Enantiornithines had similar flight feathers to modern birds, suggesting they were capable of skilled, powered flight, while still retaining the primitive teeth and wing-claws. Despite being a diverse and vibrant group in the Late Cretaceous period, the enantiornithines went the way of the other dinosaurs at the close of the Mesozoic.
As with other creatures trapped in amber, all that is left is an impression of the surface of the birds, but the detail and clarity are stunning.
In this case, we can see each individual scale and claw on the legs, separate feathers, skin, muscles and many other intimate details, including the original colours of the feathers. Even though this is only a hatchling, barely three and a half centimetres long, the fact that it is covered in well-developed feathers tells us individual enantiornithines developed in a different manner to their living relatives. Enantiornithines appear to have had fully-formed feathers at a very early stage of their development, while their modern counterparts are still only downy-covered chicks — details we would not have known if they had not had the misfortune of being encased in tree sap.
When it was revealed in , this preserved lizard, named Yantarogekko balticus , was the oldest fossil gecko ever discovered. Credit: Wolfgang Weitschat. In , the world was stunned by the announcement of a spectacularly preserved lizard in a piece of Baltic amber.
This specimen, shown here, was named Yantarogekko balticus. At the time, it was the oldest gecko known to science except for some odd, fragmentary bones. While the toes of Yantarogekko revealed features not seen in any other lizard, it also had the expanded pads seen in modern geckos that enable their legendary climbing abilities.
Ten years later came news of much older specimens preserved in amber from Myanmar. This pushes back the fossil history of geckos to around 99 million years ago, a time when all the major groups of living lizards are thought to have evolved. All of the lizards were tiny, less than a couple of centimetres long, and required micro-computed-tomography scans to reveal the exquisite details of scales, teeth and claws.
The ancient animals also had the adhesive toe pads seen in modern geckos. One specimen has its tongue sticking out, revealing a narrow, extended tip not seen in any other lizard or snake. Lizards have also been recovered from Dominican amber. In , 17 Anolis lizards were described and compared to a modern community of Anolis from the nearby Greater Antilles Islands in the Caribbean.
Remarkably few differences were observed between the 20 million-year-old fossils and their modern counterparts. Flowers are rare in the amber record, but this one, named Strychnos electri , is thought to be closely related to the strychnine tree.
Considering that amber originated from plant sap exuded in environments where other plants abounded, it has been observed that such plants are comparatively rare inclusions. Luckily, there are some breathtaking exceptions. Flowering plants emerged some 99 million years ago, when Myanmar amber was still sticky tree sap in a tropical forest. Several flowers have been preserved, including one remarkable fossil of two flowers having sex!
The male anther of one flower can clearly be seen inserted into the female stigma of another. W hen Lida Xing took the stage at the Santo Domingo conference on a Thursday morning, the audience was ready for a deep dive into Burmese amber.
He started with a description of the mines in Myanmar, which he visited twice, in and , after sneaking over the Chinese-Burmese border disguised in local clothes. When ruby miners moved into the area from the south 10 years ago, they used their more sophisticated technology to dig deeper, and began to find new deposits of amber about meters down.
Today an estimated 10 tons of amber is taken out of Burmese mines every year. Xing told the group that tens of thousands of people work in the Kachin mines, many of them teenagers the mine shafts are so narrow that only slender people can fit into them, going two at a time , and that hundreds are killed every month when the mines flood or cave in.
The generals who control the area sometimes alert Xing when an interesting inclusion is found in the amber. And there are a stunning number of inclusions: In , only 60 total species were described from Burmese-amber deposits. In alone, new species were described—the largest number in any year, from any location. Today the total number of species described from Burmese-amber deposits is around 1, The profits from selling amber are also financing the ongoing conflict in the region, leading to more danger for local people.
Read: In the new Burma, one marginalized group has yet to see peace. After spending about 10 minutes describing the Burmese mines, Xing addressed some of his most spectacular fossil findings, including a bird wing, frogs, salamanders, snakes, crustaceans—and, possibly, a second dinosaur. Xing displayed a painting of a Cretaceous-era Burmese forest, complete with trees, insects, marine life, and dinosaurs. It was enough to make the heart soar—million-year-old life, now known in spectacularly rich detail.
When he finished his talk, the room quieted, and I shifted in my seat, thinking about those teenagers scraping at the hot, dark, wet earth feet below the surface. At the meeting in Santo Domingo, Grimaldi said he was starting to avoid amber from Myanmar—partly because the Chinese scientists tend to get first dibs, and partly because he knows it has been mined at great risk. A few weeks later, after learning more about the Burmese mines from press reports, Grimaldi had made a clear decision. How much should scientists care about where their samples come from?
I asked myself, and others, that question many times during the week I spent in the Dominican Republic. Only a few truly engaged. Seyfullah has drawn a line for herself: She studies only specimens that she personally digs up, or that she buys directly from miners. In the Dominican Republic, she bought a large chunk of fossilized tree bark from the amber miners—a specimen she said will be used as a teaching tool.
As soon as you start paying for something, you open up a world of questions about its true cost. Seyfullah was slightly queasy about all the wheeling and dealing she saw at the meeting. As soon as you start putting a number on the value of a scientific sample, science changes in intangible and tangible ways, as valuable specimens often end up in the hands of collectors. Seyfullah did start talking with her colleagues at the meeting about the ethical considerations of buying and studying Burmese amber.
Some of them, she said, reasoned that their business helps desperate people make a living. Others reasoned that since scientific uses represent less than 1 percent of the overall amber market, jewelry makers should lead the ethical charge. Some researchers think the Burmese samples span at least 5 million years. Why were these trees secreting so much resin during these particular times? Were there rapid weather changes, or giant fires or floods?
The ethical questions are complicated by the fact that amber falls into a gray area in museum collections and export laws.
Not so with amber. And in Myanmar, for example, exporting fossils without permission is illegal, but amber is classified as a gemstone. Amber does fall under the auspices of the Nagoya Protocol, which provides a legal framework for the equitable sharing of benefits arising out of the utilization of genetic resources.
This effect can also help to determine the age of the resin. The determination of the glass transition temperature and its change due to postcuring is a good measure of the geological age of the resin. The measurement requires very little substance about 10 mg and is performed quickly in a total of about three hours: The time can be shortened through optimization of the measurement method.
To develop a method from the ideas presented would require further measurements of well-dated fossilized resins that I unfortunately do not have available. Age determination could then be done by correlating the glass transition temperature with the age of the sample. To do this, the following diagrams would be useful: Glass transition temperature as function of the logarithmic age. Difference of the glass transition temperature between the second and first run as a function of the logarithmic age.
Automated Reactors and In Situ Analysis. Transport and Logistics. Expertise Library. At least some of the eastern deposits are probably only several hundred to several thousand years old, and those from the northern mountains yield "true" amber [e. In addition, the phylogenetic position of insects preserved in Dominican and Baltic embers shows Dominican taxa to be relatively younger than the 40 Ma Baltic fossils.
All evidence indicates that Dominican amber is considerably younger than the highly popularized age of 40 Ma. Bibliographic information. All titles:.
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