Amber, palaeontologists and a military dictatorship

Most people are familiar with the term ‘blood diamonds’, meaning diamonds clandestinely exported from areas infested by the lethal activities of military and paramilitary forces. Indeed such conflicts are often fuelled by the large profits to be made from trading diamonds.  One such source was in Sierra Leone during the civil war of 1991-2002. Others include Liberia, Côte d’ Ivoire, Angola and the Democratic Republic of Congo. Like illicit money, gemstones can be ‘laundered’ and find their way into conventional trade. To some extent the blood diamond trade has been slowed down by a programme of certification of packaged uncut diamond ‘rough’ by bona fide producers, and banning the sale of uncertified rough. The Kimberley Programme has been criticised because certificates can be issued in corrupt ways, so that blood diamonds probably still make their way to the international diamond markets: certification may hold no fears for those who force people to ine at gun point. However, because diamonds often show geochemical signatures and minute inclusions of other minerals that are unique to individual pipe-like intrusions of kimberlite that carry deep-mantle material to the surface. So, it is technically possible – but costly – to check for suspect rough. Such controls do not apply to other gemstones. A major source of very-high value gems is Myanmar (formerly Burma), whose widely condemned military dictatorship may be engaged in their unethical trade, including smuggling to neighbouring Thailand and China to avoid scrutiny.

Foot of bird chick preserved in Cretaceous amber from Kachin, Myanmar. Credit: Pinterest, Xing Lida, China University of Geosciences)

Myanmar is well endowed with sedimentary deposits that contain amber, the solidified resin from a variety of now extinct trees. Oddly, completely clear amber has low intrinsic value: it is semi-precious, albeit attractive. But it often contains inclusions of vegetation fragments, insects, feathers and small vertebrates, of interest to palaeontologists. Myanmar amber is especially interesting as it is dated to the Middle Cretaceous (~130 Ma), older than that found around the Baltic Sea (Eocene ~44 Ma), which was the main source for European jewellery since the 12th century, and that from Canada (Upper Cretaceous ~80 Ma). Myanmar amber has been used decoratively and medicinally in China since the 3rd century CE, and in Europe since prehistoric times. It is attractive but quite common, so historically amber never commanded high prices but was widely used as a trade item. Since the publicity attending the supposed extraction of dinosaur DNA from the bodies of reptile parasites to resurrect dinosaurs in Steven Spielberg’s 1993 film Jurassic Park, public and scientific interest in amber has boomed. It is primarily the exquisite preservation of encased organisms that piques the interest of palaeontologists. Papers that rely on the Myanmar amber have grown in number over the last ten years, despite the country being infamous for military repression of tribal and religious groups in its rural areas.

One of the most conflict-riven areas is the northern state of Kachin where the most interesting amber to palaeontologists is collected by the Kachin people of the Hukawng Valley. Government forces have been in conflict with the Kachin Independence Army since the 1960s, most particularly for control of the amber industry. A recent paper has focussed on the ethical issue of publications based on fossil-bearing amber from the area (Dunne, E.M. et al. 2022. Ethics, law, and politics in palaeontological research: The case of Myanmar amber. Communications Biology, v. 5, article no. 1023; DOI: 10.1038/s42003-022-03847-2).

In 2010 the military began forcibly to take over mines in Kachin.  Between 2014 and 2021 the annual number of publication underwent a tenfold growth from between 10 to 15 to over 150, despite the fact that in 2015 the government in Yangon prohibited removal of fossils from the country. But the export laws exempt gemstones, so the growing demand for fossiliferous amber is clearly reflected in its supply to foreign scientists.  Rare specimens that include vertebrate remains command prices up to US$100,000. The Myanmar amber trade is now estimated at around US$ 1 billion per annum. The Myanmar military took over all the mines in 2017, and is clearly the main supplier to palaeontologists.

In the seven-year period, only 3 papers out of 872 included contributors from Myanmar, which also suggests an element of ‘parachute science’: unsurprisingly Myanmar-based scientists also find it difficult to visit the Kachin area. Before 2014 most of the 69 publications involved scientists in the US; since then, the top spot has been occupied by Chinese scientists who have amassed 417. It seems clear that there is a web of contacts linking together the source of Myanmar amber, its market and science. In 2020 the Society of Vertebrate Paleontology called for a moratorium on publishing data from Kachin sources. But since then there is little sign that palaeontologists have taken any notice.

See also: Ortega, R.P. 2022. Violent conflict in Myanmar linked to boom in fossil amber research, study claims. Science v. 378, p.10-11; DOI: 10.1126/science.adf0973 (This commentary includes opinion that seeks to mitigate the views of Emma Dunne and colleagues)

Dinosaur corner

Many adjectives have been applied to dinosaurs: terrifying; lumbering; long-dead; fierce; huge; nimble, carnivorous; herbivorous and so on. But exquisite and tiny do not immediately spring to mind. The mineral amber – strictly speaking a mineraloid because it isn’t crystalline – having formed from resins exuded by trees, preserves materials, including animals, that became trapped in the resin. The shores of the Baltic Sea used to be the main source of this semi-precious gemstone, but it has been overtaken by high-quality supplies from Kachin State in Myanmar. Most specimens contain small invertebrates, including spiders and insects, in varying states of preservation. Once in a while truly spectacular amber pebbles turn up. In early March 2020 the world’s media splashed a unique find: a miniature dinosaur (Xing, L. et al. 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature v. 579, p. 245–249; DOI: 10.1038/s41586-020-2068-4).

Amber pebble from Myanmar containing a tiny vertebrate’s skull (credit: Lida Xing, China University of Geosciences)

The amber specimen, from Middle Cretaceous (99 Ma) sediments, contains a perfectly preserved skull less than 2 cm long. At first glance it appears to be that of a tiny bird. The authors used micro-CT scanning to reconstruct the entire skull in 3-D. Although superficially resembling that of a bird, with eye sockets ringed by scleral ossicles that modern birds also have. These suggest that the animal was active during the daytime. Its beak-like jaws have many small teeth, as do many ancient fossil birds but not modern ones. These features led to its name: Oculudentavis khaungraaeI, translated as ‘eye-tooth bird’. So, is it a bird? A number of features shown by the skull suggest that, strictly speaking, it is not. Anatomically, it is a dinosaur, possibly descended from earlier types, such as the Jurassic winged and feathered dinosaur Archaeopterix, which evolved to early, true birds with which Oculudentavis coexisted during the Cretaceous Period. Having teeth, it was probably carnivorous and preyed on invertebrates: it may have been fatally attracted to tree resin in which insects had been trapped.

Micro-CT image of Oculudentavis khaungraaeI skull (top); artist’s impression of it in life (bottom) (credits: Xing, L. et al. 2020; Jingmai O’Connor, China University of Geosciences)

Even if it was a bird , it is smaller than the smallest living example, the bee hummingbird (Mellisuga helenae) and, weighing an estimated 2 grams,  Oculudentavis is about one-sixth the size of the smallest known fossil bird. As a dinosaur, it is two orders of magnitude smaller than the most diminutive example of those found as fossils, the chicken-sized Compsognathus. Rather than being just an oddity, Oculudentavis demonstrates that extreme miniaturisation among avian dinosaurs held out evolutionary advantages.

Watch a video about the discovery and analysis of the tiny dinosaur

See also: Benson, R.B.J. 2020. Tiny bird fossil might be the world’s smallest dinosaur. Nature, v. 579, p. 199-200; DOI: 10.1038/d41586-020-00576-6.

Artist’s rendering of a Middle Jurassic coastal plain in what is now the Isle of Skye across which a mixed dinosaur megafauna is migrating (credit: De Polo et al. 2020; Fig. 24; artist Jon Hoad)

And now for the lumbering and sometimes scary kinds of dinosaur. Since discovery of Middle Jurassic sauropod and theropod trackways with up to 0.5 m wide footprints at Brothers’ Point on the Trotternish Peninsula of Skye, the Inner Hebridean island has become a magnet for those wishing to commune with big beasts. Now the same team from the University of Edinburgh report more from the same locality (De Polo, P.E. and 9 others 2020. Novel track morphotypes from new tracksites indicate increased Middle Jurassic dinosaur diversity on the Isle of Skye, Scotland. PLoS ONE, v. 15, article e0229640; DOI: 10.1371/journal.pone.0229640). One set, referred to as Deltapodus was probably made by a species of stegosaur: the one with vertical plates on its back and a tail armed with large spikes, animated caricatures of which figure in inane YouTube clips, especially beating off Tyrannosaurs. The new locality preserves 50 dinosaur tracks that suggest a rich community of species. The most prominent suggest bipedal ornithopod herbivores and small, possible carnivorous theropods, both with three-toed feet, large quadripedal sauropods whose prints resemble those of elephants, as well as those with larger back feet than front attributed to stegosaurs. The sediment sequence displaying the tracks contains structures typical of deposition on a wide coastal plain.