Burmese amber
The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period.
The amber is of significant palaeontological interest due to the diversity of flora and fauna contained as inclusions, particularly arthropods including insects and arachnids but also birds, lizards, snakes, frogs and fragmentary dinosaur remains.
Research on the deposit has attracted controversy due to the potential role of the amber trade in funding internal conflict in Myanmar and hazardous working conditions in the mines where it is collected.
[3] A recent paleomagnetic reconstruction finds that the Burma terrane formed an island land mass in the Tethys Ocean during the Mid Cretaceous at a latitude around 5-10 degrees south of the equator.
A specimen of the ammonite Mortoniceras has been found in a sandstone bed 2 metres above the amber horizon, alongside indeterminate gastropods and bivalves.
The strata at the site are younging upwards, striking north north-east and dipping 50-70 degrees E and SE north of the ridge and striking between south south-east and south-east and dipping 35-60 degrees south-west south of the ridge, suggesting the site is on the northwest limb of a syncline plunging to the northeast.
The Hkamti site SW of the Hukawng basin has been determined to be significantly older, dating to the early Albian around ca.
[8] The Burmese amber paleoforest is considered to have been a tropical rainforest, situated near the coast, where resin was subsequently transported into a shallow marine environment.
[13] The amber itself is primarily disc-shaped and flattened along the bedding plane, and is typically reddish brown, with the colour ranging from shades of yellow to red.
[28] Over a dozen species each of Myriapoda (millipedes and centipedes, among others) and Entognatha (springtails, among others) have also been reported, along with a number of woodlice (representing some of the oldest records of the group) and various aquatic crustaceans.
[16] Only a handful of vertebrates have been described from Burmese amber, these include the albanerpetontid (a group of extinct salamander-like amphibians) Yaksha, the frog Electrorana, a number of primitive toothed birds belonging to the extinct clade Enantiornithes, including the named species Elektorornis and Fortipesavis[16], the lizards Protodraco (suggested to be the oldest agamid[30]), Cretaceogekko (suggested to be the oldest modern gecko[31]), Electroscincus (the oldest known skink[32]) Barlochersaurus,[31] Oculudentavis (formerly erroneously considered to be a bird),[33] and the snake Xiaophis.
[36] It was first mentioned in European sources by the Jesuit Priest Álvaro Semedo who visited China in 1613, it was described as being "digged out of mines, and sometimes in great pieces, it is redder than our amber though not so cleane".
Pieces that were considered high quality or fit for use as ornamentation were described as expensive, and price varied depending on the clarity and color of the amber.
[41] Leeward Capital Corp, a small Canadian mining firm, began exporting amber from Myanmar during the 1990s, resulting in the description of a number of fossil species from the deposit.
Burmese amber was estimated to make up 30% of Tenchong's gemstone market (the rest being Myanmar Jade), and was declared one of the city's eight main industries by the local government.
[5] The working conditions at the mines have been described as extremely unsafe, down 100 m (330 ft) deep pits barely wide enough to crawl through, with no accident compensation.
[51] On May 13, 2020, the Journal of Systematic Palaeontology published an editorial stating that it would no longer consider papers based whole or in part on Burmese amber material, regardless of whether in historic collections or not.
The authors disagreed with the proposal of a moratorium, describing the focus on the Burmese amber as "arbitrary" and that "The SVP's recommendation for a moratorium on Burmese amber affects fossil non-vertebrate research much more than fossil vertebrate research and clearly does not represent this part of the palaeontological community.
[55] A story in Science in 2019 stated: "Two former mine owners, speaking through an interpreter in phone interviews, say taxes have been even steeper since government troops took control of the area.
The deposit was associated with an overlying tuffaceous layer, and underlying nodules of brown sandstone yielded remains of the ammonite Sphenodiscus.
These include members of Hymenoptera (Braconidae, Diapriidae, Scelionidae) Diptera (Ceratopogonidae, Chironomidae) Dictyoptera (Blattaria, Mantodea) planthoppers, Berothidae and bark lice (Lepidopsocidae) as well as extant ant subfamilies Dolichoderinae and tentatively Ponerinae, as well as fragments of moss.
90 km southwest of the Angbamo site and predominantly consists of limestone, interbedded with mudstone and tuff, the amber is found in the unconsolidated mudstone/tuff layers.
Fauna found in the amber include: Archaeognatha, Diplopoda, Coleoptera, Araneae, Trichoptera, Neuroptera, Psocodea, Isoptera Diptera, Orthoptera, Pseudoscorpionida, Hymenoptera and Thysanoptera.
