Dinosaur age crocodilians, new research


This video says about itself:

4 May 2018

Evolution of crocodiles: Of all the reptiles alive today, crocodiles and alligators may be the least changed from their prehistoric forebears of the late Cretaceous period, over 65 million years ago—although the even earlier crocodiles of the Triassic and Jurassic periods sported some distinctly un-crocodile-like features, such as bipedal postures and vegetarian diets.

Along with pterosaurs and dinosaurs, crocodiles were an offshoot of the archosaurs, the “ruling lizards” of the early to middle Triassic period; needless to say, the earliest dinosaurs and the earliest crocodiles resembled one another a lot more than either resembled the first pterosaurs, which also evolved from archosaurs.

1. Xilousuchus
250,000,000 bc – 200,000,000 bc
2. Phytosaur
228,000,000 bc – 199,000,000 bc
3. Erpetosuchus
200,000,000 bc
4. Sarcosuchus
110,000,000 bc
5. Stomatosuchus
100,000,000 bc – 95,000,000 bc
6. Deinosuchus
80,000,000 bc
7. Champsosaurus [not a crocodile, though looking like one]
70,000,000 bc – 50,000,000 bc
8. Cretaceous-Paleogene Extinction Event
65,000,000 bc
9. Crocodylidae (Modern day crocodile)
55,000,000 bc – Present
10. Quinkana
23,000,000 bc – 40,000 bc
11. Crocodylus thorbjarnarsoni
4,200,000 bc

From the University of the Witwatersrand in South Africa:

In the gaping mouth of ancient crocodiles

As an apex predator, the crocodile’s mode of attack — its mouth — had humble beginnings

June 18, 2018

Summary: A new study has endeavoured to further explore the mouth of one of the earliest occurring and least understood groups of crocodilians, the shartegosuchids.

The mouth of today’s crocodilians inspires fear and awe, with their wide gape and the greatest known bite force in the vertebrate animal kingdom. However, this apex predator of today and its modus of attack (its mouth) had humble beginnings.

The very earliest crocodilians were very different to the beasts we know well today, they were much smaller bodied, slender and had longer legs. It is speculated that they led a much different lifestyle to the crocodiles we all know and fear today.

A new study by a team of international experts, led by University of Witwatersrand PhD candidate Kathleen Dollman and Professor Jonah Choiniere published today in the American Museum Novitates, endeavoured to further explore the mouth of one of the earliest occurring and least understand groups of crocodilians, the shartegosuchids.

In 2010, Choiniere was a part of a field team working in the Late Jurassic (±160 mya) exposures in the western Gobi in Mongolia, when he found the fossil of a small snout of a shartegosuchid. This work was co-authored by researchers based at the American Museum of Natural History, the George Washington University and the Institute for Vertebrate Palaeontology and Palaeoanthropology.

The snout was later CT scanned at the American Museum of Natural History, exposing an unusual, closed secondary palate. Crocodilians are one of only a few groups of animals that evolve a completely closed, bony secondary palate (along with turtles and mammals). A closed secondary palate has many biological implications for crocodilians, including breathing whilst under water and reinforcing the skull to allow for their incredible bite force.

This study showed that these early crocodilians, the shartegosuchids, are important because they evolved a completely closed secondary palate much earlier than previously thought. This is an interesting example of convergent evolution, whereby a similar feature evolves independently in two completely unrelated groups. The advent of a convergent evolutionary event allows scientists to test questions about why that feature evolved and even the function of that feature which in this case is the first step in understanding the purpose of a closed secondary palate in crocodilians.

“I was surprised to find that there were many features in the palate and snout that were completely different between shartegosuchids and extant crocodilians,” says Dollman. Shartegosuchids have a thickened and sculptured palate together with a tall and short rostrum, whereas extant crocodilians have a smooth palate with a long and broad rostrum.

“We would expect to see the same palatal structures and snout shapes in both shartegosuchids and extant crocodiles if they were using it for similar functions and had evolved a closed palate for similar reasons”, says Dollman. “The observed differences tell us that shartegosuchids likely had predation practices to which there is no modern analogue in crocodilians.”

“It’s been nearly 10 years since we collected this fossil after driving 5 days across the Gobi Desert,” said Choiniere, “and I am delighted that it’s formed a part of Kathleen’s PhD.”

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Dinosaur age dinoflagellates discovery in Australia


This 2015 video from the USA says about itself:

Dino Pet is a clear plastic dinosaur figure [toy] that houses living organisms called dinoflagellates that come from the ocean. For full review and shopping info: here.

Product Info: The dinoflagellates photosynthesize during the day and glow blue at night when shaken. This is called bioluminescence and is a naturally occurring process seen in many sea creatures. The Dino Pet’s instruction booklet provides more information on the science behind bioluminescence.

From the University of Adelaide in Australia:

Red tide fossils point to Jurassic sea flood

June 5, 2018

Dinosaur-age fossilised remains of tiny organisms normally found in the sea have been discovered in inland, arid Australia — suggesting the area was, for a short time at least, inundated by sea water 40 million years before Australia’s large inland sea existed.

The fossils are the egg-like cysts of microorganisms known as dinoflagellates, best known for producing red tides or algal blooms that can turn the sea water blood red. The cysts rest on the sea floor before hatching new dinoflagellates.

Researchers at the University of Adelaide, in collaboration with geological consultancy MGPalaeo, discovered these microfossils in Jurassic rocks of south-western Queensland, near the town of Roma.

Described in the journal Palynology, the fossils have been dated to the late Jurassic period, 148 million years ago. This is a time when Australia was joined to Antarctica, and where dinosaurs roamed across ancient rivers, floodplains and swamps.

“We have plenty of evidence from the 110 million-year-old vast inland Eromanga Sea, which covered a large swathe of central, eastern Australia during the Cretaceous period (following on from the Jurassic)”, says Dr Carmine Wainman, Postdoctoral Fellow in the University of Adelaide’s Australian School of Petroleum.

“We’ve seen the opalised fossils sold in Adelaide’s Rundle Mall, and the spectacular ancient marine reptiles on display in the South Australian Museum — all from the later Cretaceous period.

“However, this new microfossil evidence from the same region suggests there was a short-lived precursor to this sea 40 million years earlier.”

Dr Wainman believes these microfossils must have been brought inland by an incursion of sea water and then evolved quickly to adapt to the freshwater or brackish conditions as the sea waters slowly receded.

“There is no other feasible explanation for how they managed to reach the interior of the Australian continent when the ancient coastline was thousands of kilometres away,” Dr Wainman says.

“It was probably a result of rising sea levels during a time of greenhouse conditions before the establishment of the Eromanga Sea. With further investigations, we may find more of these microorganisms or even fossilised marine reptiles that uncover untold secrets about how this part of the world looked in the Jurassic.”

Jurassic crocodile, new discovery


This 11 May 2018 video says about itself:

A 180-million-year-old fossil has revealed an odd creature, a crocodile with a tail like a dolphin, shedding light on the evolution of these ancient animals and how they became some of the greatest predators of the Jurassic period. Researchers are hailing this new species as a “missing link” in the crocodile family tree.

Their findings, published in PeerJ, are helping to explain how some ancient crocodiles evolved into dolphin-like creatures.

It all began in 1996, when an amateur collector found the fossil on a mountainside in the Gerecse Mountains of north-west Hungary. The specimen was stored at the Hungarian Natural History Museum in Budapest until in 2017, researchers examined it more thoroughly and noticed the odd-looking vertebra on its tail fin.

During the Lower Jurassic, there existed crocodiles that had bony armor on their backs and bellies and had adapted to walk on land. There were also ones that had evolved flippers and had tail fins, but no armor. This fossil, however, appeared to have been both heavily armored and have a tail fin, making it not only a new species, but, according to the researchers, the missing link between the two groups.

Read more here.

From the University of Edinburgh in Scotland:

Jurassic fossil tail tells of missing link in crocodile family tree

May 11, 2018

A 180-million-year-old fossil has shed light on how some ancient crocodiles evolved into dolphin-like animals.

The specimen — featuring a large portion of backbone — represents a missing link in the family tree of crocodiles, and was one of the largest coastal predators of the Jurassic Period, researchers say.

The newly discovered species was nearly five metres long and had large, pointed teeth for grasping prey. It also shared key body features seen in two distinct families of prehistoric crocodiles, the team says.

Some Jurassic-era crocodiles had bony armour on their backs and bellies, and limbs adapted for walking on land. Another group had tail fins and flippers but did not have armour.

The new species was heavily armoured but also had a tail fin, suggesting it is a missing link between the two groups, researchers say.

It has been named Magyarosuchus fitosi in honour of the amateur collector who discovered it, Attila Fitos.

The fossil — unearthed on a mountain range in north-west Hungary in 1996 and stored in a museum in Budapest — was examined by a team of palaeontologists, including a researcher from the University of Edinburgh.

It was identified as a new species based on the discovery of an odd-looking vertebra that formed part of its tail fin.

The study, published in the journal PeerJ, also involved researchers in Hungary and Germany. It was supported by the Leverhulme Trust and the SYNTHESYS project, part of the European Commission’s Seventh Framework Programme.

Dr Mark Young, of the University of Edinburgh’s School of GeoSciences, who was involved in the study, said: “This fossil provides a unique insight into how crocodiles began evolving into dolphin and killer whale-like forms more than 180 million years ago. The presence of both bony armour and a tail fin highlights the remarkable diversity of Jurassic-era crocodiles.”

Dinosaur age butterflies’ colours, new research


This video says aout itself:

5 February 2016

If you traveled back to the Jurassic, you might encounter the familiar sight of butterflies sipping nectar – only the insects wouldn’t be butterflies.

From the University of Exeter in England:

Fossil study sheds light on ancient butterfly wing colors

April 11, 2018

Pioneering new research has given an illuminating new insight into the metallic, iridescent colours found on the earliest known ancestors of moths and butterflies, which habited the earth almost 200 million years ago.

An international team of researchers, including Dr Tim Starkey from the University of Exeter, have discovered new evidence for colour in Mesozoic fossils.

The structural colours of the fossils studied resulted from light scattering by intricate microstructures, extending the evidence for these light-scattering structures in the insect fossil record by more than 130 million years.

The research team examined fossilised remains dating back 180 million years, with some specimens originating from the Jurassic Coast, only a short distance from Exeter.

Using powerful electron microscopes and using optical models, the team found microscopic ridges and grooves in the insect’s wing scales, similar to those seen in today’s moths. Models revealed these tiny features are photonic structures that would have produced metallic bronze to golden colour appearances in the insect wings.

The research is published in leading journal Science Advances on Wednesday, April 11 2018.

Insects have evolved an amazing range of photonic structures that can produce iridescence, metallic colours, and other flashy effects that are important for behaviour and ecological functions.

Dr Starkey, part of Exeter’s Physics and Astronomy department, said: “The structural colours exhibited by butterflies and moths have been a longstanding research interest in Exeter, and have helped us develop biologically-inspired optical technologies for the present day.

“However, in this study we’ve looked millions of years back in time to early origins of such colours in nature, to understand how and when the evolution of colours in these insects took place.”

The study was co-authored by palaeontologists Drs Maria McNamara and Luke McDonald from UCC, in Ireland. Dr McNamara added: “Remarkably, these fossils are among the oldest known representatives of butterflies and moths.

“We didn’t expect to find wing scales preserved, let alone microscopic structures that produce colour. This tells us that colour was an important driving force in shaping the evolution of wings even in the earliest ancestors of butterflies and moths.”

Dr McDonald, previously of the Natural Photonics group in Exeter, said; “Uniquely in this study, we show that impression fossils, i.e. wing prints, are equally as capable as compression fossils at preserving the structure of scales in sufficient detail to elucidate the moths’ 180 million year old colours.”

Colorful moth wings date back to the dinosaur era. New fossils reveal the structure of the ancient insects’ light-scattering scales. By Laurel Hamers, 2:14pm, April 11, 2018.

Archaeopteryx could fly indeed


This 2014 video says about itself:

Scanning the Teyler Archaeopteryx fossil at the ESRF Grenoble

2 November 2014

In order to study the Teyler Archaeopteryx fossil, it is being scanned in Grenoble using synchrotron X-ray microtomography. The end of the video shows the specimen fully wrapped and mounted on the object table in front of the beam that is coming out the square hole in the blue box.

From the European Synchrotron Radiation Facility:

The early bird got to fly: Archaeopteryx was an active flyer

March 13, 2018

The question of whether the Late Jurassic dino-bird Archaeopteryx was an elaborately feathered ground dweller, a glider, or an active flyer has fascinated palaeontologists for decades. Valuable new information obtained with state-of-the-art synchrotron microtomography at the ESRF, the European Synchrotron (Grenoble, France), allowed an international team of scientists to answer this question in Nature Communications. The wing bones of Archaeopteryx were shaped for incidental active flight, but not for the advanced style of flying mastered by today’s birds.

Was Archaeopteryx capable of flying, and if so, how? Although it is common knowledge that modern-day birds descended from extinct dinosaurs, many questions on their early evolution and the development of avian flight remain unanswered. Traditional research methods have thus far been unable to answer the question whether Archaeopteryx flew or not. Using synchrotron microtomography at the ESRF’s beamline ID19 to probe inside Archaeopteryx fossils, an international team of scientists from the ESRF, Palacký University, Czech Republic, CNRS and Sorbonne University, France, Uppsala University, Sweden, and Bürgermeister-Müller-Museum Solnhofen, Germany, shed new light on this earliest of birds.

Reconstructing extinct behaviour poses substantial challenges for palaeontologists, especially when it comes to enigmatic animals such as the famous Archaeopteryx from the Late Jurassic sediments of southeastern Germany that is considered the oldest potentially free-flying dinosaur. This well-preserved fossil taxon shows a mosaic anatomy that illustrates the close family relations between extinct raptorial dinosaurs and living dinosaurs: the birds. Most modern bird skeletons are highly specialised for powered flight, yet many of their characteristic adaptations in particularly the shoulder are absent in the Bavarian fossils of Archaeopteryx. Although its feathered wings resemble those of modern birds flying overhead every day, the primitive shoulder structure is incompatible with the modern avian wing beat cycle.

“The cross-sectional architecture of limb bones is strongly influenced by evolutionary adaptation towards optimal strength at minimal mass, and functional adaptation to the forces experienced during life”, explains Prof. Jorge Cubo of the Sorbonne University in Paris. “By statistically comparing the bones of living animals that engage in observable habits with those of cryptic fossils, it is possible to bring new information into an old discussion”, says senior author Dr. Sophie Sanchez from Uppsala University, Sweden

Archaeopteryx skeletons are preserved in and on limestone slabs that reveal only part of their morphology. Since these fossils are among the most valuable in the world, invasive probing to reveal obscured or internal structures is therefore highly discouraged. “Fortunately, today it is no longer necessary to damage precious fossils”, states Dr. Paul Tafforeau, beamline scientist at the ESRF. “The exceptional sensitivity of X-ray imaging techniques for investigating large specimens that is available at the ESRF offers harmless microscopic insight into fossil bones and allows virtual 3D reconstructions of extraordinary quality. Exciting upgrades are underway, including a substantial improvement of the properties of our synchrotron source and a brand new beamline designated for tomography. These developments promise to give even better results on much larger specimens in the future.”

Scanning data unexpectedly revealed that the wing bones of Archaeopteryx, contrary to its shoulder girdle, shared important adaptations with those of modern flying birds. “We focused on the middle part of the arm bones because we knew those sections contain clear flight-related signals in birds”, says Dr. Emmanuel de Margerie, CNRS, France. “We immediately noticed that the bone walls of Archaeopteryx were much thinner than those of earthbound dinosaurs but looked a lot like conventional bird bones”, continues lead author Dennis Voeten of the ESRF. “Data analysis furthermore demonstrated that the bones of Archaeopteryx plot closest to those of birds like pheasants that occasionally use active flight to cross barriers or dodge predators, but not to those of gliding and soaring forms such as many birds of prey and some seabirds that are optimised for enduring flight.”

“We know that the region around Solnhofen in southeastern Germany was a tropical archipelago, and such an environment appears highly suitable for island hopping or escape flight”, remarks Dr. Martin Röper, Archaeopteryx curator and co-author of the report. “Archaeopteryx shared the Jurassic skies with primitive pterosaurs that would ultimately evolve into the gigantic pterosaurs of the Cretaceous. We found similar differences in wing bone geometry between primitive and advanced pterosaurs as those between actively flying and soaring birds”, adds Vincent Beyrand of the ESRF.

Since Archaeopteryx represents the oldest known flying member of the avialan lineage that also includes modern birds, these findings not only illustrate aspects of the lifestyle of Archaeopteryx but also provide insight into the early evolution of dinosaurian flight. “Indeed, we now know that Archaeopteryx was already actively flying around 150 million years ago, which implies that active dinosaurian flight had evolved even earlier!” says Prof. Stanislav Bureš of Palacký University in Olomouc. “However, because Archaeopteryx lacked the pectoral adaptations to fly like modern birds, the way it achieved powered flight must also have been different. We will need to return to the fossils to answer the question on exactly how this Bavarian icon of evolution used its wings”, concludes Voeten.

It is now clear that Archaeopteryx is a representative of the first wave of dinosaurian flight strategies that eventually went extinct, leaving only the modern avian flight stroke directly observable today.

Oldest Archaeopteryx bird, new research


This video says about itself:

The Perfect Reptile-Bird Hybrid Definitely Looks the Part

15 April 2016

Archeopteryx had strong feathers, bony jaws and teeth, and a tail with a line of bone running down its legs. Physically, it was exactly half-reptile, half-bird.

From: FLYING MONSTERS WITH DAVID ATTENBOROUGH

From the Ludwig-Maximilians-Universität München in Germany:

Paleontology: The eleventh Archaeopteryx

January 26, 2018

Researchers from Ludwig-Maximilians-Universitaet (LMU) in Munich report the first description of the geologically oldest fossil securely attributable to the genus Archaeopteryx, and provide a new diagnostic key for differentiating bird-like dinosaurs from their closest relatives.

Some 150 million years ago in what is now Northern Bavaria, Archaeopteryx — the oldest bird species yet discovered — inhabited a subtropical environment characterized by reef islands and lagoons set in a shallow sea that was part of the primordial Mediterranean. All the specimens of Archaeopteryx so far recovered were found in the valley of the Altmühl River, in geological settings that represent this habitat — the Jurassic Solnhofen Archipelago. The latest find was made there in 2010, and this new specimen has now been analyzed by a team of researchers led by LMU paleontologist Oliver Rauhut, a professor in the Department of Earth and Environmental Sciences who is also affiliated with the Bavarian State Collections for Paleontology and Geology in Munich. Stratigraphic analysis of the find locality reveals that the fossil is the oldest known representative of the genus Archaeopteryx.

“Specimens of Archaeopteryx are now known from three distinct rock units, which together cover a period of approximately 1 million years”, Rauhut explains. Notably, the oldest example exhibits features that were so far not known from the other specimens. “Among other things, they reveal that Archaeopteryx was very similar to advanced predatory dinosaurs in many respects”, says Rauhut. Moreover, in the new study, he and his colleagues provide a diagnosis that allows to reliably distinguish Archaeopteryx from its closest relatives, both non-avialan theropod dinosaurs and basal birds. This key will be very valuable, as a whole series of bird-like predatory dinosaurs has been described in recent years, mainly from China, which has greatly complicated the taxonomical classification of the group.

The new specimen is the 12th fossil to be attributed to the genus. However, in a study published in the online journal BMC Evolutionary Biology last year, Rauhut’s group reported that the first of these to come to light — the so-called Haarlem specimen discovered in 1861 — does not actually belong to the group. This result thus reduces the number of Archaeopteryx fossils to 11, although some doubts remain concerning the assignment of two of these. This underlines the necessity for a diagnosis to clearly identify Archaeopteryx.

Moreover, the investigation of the 11th specimen demonstrates that the known specimens span a remarkable range of anatomical variation. Potential explanations for the broad spectrum of variation extend from intraspecific developmental polymorphism to evolutionary differentiation, i.e., the possibility that the fossil material so far recovered represents more than one species. “The high degree of variation in the teeth is particularly striking — none of the specimens shows the same pattern of dentition as any other, which could reflect differences in diet”, Rauhut points out. “This is very reminiscent of the famous case of Darwin’s finches on the Galapagos, which show remarkable variation in their beak shapes. It is even conceivable that this primeval bird genus might, in a similar fashion, have diversified into several specialized forms on the islands of the Solnhofener Archipelago. In that case, the Archaeopteryx fossils could represent a species flock, a Jurassic analog of Darwin’s finches.”

New dinosaur species with ‘hummingbird’ colours


This 15 January 2018 video is called New ‘rainbow’ dinosaurs might have sparkled like a hummingbird.

From daily The Independent in Britain today:

Newly discovered ‘rainbow’ dinosaur had shiny, colourful feathers like a hummingbird

Microscopic analysis of 160 million-year-old fossil suggests prehistoric reptile had iridescent plumage similar to that found in some modern bird species

Josh Gabbatiss, Science Correspondent

A duck-sized dinosaur found in China had a head and chest covered in shiny feathers similar to those seen on hummingbirds.

The creature has been named Caihong juji, meaning “rainbow with the big crest” in Mandarin.

When palaeontologists analysed a fossil of the dinosaur, first discovered by a farmer in north-eastern China, they found evidence of brightly-coloured plumage.

Iridescent feathers, which are found on some modern bird species, have a metallic sheen and change colour when viewed from different angles, giving them a “rainbow-like” appearance.

“When you look at the fossil record, you normally only see hard parts like bone, but every once in a while soft parts like feathers are preserved and you get a glimpse into the past,” said Dr Chad Eliason, a bird researcher at The Field Museum in Chicago and one of the authors of the paper describing the dinosaur.

“The preservation of this dinosaur is incredible; we were really excited when we realised the level of detail we were able to see on the feathers.”

Their findings were published in the journal Nature Communications.

When Dr Eliason and his colleagues examined the preserved feathers under a microscope, they could see tiny imprints of cells called melanosomes.

Melanosomes are the cells that contain pigment and give animals their colour.

At around 160 million-years-old, the pigment in the cells had long since degraded, but the scientists were able to determine the dinosaur’s appearance based on the structure of the cells.

Comparison of the ancient melanosomes of the Caihong with modern bird species revealed close similarities with the cells responsible for the iridescent plumage seen in hummingbirds.

Iridescent feathers were found covering the dinosaur’s head and chest, as well as around the base of its tail.

The skull of the Caihong is similar to that of the Velociraptor, but it also has a bony crest in the middle of its head.

The discovery opens up questions about how iridescence first evolved.

It could be that the Caihong’s “rainbow” feathers were used to attract mates, just like modern peacocks use their colourful tails.

“I came out of the project with a whole different set of questions that I wanted answers to”, said Dr Eliason.

“When I open up a drawer full of birds in the Field Museum’s collections, now I want to know when those iridescent feathers first developed, and how.”