New bird-like dinosaur discovery


This video says about itself:

Synchrotron sheds light on the amphibious lifestyle of a new raptorial dinosaur

6 December 2017

An exceptionally well-preserved dinosaur skeleton from Mongolia unites an unexpected combination of features that defines a new group of semi-aquatic predators related to Velociraptor. Detailed 3D synchrotron analysis allowed an international team of researchers to present the bizarre 75 million-year-old predator, named Halszkaraptor escuilliei, in Nature.

From Nature:

Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs

06 December 2017

Abstract

Maniraptora includes birds and their closest relatives among theropod dinosaurs1,2,3,4,5.

During the Cretaceous period, several maniraptoran lineages diverged from the ancestral coelurosaurian bauplan and evolved novel ecomorphologies, including active flight2, gigantism3, cursoriality4 and herbivory5. Propagation X-ray phase-contrast synchrotron microtomography of a well-preserved maniraptoran from Mongolia, still partially embedded in the rock matrix, revealed a mosaic of features, most of them absent among non-avian maniraptorans but shared by reptilian and avian groups with aquatic or semiaquatic ecologies6,7,8,9,10,11,12,13,14. This new theropod, Halszkaraptor escuilliei gen. et sp. nov., is related to other enigmatic Late Cretaceous maniraptorans from Mongolia15,16 in a novel clade at the root of Dromaeosauridae17. This lineage adds an amphibious ecomorphology to those evolved by maniraptorans: it acquired a predatory mode that relied mainly on neck hyperelongation for food procurement, it coupled the obligatory bipedalism of theropods with forelimb proportions that may support a swimming function, and it developed postural adaptations convergent with short-tailed birds.

See also here.

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215 pterosaur eggs discovered


This video says about itself:

30 November 2017

They were known to rule the skies in the Jurassic and Cretaceous periods, but it seems that pterosaurs had a slow start in life. A new study has revealed that the giant reptiles had a two year incubation and couldn’t fly when they hatched. The findings suggest that young pterosaurs were ‘less precocious than previously assumed.’ The researchers analysed 215 eggs of the pterosaur species Hamipterus tianshanensis found in China.

From the American Association for the Advancement of Science in the USA:

Hundreds of fossilized eggs shed light on pterosaur development

November 30, 2017

An invaluable collection of more than 200 eggs is providing new insights into the development and nesting habits of pterosaurs.

To date, only a small handful of pterosaur eggs with a well-preserved 3-D structure and embryo inside have been found and analyzed — three eggs from Argentina and five from China. This sparse sample size was dramatically increased upon the discovery of 215 eggs of the pterosaur species Hamipterus tianshanensis from a Lower Cretaceous site in China.

Xiaolin Wang et al. used computed tomography scanning to peer inside the eggs, 16 of which contain embryonic remains of varying intactness. The most complete embryo contains a partial wing and cranial bones, including a complete lower jaw. The samples of thigh bones that remain intact are well-developed, suggesting that the species benefited from functional hind legs shortly after hatching.

However, the structure supporting the pectoral muscle appears to be underdeveloped during the embryonic stage, suggesting that newborns were likely not able to fly. Therefore, the authors propose that newborns likely needed some parental care. Based on growth marks, the team estimates one of the individuals to be at least 2 years old and still growing at the time of its death, supporting the growing body of evidence that pterosaurs had long incubation periods.

Lastly, the fact that a single collection of embryos exhibits a range of developmental stages hints that pterosaurs participated in colonial nesting behavior, the authors say. Denis Deeming discusses these findings in a related Perspective.

Dinosaur age mammalian human ancestors discovery in England


This video from England says about itself:

6 November 2017

Fossilised teeth of 145 million year-old ‘rat’ that is mankind’s oldest ancestor

Fossil remains of two rat-like creatures understood to be the oldest known ancestors of humans have been discovered in Dorset.

The small furry animals scurried in the shadow of the dinosaurs 145 million years ago.

Scientists believe they can draw a direct evolutionary line from the ancient mammals to people living today.

Two teeth belonging to two different species were sifted out of samples of Cretaceous period rock collected from exposed cliffs near Swanage.

From the University of Portsmouth in England:

Humankind’s earliest ancestors discovered in southern England

November 7, 2017

Fossils of the oldest mammals related to humankind have been discovered on the Jurassic Coast of Dorset.

The two teeth are from small, rat-like creatures that lived 145 million years ago in the shadow of the dinosaurs. They are the earliest undisputed fossils of mammals belonging to the line that led to human beings.

They are also the ancestors to most mammals alive today, including creatures as diverse as the Blue Whale and the Pigmy Shrew. The findings are published in the journal Acta Palaeontologica Polonica, in a paper by Dr Steve Sweetman, Research Fellow at the University of Portsmouth, and co-authors from the same university. Dr Sweetman, whose primary research interest concerns all the small vertebrates that lived with the dinosaurs, identified the teeth but it was University of Portsmouth undergraduate student Grant Smith who made the discovery.

Dr Sweetman said: “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!”

“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.”

Dr Sweetman believes the mammals were small, furry creatures and most likely nocturnal. One, a possible burrower, probably ate insects and the larger may have eaten plants as well.

He said: “The teeth are of a highly advanced type that can pierce, cut and crush food. They are also very worn which suggests the animals to which they belonged lived to a good age for their species. No mean feat when you’re sharing your habitat with predatory dinosaurs!”

The teeth were recovered from rocks exposed in cliffs near Swanage which has given up thousands of iconic fossils. Grant, now reading for his Master’s degree at The University of Portsmouth, said that he knew he was looking at something mammalian but didn’t realise he had discovered something quite so special. His supervisor, Dave Martill, Professor of Palaeobiology, confirmed that they were mammalian, but suggested Dr Sweetman, a mammal expert should see them.

Professor Martill said: “We looked at them with a microscope but despite over 30 years’ experience these teeth looked very different and we decided we needed to bring in a third pair of eyes and more expertise in the field in the form of our colleague, Dr Sweetman.

“Steve made the connection immediately, but what I’m most pleased about is that a student 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, christened after Charlie Newman, the landlord of the Square and Compass pub in Worth Matravers, close to where the fossils were discovered.

Sinosauropteryx dinosaurs, new study


This video says about itself:

Dinosaur May Have Looked Like a Raccoon | National Geographic

30 October 2017

A new study of the Sinosauropteryx fossil may shed some light on its appearance and habitat.

Unusual herbivorous dinosaur discovery


This video says about itself:

op 26 October 2017

An ‘ugly’ dinosaur with huge scissor-style teeth that roamed the south of France 80 million years ago has been discovered by scientists.The plant eater – which grew to more than 16 feet long – had an unusually short face with powerful jaws that enabled it to snack on tough riverside palm trees.Its two-and-a-half inch teeth worked ‘like a pair of scissors’ as it chewed the hard foliage, before swallowing.

Matheronodon provincialis has been identified as a member of rhabdodontids – a group of herbivorous bipedal dinosaurs – from the late Campanian period about 84 to 72 million years ago. They were descendants of the iguanodontian dinosaurs from the Upper Jurassic.

By Helen Thompson, 4:00pm, October 26, 2017:

New dinosaur sported a curious set of chompers

Fossils discovered in France linked to previously unknown Cretaceous species

An ancient vegetarian dinosaur from the French countryside has given paleontologists something to sink their teeth into.

The most striking feature of a new species of rhabdodontid that lived from 84 million to 72 million years ago is its oversized, scissorslike teeth, paleontologist Pascal Godefroit, of the Royal Belgian Institute of Natural Sciences in Brussels, and his colleagues report October 26 in Scientific Reports. Compared with other dinos of its kind, Matheronodon provincialis’ teeth were at least twice as large but fewer in number. Some teeth reached up to 6 centimeters long, while others grew up to 5 centimeters wide. They looked like a caricature of normal rhabdodontid teeth, Godefroit says.

Of hundreds of fossils unearthed over the last two decades at a site called Velaux-La Bastide Neuve in the French countryside, a handful of jaw bones and teeth now have been linked to this new species, Matheronodon provincialis. The toothy dino belongs to a group of herbivorous, bipedal dinosaurs common in the Cretaceous Period. Rhabdodontids sported bladelike teeth, and likely noshed on the tough woody tissue parts of plants. Palm trees, common in Europe at the time, might have been on the menu.

Rhabdodontid teeth have ridges covered by a thick layer of enamel on one side and little to no ridges or enamel on the other. Teeth in the upper jaw have more ridges and enamel on the outer edge, while the reverse is true for bottom teeth. A closer look at the microstructure of M. provincialis’ teeth revealed an exaggerated version of this — many more ridges and lopsided enamel coating. Enamel typically protects from wear and tear, so chewing would have sharpened the dino’s teeth. “They operated like self-sharpening serrated scissors,” Godefroit says.

Cretaceous dinosaur discovery in Uzbekistan


This 2013 video is called Alvarezsaurus-the fast dino.

From PLOS ONE:

Alvarezsaurid dinosaur from the late Cretaceous found in Uzbekistan

Several distinctive bones identify this rare theropod

October 25, 2017

Bones from an Alvarezsaurid dinosaur were discovered in Uzbekistan and could shed light on the evolution and origin of the species, according to a study published October 25, 2017 in the open-access journal PLOS ONE by Alexander Averianov of Zoological Institute of the Russian Academy of Sciences, Russia and Hans-Dieter Sues of the Smithsonian Institution, USA.

Previous studies have described Alvarezsauridae as small, long-legged, bipedal dinosaurs with short forelimbs that featured bird-like hands. Since Alvarezsaurid remains are extremely rare, there is plenty to learn about the evolution of this species.

The authors of this study analyzed previously excavated Alvarezsaurid remains from the Turonian Bissekty Formation of Uzbekistan. They examined the vertebrae, the bird-like bone that fuses the wrist and knuckle known as the carpometacarpus, and pieces of what would be the fingers or toes, known as the phalanx. They then measured and compared the shapes and sizes of these bones with those from similar species from the literature.

The authors state that the characteristics for the Alvarezsaurid bones are so distinctive that it could be identified just from the seven bones collected at the Bissekty Formation. These distinctive features included rounded vertebrae located close to the tail, a large and depressed second metacarpal, and a robust second digit with a claw-like end.

While there are competing theories about where the Alvarezsaurid originated, the authors suggest that the discovery of an Alvarezsaurid at this site in Uzbekistan indicates that this group had an evolutionary history in Asia and provides evidence that this continent could have been where the clade originated.

Lead author Hans Sues says: “Our paper reports the discovery of the earliest known alvarezsaurid dinosaur from the Northern Hemisphere, based on 90-million-year-old fossils from Central Asia. Alvarezsaurids were unusual small predatory dinosaurs that had very short but powerfuly built arms that ended in a single large digit.”

Dinosaur age bird could already fly well


Holotype of Junornis houi. (From Liu et. al; 2017)

From PLOS ONE:

Flight aerodynamics in enantiornithines: Information from a new Chinese Early Cretaceous bird

Di Liu, Luis M. Chiappe, Francisco Serrano, Michael Habib, Yuguang Zhang, Qinjing Meng

October 11, 2017

Abstract

We describe an exquisitely preserved new avian fossil (BMNHC-PH-919) from the Lower Cretaceous Yixian Formation of eastern Inner Mongolia, China.

Although morphologically similar to Cathayornithidae and other small-sized enantiornithines from China’s Jehol Biota, many morphological features indicate that it represents a new species, here named Junornis houi.

The new fossil displays most of its plumage including a pair of elongated, rachis-dominated tail feathers similarly present in a variety of other enantiornithines. BMNHC-PH-919 represents the first record of a Jehol enantiornithine from Inner Mongolia, thus extending the known distribution of these birds into the eastern portion of this region.

Furthermore, its well-preserved skeleton and wing outline provide insight into the aerodynamic performance of enantiornithines, suggesting that these birds had evolved bounding flight—a flight mode common to passeriforms and other small living birds—as early as 125 million years ago.

See also here.