Tag Archives: Archaeopteryx

Archaeopteryx.

Fossil Friday: Alcmonavis poeschli, the second-oldest bird we’ve ever found

Researchers have discovered the second species of Jurassic bird capable of flight and christened it Alcmonavis poeschli.

Archaeopteryx.

Archaeopteryx.
Image via Pixabay

The fossilized remains of the earliest-known primal bird were discovered in 1861. Since then, this species (Archaeopteryx) has been considered the only bird to live during the Jurassic period. As such, it was the direct ancestor of all of today’s birds, as well as the oldest-known flying representative of the bird family.

However, a group of researchers led by Professor Oliver Rauhut from the Department of Earth and Environmental Sciences as well as the Bavarian State Collection of Paleontology and Geology repot finding a new, previously unknown bird from the same period: Alcmonavis poeschli.

Pioneers of flight

“At first, we assumed that this was another specimen of Archaeopteryx. There are similarities, but after detailed comparisons with Archaeopteryx and other, geologically younger birds, its fossil remains suggested that we were dealing with a somewhat more derived bird,” says Rauhut, a paleontologist at the Department of Earth and Environmental Sciences as well as the Bavarian State Collection of Paleontology and Geology.

All the fossils of Archaeopteryx we’ve found so far were recovered from the Altmühl Valley, which is part of the Solnhofen Archipelago in Germany. During the Jurassic (around 150 million years ago), this region comprised mostly of reef islands, basically a subtropical lagoon landscape. In such an environment, flight was definitely an advantage.

It seems that Archaeopteryx wasn’t the only one to figure this out. Rauhut’s team has taxonomically identified the new species from the fossilized remains of one of its left wings. They report that Alcmonavis poeschli was somewhat larger than Archaeopteryx and was probably the better flier out of the two species. Alcmonavis seems to have traits more similar to today’s birds than Archaeopteryx, suggesting that it was better adapted to active flight (the one that involves flapping wings) than the latter. The discovery also suggests that Jurassic skies saw more traffic than we’d assumed up to now.

“The wing muscles indicate a greater capacity for flying,” Rauhut says about the new species, adding that its discovery “suggests that the diversity of birds in the late Jurassic era was greater than previously thought.”

The new species will likely also re-galvanize discussions around the evolution of active flight. We’ve previously seen some of the efforts researchers are using to find out when this ability first evolved, but the species they looked at in that study, Caudipteryx, lived in the early Cretaceous period — roughly 20 million years after Archaeopteryx and Alcmonavis. By contrast, Alcmonavis’ wing suggests that the “evolution of flight must have progressed relatively quickly,” says Dr. Christian Foth from the University of Fribourg (Switzerland), one of the co-authors of the study.

As for the name, Alcmonavis was named for the old Celtic word for the river Altmühl, Alcmona, and its discoverer Roland Pöschl, who leads the excavation at the Schaudiberg quarry where the fossil was discovered. The team explains that a fossil of Archaeopteryx was also discovered in the same unit of limestones as the new species — evidence that the two species lived during the same period.

The paper “A non-archaeopterygid avialan theropod from the Late Jurassic of southern Germany” has been published in the journal eLife.

Oldest feather does not belong to Archaeopteryx

The mystery of a 150-million-year-old feather has finally been solved — least partially: it didn’t belong to Archaeopteryx, but its owner remains elusive.

The isolated “Archaeopteryx” feather is the first fossil feather ever discovered. The top image shows the feather as it looks today under white light. The middle image, the original drawing from 1862 by Hermann von Meyer. Bottom image is Laser-Stimulated Fluorescence (LSF). Note how the quill is not visible today, but clearly visible in the original drawing. LSF imaging showing the halo of the missing quill. Scale bar is 1cm. Image Credits: The University of Hong Kong.

The discovery of the first Archaeopteryx fossil in 1860 was a pivotal moment for both biology and geology. It showed a transitional creature, a link between dinosaur and birds, confirming what many scientists were already starting to support: that birds evolved from lizards. This 150-million-year-old creature fits like a charm into these theories and is still crucial for our understanding of evolution.

But just before Archaeopteryx was discovered, a single, elusive, fossilized feather was uncovered. To this day, this is the oldest feather we’ve ever discovered. This feather was thought to belong to an Archaeopteryx and even used to name this creature — but it might not have belonged to Archaeopteryx at all.

Right from the start, there were some doubts. Initial descriptions of the fossil mention a rather long quill visible on the fossil, which would indicate that it is a primary feather. However, the quill is no longer visible today, and has not been for a long time. There have been several attempts to uncover the missing quill with imaging techniques, but none found anything. So was the quill still there?

Researchers have now used a novel imaging technique called Laser-Stimulated Fluorescence (LSF) to analyze the fossil. LSF revealed the missing quill (or rather, its remaining halo), settling the old mystery.

“It is amazing that this new technique allows us to resolve the 150-year-old mystery of the missing quill,” says Daniela Schwarz, co-author in the study and curator for the fossil reptiles and bird collection of the Museum für Naturkunde, Berlin.

But the method also dethroned an idol: it most certainly did not belong to Archaeopteryx the team says. LSF allowed an unprecedented view into the structure of the feather, revealing the lack of a distinct s-shaped centerline, a defining characteristic of covert feathers. The team also ruled out the possibility that it could be a primary, secondary, or tail feather.

A 2011 study found that Archaeopteryx was almost certainly black. This is an artistic reconstruction by Nobu Tamura, showing what the bird might have looked like.

So if it didn’t belong to Archaeopteryx, then who did it belong to?

Well, researchers aren’t really sure, but it was probably another feathered dinosaur. The fact that such a creature exists suggests that there was much more diversity in feathered dinosaurs than we originally thought. Archaeopteryx remains a key link in dinosaur-bird evolution, but maybe it wasn’t all that unique — and maybe several other creatures boasted similar features.

It’s remarkable how new techniques enable us to study ancient creatures. We will definitely be hearing more of LSF in the future, researchers conclude.

“The success of the LSF technique here is sure to lead to more discoveries and applications in other fields. But, you’ll have to wait and see what we find next!” added Tom Kaye, the study’s lead author.

Archaeopteryx lived in the late Jurassic, some 150 million years ago. It had more in common with dinosaurs than birds (jaws with sharp teeth, three fingers with claws, a long bony tail, hyperextensible second toes), but it still exhibits definite bird-like features, such as its broad, feathered wings.

The paper ‘Detection of lost calamus challenges identity of isolated Archaeopteryx feather’ by Kaye, M. Pittman, G. Mayr, D Schwarz and X. Xu, has been published in Scientific Reports.

 

Amazing fossil shows that Earth’s earliest birds evolved just like Darwin’s finches

Archaeopteryx, the world’s earliest known bird genus, is the much-sought link between reptiles and birds. Now, a ‘new’ Archaeopteryx fossil sheds new light on how these creatures evolved — and they’re a lot like modern birds.

The 11th fossil

Image credits: O. Rauhut, LMU.

This is only the 11th Archaeopteryx ever found and it’s also the oldest geologically, dating approximately 150 million years. Researchers at Ludwig-Maximilians-Universitaet in Munich have analyzed it and compared it to newer, more evolved specimens, noting the key differences. Palaeontologists Christian Foth and Oliver Rauhut, who have been studying Archaeopteryx for years, say this latest finding indicates that the species has been around for much longer than we thought.

“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 not observed in the other specimens. “Among other things, they reveal that Archaeopteryx was very similar to advanced predatory dinosaurs in many respects,” says Rauhut.

Archaeopteryx (which translates as “first wing” or “ancient wing”) was a transitional creature between the non-avian feathered dinosaurs and modern birds. Despite their small size, wings, and presumed ability to fly or at least glide, the species has more in common with other small dinosaurs than with modern birds.

The geologically oldest, but most recently discovered specimen of Archaeopteryx. Credit: O. Rauhut, LMU Munich.

The fossil shows significant differences from other fossils — most notably in terms of teeth. Actually, all of the discovered Archaeopteryx fossils have different types of teeth. Rauhut believes that since the creatures lived in different times and slightly different environments, their dentition evolved in different ways.

Interestingly, these findings sound a lot like what Charles Darwin found when he was studying finches in the Galapagos. What Darwin found on the islands were several populations which looked very much alike, but had evolved different beaks based on the particularities of their environment.

Darwin’s finches are a classic case study in evolution. Image in public domain.

“When Darwin visited the Galapagos Islands, he found finches that were very similar generally, but differed in the shape of their beaks,” Rahut says. “Darwin could show that these finches represented different species, all with their special adaptation to a certain food source, hence the differences in beak morphology.” The finches descended from a common ancestor and evolved to exploit different food sources on different islands.”

“Archaeopteryx also inhabited an archipelago of tropical islands that its ancestor probably invaded a short time before,” he says. “The different patterns in the dentition in Archaeopteryx might also indicate different food adaptations.”

It’s believable that, like the finches, these primeval creatures diversified on different islands on what was once the Solnhofener Archipelago. If that is indeed the case, then we might be dealing with a whole flock of Archaeopteryx.

The paper has been published in the journal PeerJ.

bird flying dinosaur

This 125-million-year old bird possibly flew above dinosaurs

The remarkably well preserved fossil of a wing that belonged to an early Cretaceous bird suggests some of the first avian creatures could fly. The remains were unearthed from a limestone site in Spain, and exhibit features reminiscent of modern birds like intricate arrangement of muscles, tendons and ligaments. This soft tissue system is excellent for controlling position and allows rapid adjustment of the wing to navigate through the air.

bird flying dinosaur

Image credit: STEPHANIE ABRAMOWICZ

Among reptiles, powered flight is known to have evolved at least twice: pterodactyls  and birds. It’s common knowledge now that birds evolved from  theropod dinosaurs, which were also covered in feathers. The most famous example is the bird-dinosaur Archaeopteryx from the Upper Jurassic of Germany who lived 150 million years ago. With the claws and teeth of a dinosaur, but the feathers of a bird, it was clearly a transitional form. Some even believe it was capable of flight, as evidenced by  robust shafts on the wings, feathered hind legs and  a feather arrangement that should have supported flight. Whether or not it could fly or just glide is a matter of debate.

The new, yet to be named, bird species discovered in central Spain is further evidence that early birds could fly, as supported by the soft tissue fossils (a strikingly rare find!). Guillermo Navalón, lead researcher, says  it’s surprising that these modern feats were found in early birds. At the very least, this means ancient birds were capable of aerodynamic feats in a fashion similar to living birds.

“The anatomical match between the muscle network preserved in the fossil and those that characterize the wings of living birds strongly indicates that some of the earliest birds were capable of aerodynamic prowess like many present-day birds,” said Luis Chiappe, one of the authors of the study, who is with the National History Museum of Los Angeles County, in a press release.

The bird was part of the group of “true birds” known as Enantiornithes, the other being Ornithurines.

But even given the “unique glimpse into the anatomy of the wings of the earliest birds”, scientists can’t tell for sure if the 125-million-year old bird could fly. They might have been exceptional flyers, soaring high above giant dinosaurs, or merely capable of short flights from the ground and glides.

“The new fossil provides us with a unique glimpse into the anatomy of the wing of the birds that lived amongst some of the largest dinosaurs,” Chiappe said. “Fossils such as this are allowing scientists to dissect the most intricate aspects of the early evolution of the flight of birds.”

Bird like fossil is older than Archaeopterix

The fossil, which still retains impressions of feathers, is 160 million years old, predating the oldest Archaeopterix fossil found by 10 million years. Scientits have named it Aurornis, which means “dawn bird”.

Aurornis and Archaeopteryx

aurornis xui

Aurornis enables us not only to better understand the emergence of birds, but also to understand how powerful flight originated. About 50cm tail to beak, the animal has very primitive skeletal features that puts it at the very base of bird evolution. It had claws and a long tail with front and hind legs similar to those of Archaeopteryx, but some features of its bones were more primitive.

Archaeopteryx holds a very prized position in paleontology, some considering it the most significant fossil ever found. The fossil, discovered in Germany in 1861, proved that modern birds evolved from dinosaurs, and was the first fossil to support Darwin’s theory of evolution, which had been published just two years earlier.

But this finding pushes Archaeopteryx off its pedestal.

“It’s an important fossil,” said Gareth Dyke, a senior palaeontologist involved in the study at Southampton University. “Aurornis pushes Archaeopteryx off its perch as the oldest member of the bird lineage.”

Artist's impression of the oldest known bird

Geologists working at the Yizhou Fossil and Geology Park in north-eastern China explained that the fossil has a very interesting story. It was actually bought from a local fossil dealer, who claimed they had been unearthed in Yaoluguo in western Liaoning, where sedimentary rock was laid down 153m to 165m years ago. It’s not that uncommon for paleontologists to work with dealers (especially in China), but this is a pretty risky business when it comes to gauging the age of the fossils. This usually leads to an influx of fossils to the market, out of which many are fakes, or fake dated.

But this one seems really legit. When Pascal Godefroit and others at the Royal Belgian Institute of Natural Sciences in Brussels revealed the intricate details of the skeleton, they noticed no signs of forgery.

Shaking up the avian group

The first Archaeopteryx fossil found.

The first Archaeopteryx fossil found.

But the real discussion is about flight and birds. Archaeopteryx could clearly fly – there’s no doubt about that. In the past few years, there trend has been to believe that Archaeopteryx was in fact not a bird. This study places it back to its rightful place.

“This work makes Archaeopteryx a bird again, and given that we have the original specimen here in London, we’re very pleased to have it reinstated,” said Paul Barrett at the Natural History Museum in London. “It makes life simpler. If Archaeopteryx was an early bird, we only have to worry about one origin of flight.”

But with, Aurorinis, the story is quite different.

“The new species is certainly an older member of the bird lineage than Archaeopteryx, and it’s fair to call it a very primitive bird. But what you call a bird comes down to what you call a bird, and a lot of definitions depend on Archaeopteryx,” said Barrett.

But it’s pretty hard to draw some conclusions with just one fossil.

“Previous phylogenetic investigations were based on maybe only 200 morphological characteristics. Here, we recognise almost 1,500 characteristics,” explained Dr Godefroit. “So it’s a much bigger and more robust analysis, and according to this new investigation Archaeopteryx is again considered an ancestor of birds and the new creature we describe is also a basal bird; and in fact it is even more primitive than Archaeopteryx,” he explained.

But this finding shakes the avian tree even more – it also re-shuffles the Troodontidae, a family of bird-like dinosaurs. Dr Godefroit and colleagues now consider these to be a sister group of the avialans.

troodontid

An example of a troodontid.

“What we’re arguing over here is actually very small, esoteric features of the anatomy,” commented Dr Paul Barrett from the Natural History Museum, London, UK. “We’re looking at a nexus of animals around bird origins – birds themselves and a bunch of dinosaurs that are almost, but not quite, birds. “There is a really grey, wobbly line between the two. Just one or two changes across a huge body of data can make the difference between an animal being on one side of this bird-dinosaur divide or the other.

Picture sources: 1 2

Artist impression of Archaeopteryx lithographica by Carl Buell

Modern birds evolved from gliding dinosaurs

Artist impression of Archaeopteryx lithographica by Carl Buell

Artist impression of Archaeopteryx lithographica by Carl Buell

Today’s birds’ ancestors descended from non-avian dinosaurs according to a recent paper that thoroughly studied Anchiornis (155 million years ago) and Archaeopteryx (between 152 million and 168 million years ago) – the oldest known feathered dinosaurs.

Archaeopteryx is so far the oldest bird-like dinosaur found thus far, and since it was first discovered almost 150 years ago, it was thought that it could fly around just like other bird today.  In the meantime, studies have shown that it is not a primitive bird, but just another feathered dinosaur. Recently, Yale University paleontologist Nicholas Longrich and colleagues Jakob Vinther and Anthony Russell have shown that  Archaeopteryx, as well as its cousin Anchiornis, had a most curious plumage, very much different from that encountered in modern birds, which warrants a new way of envisioning them.

Around the time of their discovery, in the mid-1800s, Darwin’s theory of evolution was sweeping controversy through out Europe, and people easily assumed that these archaic birds function much in the same way as modern birds. We now need to re-think this.

Feather by feather

For starters, the birds had small feathers on its hind legs. Upon closer inspection it was found that compared to the single layer of feathers that give modern birds their dextrous flight abilities, the fossils exhibited a peculiar plumage pattern in which the feathers are stacked in layers on top of each other, almost like two-ply tissues.

“I realized you couldn’t really get from what the fossils showed to the way people were drawing it,” Longrich said. “People have been drawing the wing this one way for more than 100 years, and had this particular idea about what the wing would look like. And this is coming along after more than a century and saying we got it wrong.”

Bird ancestors gliders, not flyers

This feature was encountered in both feathered dinosaurs, but the two weren’t the same. While as Archaeopteryx had multiple layers of long flight feathers,  Anchiornis had an abundance of simple, strip-like feathers that overlap, like penguins today. What this means is that most likely these multiple overlapping layers wouldn’t have made the dinosaurs very much efficient flyers. The two dinosaurs most likely relied on gliding to escape predators and move over large distances.

“Modern birds have the ability to separate their wing feathers sort of like a Venetian blind,” Longrich said. “This allows them to raise the wing rapidly, and seems to be critical to flapping flight at low speeds.”

“The feather arrangement in Archaeopteryx and Anchiornis wouldn’t let them do this,” he added, “so it may have made takeoff from the ground and flapping at low speeds more difficult.”

Still, those feathers sure came in handy when averting predators.

“Gliding is a fast way to move from tree-to-tree. Instead of climbing down one tree and running up the next, you just glide quickly from one to the other,” Longrich explained.

“I would imagine that the dinosaurian ancestors of birds were living in the trees,” he noted, “probably to find food-like insects, lizards and mammals, and to avoid becoming food for other dinosaurs.”

Arkhat Abzhanov, associate professor of organismic and evolutionary biology at Harvard University, said that the study sheds new light on both species and the evolution of wing design. Longrich and colleagues believe wing feather arrangement seen in modern birds may have evolved within a period spanning a few tens of millions of years and then remained largely unchanged for the past 130 million years.

“Interpreting these fossils is really complicated, and there’s this interplay between having an interpretation going into it that will help guide you to understand the specimen, but also ignorance or openminededness, like a child would have, where you’re just kind of seeing what’s there and interpreting what’s there,” Longrich said. “That kind of naïve interpretation and the ability to look at the fossils that way, even after you’ve seen a lot of them, is really important.”

The findings were published in the journal Current Biology.

source: Boston

Artist's impression of the birdlike dinosaur known as Xiaotingia zhengi. (c) Xing Lida and Liu Yi

Oldest bird might not be a bird in the first place

Artist's impression of the birdlike dinosaur known as Xiaotingia zhengi. (c) Xing Lida and Liu Yi

Artist's impression of the birdlike dinosaur known as Xiaotingia zhengi. (c) Xing Lida and Liu Yi

In a paper published in the journal Nature, Chinese paleontologists have detailed their impressions on the finding of a chicken-sized feathered dinosaur which might lead to a total reconsideration of the origin of birds on Earth.

In 1861, just two years after Darwin published his infamous Origin of Species, scientists unearthed the fossils of Archaeopteryx, hailed to this day as the oldest bird and an important evolutionary link between dinosaurs and the feathered creatures of today. In recent years, however, doubts have arisen after similar older bird-like fossils, complete with three finger legs and feathers, have been discovered.

Now, the discovery of Xiaotingia, found by a collector in China’s Liaoning Province, has lead renowned Chinese paleontologists to believe that Archaeopteryx is not what it seems – not a primitive bird, but just another feathered dinosaur. Xiaotingia, dates back 155 million years to the Jurassic Period.

An Archaeopteryx specimen highlights wing and tail feather impressions. (c) G. Mayr / Senckenberg

An Archaeopteryx specimen highlights wing and tail feather impressions. (c) G. Mayr / Senckenberg

Using a complex computer model in which they fed 89 fossilized dinosaur and bird species, including Archaeopteryx, they analyzed the skeletal measurements in detail. Without the Xiaotingia fossil added to the system, Archaeopteryx was put on a evolutionary line leading to modern-day birds. When Xiaotingia was included, the algorithm classed Archaeopteryx in a group of birdlike dinosaurs known as deinonychosaurs.

“There are many, many features that suggest that Xiaotingia and Archaeopteryx are a type of dinosaur called Deinonychosaurs rather than birds. For example, both have a large hole in front of the eye; this big hole is only seen in these species and is not present in any other birds,” professor Xu Xing said.

Archaeopteryx and Xiaotingia are very, very similar to other Deinonychosaurs in having a quite interesting feature – the whole group is categorised by a highly specialised second pedo-digit which is highly extensible, and both Archaeopteryx and Xiaotingia show initial development of this feature,” he went on to continue.

Since its discovery 150 years ago, Archaeopteryx has almost unanimously hailed by evolutionists as the most primitive bird, which lead every theory related to the formation of birds to be linked with it. A new set of hypothesis might have to be re-written now, however. A slew of debates will likely follow soon in the scientific community, as scientists hanging on to the iconic Archaepteryx status will ask for more substantial evidence.

“The reality is, that next fossil find could kick Archaeopteryx right back into birds. That’s the thing that’s really exciting about all of this,” said Prof Lawrence Witmer from Ohio University.

Missing flying reptile link found

200910132132512An international team of researchers from the University of Leicester (UK), and the Geological Institute, Beijing (China) managed to identify a new type of a flying reptile that can prove to be a crucial step in understanding evolution, or at least a big part of it. Pterosauria was the general name given for flying or gliding reptiles, and pterodactyls are the most famous example of them. They roamed and ruled the sky in the Jurassic area for more than 130 million years.

Researchers have already separated this group into two significantly different parts for a long time now: the primitive long-tailed forms and their more evolved, advanced short tail pterosaurs, some of which could reach amazing sizes. However, the gap between these two groups was so large that it seemed it could never be filled – until now.

In a study published in the Proceedings of the Royal Society B: Biological Sciences, scientists described a newly found animal that fits exactly in the middle of that gap;the pterosaur was named Christened Darwinopterus, as an homage to the 200th anniversary of Charles Darwin’s birth and the 150th celebration of his publication that changed the world, On the origin of species.

Gaps in fossil records are really not that uncommon, because only a smart part of the animals that lived becomes fossilized, and a small part of that small part gets found by researchers. Our understanding of those animals, as a result is seriously impaired. Such was the case with the pterosaurs. However, more than 20 skeletons of Darwinopterus (some of them complete) were found earlier this week in North-Eastern China in rocks that were dated to approximately 160 million years old. It had rows of sharp teeth, a flexible neck and long jaws, all of which suggest that this animal (who was about as big as a crow) hunted other contemporary flying animals.

“Darwinopterus came as quite a shock to us” explained David Unwin part of the research team and based at the University of Leicester’s School of Museum Studies. “We had always expected a gap-filler with typically intermediate features such as a moderately elongate tail – neither long nor short – but the strange thing about Darwinopterus is that it has a head and neck just like that of advanced pterosaurs, while the rest of the skeleton, including a very long tail, is identical to that of primitive forms”.

Dr Unwin added: “The geological age of Darwinopterus and bizarre combination of advanced and primitive features reveal a great deal about the evolution of advanced pterosaurs from their primitive ancestors. First, it was quick, with lots of big changes concentrated into a short period of time. Second, whole groups of features (termed modules by the researchers) that form important structures such as the skull, the neck, or the tail, seem to have evolved together. But, as Darwinopterus shows, not all these modules changed at the same time. The head and neck evolved first, followed later by the body, tail, wings and legs. It seems that natural selection was acting on and changing entire modules and not, as would normally be expected, just on single features such as the shape of the snout, or the form of a tooth. This supports the controversial idea of a relatively rapid “modular” form of evolution.

200910132132510

However, this research doesn’t actually solve a problem, it just shows that it can be solved. In order to fill all the steps that need to be filled, researchers have a lot of work ahead of them. However, the importance of this should in no case be underestimated, because if solved, it wouldn’t only show how it works, but also how massive rapid evolution took place on a large scale.

Dr Unwin concludes200910132132511: “Frustratingly, these events, which are responsible for much of the variety of life that we see all around us, are only rarely recorded by fossils. Darwin was acutely aware of this, as he noted in the Origin of species, and hoped that one day fossils would help to fill these gaps. Darwinopterus is a small but important step in that direction.”

9 Dinosaurs that marked the planet

How the dinosaurs appeared is clear, but it’s not so clear how they dissapeared. One thing’s for sure, they ruled this planet for a significant amount of time. But how much truth is behind this avalanche of publicity and fiction, and which dinosaurs are the true leaders of these amazing lizards?? Here’s just a small list, by no means comprehensive of these vertebrates which dominated the earth for a period of about 160 millions of years. As a matter of fact, there are about 10 000 species of dinosaurs living today, but we know them as birds.

  • Amphicoelias fragillimus

There’s a really big chance this name won’t say anything to you; it didn’t to tell anything to scientists until a few years ago. Despite the fact that no full fossils have been found, it is widely regarded as the larges dinosaur to have ever lived, coming close to the biggest animal of all time, the blue whale. It’s believed to be the larges vertebrade, varying in length from 40 to 60 meters. The femur of Amphicoelias is unusually long, slender, and round in cross section, and it is very fragile, which is why scientists have nick named it the crumbling giant.

  • Velociraptor

Jumping from the biggest to a (relatively) small dinosaur, you’d never suspect that this “little” dinosaur was in fact the most feared predator for most dinosaur herbivores. Measuring about 2 meters, it walked on two legs and were similar in construction in many ways to birds. Actually, there are some reasons to believe that these dinosaurs were covered in feathers, which would mean that our perception of them could be totally wrong. If we were to see one of these cooperative hunters today, perhaps we would think that we are looking at a very strange bird.

  • Brachiosaurus

Brachiosaurus is another huge creature, actually the tallest of all dinosaurs. Its name means “armed lizard”, and it was named in this way because its forelimbs are bigger than the hind limbs. It is not certain if it was cold blooded or warm blooded, which leads to the fact that scientists are not sure how much it would take to mature (in the first case 100 years, in the second 10 years). It is believed that due to the size and the fact that it walked in herds, it had nothing to fear from even the biggest predators.

  • Tyrannosaurus rex

With a name that means tyrant king, T. Rex is the most known dinosaur in the world today, but not just due to its amazing characteristics. It had a huge massive had, which was balanced only by the huge tail in the back. Still, the general image of this creature is not accurate, because research showed that it was mostly a scavenger, hunting only on rare ocasions; still, that debate is not yet settled. This fact could have other implications, showing how well it could turn and how fast it could run. Still, it remains one of the biggest predators ever, and it’s definitely a badge for the jurassic period.

  • Spinosaurus aegyptiacus

T Rex may be the well known, but Spinosaurus was by far the biggest predator of all dinosaurs. The bad thing is that many remains have been destroyed so scientists are not very sure just what its appearance was, but they made some pretty accurate appreciations, using the few remains they found. This dinosaur had a sail which was formed of very tall neural spines growing on the back vertebra; these spines were huge, growing up to eleven times the height of the vertebrae from which they grew, reaching two meters. There is also some speculation that Spinosaurus was a fisher, but the most probable thing is that ate terrestrial and aquatic.

  • Triceratops

Triceratops was one of the latest herbivorous dinosaurs that appeared, and it’s very easy to recognize because of the horns which resemble a rhinoceros. Actually, the name means three horned. They probably had up to 9 meters, and the head could be to about a third of the body. The classic believe is that horns were used for defence against predators, but more recently, the theory is that they were used as to court the females, in a pretty similar way to deers or other horned animals today.

  • Ichthyosaur

It’s time to move to the aquatic dinosaurs; Ichthyosaurs in particular were giant marine reptiles that resembled fish and dolphins, reigning pretty much in all of the mesozoic period. That is until they were surpassed in efficiency by the plesiosaurs. Some species of Ichthyosaurs lived to huge sizes, up to 15 meters, but the latest ones were a bit smaller.

  • Plesiosaurs

Plesiosaurs were the best aquatic predators that the jurassic period had to show. Imposing in the dangerous waters of the age was by no means an easy task, and it truly required some amazing abilities. They developed and thrived with no real opposition, until the Cretaceous–Tertiary extinction event, which occured approximately 65.5 million years ago. They had a small head and long neck, and were actually slow swimmers. But they used the neck to create really fast movements of the head, grabbing fish or cephalopods. Also, they presented an unbelievable evolutionary trait, four flippers, which gave them great mobility so they could rotate their body too.

  • Archaeopteryx

Archaeopteryx was not a dinosaur, but rather the link between dinosaurs and birds. Similar in size to modern day birds, it was just about 0.5 metres long. It has broad wings, feathers, and is able to fly, but it still has more in common with dinosaurs, such as jaws with sharp teeth, three fingers with claws, a long bony tail, hyperextensible second toes (“killing claw”), feathers (which also suggest homeothermy), and various skeletal features. It is a key element in the evolutionary debate, and one of the most studied creatures of all time.



Scientists discover ‘world’s first bird’, and compare it to another

glider

Archaeopteryx has been the subject of many controversies, but it is now widely considered as the world’s oldest bird; however, reptiles were flying for 50 million years when it appeared, even before the world was roamed by dinosaurs. Now, paleontologists have unveiled an extraordinary prehistoric ‘flying’ reptile which lived 235 million years ago.It’s called kuehneosaurs and it was first unearthed in the Britain by Archaeologists in the 1950s but until now nobody has studied their ability to fly or glide; a team of scientists from the University of Bristol, England conducted a study which led to surprising conclusions. These early flyers used extraordinary extensions of their ribs which used friction with air to form large gliding surfaces on the side of the body. They were up to 70 cm in size, and it was first assumed that they were able to fly, so scientists didn’t even think about studying their ability to glide. The team built lifesized models of the two genera.

They are Kuehneosuchus, which was a glider and had elongate wings and Kuehneosaurus which had much shorter wings which were used in a way similar to parachuting. Scientists are studying the possibility that these two were in fact the male and female of the same species, because in other aspects there is little or no difference. Koen Stein, who worked at this project:

“We didn’t think kuehneosaurs would have been very efficient in the air, but all the work up to now had been speculation, so we decided to build models and test them in the wind tunnel in the Department of Aerospace Engineering at Bristol.
“Surprisingly, we found that Kuehneosuchus was aerodynamically very stable. Jumping from a five-metre tree, it could easily have crossed nine metres distance before landing on the ground. The other form, Kuehneosaurus, was more of a parachutist than a glider.”

What’s for sure is that the species lived in the warm late Triassic period from 235 to 200 million years ago, and 80 million years before the largest dinosaurs of the Jurassic period, and 50 million years before the earliest known bird, archaeopteryx, which lived in what is now southern Germany. The rest remains to be found out.