryos Provides Insight into the Life History of a Pterosaur” by Xiaolin Wang, Alexander W. A. Kellner, Shunxing Jiang, Xin Cheng, Qiang Wang, Yingxia Ma, Yahefujiang Paidoula, Taissa Rodrigues, He Chen, Juliana M. Sayão, Ning Li, Jialiang Zhang, Renan A. M. Bantim, Xi Meng, Xinjun Zhang, Rui Qiu and Zhonghe Zhou published in the journal “Science”.

30 11, 2017

“Fuzzysaurs” Dinosaurs May Have Been Fluffier Than Previously Thought

By | November 30th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

For Dinosaurs Think “Fuzzysaurs”

A new study suggests that dinosaurs may have been somewhat more fluffy than previously thought.  To date, most illustrations of feathered dinosaurs have been analogous to modern, living birds, after all, the majority of scientists believe that birds are living dinosaurs and closely related to a group of Theropod dinosaurs (Maniraptora).  However, in a paper published in the journal of the Palaeontological Association, a team of Bristol University researchers have revealed new details about feathered dinosaurs, allowing palaeoartists the chance to refine how these animals are depicted.  It seems that dinosaurs may have been quite fluffy, a feathered Theropod dinosaur is one thing, but a fuzzy Velociraptor, that may take a little while to sink in.

New Study Gives Anchiornis a New Look

A clambering Anchiornis with contour feather illustration.

A clambering Anchiornis illustration with a drawing of the forked contour feather.

Picture Credit: Rebecca Gelernter

The Contour Feathers of Anchiornis

The researchers, which included Dr Jakob Vinther (Bristol University), examined, at high resolution, an exceptionally well-preserved fossil of an Anchiornis (A. huxleyi) comparing its fossilised feathers to those of other dinosaurs and extinct birds.  Anchiornis is known from numerous fossil specimens from north-eastern China (Liaoning Province).  It is likely that the specimens hail from the Tiaojishan Formation of Upper Jurassic rocks and these fossils are estimated to be around 160 million years old.  Where this crow-sized, four-winged creature sits (or should that be perches/or clambers), on the Dinosauria family tree remains open to debate.  The fossils may precede Archaeopteryx by several million years and when first described Anchiornis (the name means “near bird”), was seen as a transitional form, very close to the split between dinosaurs and birds (Aves).  Other studies have challenged this placement, with an affinity with the troodontids being proposed.

Currently, the consensus seems to be that Anchiornis is a basal member of the Paraves clade, a part of the Maniraptora that incorporates the dromaeosaurids, the troodontids and the avialans, those dinosaurs that lead directly to birds as we know them today.

Anchiornis huxleyi – Illustrated from a Recent Research Paper (Spring 2017)

An illustration of Anchiornis huxleyi.

An illustration of Anchiornis huxleyi.

Picture Credit: Tony Csotonyi

The feathers around the body of Anchiornis, known as contour feathers, revealed a newly-described, extinct, primitive feather form consisting of a short quill with long, independent, flexible barbs erupting from the quill at low angles to form two vanes and a forked feather shape.  The scientists conclude that the details of the contour fossils were preserved as some of these feathers became detached from the body during decomposition.  When buried and fossilised, this taphonomy made the feather structure easier to analyse.

Fluffy Anchiornis

Such feathers would have given Anchiornis a fluffy appearance relative to the streamlined bodies of modern flying birds, whose feathers have tightly-zipped vanes forming continuous surfaces. Anchiornis’s unzipped feathers might have affected the animal’s ability to control its temperature and repel water, possibly being less effective than the vanes of most modern feathers.  This shaggy, fuzzy plumage would also have increased drag when Anchiornis took to the air.  It was probably not capable of powered flight, most likely it was a glider, however, these contour feathers lacked the aerodynamic qualities of the feathers of extant birds.

Comparing Contour Feathers – Anchiornis Against a More Recent Fossil Specimen

Contour feather comparison.

Anchiornis contour feathers (left) compared to a modern form of contour feather preserved in the fossil record.

Picture Credit: Bristol University

Having to Compensate for the Forked Contour Feathers

In addition, the wing feathers of Anchiornis lack the aerodynamic, asymmetrical qualities of modern flight feathers.  This new study shows that the vanes on the feathers of Anchiornis were not so tightly “zipped” together when compared to those of modern birds.  The feathers of Anchiornis would have provided little lift for the animal, so to compensate Paravians like Anchiornis packed many rows of long feathers into the wing, in contrast to extant, volant birds where most of the wing surface is formed by just one row of feathers.  Anchiornis had four wings, feathers on the legs as well as the arms and elongated feathers on the tail.  These structures would have increased the surface area of the animal assisting with gliding and helping to keep the animal stable in mid-air.

Palaeoartist Works with Palaeontologists

Scientific illustrator Rebecca Gelernter collaborated with researchers Evan Saitta and Dr Vinther, (University of Bristol’s School of Earth Sciences and School of Biological Sciences), to produce a life reconstruction of Anchiornis (see above).  The colour patterns in Rebecca’s illustration are very similar to those in the earlier drawing produced by Julius Csotonyi, details of the feather pigmentation of Anchiornis had been revealed in a previous study, but this new illustration shows a more fuzzy, fluffy prehistoric animal.

Commenting on the new depiction of Anchiornis, researcher Evan Saitta said:

“The novel aspects of the wing and contour feathers, as well as fully-feathered hands and feet, are added to the depiction.  Most provocatively, Anchiornis is presented in this artwork climbing in the manner of Hoatzin chicks, the only living bird whose juveniles retain a relic of their dinosaurian past, a functional claw.  This contrasts much previous art that places Paravians perched on top of branches like modern birds.  However, such perching is unlikely given the lack of a reversed toe as in modern perching birds and climbing is consistent with the well-developed arms and claws in Paravians.  Overall, our study provides some new insight into the appearance of dinosaurs, their behaviour and physiology, and the evolution of feathers, birds, and powered flight.”

Anchiornis Fossil Material (Liaoning Province)

Anchiornis fossil specmen.

The fossilised remains of an Anchiornis (A. huxleyi).

Picture Credit: Thierry Hubin

Rebecca Gelernter added:

“Paleoart is a weird blend of strict anatomical drawing, wildlife art, and speculative biology. The goal is to depict extinct animals and plants as accurately as possible given the available data and knowledge of the subject’s closest living relatives.  As a result of this study and other recent work, this is now possible to an unprecedented degree for Anchiornis.  It’s easy to see it as a living animal with complex behaviours, not just a flattened fossil.”

For an article published in March 2017 that provides further information on Anchiornis research: Very Near to “Near Bird”

Everything Dinosaur acknowledges the assistance of a Bristol University press release in the compilation of this article.

The scientific paper: “Additional Information on the Primitive Contour and Wing Feathering of Paravian Dinosaurs” by E. Saitta, R. Gelernter and J. Vinther published in Palaeontology, the journal of the Palaeontological Association.

28 11, 2017

Sauropod Feet Had Plenty of Traction

By | November 28th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Sauropod Print from South Korea Reveals Polygonal Scales

A team of scientists based in South Korea have published a paper in the academic journal “Nature” that reports on the discovery of a Sauropod dinosaur footprint that has preserved the impression of the underside of the foot. The polygon-shaped scales on the underside of the long-necked dinosaur’s feet (plantar surface), would have provided grip and traction, helping these large creatures to traverse soft mud and slippery ground.

Sauropod Foot Impression Fossil (South Korea)

The preserved impression of the underside of a Sauropod's foot.

Distinct skin impressions in a sauropod footprint (a) and on its cast (b) described in the study published in the journal “Nature”.

Picture Credit: Nature

Largest Sauropod with Underside Surface Preserved

The very distinctive foot impression and its cast, reported upon in this study, represent the largest known Sauropod footprint with skin details found to date.  The single print measures more than fifty centimetres across.  The footprint impression was left in silty mudstone as a large Sauropod crossed a mudflat in the late Early Cretaceous (Albian faunal stage of the Early Cretaceous).

The researchers from Pukyong National University, Busan (South Korea) and Seoul National University (Seoul), describe a single footprint from the Lower Cretaceous Haman Formation discovered in south-eastern South Korea, they suggest that the floodplain sediments were formed by sheetflood processes, where shallow water moves relatively slowly across slightly sloping ground.  The palaeoenvironment is interpreted as being a semi-arid area with lakes and ponds which was occasionally subjected to wetter weather, resulting in some flooding.

Microbial mats formed across the low-lying ground, adjacent to the water sources and the presence of these microbial mats may have helped with the preservation of the foot details.

A Reconstruction of the Sauropod Foot (Underside)

Illustration of the underside surface of the Sauropod foot.

Reconstruction of the plantar surface (underside) of a Sauropod foot with polygonal skin.

Picture Credit: Hyun Jeong Yoo

The researchers conclude that some Sauropods by the late Early Cretaceous had a well-developed polygonal skin texture covering nearly the whole of their foot pads.  This foot pattern is reminiscent to that found on the pads of extant elephants.  These scales would have helped increase stability when these large and heavy animals crossed wet ground.

23 11, 2017

Scaling the Heights of Feather Evolution

By | November 23rd, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

How Reptilian Scales Became Feathers

Birds and alligators might look very different, but they are related, belonging to the Archosauria clade, that diverse and extensive group of diapsids that dominated life on Earth during the Mesozoic. There are a number of groups of reptiles that are more closely related to birds than alligators, for instance there is the Dinosauria.  At least dinosaurs and birds belong to the same sub-clade of the Archosaurs (the Avemetatarsalia), whereas, in contrast, alligators and their crocodilian cousins are placed in the other major sub-clade of the Archosaurs – the Crurotarsi.

A team of scientists based at the University of Southern California have shed light on the evolutionary process that led to the development of feathers from reptilian scales.  The manipulation of genes in embryonic alligator skin and developing chicks has enabled the researchers to replicate the evolutionary process that led to the development of primitive feathers within members of the Archosauria.

Numerous Feathered Dinosaur Have Been Described – But How Did Feathers Evolve?

Huanansaurus dinosaur illustrated.

A new feathered dinosaur from China, but how did feathers evolve from the scales of reptiles?

Picture Credit: Chuang Zhao

Genetic Research Maps the Transition from Scaly Skin to Filamentous Feathers

Most scientists believe that feathers evolved primarily for insulation or display and that powered flight was secondary.  Over the last two decades or so, there have been remarkable dinosaur fossil discoveries, mainly from the Cretaceous deposits in Liaoning Province (north-eastern China), that have revealed a myriad of different types of feathered dinosaur, but the mechanism for feather evolution was poorly understood.  For example, many different types of feather-like structures have been identified in the fossil record, the famous Archaeopteryx (A. lithographica) from the Upper Jurassic limestone deposits of Solnhofen, Germany, has asymmetrical flight feathers, very similar to those found in living birds.  These feathers are more complex than those seen in non-avian, non-volant dinosaurs of the Jehol Biota, that lived some 30 million years after Archaeopteryx was flying around.

Archaeopteryx Possessed Both Asymmetrical Flight Feathers and Symmetrical Feathers

Feather preservation on Archaeopteryx.

Excellent feather preservation.  Asymmetrical feathers (flight feathers on the wings), whilst the hind limbs of Archaeopteryx had symmetrical feathers that probably played very little role in powered flight.

Picture Credit: Helmut Tischlinger with additional labelling by Everything Dinosaur

What are Feathers and Reptile Scales Made Of?

The feathers of birds and the scales of reptiles are essentially, made of the same protein – keratin.  However, there are subtle differences in the composition of the keratin that makes up feathers and scales.  It has been known for more than ten years, that the type of keratin that forms feathers is present in embryonic alligator scales.  This form of feather-forming keratin, is suppressed by the expression of genetic information during the embryological development of the alligator, and as a result, as far as we at Everything Dinosaur know, the form of keratin that leads to feathers has not been detected within the dermal scales of adult crocodilians.  The presence of this homologous keratin in both chicks and alligators suggests that this trait was inherited from a common ancestor, a member of the Archosaur clade (Archosauriformes), that existed prior to the evolution of the two basic types of Archosaur based on their ankle bones (Avemetatarsalia and the Crurotarsi).

An Evolutionary Heritage Embedded in the DNA of Living Archosaurs

A team of scientists, led by researchers from the University of Southern California have started to unravel the genetic mechanisms that dictate how the outer skin and related tissues of living Archosaurs is formed.  They have been able to focus in on the variety of genes that are involved in scale and feather development.  The scientific paper detailing this research has been published in the academic journal “Molecular Biology and Evolution”.

Commenting on this new study, corresponding author for the paper, Dr Cheng-Ming Choung (Department of Pathology, Keck School of Medicine, University of Southern California), stated:

“We now have a potential molecular explanation for these hypothesised missing links.  Our analyses led to the identification of five morpho-regulatory modules that are essential for modern feather formation.  We propose that these modules may originally evolve as different strategies for better adaptation.  Eventually, the integrative combination of five morpho-regulatory modules achieves the highly successful feather architecture today, allows the Aves class to claim most of the open sky as their ecological niche.”

In this study, the scientists first mapped the genes of developing chicks and embryonic alligators to identify the differences in gene expression between the two Archosaurs and to pin-point the key genes involved in the formation of feathers or scales.  Once this phase of the research had been concluded, the team then placed the genes associated with feather development in chicks into alligator eggs to see if the alligator genes for scales could be overridden by switching on the chicken feather genes.

Highly-magnified Thin Slice Through an Alligator Scale Showing Filamentous Development

Growing feathers in embryonic alligator skin cells.

Normal embryonic alligator scales (left) compared with the elongated feather-like appendage following genetic manipulation of the alligator scales (right).

Picture Credit: University of Southern California

In addition, the gene replacement led to the identification of several intermediate types of shape from scales to more complex forms of filamentous feathers.  Some of the shapes identified resemble the filamentous appendages associated with feathered dinosaur fossils, whilst other shapes formed have similar characteristics to those found in the feathers of modern birds.  This research has provided a further insight into how a new organ might evolve and has significantly increased the list of genes and molecules known to influence feather development.  It has also highlighted the growing role of developmental biology and genetic mapping when it comes to interpreting the fossil record.

The scientific paper: “Multiple Regulatory Modules are Required for Scale-to-Feather Conversion” by Ping Wu Jie Yan Yung-Chih Lai Chen Siang Ng Ang Li Xueyuan Jiang Ruth Elsey Randall Widelitz Ruchi Bajpai Wen-Hsiung Li Cheng-Ming Chuong and published in the journal of Molecular Biology and Evolution.

For an article on a recently described feathered, terrestrial dinosaur: Silky Dinosaur Ruffles Feathers

To read a recent article on the discovery of a troodontid dinosaur with pennaceous feathers: Chinese Dinosaur with Pennaceous Feathers

16 11, 2017

Cataloguing the Ancient Forests of Antarctica

By | November 16th, 2017|Dinosaur and Prehistoric Animal News Stories, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Permian, Triassic and Jurassic-aged Forests Explored on the Coldest Continent

Over the next few months, a team of intrepid scientists will be hoping to continue their exploration of some of the most remote fossil locations in the world.  Researchers from the University of Wisconsin-Milwaukee have been mapping the sedimentary deposits at McIntyre Promontory, at the head of the Ramsey Glacier in Antarctica.  To date, the team have recorded an extensive series of strata ranging in ages from the Late Permian to the Jurassic, the numerous plant fossils found are helping the scientists to better understand the evolution of forests and their flora over the southernmost portions of Gondwana.

Remains of Prehistoric Forests Uncovered in Antarctica

Prehistoric tree trunk (geology hammer provides scale).

An ancient tree trunk discovered in Antarctica.

Picture Credit: University of Wisconsin-Milwaukee

Antarctica in the Late Permian Period

A total of thirteen trees have been found with numerous fragmentary fossils of other plants, including Ginkgos and Glossopteris.  The oldest plants described by this research team, date from the Late Permian of around 260 million years ago.  Some of the fossils have stems and roots attached and have been preserved “in situ”.  No transport of fossil material is involved, the fossils are preserved where the plants grew.  The flora of this southerly habitat has been preserved thanks to occasional volcanic events that buried the primitive forests in ash.

Commenting on the significance of the Antarctic ancient flora, palaeoecologist and visiting assistant professor at the University of Wisconsin-Milwaukee Department of Geosciences, Erik Gulbranson stated:

“People have known about the fossils in Antarctica since the 1910-12 Robert Falcon Scott expedition.  However, most of Antarctica is still unexplored.  Sometimes, you might be the first person to ever climb a particular mountain.”

Beautifully Preserved Plant Fossils

Ancient plant fossils from Antarctica.

Ancient plant fossil remains.

Picture Credit: University of Wisconsin-Milwaukee

The Late Permian forests preceded the most extensive mass extinction event in the Phanerozoic (end Permian mass extinction event),  the scientists are hoping to use their growing knowledge of the ancient Antarctic forests to look at the possible impact on global warming on extant plant communities.  In addition, as the Antarctic forests grew at polar latitudes where plants can’t grow today, Gulbranson believes that the trees were an extremely hardy species and he and his colleagues are trying to determine why they died out.

Just like their modern counterparts, prehistoric tree fossils can reveal seasonal growth rings.  These rings when examined in microscopic detail can reveal patterns of seasonal growth.  Antarctica during the Late Permian was further north than it is today, even so, despite the milder climate, the forests would have had to endure prolonged periods of darkness, when the sun never emerged above the horizon.  The research team hopes to use the ancient growth rings to learn more about how these forests coped with such extremes.

Ancient Tree Trunks Can Help Decipher Seasonal Growth Patterns

Antarctic prehistoric plant life.

Ancient trees can reveal evidence of seasonal growth.

Picture Credit: University of Wisconsin-Milwaukee

Climate Change and the End Permian Mass Extinction Event

The cause or causes of the end Permian extinction event remain an area of controversy within palaeontology, although many scientists now believe that a huge increase in atmospheric greenhouse gases such as methane and CO2 which resulted from extensive global volcanic activity led to world-wide climate change.  John Isbell (University of Wisconsin-Milwaukee), has visited Antarctica before, on this expedition he examined the matrix and other sediments surrounding the in situ fossils to determine how these plant remains fitted into the geology of Antarctica.

To read an article written by Everything Dinosaur in 2015, that explains how rocks from South Africa are helping scientists to unravel global extinction events: Karoo Rocks Provide a Fresh Insight into Extinction Events

The Plant Fossils Might Represent New Species

The prehistoric forests of Antarctica.

Delicate plant fronds have been preserved.

Picture Credit: University of Wisconsin-Milwaukee

The extensive forests may have stretched across the whole of the super-continent Gondwana.  Evidence of Glossopteris fossils and other plant remains have been used to help substantiate the theory of continental drift.  These Permian forests would have looked very different from today’s temperate woodlands, the flora would have been dominated by mosses, ferns, Pteridosperms (seed ferns) and conifers.

Erik Gulbranson explained that the Antarctic fossils have provided important information about plant diversity at higher latitudes. During the Permian, forests were a potentially low diversity assemblage of different plant types with specific functions that affected how the entire forest responded to environmental change.  This is in direct contrast to today’s high-latitude forests that display greater plant diversity.

Gulbranson added:

“This plant group must have been capable of surviving and thriving in a variety of environments.  It’s extremely rare, even today, for a group to appear across nearly an entire hemisphere of the globe.”

Tough Forests Failed to Survive Climate Change

The researchers conclude that these tough trees and plants did not survive the climate change that marked the end of the Permian.  Younger plant fossils from Triassic and Jurassic sediments provide evidence of the changing Antarctic flora over time, but many of the types of plants found in the Permian forests, despite their resilience, died out.

Erik Gulbranson Can Study the Permian Plant Fossils in the University Laboratory

Plant fossils being examined.

Examining the Permian plant fossils (Erik Gulbranson – University of Wisconsin-Milwaukee).

Picture Credit: University of Wisconsin-Milwaukee/Troye Fox

By analysing the preserved tree growth rings, the scientists have found that these trees transitioned from summer activity to winter dormancy very rapidly, perhaps within a few weeks.  Extant plants make the same transition over the course of several months and also conserve water by making food during the day and resting at night.  Scientists don’t yet know how months of perpetual light would have affected the plants’ day-and-night cycles.

The team hope to return to the various Antarctic dig sites in the early part of 2018.  They hope to learn more about the annual growth cycles of the trees and to determine how the forests coped with rising levels of greenhouse gases and a warming climate.  It is hoped that by studying the Permian flora of Antarctica, models looking at how living plants will cope with climate change can be developed.

14 11, 2017

Evidence of Placental Mammals – Early Cretaceous Purbeck

By | November 14th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|1 Comment

Durlstotherium newmani and Durlstodon ensomi

Finally got round to reading the paper on the discovery of evidence of Eutherian (placental) mammals in Early Cretaceous deposits on, ironically, “the Jurassic Coast”.  The two teeth found during sieving of material collected on the Dorset coast by University of Portsmouth undergraduate student Grant Smith, has led to the erection of two new mammal species.  These fossils represent the earliest, undisputed fossils of mammals that belong to that same group of mammals – the placentals, as we do.  It is wonderful to think that the Dorset coast can still provide amazing fossil discoveries and secondly, it is great that such an important discovery can be made by a relative newcomer to the science of palaeontology.  When done to all involved in the research and the writing of the academic paper, published in the journal “Acta Palaeontologica Polonica”.

It also gives us an excuse to include the amazing image created by Dr Mark Witton that illustrates the Purbeck palaeoenvironment around the beginning of the Cretaceous.

Dorset Around 145 Million Years Ago

Purbeck Lagoon 145 mya as darkness falls Durlstodon (top left) looks on whilst two Durlstotherium scurry through the undergrowth. In the centre a Durlstotherium has been caught by Nuthetes destructor.

Picture Credit: Mark Witton

The two teeth, found at Durlston Bay near Swanage, represent two rat-like Eutherian mammals.  These creatures have been named Durlstotherium newmani and Durlstodon ensomi.  In Dr Witton’s remarkable illustration (above), a scene at dusk is depicted.  It is most likely that these early placentals were nocturnal, even so, as darkness fell there were still plenty of dangers lurking.  The Sauropods in the background might not pose much of a threat to our distant ancestors but in the centre of the image, a Durlstotherium has been caught by a two-metre-long Theropod dinosaur Nuthetes destructor.  This dinosaur is mainly known from isolated teeth and based on such fragmentary evidence it is difficult to place Nuthetes within the dinosaur family tree, however, it has been suggested that it was a dromaeosaurid.  Thus, the Purbeck area of southern England during the Early Cretaceous was not only home to placental mammals but, potentially, also the residence of the earliest known member of the Dromaeosauridae.

One of the authors of the paper on the two new mammals, Dr Steve Sweetman (Research Fellow at the University of Portsmouth), concluded that the fossilised teeth and jaw fragment ascribed to N. destructor indicate a taxonomic affinity with the Velociraptor branch of the Dromaeosauridae family.

Various Views of the Two Fossil Teeth (Durlstotherium and Durlstodon)

Purbeck Mesozoic mammal teeth.

Two fossil teeth of the Purbeck Mesozoic mammals, Durlstotherium (A1-4) and Durlstodon (B1-4) , named after Durlston Bay in Dorset.

Picture Credit: Portsmouth University

Dr Sweetman, an expert in the dentition of small vertebrates explained how Grant Smith discovered the fossil teeth:

“Grant was sifting through small samples of earliest Cretaceous rocks collected on the coast of Dorset as part of his undergraduate dissertation project in the hope of finding some interesting remains.  Quite unexpectedly he found not one but two quite remarkable teeth of a type never before seen from rocks of this age.  I was asked to look at them and give an opinion and even at first glance my jaw dropped!”

With Mammal Fossils It’s All About the Teeth

While these Dorset fossils may seem a little underwhelming, comprising only two molar teeth with no roots, that measure just a few millimetres across, the unique specialisations of mammal teeth for processing food result in complex tooth shapes.  These shapes evolve in patterns that allow palaeontologists to identify what group a mammal belongs to, meaning that even a single tooth can permit palaeontologists to gather a great deal of information.

The wonderful thing about mammal teeth is that they are very distinctive.  Every type of mammal has a different set of teeth.  The teeth vary in shape from the back to the front of the jaw and you can tell from a single tooth fossil exactly where in the jaw it was located, whether it came from the upper or lower jaw, whether it was on the right side of the skull of the left side.  The pattern on the crowns of the teeth (molars and premolars) provides information on the type of diet the animal had.  These fossil teeth from the Early Cretaceous of Dorset, might be extremely small, but they can tell us a great deal about the animals which had the teeth and provide information on the evolutionary relationship between these animals and other members of the Mammalia.

Dr Sweetman added:

“The teeth are of a type so highly evolved that I realised straight away I was looking at remains of Early Cretaceous mammals that more closely resembled those that lived during the latest Cretaceous, some 60 million years later in geological history.  In the world of palaeontology, there has been a lot of debate around a specimen found in China*, which is approximately 160 million years old.  This was originally said to be of the same type as ours but recent studies have ruled this out.  That being the case, our 145 million year old teeth are undoubtedly the earliest yet known from the line of mammals that lead to our own species.”

* The fossil from China that Dr Sweetman is referring to Juramaia sinensis a tiny, shrew-like mammal, fossils of which come from 160 million-year-old deposits from the Tiaojishan Formation of Liaoning Province.  Juramaia was named in 2011, it has been controversially described as a basal Eutherian mammal and it suggests that the very earliest placentals were probably arboreal.

To read Everything Dinosaur’s article about this fossil discovery: The “Mother” of all Placental Mammals

If Juramaia is proved to be an Eutherian, then this indicates that placental mammals had their origins in Asia in the Jurassic and that they had spread across Asia to Europe (Laurasia) by the Early Cretaceous.

Scanning Electron Microscope Images of the Tiny Purbeck Teeth

Early Cretaceous mammal teeth from Swanage (Dorset).

Purbeck Mesozoic mammal teeth under the electron microscope.

Picture Credit: Portsmouth University

Very Worn Molars

The crowns of the teeth are very worn, this suggests that despite the threat of being eaten by predatory dinosaurs, both mammals lived a long time.

Professor David Martill, who supervised the research project and is a co-author of the scientific paper stated:

“What I’m most pleased about is that a student [David Grant] who is a complete beginner, was able to make a remarkable scientific discovery in palaeontology and see his discovery and his name published in a scientific paper.  The Jurassic Coast is always unveiling fresh secrets and I’d like to think that similar discoveries will continue to be made right on our doorstep.”

One of the new species has been named Durlstotherium newmani, honouring Charlie Newman, a keen, amateur fossil hunter and the landlord of the Square and Compass pub in the village of Worth Matravers, near to where the fossils were discovered.  The trivial name of the second species, Durlstodon ensomi honours Paul Ensom, a palaeontologist who did much to improve our understanding of the palaeoenvironments represented by the geology of Dorset.

13 11, 2017

“Thunderfoot” A Real “Ground Shaker”

By | November 13th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Brontopodus plagnensis – New Ichnospecies Named for Giant Sauropod Tracks

A series of dinosaur footprints, made by a giant, long-necked, plant-eating dinosaur have been assigned an ichnospecies name.  The tracks from the Jura plateau of France, located near the village of Plagne not too far from the Swiss border are, at around 155 metres in length, the longest Sauropod trackways known to science.  The ichnospecies has been named Brontopodus plagnensis, this translates as “thunderfoot of Plagne”.  The ichnogenus Brontopodus has had a number of ichnospecies assigned to it already, including tracks from the southern United States and dinosaur footprints found in Early Cretaceous rocks in China.

A View of Part of the Sauropod Trackway

Sauropod Tracks (Brontopodus plagnensis).

A picture of the Sauropod trackway (Plagne, France).

Picture Credit: P. Dumas/Centre National de la Recherche Scientifique

To read an article about Sauropod tracks found on the Isle of Skye: Isle of Skye Sauropods and their Water World

Enormous Stride Length = Enormous Dinosaur

The stride length of this huge Sauropod has been measured at 2.7 metres, the dinosaur was walking at around 4 kilometres/hour, which means that the average human would have had no trouble keeping up with it, however, you might have had to jog alongside, as its huge strides would have meant that it covered a great deal of ground with every pace.  From the footprints, the scientists, which included French palaeontologist Jean-Michel Mazin, have calculated that this dinosaur might have been around 35 metres in length and weighed perhaps as much as forty tonnes.

Early Tithonian Trackways

The research team, writing in the journal “Geobios” have precisely dated the tracks to the Early Tithonian faunal stage of the Late Jurassic, the prints are approximately 150 million years old.  The footprints show varying degrees of preservation along the trackway, the palaeoenvironment has been described as a littoral mudflat, a flat area close to a shoreline.  During the Late Jurassic, much of western Europe was covered by a warm tropical sea, the presence of large dinosaurs indicates that there must have been enough food resources on the archipelago of islands in the area to sustain megaherbivores.   Perhaps, these tracks represent a dinosaur crossing mudflats at low tide walking between islands.  Numerous dinosaur tracks are known from this region, including a series of tridactyl (three-toed prints), assigned to the ichnogenus Megalosauripus.  The prefix ichno- is added when a taxon is described based solely on trace fossils of an animal, rather than on anatomical remains such as its bones and teeth.

An Illustration of Brontopodus plagnensis and an Estimation of Its Size

A drawing of Brontopodus plagnensis.

An illustration of Brontopodus plagnensis.

Picture Credit: A. Bénéteau, photography Dinojura

To read Everything Dinosaur’s 2009 article about the original discovery of the trackways: On the Trail of Big Foot – Giant Sauropod Trackways Discovered in France

The scientific paper: “The Dinosaur Tracksite of Plagne (Early Tithonian, Late Jurassic; Jura Mountains, France): The Longest Known Sauropod Trackway” by Jean-Michel Mazin, Pierre Hantzpergue and Nicolas Olivier published in the journal Geobios.

12 11, 2017

Giant Otter with a Bite Like No Other Otter

By | November 12th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

The Very Powerful Bite of Siamogale melilutra

Back in January, Everything Dinosaur reported upon the scientific description of a new species of giant otter from the Late Miocene of south-west China.  At around fifty kilogrammes in weight, the new species Siamogale melilutra, is a much more heavy-set and robust animal compared to extant otter species.  At the time, the scientists responsible for studying the fossil material, which included an almost complete but crushed cranium, speculated on what this super-sized member of the weasel family would have fed on.  Writing in the journal “Scientific Reports”, some of the scientists involved in the original description have followed up this research by publishing a new paper on the feeding capabilities of such a powerful carnivore.

This wolf-sized, aquatic predator had a surprisingly strong bite that might have made S. melilutra an apex predator.

A Digitally Reconstructed View of the Skull and Jaws of Siamogale melilutra

Digitally restored cranium of S. melilutra right lateral view.

A digitally reconstructed cranium of S. melilutra .

Picture Credit: Scientific Reports

Comparing Otter Skulls and Jaws

The researchers digitally recreated jaw models of extinct otters as well as ten extant species (living species of otters) and then subjected these models to engineering stress tests.  The researchers discovered that the jaw of Siamogale melilutra was six times stronger than expected.  Although, the teeth morphology and biting efficiency was found to be very similar to living otters, these very strong jaws open up the possibility that Siamogale melilutra fed on a range of animals that its modern-day contemporaries could not.  Sea Otters (Enhydra lutris) and the African Cape Clawless Otter (Aonyx capensis), specialise in feeding upon shellfish and have a durophagous diet.  Even accounting for the size difference between the Miocene giant Siamogale melilutra and these living otter species, the jaws of S. melilutra are much stronger.

Comparing the Stress on Jaws on Living and Extinct Species of Otter

Calculating the bite of Siamogale melilutra.

Stress during biting (otter jaw comparison).

Picture Credit: Scientific Reports

The picture above shows the results of computer modelling to indicate potential bite force stresses in a number of otter species.  Warmer colours depict high levels of bite stress, whilst cooler colours depict areas of lower stress.

(a) Pteronura brasiliensis (Giant South-American Otter)

(b) Lontra canadensis (North American River Otter)

(c) Lontra longicaudis (Neotropical Otter of Central America)

(d) Lontra felina (South American Marine Otter)

(e) Enhydra lutris (Sea or Marine Otter)

(f) Hydrictis maculicollis (Spotted-necked Otter)

(g) Siamogale melilutra – extinct Miocene species

(h) Lutra lutra (European Otter)

(I) Aonyx capensis (African Cape Clawless Otter)

(j) Aonyx cinerea (Asian Small-clawed Otter)

(k) Lutrogale perspicillata (Indian Smooth-coated Otter)

The research team conclude that S. melilutra has no living analog.  Its huge size and powerful jaws could have enabled this otter to exploit an environmental niche not found in living otter species.  It might even have been an apex predator.

To read Everything Dinosaur’s article on the scientific description of Siamogale melilutraSuper-sized Otter as Big as a Wolf

The scientific paper: “Feeding Capability in the Extinct Giant Siamogale melilutra and Comparative Mandibular Biomechanics of Living Lutrinae” by Z. Jack Tseng, Denise F. Su, Xiaoming Wang, Stuart C. White and Xueping Ji published in the journal “Scientific Reports”.

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