Category Archives: MYANMAR

Smallest Dinosaur ever Found Preserved in 99- million-year-old Piece of Amber

Smallest Dinosaur ever Found Preserved in 99- million-year-old Piece of Amber

The head of a flying dinosaur that is hardly bigger than a bee hummingbird has been discovered in 99-million-year-old amber. The piece of polished amber, just 31mm by 20mm by 8.5mm, was found in Kachin Province of northern Myanmar, an area becoming increasingly well-known for its remarkable amber-encased fossils.

The piece of amber measures only 1.25 inches (31.5 millimeters) in length. The skull is a mere 0.6 inches (11 millimeters).

The amber contains the skull of Oculudentavis khaungraae, a newly described dinosaur and one of the smallest ever discovered. Its tiny stature is forcing paleontologists to rethink the lower limits of body size in birds, and the nearly 100-million-year-old fossil is challenging the current understanding of when and how dinosaur giants shrank into the birds of today.

A Mysterious Transformation

Tiny Oculudentavis may have occupied a unique ecological niche in the ancient world.

The evolutionary transition of dinosaurs to modern birds is one of the most astounding transformations in the history of life: large, bipedal and mostly carnivorous dinosaurs morphed into small, flying birds. Famous discoveries like Archaeopteryx and more recently the fossils from the Jehol Biota in China have given researchers some hints about the process. But finds from this evolutionary phase — which researchers think began about 200 million years ago — are rare.

Paleontologists are far from having a complete picture of the evolution of birds, and even farther from a full inventory of Earth’s ecosystems in the age of dinosaurs. Our research on the tiny Oculudentavis, published in the journal Nature, adds valuable information to the puzzle of when, how, and to what extent dinosaurs shrank.

Clues in Bone

Smallest Dinosaur ever Found Preserved in 99- million-year-old Piece of Amber
This high-resolution scan allowed us to see the intricacies of a bone structure unlike any before seen in birds or dinosaurs.

This high-resolution scan allowed us to see the intricacies of a bone structure unlike any before seen in birds or dinosaurs.

Our team needed to see the minute details of the skull, and we needed to do it without cracking or ruining the specimen – a difficult task with a skull encased in 99-million-year old amber from Myanmar. To do that, we scanned the skull with high-resolution X-rays and created a digital model with very fine anatomical detail. What emerged was a picture of overall bird-like anatomy. But in some interesting ways, Oculudentavis is unlike any bird or dinosaur that has ever been found.

The obvious curiosity of the fossil is its size: Oculudentavis rivaled the smallest bird living today, the bee hummingbird, and likely was no more than 1.6 inches (4 centimeters) from beak to tail. We considered whether the skull possibly belonged to a very young animal, but the extent and pattern of bone growth and the proportional size of the eye pointed to a mature bird.

With a total skull length of just about 0.6 inches (1.5 centimeters), Oculudentavis pushes against what is considered the lower limit of size in birds: the head still had to hold functional eyes, a brain, and jaws. The small size is especially surprising if one considers that Oculudentavis lived during the same time as giant plant-eating dinosaurs like Argentinosaurus.

Small and Specialized

The small size of Oculudentavis is striking, but to a trained eye, there are other extremely unusual features, too.

First of all, the skull seems to be built for strength. The bones show an unusual pattern of fusion and the skull lacks an antorbital fenestra, a small hole often found in front of the eye.

The eyes of Oculudentavis also surprised us. The shape of the bones found within the eye, the scleral ossicles, suggests that it probably had conical eyes with small pupils. This type of eye structure is especially well adapted for moving around in bright light. While daytime activity might be expected for an ancient bird from the age of dinosaurs, the shape of the ossicles is entirely distinct from any other dinosaur and resembles those of modern-day lizards.

Adding to the list of unexpected features, the upper jaw carries at least 23 small teeth. These teeth extend all the way back beneath the eye and are not set in deep pockets, an unusual arrangement for most ancient birds. The large number of teeth and their sharp cutting edges suggest that Oculudentavis was a predator that may have fed on small bugs.

The sum of these traits — a strong skull, good eyesight, and a hunter’s set of teeth — suggests to us that Oculudentavis led a life previously unknown among ancient birds: it was a hummingbird-sized daytime predator.

One of the Earliest and Tiniest Birds?

Placing Oculudentavis in the tree of life is, given its strange anatomy, challenging. Our phylogenetic analysis — the investigation of its relationships to other dinosaurs — identifies Oculudentavis as one of the most ancient birds. Only Archaeopteryx branched off earlier.

Scientists consider the nectar-feeding hummingbirds — which appeared 30 million years ago — the smallest dinosaurs on record. But if our placement of Oculudentavis holds true, the miniaturization of dinosaurs may have peaked far earlier than paleontologists previously thought. In fact, the largest and the smallest dinosaurs may have walked and flown the same earth nearly 100 million years ago.

Our work demonstrates how little scientists know about the little things in the history of life. Scientists’ snapshot of fossil ecosystems in the dinosaur age is incomplete and leaves so many questions unanswered. But paleontologists are eager to take on these questions.

What other tiny species were out there? What was their ecological function? Was Oculudentavis the only visually guided bug hunter? To better understand the evolution of the diversity of life we need more emphasis and recognition of the small.

Amber holds strong potential to fill that gap. Maybe one day a scientist will hold up another piece, and let sunshine reveal a complete Oculudentavis, or even a previously unknown species. More finds in amber will help illuminate the world of the tiny vertebrates in the age of dinosaurs.

100-million-year old giant sperm found trapped in amber

100-million-year old giant sperm found trapped in amber

The world’s oldest animal sperm has been found in a tiny crustacean trapped in Amber about 100 million years ago in Myanmar by the international partnership of researchers from London’s Queen Mary University and the Chinese Academy of Science in Nanjing.

Dr. He Wang of the Chinese Academy of Science in Nanjing led the study team to locate sperm in a new species called Myanmarcypris hui. They predict that the animals had sex just before their entrapment in the piece of amber (tree resin), which formed in the Cretaceous period.

Sperm fossilized was exceptionally rare;  previously the oldest known examples were only 17 million years old. Myanmarcypris hui is an ostracod, a kind of crustacean that has existed for 500 million years and lives in all kinds of aquatic environments from deep oceans to lakes and rivers.

One of the ostracods trapped in amber.

Their fossil shells are common and abundant but finding specimens preserved in ancient amber with their appendages and internal organs intact provides a rare and exciting opportunity to learn more about their evolution.

Professor Dave Horne, Professor of Micropalaeontology at Queen Mary University of London said: “Analyses of fossil ostracod shells are hugely informative about past environments and climates, as well as shedding light on evolutionary puzzles, but exceptional occurrences of fossilized soft parts like this result in remarkable advances in our understanding.”

Besides a few insects, 39 ostracod crustaceans were entrapped in this tiny piece of Cretaceous amber found in Myanmar, including one containing the world’s oldest sperm cells.

During the Cretaceous period in what is now Myanmar, the ostracods were probably living in a coastal lagoon fringed by trees where they became trapped in a blob of tree resin.

The Kachin amber of Myanmar has previously yielded outstanding finds including frogs, snakes, and a feathered dinosaur tail. Bo Wang, also of the Chinese Academy of Science in Nanjing added: “Hundreds of new species have been described in the past five years, and many of them have made evolutionary biologists re-consider long-standing hypotheses on how certain lineages developed and how ecological relationships evolved.”

The study, published in Royal Society Proceedings B, also has implications for understanding the evolutionary history of an unusual mode of sexual reproduction involving “giant sperm.”

The new ostracod finds may be extremely small but in one sense they are giants. Males of most animals (including humans) typically produce tens of millions of really small sperm in very large quantities, but there are exceptions.

Some tiny fruit flies (insects) and ostracods (crustaceans) are famous for investing in quality rather than quantity: relatively small numbers of “giant” sperm that are many times longer than the animal itself, a by-product of evolutionary competition for reproductive success.

The new discovery is not only by far the oldest example of fossil sperm ever found but also shows that these ostracods had already evolved giant sperm, and specially-adapted organs to transfer them from male to female, 100 million years ago.

Each ostracod is less than a millimeter long. Using X-ray microscopy the team made computer-aided 3-D reconstructions of the ostracods embedded in the amber, revealing incredible detail.

A 3D reconstruction of the female ostracod. 
Artist’s reconstruction of the Cretaceous ostracod crustacean Myanmarcypris hui male (right) and female (left) during mating.

“The results were amazing — not only did we find their tiny appendages to be preserved inside their shells, but we could also see their reproductive organs,” added He Wang. “But when we identified the sperm inside the female and knowing the age of the amber, it was one of those special Eureka-moments in a researcher’s life.”

Wang’s team found adult males and females but it was a female specimen that contained the sperm, indicating that it must have had sex shortly before becoming trapped in the amber.

The reconstructions also revealed the distinctive muscular sperm pumps and penises (two of each) that male ostracods use to inseminate the females, who store them in bag-like receptacles until eggs are ready to be fertilized.

Such extensive adaptation raises the question of whether reproduction with giant sperms can be an evolutionarily-stable character. “To show that using giant sperms in reproduction is not an extinction-doomed extravagance of evolution, but a serious long-term advantage for the survival of a species, we need to know when they first appeared,” says co-author Dr. Renate Matzke-Karasz of Ludwig-Maximilians-University in Munich.

This new evidence of the persistence of reproduction with giant sperm for a hundred million years shows it to be a highly successful reproductive strategy that evolved only once in this group — quite impressive for a trait that demands such a substantial investment from both males and females, especially when you consider that many ostracods can reproduce asexually, without needing males at all.

“Sexual reproduction with giant sperm must be very advantageous,” says Matzke-Karasz.

99 million years old dinosaur-era bird wings found trapped in amber

99 million years old dinosaur-era bird wings found trapped in amber

The new specimens come from a famous amber deposit in northeastern Myanmar, which has produced thousands of exquisite specimens of insects of all shapes and sizes

Beijing: In a first, scientists have discovered specimens of complete wings of tiny, prehistoric birds that were trapped in amber 100 million years ago and preserved in exquisite detail.

Thousands of fossil birds from the time of the dinosaurs have been uncovered in China. However, most of these fossils are flattened in the rock, even though they commonly preserve fossils.

The new specimens, discovered by researchers including Xing Lida from the China University of Geosciences, and Mike Benton from the University of Bristol in the UK, come from a famous amber deposit in northeastern Myanmar, which has produced thousands of exquisite specimens of insects of all shapes and sizes, as well as spiders, scorpions, lizards, and isolated feathers.

This is the first time that whole portions of birds have been noted.

The fossil wings are tiny, only two or three centimeters long, and they contain the bones of the wing, including three long fingers armed with sharp claws, for clambering about in trees, as well as the feathers, all preserved in exquisite detail.

The anatomy of the hand shows these come from enantiornithine birds, a major group in the Cretaceous, but which died out at the same time as the dinosaurs, 66 million years ago.

Amber is a solidified tree sap, and the Burmese amber occurs in small blocks that are polished to unveil treasures within. “These fossil wings show amazing detail.

Feathers of 99 million-year-old bird wings preserved in amber.

The individual feathers show every filament and whisker, whether they are flight feathers or down feathers, and there are even traces of colour – spots and stripes,” said Benton.

“The fact that the tiny birds were clambering about in the trees suggests that they had advanced development, meaning they were ready for action as soon as they hatched,” said Lida.

“These birds did not hang about in the nest waiting to be fed but set off looking for food, and sadly died perhaps because of their small size and lack of experience,” he said.

“Isolated feathers in other amber samples show that adult birds might have avoided the sticky sap, or pulled themselves free,” he added.

The Burmese amber deposits are producing a treasure trove of remarkable early fossils, and they document a particularly active time in the evolution of life on land, the Cretaceous terrestrial revolution.

An illustration of a Enantiornithine partially ensnared by tree resin, based on one of the specimens discovered.

Flowering plants were flourishing and diversifying, and insects that fed on the leaves and nectar of the flowers were also diversifying fasts, as too were their predators, such as spiders, lizards, mammals, and birds.

This Gecko Has Been Trapped In Amber For 100 Million Years

This Gecko Has Been Trapped In Amber For 100 Million Years

Researchers at the University of Oregon state and the Natural History Museum in London confirmed that they had found the oldest known gecko fossil with life-like pieces after 100 million years of the amber-buried skeleton.

This ancient chameleon relative is the oldest found to date, beating out the previous title-holder by roughly 80 million years.

The tiny foot of this ancient lizard also displays the tiny “lamellae” or sticky headdress hairs, that to this day give modern geckos their unusual ability to cling to surfaces or run across a ceiling. Research programs around the world have tried to mimic this bizarre adhesive capability, with limited success.

This gecko’s running days are over, however, as only the foot, toes, and part of a tail are left in the stone. The rest might have become lunch for a small dinosaur or another predator during an ancient fight in the tropical forests of Myanmar during the Lower Cretaceous Period, from 97 million to 110 million years ago.

These ancient amber fossils from Burma in Southeast Asia help complete the patchy record of lizard evolution.

The find is at least 40 million years older than the oldest known gecko fossil, shedding additional light on the evolution and history of these ancient lizards that scampered among the feet of giant dinosaurs then and still are common in tropical or sub-tropical regions all over the world.

The findings were just published in Zootaxa, a professional journal.

“It’s the unusual toe pads and clinging ability of some geckos that make them such a fascinating group of animals, so we were very fortunate to find such a well-preserved foot in this fossil specimen,” said George Poinar, Jr., a courtesy professor at OSU and one of the world’s leading experts on insects, plants and other life forms trapped in amber, a semi-precious stone that begins as tree sap.

“There’s a gecko society, gecko clubs, just a lot of interest in these animals because of their unusual characteristics,” Poinar said. “So there are a lot of people pretty excited about this.”

Based on the number of lamellae found on its toe pads, this gecko was probably a very small juvenile of what would have become a comparatively large adult, possibly up to a foot long, the researchers say. Modern geckos get no more than about 16 inches long, although it’s possible there were larger species millions of years ago.

The juvenile gecko found in the fossil was less than an inch in length when it died – possibly by being eaten or attacked since only partial remains were found.

The discovery has been announced as a new genus and species of gecko, now extinct, and has been named Cretaceogekko. It had a striped pattern that probably served as camouflage.

There are more than 1,200 species of geckos in the world today, common in warm or tropical regions, including parts of the southern United States. They are frequently kept as pets, and often are welcome in the homes of some tropical residents because they help control insects. Some are very colorful. They use long tongues to lick, clean, and moisturize their eyes.

“Geckos are territorial, and when I lived in Africa in the early 1980s we used to have them in our house,” Poinar said. “They are pretty friendly and don’t bother humans. Certain individuals would move into the house, we’d give them names, and they would run around the house, catch mosquitoes, help control bugs. They would crawl across the ceiling and look down at you.”

The new study provides evidence that geckos were definitely in Asia by 100 million years ago, and had already evolved their bizarre foot structure at that time. The amber fossil was mined in the Hukawng Valley in Myanmar, and during its life, the gecko probably lived in a moist, tropical forest with ample opportunities for climbing.

3D printing the fossils allow researchers to study them without risking damage to the originals. They can also enlarge the printed fossils to get a look at minute details.
This 3D print of the early gecko trapped in amber gives a much clearer view of the lizard’s remarkable preservation—right down to its teeth.
This micro-CT scan of the oldest known fossil chameleon shows the hyoid bone highlighted in blue, which indicates that the lizard had a projectile tongue like modern chameleons.

The ability of geckos to walk on vertical walls or even upside down is due to the presence of thousands of “setae” on their toes, very tiny, hairlike structures that have tips which attach to surfaces by van der Walls forces. It’s a type of incredibly strong, dry adhesion shared by virtually no other group of animals.

It’s not known exactly how old this group of animals is, and when they evolved their adhesive toe pads. However, the new study makes it clear that this ability was in place at least 100 million years ago, in nature. Modern research programs still have not been able to completely duplicate it.

Scientists at the University of California at Berkeley reported earlier this year that they have developed a new “anti-sliding” adhesive that they said was the closest man-made material yet to mimic the ability of geckos – they think it might help a robot climb up the side of walls. A research team at the Massachusetts Institute of Technology this year created a waterproof adhesive bandage inspired by geckos, that may someday be used in surgery. And of course, geckos have become an advertising icon for the insurance company Geico.

This study is just one of many in which Poinar and colleagues have used the unusual characteristics of amber to study ancient life forms and develop information on the ecology of ancient ecosystems.

As a stone that first begins to form as sap oozing from a tree, amber can trap small insects or other life forms and preserve them in near-perfect detail for observation millions of years later.

Dwarfs under dinosaur legs: 99-million-year-old millipede discovered in Burmese amber

99-Million-Year-Old Millipede Trapped In Amber Discovered In Myanmar

The analysis of an amber-trapped, 99 million-year-old fossilized millipede is bringing scientists to utterly rethink the evolution of the entire millipede species.

Researchers found that the perfectly preserved 8.2 mm specimen found in Burma was an entirely new species, according to a study published in the journal ZooKeys, due to its peculiar morphology that differed greatly from existing millipede classifications.

Professor Pavel Stoev at the Bulgarian National Natural History Museum told us in a statement that “We were very surprised that this animal can not be placed into the present Millipede classification.

Dwarfs under dinosaur legs: 99-million-year-old millipede discovered in Burmese amber
The 8.5-millimeter millipede had five-unit compound eyes and an unusually hairless rear end

“Even though their general appearance has remained unchanged in the last 100 million years, as our planet underwent dramatic changes several times in this period, some morphological traits in Callipodida lineage have evolved significantly.”

As a result of this exciting find, Stoev together with his colleagues Dr. Thomas Wesener and Leif Moritz of the Zoological Research Museum Alexander Koenig in Germany had to revise the current millipede classification and introduce a new suborder for the specimen. There have only been a handful of millipede suborders described in the last five decades.

To get a more accurate look at the fossilized millipede’s morphology, researchers used 3D X-ray microscopy to construct a virtual model of the ancient millipede, including its internal features.

The examination showed that the 99 million-year-old millipede was, in fact, significantly different from other early millipede species. The researchers named the new species Burmanopetalum inexpectatum, with the latter word meaning “unexpected” in Latin.

Among the Burmanopetalum inexpectatum’s unique traits are its eye, which is composed of five optical units where other millipede orders usually have but two or three.

Another fascinating trait of the newly discovered millipede is its smooth hypoproct, which is the spot located in between the anal opening and the genitalia of an insect.

By comparison, its younger brethren usually have hypopcrocts that are covered in bristles. These highly unusual traits have given scientists a completely new perspective regarding how its kind evolved.

The researchers used micro-CT scans to create a 3-D model of the ancient millipede

Not to be confused with centipedes, millipedes belong to the Diplopoda class which is Latin for “double foot.” The name refers to the two pairs of legs that these critters have on each of their body segments in addition to its many tiny legs. By comparison, centipedes have only one pair of legs per body segment.

Also unlike centipedes, millipedes are not active predators and they survive on a diet of decaying plant matter. When threatened, millipedes will secrete poisonous chemicals to deter animals that may want to hurt or eat them.

Scientists estimate that there are 80,000 species of millipedes, yet only a fraction have been discovered and studied.

This ancient insect’s peculiar characteristics are not the only thing that sets it apart, however. The fact that it was discovered in Myanmar is also significant because scientists have never discovered a Callipodidan in Myanmar before, which means that this order of insects must have existed in the Southeast Asian region as well.

The Burmese amber that the millipede had been trapped in was part of a private collection of animals that belonged to Patrick Müller.

This collection included 400 amber stones that the scientists had been granted access to, and is the largest collection of its kind in Europe and the third-largest in the world.

Much of the collection is now deposited at the Museum Koenig in Bonn, Germany, where other researchers from around the world may gain access to study the collection, too.

This 99-Million-Year-Old Dinosaur Tail Trapped in Amber Hints at Feather Evolution

This 99-Million-Year-Old Dinosaur Tail Trapped in Amber Hints at Feather Evolution

A feathered dinosaur’s tail has been found in Myanmar amber perfectly preserved. The one-of – a-kind breakthrough helps to put a new perspective on the evolution of a group that dominant in the world for more than 160 million years.

The examination of the specimen suggests the tail was chestnut brown on top and white on its underside. The tail is described in the journal Current Biology.

“This is the first time we’ve found dinosaur material preserved in amber,” co-author Ryan McKellar, of the Royal Saskatchewan Museum in Canada, told the BBC News website. The study’s first author, Lida Xing from the China University of Geosciences in Beijing, discovered the remarkable fossil at an amber market in Myitkina, Myanmar.

The 99-million-year-old amber had already been polished for jewellery and the seller had thought it was plant material. On closer inspection, however, it turned out to be the tail of a feathered dinosaur about the size of a sparrow.

Lida Xing was able to establish where it had come from by tracking down the amber miner who had originally dug out the specimen. Dr. McKellar said examination of the tail’s anatomy showed it definitely belonged to a feathered dinosaur and not an ancient bird.

The dinosaur’s plumage is preserved in exquisite detail
The specimen sheds new light on feather evolution

“We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives,” he explained.

“Instead, the tail is long and flexible, with keels of feathers running down each side.”

Dr. McKellar said there are signs the dinosaur still contained fluids when it was incorporated into the tree resin that eventually formed the amber. This indicates that it could even have become trapped in the sticky substance while it was still alive.

Co-author Prof Mike Benton, from the University of Bristol, added: “It’s amazing to see all the details of a dinosaur tail – the bones, flesh, skin, and feathers – and to imagine how this little fellow got his tail caught in the resin, and then presumably died because he could not wrestle free.”

Examination of the chemistry of the tail where it was exposed at the surface of the amber even shows up traces of ferrous iron, a relic of the blood that was once in the sample.

The findings also shed light on how feathers were arranged on these dinosaurs because 3D features are often lost due to the compression that occurs when corpses become fossils in sedimentary rocks.

The feathers lack the well-developed central shaft – a rachis – known from modern birds. Their structure suggests that the two finest tiers of branching in modern feathers, known as barbs and barbules, arose before the rachis formed.

This CT scan reveals how feathers were inserted along the tail

Kachin State, in north-eastern Myanmar, where the specimen was found, has been producing amber for 2,000 years. But because of the large number of insects preserved in the deposits, over the last 20 years it has become a focus for scientists who study ancient arthropods.

“The larger amber pieces often get broken up in the mining process. By the time we see them, they have often been turned into things like jewellery. We never know how much of the specimen has been missed,” said Dr. McKellar.

“If you had a complete specimen, for example, you could look at how feathers were arranged across the whole body. Or you could look at other soft tissue features that don’t usually get preserved.”

Other preserved parts of a feathered dinosaur might also reveal whether it was a flying or gliding animal.

“There have been other, anecdotal reports of similar specimens coming from the region. But if they disappear into private collections, then they’re lost to science,” Dr. McKellar explained.

Dr. Paul Barrett, from London’s Natural History Museum, called the specimen a “beautiful fossil”, describing it as a “really rare occurrence of vertebrate material in amber”.

He told BBC News: “Feathers have been recovered in amber before, so that aspect isn’t new, but what this new specimen shows is the 3D arrangement of feathers in a Mesozoic dinosaur/bird for the first time, as almost all of the other feathered dinosaur fossils and Mesozoic bird skeletons that we have been flattened and 2D only, which has obscured some important features of their anatomy.

“The new amber specimen confirms ideas from developmental biologists about the order in which some of the detailed features of modern feathers, such as barbs and barbules (the little hooks that hold the barbs together so that the feather can form a nice neat vane), would have appeared also.”

Earlier this year, scientists also described ancient bird wings that had been discovered in amber from the same area of Myanmar.

Spider-Like Creature With a Tail Was Just Found in 100 Million-Year-Old Amber

Spider-Like Creature With a Tail Was Just Found in 100 Million-Year-Old Amber

Amber mined for centuries in Myanmar for jewelry is a treasure trove for understanding the evolution of spiders and their other arachnid relatives.

This week, two independent teams describe four 100-million-year-old specimens encased in amber that look like a cross between a spider and a scorpion.

The discovery, “could help close major gaps in our understanding of spider evolution,” says Prashant Sharma, an evolutionary developmental biologist at the University of Wisconsin in Madison who was not involved in the work.

Arachnids are a group of eight-legged invertebrates that includes scorpions, ticks, and spiders. Spiders, which crawled into existence some 300 million years ago, are known for their spinnerets—modified “legs” that produce silk and control its extrusion from tiny pores called spigots.

Male spiders have also evolved another modified “leg” between their fangs and the back four pairs of legs that inserts sperm into the female.

All but the most primitive spiders have smooth backs, unlike the segmented abdomens of scorpions, which are believed to have diverged from an ancestral arachnid more than 430 million years ago.

But in 1989, researchers discovered a suspicious, spigot-bearing fossil that was 100 million years older than the earliest known spider.

By 2008, paleobiologists realized that this ancient silk producer was just a spider relative, perhaps a stepping stone to true spiders.

Researchers put it into the group Uraraneida, which was thought to have thrived between 400 million and 250 million years ago. That left unanswered many questions about when spinnerets and other spider traits first evolved.

Then, several years ago, amber fossil dealers independently approached two paleobiologists at the Nanjing Institute of Geology and Paleontology in China with what looked like 5-millimeter-long Uraraneida encased in amber.

One of them, Wang Bo, pulled together a team to look at his two specimens, which they eventually named Chimerachne yingi (“chimera spider” in Latin). The other paleobiologist, Huang Diying, assembled a second team that examined a different pair of these fossils.

The two groups say they didn’t know about each other until after they submitted their results to the same journal. But, despite some differences, “they draw the same conclusion—that fossil uraraneids, as this group is called, are the closest extinct relatives of spiders,” says Greg Edgecombe, a paleobiologist at the Natural History Museum in London, who was not involved with the work.

Amber preserved in exquisite detail these 100-million-year-old close relatives to spiders.

One group’s specimens give a really clear view of the top of this organism and the other, a great look at the underside, spinnerets and all, Huang and his colleagues report today in Nature Ecology and Evolution.

“The degree of preservation is exquisite, and the fossils’ anatomy is easy to interpret,” Sharma says. The presence of the spinnerets, he adds, means they must have originated “very early” in arachnid evolution. The male specimens also have the special appendages for inserting sperm into the female.

Yet they also have a segmented abdomen and a long tail, like a whip scorpion’s whip, Wang and his colleagues report today in the same journal. “These things appear to be essentially spiders with tails!” says Jason Bond, an evolutionary biologist at Auburn University in Alabama who was not involved with the work.

This means that early arachnids had a mix of all these traits, which were selectively lost in their descendants, giving rise to the array of arachnids seen today.

And what is even more amazing, says Bond, is that the amber is only 100 million years old. So these spider relatives hunted side by side with spiders for 200 million years.