Amber Inclusions – Learn more about fascinating discoveries!

Inclusion is a term used to call pieces of extinct species of animals and plants that are dated up to 40 million years old. Resin from extinct trees, as falling down to the ground was trapped inside the drops plants and tiny animals preserving them until modern times. Nowadays amber inclusions are of special interest for researchers and scientists, as they contain mysteries of the past.

Organic inclusions are pieces of fossiled species that were preserved in fossil resin (animals, insects, arachnids). Sometimes other animals can be found as well. Spices that had been trapped in resin might have been dead or alive. To form fossiled inclusion, the piece has to be fully covered by resin and has no oxygen access.

The oldest inclusion to be found, are those found in the Triassic amber, which was formed in the Triassic epoch – the earliest period of the Mesozoic era. The earliest is dated back to the Quaternary. The higher number of organic amber inclusions is found in Baltic, Dominican, and Liban amber. They are a source of information of the highest importance, as they contain well-preserved fauna and flora that existed millions of years ago. They are especially interesting for paleontologists and in the field of reconstruction evolutionary steps of insects and arachnids. Vast collections of inclusions can be found in various scientific institutions such as museums. Sometimes amber with inclusion is also used in jewelry.

Brocken Inaglory / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

Burmese amber – a rich source of inclusions

Burmese amber (dated to be about 100 million years old) is one of the best sources of the inclusions such as butterflies, spiders, lizards or scorpions. Amber is a very precious material created by nature. It is a fossil resin of ancient evergreen trees that has been transformed for millions of years into its hardened form known as amber. The fact that it contains pieces of ancient species preserved inside makes it even more special. Burmese amber is of the special interest of scientists as it contains pieces of organisms that are up to 100 million years old!

Burmese amber also, known as burmite, is a type of amber which sources can be found in the South-east Asian country – Myanmar. The amber was being recovered there for centuries but in the early XX century, due to the political changes, they all were closed. In 1999 the mines were reopened and the amber began to be exported to different countries, mostly to China, European Countries, and the United States. Amber is a very precious material because it is a natural source of the ancient species of plants and animals, that were preserved until today. How the inclusion is made? Incests are trapped in sticky resin, and then fully covered by the gold, sticky liquid. The trap reduces oxygen access and also starts the process of dehydration what results in the death of the trapped insect. This process preserves insects in their original, unchanged form.

In the amber recovered from the sources located in Maynmar animals such as insects, invertebrates, ants, butterflies, and beetles are found. Sometimes even more species are found such as spiders, scorpions, tiny snakes, or feather which are very fascinating for the scientist.

Tingting Yu, Richard Kelly, Lin Mu, Andrew Ross, Jim Kennedy, Pierre Broly, Fangyuan Xia, Haichun Zhang, Bo Wang, and David Dilcher / CC BY (https://creativecommons.org/licenses/by/4.0)

What do scientists think about the inclusions found in the Burmese amber?

According to one of them: „A large pieces with inclusions are desired by collectors and can be very expensive. It is a problem for the researchers because the stones forces are to be bought and because we cannot afford them, they are excluded from scientific research.” Organic inclusions don’t contain DNA because it is fully destroyed in the resin. Inclusions help to recreate the evolutionary path of the found species and are a great source of information about the ancient ecosystem. These researches are important because thanks to them it is possible to recreate the ecosystem of the Cretaceous. It was a very important period for the evolution of plants. In the Cretaceous, the whole ecosystem was rebuilt, what initiated the evolution of many animals.

Oregon State University / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.0)

Inclusions in the Baltic amber

IInclusions in the Baltic amber are about 40 million years old when the resin from ancient trees trapped pieces of organisms such as – leaves, bark pieces, tiny animals such as insects or invertebrates. Not only organic inclusions are found in the Baltic amber but also inorganic such as air bubbles or water drops. Sometimes amber pieces containing sand or dust can be found.

Anders L. Damgaard – www.amber-inclusions.dk – Baltic-amber-beetle / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

In which forms of the baltic amber inclusions occur?

The richest in inclusions are the amber pieces in the stalactite form due to the way the resin flowed. Inclusions are rarer to be found in the lump form because those are created inside the tree. There is also one more type known as the so-called „glued” form that was created from different resin layers. One amber piece may contain a large number of inclusion of one or several species.

Fauna and Flora Inclusions

Fauna and flora inclusions were the reason why the scientists were able to find animal and plant species that lived millions of years ago. Researchers discovered a large number of species preserved in amber and learn more about the ancient ecosystem. The most important are the inclusions containing animal pieces. In amber pieces, a huge number of animals were preserved from many different epochs. They are mostly the representatives of extinct species. Amber preserved them in unchanged form for millions of years. Thanks to that, complex experiments can be conducted. Fauna inclusions are much more common than plant inclusions. Sometimes inclusion with fragments of bodies can be found such as wings, claws or teeth.

The photographer and www.AntWeb.org / CC BY (https://creativecommons.org/licenses/by/4.0)

V. Kolyada & E. Perkovsky / CC BY (https://creativecommons.org/licenses/by/3.0)

Artificial Inclusions

Inclusions for years are fascinating for many. It led to the development of artificial pieces made of plastic. To check its originality, a simple test with a needle is enough. Simply gently pierce the stone, if u can smell a characteristic resin aroma, the piece is real. Counterfeit amber pieces with inclusions are popular in China.

The largest group of insects preserved in amber.

The group of insects which is the most common in amber is flies of the order Diptera. Up to 70% of fauna inclusions contain a fly. Another large group is the Hymenoptera insects (up to 10%). They are mostly ants but also for example bees. Beetles of the order Coleoptra is the third the largest group of fauna inclusions. The most common are incents whose larvae lived under the tree bark. Another popular group is the animals that lived on the trees such as greenflies, butterflies or spiders which are rarest to be found in amber. The most common arachnids to be found in amber are thone of the order Acarina and Araneae. Additionally, they share the most similarities with modern arachnids.

Kate Martynova / CC BY (https://creativecommons.org/licenses/by/3.0)

Types of amber traps

There are four main types of amber traps: glue trap, lava trap, drop trap, puddle trap.

• Glue trap – resin creates stalactites on the side of the tree which trap the flying animals such as flies. It also catches species that travel with wind such as spiders, protozoa, as well as various objects such as seeds or feathers.
• Lava trap – resin flows on the tree side and traps everything on its ways such as eggs, larvae, pupae, or slow animals such as snails, centipedes or bark beetles.
• Drop trap – resin drops trap little animals and plants on the lower parts of the tree or on the ground.
• Puddle trap – resin creates a puddle under its source and then traps little animals, dead insects as well as animal pieces or other material objects.

Zooinclusions division:

Zooinclusions are animal inclusion which can be found in amber. They can be categorized by their size. Microinclusions are smaller than 1 mm, mezoinclusions are from 1 to 5 mm big and macroinculsions are bigger than 5 mm. The first category usually is made of: eggs, protozoa, mites, and elements of larger animals that are recognized through professional and specialized optical equipment. Mezoinclusions and makroinclusions are made of flying insects or invertebrates. Sometimes macroinclusions contain Vertebrata such as snakes, lizards or little birds.

AlejandroLinaresGarcia / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

How do they look?

Zooinclusions are dry and empty inside. All tissues of animals preserved in resin, as well as DNA, were destroyed. Most of mezoinclusions and makroinclusions are covered by a milky layer made of water drops and little gas bubbles, which are the effect of the resin drying.

Examples of zooinclusions

• A lizard found in amber in Gdańsk
  One of the most impressive inclusions including Vertebrata is a lizard found in Gdańsk, Poland. The finding is also called Gierłowska’s lizard. It is the only lizard inclusion that was found in Poland. Inside of a 40-million-year-old amber piece, a mummified lizard has been found. It is an impressing and untypical discovery. It is the second lizard preserver in amber to be ever found! The first one discovered in 1875 by Richard Klebs. Amber piece with Gierłowska’s lizard was found in 1997 on one of the Gdańsk beaches. It was gifted to a museum by Leopold Kronenberg’s Bank Foundation. In the amber not only lizard was preserved but also sever elements of ancient plants. These little elements are important to correctly identify amber’s age. The milky white surface on the lizard’s feet may suggest that it is a Baltic species. It was exhibited for the first time during the symposium „Amber and other fossil resins” in Gdańsk, 1997.

• 100 million year old bee found in amber
  In one of the amber mine in Maymar an ancient bee, together with pollen was found preserved in amber. The discovery is about 100 million years old. It was identified by George Poinar Jr., a researcher from Oregon State University. To further identify the insect, he classified it as a representative of an unknown family, genus, and species and called it Apicula Discoscapa from the family Discoscapidae. It is the first-ever example of the ancient bee, as well as the first one of the beetle parasites that can still be found in modern bees. This unique discovery gives a whole new perspective to the evolution of bees, as well as the diversity of blooming plants. The fossilized bee has similar treats with modern bees such as a pair of spurs on the posterior tibia, plum hair, rounded frontal lobe. It has also a few similar treats with modern wasps such as antenna sockets located very low, as well as sporadic features of wing veins. What makes the newly discovered insect found in amber unique? It has pollen located on its body, which may suggest that the bee fed on flowers. The bee has also 21 larvae of parasites located on itself, which as well been preserved in amber.

Denis J. Brothers / CC BY (https://creativecommons.org/licenses/by/3.0)

• The head of the tiniest dinosaur which lived 100 million years ago has been discovered in amber. Amber was found in Myanmar.
  It is about 100 million years old. Its a unique amber piece with the head of the smallest dinosaur which contains a piece of its soft tissue – tongue. It has been called Oculudentavis khaungraae. Its size is similar to the size of the smallest the size of a bee hummingbird, which weighs less than 2.0g Thanks to the computer reconstruction its size could be established. The dinosaur was 5 cm long. Additionally, in the amber piece, a pair of reptilian eyes and 100 sharp teeth were found. The Academy of science claimed that the animal may be a missing link between reptilians and birds. What stays in favor of this thesis is the ring located around the eye sockets of the animal, which is made of the same bone structures that can be found in modern reptilians. Its shape is similar to the shape of the owl eyes and they are sticking out of its head in an unknown way. This feature has never been observed in any other animal species. Jingami O’Connor, a paleontologist from the Chinese Academy of Science in Beijing, summarized the discovery: I love how natural selection creates amazing species like the one found in amber. We are lucky that the piece survived 99 million years. Additionally, the dinosaur was a predator, which may be suggested by a large number of teeth. This discovery may be of the highest importance for the new discoveries in the field of interspecies evolution and the processes of miniaturization of animals that occur in closed environments.

Fot. Profesor Xing Lida/ press material/East News

Museum of amber inclusions

The Museum of amber inclusion was established in 1998 in Gdańsk, Poland. It is an integral part of the department of Evolutionary Entomology at the Department of Invertebrate Zoology and Parasitology at the Faculty of Biology of the University of Gdańsk. The museum establishment was initiated by researchers, scientists and amber enthusiasts from Gdańk. Their goal is to collect and analyze amber inclusions. Museum of amber inclusions has its own mission: collecting and storing amber inclusions, collecting natural forms of amber and conducting various different scientific projects to further develop knowledge about amber.

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