Dinosaur age diving bird discovery in Japan


This video says about itself:

Hesperornis Tribute

3 May 2009

Hesperornis is an extinct genus of flightless aquatic birds that lived during the Santonian to Campanian sub-epochs of the Late Cretaceous (89-65 mya). One of the lesser known discoveries of paleontologist O. C. Marsh in the late 19th century Bone Wars, it was an important early find in the history of avian paleontology. Famous locations for Hesperornis are the Late Cretaceous marine limestones from Kansas and the marine shales from Canada, but the genus had probably a Holarctic distribution.

Hesperornis was a large bird, reaching up to 2 meters (6.5 feet) in length. It had virtually no wings, and swam with its powerful hind legs. The toes were probably lobed rather than being webbed, as in today’s grebes; like in these, the toes could rotate well, which is necessary to decrease drag in lobed feet but not in webbed ones such as in loons, where the toes are simply folded together.

Like many other Mesozoic birds such as Ichthyornis, Hesperornis had teeth in its beak which were used to hold prey (most likely fish). In the hesperornithiform lineage they were of a different arrangement than in any other known bird (or in non-avian theropod dinosaurs), with the teeth sitting in a longitudinal groove rather than in individual sockets, in a notable case of convergent evolution with mosasaurs.

The first Hesperornis specimen was discovered in 1871 by Othniel Charles Marsh. Marsh was undertaking a second western expedition, accompanied by ten students. The team headed to Kansas where Marsh had dug before. Aside from finding more bones belonging to the flying reptile Pteranodon, Marsh discovered the skeleton of a “large fossil bird, at least five feet in height”. The specimen was large, wingless, and had strong legs—Marsh considered it a diving species. Unfortunately, the specimen lacked a head. Marsh named the find Hesperornis regalis, or “great ruling bird” [Western ruling bird].

Hesperornis hunted in the waters of such contemporary shelf seas as the North American Inland Sea, the Turgai Strait and the prehistoric North Sea, which then were subtropical to tropical waters, much warmer than today. They probably fed mainly on fish, maybe also crustaceans, cephalopods and mollusks as do the diving seabirds of today. Their teeth were helpful in dealing with slippery or hard-shelled prey.

On land, Hesperornis may or may not have been able to walk. They certainly were not able to stand upright like penguins as in the early reconstructions. Their legs attached far at the back and sideways, with even the lower leg being tightly attached to the body. Thus, they were limited to a clumsy hobble at best on land and would indeed have been more nimble if they moved by sliding on their belly or galumphing. Indeed, the leg skeleton of the hesperornithids was so much adapted to diving that their mode of locomotion while ashore, as well as where it laid its eggs and how it cared for its young is a matter of much speculation.

Some have even pointed out that it cannot be completely ruled out that these birds were ovoviviparous instead of incubating their eggs. In any case, young Hesperornis grew fairly quickly and continuously to adulthood, as is the case in modern birds, but not Enantiornithes. More young birds are known from the fossil record of the more northernly sites than from locations further south. This suggests that at least some species were migratory like today’s penguins which swim polewards in the summer.

Hesperornis were preyed upon by large marine carnivores. Tylosaurus proriger specimen SDSMT 10439 contains the bones of a Hesperornis in its gut, for example.

Now, a relative of Hesperornis has been discovered.

From the Perot Museum of Nature and Science in the USA:

Amateur collectors in Japan discover country’s first and oldest fossil diving bird

August 8, 2017

Summary: Two brothers from a small town in Hokkaido, Japan, made the discovery of their lives — the first and oldest fossil bird ever identified in their country. Identified as a new species, it has been named Chupkaornis keraorum.

During a walk near a reservoir in a small Japanese town, amateur collectors made the discovery of their lives — the first and oldest fossil bird ever identified in their country.

After sharing their mysterious find with paleontologists at Hokkaido University, brothers Masatoshi and Yasuji Kera later learned the skeletal remains were that of an iconic marine diving bird from the Late Cretaceous Period, one that is often found in the Northern Hemisphere but rarely in Asia. The remarkable specimen — which includes nine skeletal elements from one individual, including the thoracic vertebrae and the femoral bones — is being heralded as the “best preserved hesperornithiform material from Asia” and to be “the first report of the hesperorinthiforms from the eastern margin of the Eurasian Continent.”

Identified as a new species, it has been named Chupkaornis keraorum — Chupka is the Ainu word used by indigenous people from Hokkaido for ‘eastern,’ and keraorum is named after Masatoshi and Yasuji Kera, who discovered the specimen. The bird would have lived during the time when dinosaurs roamed the land.

The scientific paper describing the find, entitled “The oldest Asian Hesperornithiform from the Upper Cretaceous of Japan, and the phylogenetic reassessment of Hesperornithiformes,” has been posted on the Journal of Systematic Palaeontology website.

“This amazing find illustrates the special relationship paleontologists and other scientists have with ordinary citizens who come upon interesting and unusual objects,” said Tanaka. “Thanks to the wisdom and willingness of Masatoshi and Yasuji Kera to share their discovery with us at Hokkaido University, they have made a major contribution to science, and we are very grateful.”

The bones, estimated to be anywhere from 90 million to 84 million years old, were unearthed from the Upper Cretaceous Kashima Formation of the Yezo Group in Mikasa City, Hokkaido. The fossil bird consists of four cervical vertebrae, two thoracic vertebrae, the distal end of the left and right femora, and the middle part of the right fibula. The specimen is currently housed in the collection of the Mikasa City Museum in Hokkaido, Japan.

“Hespeornithiforms is the oldest group of birds that succeeded to adapt for diving in ocean. This study provides better understanding in the early evolution of this group and the origin of diving in birds,” added Tanaka.

Chupkaornis has a unique combination of characteristics: finger-like projected tibiofibular crest of femur; deep, emarginated lateral excavation with the sharply defined edge of the ventral margin of that the thoracic vertebrae (those vertebrae in the upper back); and the heterocoelous articular surface of the thoracic vertebrae. Phylogenetic analysis of this study revealed that Chupkaornis is one of the basal hesperornithiforms, thereby providing details of the evolution of this iconic group of diving birds.

“In Japan, many important vertebrate fossils have been discovered by amateurs because most of the land is covered with vegetation, and there are few exposures of fossil-bearing Cretaceous rocks. This research is a result of collaboration with amateurs, and I am thankful to their help and understanding of science,” said Kobayashi.

Hesperornithiformes were toothed, foot-propelled diving birds and one of the most widely distributed groups of birds in the Cretaceous of the northern hemisphere. These birds had extremely reduced forelimbs and powerful hind limbs, suggesting that they were flightless sea-going predatory birds. Most of hesperornithiform fossils have been discovered from North America so far. The discovery of Chupkaornis, the oldest Asian hesperornithiform, suggests that basal hesperornithiform had dispersed to the eastern margin of Asia no later than 90 million to 84 million years old.

The discovery has broader aspects — and that’s why Dr. Fiorillo, curator and vice president of research and collections at the Perot Museum of Nature and Science, is involved. Dr. Fiorillo is considered one of the world’s preeminent experts on arctic dinosaurs for his decades of research in Alaska. He has deep interest in the Beringia land bridge that connects North America to Asia. He was asked to collaborate on this discovery because several of the co-authors of the paper, including Kobayashi and lead-author Tanaka, have been members of his field team during past Alaska expeditions.

“This study not only tells important new information about the evolution of this unusual group of birds, it also helps further our understanding of life in the ancient northern Pacific region, more specifically what was going on in the ocean while dinosaurs walked the land” said Fiorillo.

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Dinosaur age snails discovered near Prado museum, Spain


This video says about itself:

1 August 2015

Concavenator” is a genus of theropod dinosaur that lived approximately 130 million years ago during the early Cretaceous period. The type species is “C. corcovatus”. “Concavenator corcovatus” means “hump backed hunter from Cuenca”. The fossil was discovered in the Las Hoyas fossil site of Spain by paleontologists José Luis Sanz, Francisco Ortega and Fernando Escaso from the Autonomous University of Madrid and the National University of Distance Learning.

“Concavenator” was a medium-sized primitive carcharodontosaurian dinosaur possessing several unique features. Two extremely tall vertebrae in front of the hips formed a tall but narrow and pointed crest on the dinosaur’s back. The function of such crests is currently unknown. Paleontologist Roger Benson from Cambridge University speculated that one possibility is that “it is analogous to head-crests used in visual displays”, but the Spanish scientists who discovered it noted it could also be a thermal regulator.

Additionally, the forelimb of “Concavenator” preserved evidence of what may be quill knobs or homologous structures, an anatomical feature so far known only in animals with large, quilled feathers on the forelimb.

“Concavenator” had structures resembling quill knobs on its forearm, a feature known only in birds and other feathered theropods, such as “Velociraptor“. Quill knobs are created by ligaments which attach to the feather follicle, and since scales do not form from follicles, the authors ruled out the possibility that they could indicate the presence of long display scales on the arm. Instead, the knobs probably anchored simple, hollow, quill-like structures. Such structures are known both in coelurosaurs such as “Dilong” and in some ornithischians like “Tianyulong” and “Psittacosaurus“.

If the ornithischian quills are homologous with bird feathers, their presence in an allosauroid like “Concavenator” would be expected. However, if ornithischian quills are not related to feathers, the presence of these structures in “Concavenator” would show that feathers had begun to appear in earlier, more primitive forms than coelurosaurs. Feathers or related structures would then likely be present in the first members of the clade Neotetanurae, which lived in the Middle Jurassic. No impressions of any kind of integument were found near the arm, although extensive scale impressions were preserved on other portions of the body, including broad, rectangular scales on the underside of the tail, bird-like scutes on the feet, and plantar pads on the undersides of the feet.

Some amount of skepticism exists among experts about the validity of the interpretation that the ulna bumps represent quill knobs, though a more detailed analysis has not yet been published. Darren Naish of the blog Tetrapod Zoology speculates that the bumps would have been unusually far up and irregularly spaced for quill knobs. He additionally pointed out that many animals have similar structures along intermuscular lines that act as tendon attachment points among other things. This dissent has been supported by Christian Foth and others.

From FECYT – Spanish Foundation for Science and Technology:

Cretaceous snails conceal themselves in monuments in Madrid

August 3, 2017

The fountains standing next to the Museo del Prado are built using a sedimentary rock full of gastropod shells from the time of the dinosaurs. These fossils have revealed the origin of the stone: forgotten quarries in Redueña, in the province of Madrid, where the building material for the Fountain of Apollo and the Palacio de las Cortes also came from.

In the Fountain of Apollo stone (shown in the image) and the four fountains facing the Museo del Prado, the Trochactaeon lamarcki fossils, a species of gastropod which lived around 85 million years ago, are easily seen. Credit: D.M. Freire-Lista /IGEO

In the Fountain of Apollo stone (shown in the image) and the four fountains facing the Museo del Prado, the Trochactaeon lamarcki fossils, a species of gastropod which lived around 85 million years ago, are easily seen. Credit: D.M. Freire-Lista /IGEO

The tourists who visit the Museo del Prado can take the opportunity to see fossils of snails that lived alongside dinosaurs millions of years ago. They are embedded in the stone of four small fountains designed by the architect Ventura Rodríguez in the 18th century, which stand next to the art gallery.

Now, researchers from the Institute of Geosciences (IGEO, a CSIC-UCM joint centre) have discovered the old quarries where the rock was extracted in order to sculpt these fountains and other monuments in Madrid. The study was published in the journal AIMS Geosciences.

“These quarries, lost over a century ago, are located in Redueña in the province of Madrid,” according to David M. Freire-Lista, one of the authors: “Here the geological formation of the dolomite (a sedimentary rock similar to limestone) known as Castrojimeno presents characteristic features, such as a layer containing fossils that do not appear in other areas.”

Specifically, numerous gastropod fossils (measuring up to 2.5 cm) of the species Trochactaeon lamarcki, which lived in the Upper Cretaceous approximately 85 million years ago, were identified in the fountain stone, which has proven key for dating and tracing the origin of the rocks.

Through historical documents and direct observation, the researchers then confirmed that they are the same quarries which supplied the stone used to construct the jambs, lintels and mantelpieces in the Palacio de las Cortes, where the Spanish Parliament sits.

The same material was also used to build the Fountain of Apollo, located in the Paseo del Prado between the most famous fountains, Neptune and Cybele, whose terrazzo stone was also from Redueña -according to the original plans drawn up by Ventura Rodríguez-, although over time it was replaced by another.

“The dolomite from Redueña containing gastropods was highly used in monuments dating back to the 18th century due to its light colour, ease of carving, and the proximity to Madrid,” points out Freire-Lista. “Its petrographic and petrophysical properties, being of particular note its low solubility and porosity, lend it an excellent quality and durability for use in places where water is present, such as these fountains,” he adds.

Nevertheless, the researchers warn that the passage of time affects even the most resistant stones, and they consider it necessary to carry out petrophysical studies, using non-destructive techniques, to determine the degree of deterioration of the monuments and to take measures for their successful conservation.

200 million years of geological history in the Trinitarians

In another study published in the journal Ge-conservación, the same authors analysed the material used to construct the Convento de las Trinitarias Descalzas de San Ildefonso in Madrid, where the remains of Miguel de Cervantes lie, and they have also found Cretaceous dolomite (in this instance Tamajón-Redueña stone, without gastropods) in the coats of arms and low reliefs on the church’s façade.

“This convent is constructed using the four traditional building stones most representative of the capital: flint, granite, Cretaceous dolomite and Miocene limestone, and the presence of these four on its façade makes it a showcase of the last 200 million years of geological history of the region of Madrid,” concludes the researcher.

Dinosaur age flowers


This video says about itself:

When Did the First Flower Bloom?

3 July 2017

During the Cretaceous Period, dinosaurs were more diverse, more fierce, and more strange than ever. But something else was happening under the feet of the terrible lizards: for the first time in history, there were flowers.

From the University of Vienna in Austria:

What flowers looked like 100 million years ago

August 2, 2017

Flowering plants with at least 300,000 species are by far the most diverse group of plants on Earth. They include almost all the species used by people for food, medicine, and many other purposes. However, flowering plants arose only about 140 million years ago, quite late in the evolution of plants, toward the end of the age of the dinosaurs, but since then have diversified spectacularly. No one knows exactly how this happened, and the origin and early evolution of flowering plants and especially their flowers still remains one of the biggest enigmas in biology, almost 140 years after Charles Darwin called their rapid rise in the Cretaceous “an abominable mystery.”

This new study, the “eFLOWER project,” is an unprecedented international effort to combine information on the structure of flowers with the latest information on the evolutionary tree of flowering plants based on DNA. The results shed new light on the early evolution of flowers as well as major patterns in floral evolution across all living flowering plants.

Among the most surprising results is a new model of the original ancestral flower that does not match any of the ideas proposed previously. “When we finally got the full results, I was quite startled until I realized that they actually made good sense,” said Hervé Sauquet, the leader of the study and an Associate Professor at Université Paris-Sud in France. “No one has really been thinking about the early evolution of flowers in this way, yet so much is easily explained by the new scenario that emerges from our models.”

According to the new study, the ancestral flower was bisexual, with both female (carpels) and male (stamens) parts, and with multiple whorls (concentric cycles) of petal-like organs, in sets of threes. About 20% of flowers today have such “trimerous” whorls, but typically fewer: lilies have two, magnolias have three. “These results call into question much of what has been thought and taught previously about floral evolution!,” said Juerg Schoenenberger, a Professor at the University of Vienna, who coordinated the study together with Hervé Sauquet. It has long been assumed that the ancestral flower had all organs arranged in a spiral.

The researchers also reconstructed what flowers looked like at all the key divergences in the flowering plant evolutionary tree, including the early evolution of monocots (e.g., orchids, lilies, and grasses) and eudicots (e.g., poppies, roses, and sunflowers), the two largest groups of flowering plants. “The results are really exciting!” said Maria von Balthazar, a Senior Scientist and specialist of floral morphology and development at the University of Vienna. “This is the first time that we have a clear vision for the early evolution of flowers across all angiosperms.”

The new study sheds new light on the earliest phases in the evolution of flowers and offers for the first time a simple, plausible scenario to explain the spectacular diversity of floral forms. Nevertheless, many questions remain. The fossil record of flowering plants is still very incomplete, and scientists have not yet found fossil flowers as old as the group itself. “This study is a very important step toward developing a new and increasingly sophisticated understanding of the major patterns in the evolution of flowers,” said Peter Crane, President of the Oak Spring Garden Foundation and a colleague familiar with the results of the study. “It reflects great progress and the results on the earliest flowers are especially intriguing.”

See also here.

Dinosaur age crustaceans’ parental care


This 2013 video says about itself:

Tanaid, a shrimp-like … animal. MicroCT scan, SkyScan1172, SkyScan CTVox rendering. By Maria Candas & Phil Salmon, Marine Biology Research Station, Ferrol, Galicia, Spain.

From the Universidad de Barcelona in Spain:

Cretaceous Tanaidaceans took care of their offspring more than 105 million years ago

July 14, 2017

A scientific team has found the first evidence of parental care in Tanaidaceans, dating back to more than 105 million years, according to a new study published in the journal Scientific Reports, from Nature group. These new findings are based on the study of three small crustaceans from different species of the Cretaceous -Alavatanais carabe, Alavatanais margulisae and Daenerytanais maieuticus- preserved in amber pieces from the sites in Peñacerrada (Álava, Spain) and La Buzinie (Charente, France), reference models in the study of fossil records in amber with bioinclusions of the Mesozoic in Europe.

The authors of the study are the researchers Alba Sánchez and Xavier Delclòs, from the Faculty of Earth Sciences and the Biodiversity Research Institute (IRBio) of the University of Barcelona; Enrique Peñalver, from the Geological and Mining Institute of Spain; Michael S. Engel, from the University of Kansas (United States); Graham Bird (New Zealand), and Vincent Perrichot, from the University Rennes 1 (France).

Parental care: protecting offspring millions of years ago

Lots of extant crustacean species show parental care, increasing survival possibilities in the natural habitat. This reproductive strategy, which evolved independently in different lineages, is common in terrestrial and water aquatic species (in oceans, lakes, etc.).

However, there is not a lot of fossil evidence of caring behaviours in crustaceans. Although parental care is documented in fossil records -for instance in ostracods from 450 million years ago- the published article in the journal Scientific Reports shows the first evidence of this behavior in Tanaidacea; a group of small crustaceans belonging to the superorder Peracarida.

“These new findings make up for the first fossil evidence of parental care in the order Tanaidacea. The findings show that certain caring behaviours and related morphological adaptations already existed during the Lower Cretaceous and were almost kept without changes for more than 105 million years” says the researcher Alba Sánchez (UB-IRBio), first author of the study.

Marsupial care of brood-offspring

A feature of Tanaidaceans -and other peracarid crustaceans- is that females have the marsupium, a ventral brood pouch to retain and protect the eggs. After the fertilization, eggs develop into embryos and then young individuals inside the marsupium.

According to the lecturer Xavier Delclòs (UB-IRBio), “The marsupium represents a safe environment for the offspring and may contribute to the success of tanaidaceans in different habitats (marine and freshwater environments, and even humid terrestrial areas), as proposed for some tanaidaceans found in Cretaceous amber.”

Daenerytanais maieuticus: the Khaleesi of crustaceans

According to the new study, the two tanaidacean specimens found in amber pieces from Álava (Spain) -two females of Alavatanais carabe and Alavatanais margulisae- show structures involved in the formation of a marsupium to carry eggs and offspring in sexually mature females.

Regarding the French site of La Buzinie, the specimen they identified is a female of Daenerytanais maieuticus, which was preserved in amber together with her marsupium full of eggs. This fossil, representing a new genus and species, is named after the fiction character Daenerys Targaryen, “Mother of Dragons,” from the series of fantasy novels A Song of Ice and Fire, written by George R. R. Martin, which inspired the well-known TV series Game of Thrones.

The article, published in the journal Scientific Reports is framed within the research studies of the group AMBARES (Ambers of Spain) and the UB Research Group Sedimentary Geology, and it has the financing of autonomous and national government funds and the collaboration of the Museum of Natural Sciences of Álava (Spain).

Tyrannosaurus rex, new research


This video from the USA says about itself:

Kinect 3D Scanning of SUE the T-rex

This was done at the Field Museum of Natural History in Chicago, IL on 10/10/2016.

In charge of the scanning was Anshuman Das, PhD. He is a Postdoctoral Associate, MIT Media Lab & MIT Data Center for Technology+Design.

The consultant for animal bite marks was Kenneth Cohrn DDS, D-ABFO. He is a Forensic Odontologist, Assistant Adjunct Professor, Department of Pathology and Immunology and consultant to C. A. Pound Identification Lab and Veterinary School, University of Florida.

From the Massachusetts Institute of Technology in the USA:

Kinect scan of T. rex skull addresses paleontological mystery

July 5, 2017

Summary: A new system with $150 worth of hardware offers alternative to 3-D scanners that cost 200 times as much, report scientists who have used it on the skull of a T. rex dinosaur.

Last year, a team of forensic dentists got authorization to perform a 3-D scan of the prized Tyrannosaurus rex skull at the Field Museum of Natural History in Chicago, in an effort to try to explain some strange holes in the jawbone.

Upon discovering that their high-resolution dental scanners couldn’t handle a jaw as big as a tyrannosaur‘s, they contacted the Camera Culture group at MIT’s Media Lab, which had recently made headlines with a prototype system for producing high-resolution 3-D scans.

The prototype wasn’t ready for a job that big, however, so Camera Culture researchers used $150 in hardware and some free software to rig up a system that has since produced a 3-D scan of the entire five-foot-long T. rex skull, which a team of researchers — including dentists, anthropologists, veterinarians, and paleontologists — is using to analyze the holes.

The Media Lab researchers report their results in the latest issue of the journal PLOS One.

“A lot of people will be able to start using this,” says Anshuman Das, a research scientist at the Camera Culture group and first author on the paper. “That’s the message I want to send out to people who would generally be cut off from using technology — for example, paleontologists or museums that are on a very tight budget. There are so many other fields that could benefit from this.”

Das is joined on the paper by Ramesh Raskar, a professor of media arts and science at MIT, who directs the Camera Culture group, and by Denise Murmann and Kenneth Cohrn, the forensic dentists who launched the project.

The system uses a Microsoft Kinect, a depth-sensing camera designed for video gaming. The Kinect’s built-in software produces a “point cloud,” a 3-D map of points in a visual scene from which short bursts of infrared light have been reflected back to a sensor. Free software called MeshLab analyzes the point cloud and infers the shape of the surfaces that produced it.

A high-end commercial 3-D scanner costs tens of thousands of dollars and has a depth resolution of about 50 to 100 micrometers. The Kinect’s resolution is only about 500 micrometers, but it costs roughly $100. And 500 micrometers appears to be good enough to shed some light on the question of the mysterious holes in the jaw of the T. rex skull.

Cretaceous conundrum

Discovered in 1990, the Field Museum’s T. rex skeleton, known as Sue, is the largest and most complete yet found. For years, it was widely assumed that the holes in the jaw were teeth marks, probably from an attack by another tyrannosaur. Ridges of growth around the edges of the holes show that Sue survived whatever caused them.

But the spacing between the holes is irregular, which is inconsistent with bite patterns. In 2009, a group of paleontologists from the University of Wisconsin suggested that the holes could have been caused by a protozoal infection, contracted from eating infected prey, that penetrated Sue’s jaw from the inside out.

The 3-D scan produced by the MIT researchers and their collaborators sheds doubt on both these hypotheses. It shows that the angles at which the holes bore through the jaw are inconsistent enough that they almost certainly weren’t caused by a single bite. But it also shows that the holes taper from the outside in, which undermines the hypothesis of a mouth infection.

One of the great advantages of 3-D scans is that they can be shared remotely. The Field Museum limits the time that researchers can spend with Sue’s skull, so the Wisconsin paleontologists’ analysis was largely based on photographs. But photographs don’t permit the comparison of the holes’ diameters at the inner and outer surfaces.

And if researchers working with a scan needed to examine a particular feature in close detail, they could use a 3-D printer to build a replica. To demonstrate this capacity, Das and his colleagues used their scan of Sue’s skull to produce a few models of it, at one-eighth the actual size.

Remote research

Das envisions that Kinect scans could prove as useful in other fields, such as archaeology and anthropology, as they could in paleontology. An archaeologist who unearths a large, fragile, artifact in a remote corner of the world could scan it and immediately share the scan with colleagues around the world.

“It’s that critical size,” Das says. “If it’s something really small, you can use a 3-D scanner. But if you have something stationary that’s difficult to move, you just put on the [Kinect] rig and walk around.”

Indeed, when Das scanned Sue’s skull, he mounted the Kinect in a modified camera harness and wore it on his chest. The space in which he performed the scan was irregularly shaped and presented various immovable obstacles, so it took him some time to find a route that would permit him to maintain a fixed distance from the skull as he walked around. But once he identified the route, the scan itself took about two minutes.

In ongoing work, Das, Murmann, Cohrn, Raskar, and a team of collaborators including the Wisconsin paleontologists, are looking at fragmentation patterns at the edges of the holes and at the holes’ depths and diameters, to see if they can infer anything about the shape, hardness, and velocity of whatever object might have caused them.

Oviraptorosaur dinosaur eggs, new study


This video says about itself:

9 May 2017

Eggs four times bigger than ostriches’ reveal a giant dinosaur.

A clutch of enormous fossil eggs from China has led to the discovery of a new species of giant bird-like dinosaur.

Flightless Beibeilong sinensis, which lived around 90 million years ago, had feathers, primitive wings and a beak, but dwarfed any of its modern bird relatives.

Based on their analysis of a hatchling that died while emerging from one of the eggs, experts believe the adult creature was around eight metres long and weighed three tons.

Other dinosaurs of the same type, known as oviraptorosaurs, have seldom measured more than about two metres.

Several Beibeilong eggs were found in Henan Province, central China, in a ring-shaped clutch which was part of a nest two to three metres in diameter.

The eggs are up to 45 centimetres across and weighed about 5 kilograms.

“For many years, it was a mystery as to what kind of dinosaur laid these enormous eggs,” says Darla Zelenitsky, from the University of Calgary, Canada. “Because fossils of large theropods, like tyrannosaurs, were also found in the rocks in Henan, some people initially thought the eggs may have belonged to a tyrannosaur.”

“Thanks to this fossil, we now know that these eggs were laid by a gigantic oviraptorosaur, a dinosaur that would have looked a lot like an overgrown cassowary. It would have been a sight to behold with a three-ton animal like this sitting on its nest of eggs.”

The new species of giant oviraptorosaur is thought to be the largest dinosaur known that cared for its young in a similar way to modern birds.

The scientists estimated the size of the adult after studying the bones of the hatchling and making comparisons with other dinosaurs.

It was the stillborn dinosaur that led to the name chosen for the species. Beibeilong sinensis translates as “baby dragon from China”.

From CNRS in France:

Brooding dinosaurs

Oviraptorosaurs incubated their eggs with their bodies within a 35–40° C range

June 28, 2017

A new method used to perform geochemical analysis of fossilized eggs from China has shown that oviraptorosaurs incubated their eggs with their bodies within a 35-40° C range, similar to extant birds today. This finding is the result of Franco-Chinese collaboration coordinated by Romain Amiot of the Laboratoire de géologie de Lyon: Terre, planètes et environnement (CNRS/ENS de Lyon/Université Claude Bernard Lyon 1).

Dinosaurs‘ reproductive strategies, and in particular the way they incubated their eggs, still raise numerous scientific questions. Until now, interpretations have been based on indirect indices such as the morphology of fossilized eggshells or the organization of nests. Researchers from Lyon, working in collaboration with a Chinese team, have developed a method based on the geochemical analysis of fossilized eggs and have calculated for the first time that the oviraptorosaur eggs were incubated within a 35-40° C temperature range.

Oviraptorosaurs were feathered bipedal dinosaurs with a beak, giving them an appearance reminiscent of certain birds. A member of the theropod group,[1] they weighed a few dozen kilos and could measure up to two meters in length. In order to determine the temperature at which these dinosaurs incubated their eggs, the researchers analyzed seven fossilized eggs recovered from southern China. These 70-million-year-old eggs still contain embryos. Both the eggshells and the embryo bones were analyzed in order to determine their oxygen isotope composition.[2] During the formation of the embryo skeletons, oxygen from the egg fluids was transferred to the embryo bones, the isotopic abundance of which would depend on the temperature of the egg. Taking these measurements into account, the researchers — assisted by a physiologist colleague — were able to model the different developmental stages integrating the oxygen isotope compositions. In doing so, they were able to ascertain the temperature at which the egg was formed: between 35 and 40° C. By way of comparison, crocodiles, which bury their eggs, incubate their eggs at a temperature of around 30° C, while hen’s eggs are incubated at 37.5° C. According to the researchers, the incubation temperature calculated for the oviraptorosaurs eggs is thus coherent with the way these dinosaurs are thought to have incubated their eggs.

This result confirms the discovery made in the 1990s of fossilized oviraptorosaurs stretched across their clutch, suggesting that they incubated their eggs. The work also opens new avenues for research in paleontology: the method employed makes it possible to ascertain the incubation strategies adopted by other dinosaurs. No doubt some dinosaurs, weighing several dozen metric tons, could not lie on their eggs to incubate them, but they may have used other external heat sources, for example by covering their clutch with a mound of plant matter, which would have provided heat as it decomposed. The estimated incubation temperature will be a reflection of the incubation strategy employed, subject to being able access these rare and precious fossils for corroborative purposes.

This research, which is part of the above-mentioned Franco-Chinese collaboration, involved the Laboratoire de géologie de Lyon : Terre, planètes et environnement (CNRS/ENS de Lyon/Université Claude Bernard Lyon 1), the Laboratoire de biologie et de biométrie évolutive (CNRS/Université Claude Bernard Lyon 1/VetAgroSup) as well as the Laboratoire d’écologie des hydrosystèmes naturels anthropisés (CNRS/Université Claude Bernard Lyon 1/ENTPE).

[1] The current classification distinguishes two groups of dinosaurs: ornithischians and saurischians. Theropod dinosaurs form a group within the order of saurischian dinosaurs. Characterized by their bipedal posture, most were carnivorous.

[2] The oxygen isotope composition refers to the relative abundance of oxygen’s two main stable isotopes, oxygen-16 (16O) and oxygen-18 (18O).

From dinosaur age mammal to human, new research


Placental mammal family tree

Numbers on red branches from the first eutherian ancestor to Homo sapiens are the numbers of breakpoints in reconstructed ancestral chromosome fragments. Breakpoints are locations where a chromosome broke open, allowing for rearrangements. The number of breakpoints per million years is in parentheses. A total of 162 chromosomal breakpoints were identified between the eutherian ancestor and the formation of humans as a species.
Credit: Harris Lewin, UC Davis

From the University of California – Davis in the USA:

Reconstruction of ancient chromosomes offers insight into mammalian evolution

June 21, 2017

Summary: Researchers have gone back in time, at least virtually, computationally recreating the chromosomes of the first eutherian mammal, the long-extinct, shrewlike ancestor of all placental mammals.

What if researchers could go back in time 105 million years and accurately sequence the chromosomes of the first placental mammal? What would it reveal about evolution and modern mammals, including humans?

In a study published this week in Proceedings of the National Academy of Sciences, researchers have gone back in time, at least virtually, computationally recreating the chromosomes of the first eutherian mammal, the long-extinct, shrewlike ancestor of all placental mammals.

“The revolution in DNA sequencing has provided us with enough chromosome-scale genome assemblies to permit the computational reconstruction of the eutherian ancestor, as well as other key ancestors along the lineage leading to modern humans,” said Harris Lewin, a lead author of the study and a professor of evolution and ecology and Robert and Rosabel Osborne Endowed Chair at the University of California, Davis.

“We now understand the major steps of chromosomal evolution that led to the genome organization of more than half the existing orders of mammals. These studies will allow us to determine the role of chromosome rearrangements in the formation of new mammal species and how such rearrangements result in adaptive changes that are specific to the different mammalian lineages,” said Lewin.

The findings also have broad implications for understanding how chromosomal rearrangements over millions of years may contribute to human diseases, such as cancer.

“By gaining a better understanding of the relationship between evolutionary breakpoints and cancer breakpoints, the essential molecular features of chromosomes that lead to their instability can be revealed,” said Lewin. “Our studies can be extended to the early detection of cancer by identifying diagnostic chromosome rearrangements in humans and other animals, and possibly novel targets for personalized therapy.”

Descrambling chromosomes

To recreate the chromosomes of these ancient relatives, the team began with the sequenced genomes of 19 existing placental mammals — all eutherian descendants — including human, goat, dog, orangutan, cattle, mouse and chimpanzee, among others.

The researchers then utilized a new algorithm they developed called DESCHRAMBLER. The algorithm computed (“descrambled”) the most likely order and orientation of 2,404 chromosome fragments that were common among the 19 placental mammals’ genomes.

“It is the largest and most comprehensive such analysis performed to date, and DESCHRAMBLER was shown to produce highly accurate reconstructions using data simulation and by benchmarking it against other reconstruction tools,” said Jian Ma, the study’s co-senior author and an associate professor of computational biology at Carnegie Mellon University in Pittsburgh.

In addition to the eutherian ancestor, reconstructions were made for the six other ancestral genomes on the human evolutionary tree: boreoeutherian, euarchontoglires, simian (primates), catarrhini (Old World monkeys), great apes and human-chimpanzee. The reconstructions give a detailed picture of the various chromosomal changes — translocations, inversions, fissions and other complex rearrangements — that have occurred over the 105 million years between the first mammal and Homo sapiens.

Rates of evolution vary

One discovery is that the first eutherian ancestor likely had 42 chromosomes, four less than humans. Researchers identified 162 chromosomal breakpoints — locations where a chromosome broke open, allowing for rearrangements — between the eutherian ancestor and the formation of humans as a species.

The rates of evolution of ancestral chromosomes differed greatly among the different mammal lineages. But some chromosomes remained extremely stable over time. For example, six of the reconstructed eutherian ancestral chromosomes showed no rearrangements for almost 100 million years until the appearance of the common ancestor of human and chimpanzee.

Orangutan chromosomes were found to be the slowest evolving of all primates and still retain eight chromosomes that have not changed much with respect to gene order orientation as compared with the eutherian ancestor. In contrast, the lineage leading to chimpanzees had the highest rate of chromosome rearrangements among primates.

“When chromosomes rearrange, new genes and regulatory elements may form that alter the regulation of expression of hundreds of genes, or more. At least some of these events may be responsible for the major phenotypic differences we observe between the mammal orders,” said Denis Larkin, co-senior author of the study and a reader in comparative genomics at the Royal Veterinary College at the University of London.

The chromosomes of the oldest three ancestors (eutherian, boreoeutherian, and euarchontoglires) were each found to include more than 80 percent of the entire length of the human genome, the most detailed reconstructions reported to date. The reconstructed chromosomes of the most recent common ancestor of simians, catarrhini, great apes, and humans and chimpanzees included more than 90 percent of human genome sequence, providing a structural framework for understanding primate evolution.