Amber gives a glimpse of Gondwana's forest bugs
Thursday, 15 February 2018
Egyptians, Greeks and Romans have long cut, carved, and polished amber to make fine jewellery, necklaces, beads, and decorative objects such as, rings, dice, sculptured portraits, and magical amulets to ward off evil spirits and diseases.
European amber originated from the coasts of Poland and Russia, where the Baltic Sea drowned a pine forest 44 million years ago. It is calculated that 100,000 tonnes of amber is still buried under the Baltic Sea, and is often washed up on beaches after storms. Today, over 400 tonnes of Baltic amber are extracted and traded every year. Rarely, insects, lizards, fur, and feathers are embalmed in the amber, giving us a picture of animal life in an ancient forest.
Amber is also mined in Burma, where 42 insect species have been identified from the 99-million-year-old deposits. In Mexico, 22 kinds of insects have been found in 25-million-year-old amber, and 43 insects, scorpions, worms, and crustaceans found in Dominican Republic amber, giving biologists a detailed reconstruction of a long-vanished forest insect community.
New Zealand kauri gum goes under three names. The stuff oozing out of the trees, or recently buried in the ground, is known as kauri gum. Sub-fossil gum is known as 'copal', and kauri gum over a million years old is known as 'amber'. The ancient amber is produced by ancestors of present-day kauri, and is found in old lake sediments, or as tiny droplets scattered through coal seams in the South Island.
**READ MORE:
* Guano enriches man and plants, sometimes too much
* Mutations have greatly benefited mankind
* Can genetic engineering make denim production green?
* Scientists who lie, cheat and defraud
* Feathered dinosaurs changed the definition of birds**
Over the last year or two, Kiwi scientists Daphne Lee and Uwe Kaulfuss (University of Otago), Dallas Mildenhall (Geological and Nuclear Science) and 23 other foreign specialists have sliced and polished thousands of tiny fragments of fossil amber from Nelson, Westland, Otago and Southland. The fragments were then examined under light and scanning electron microscopes.
Preserved pollen grains reveal the nature of the forest, half of whose species are now extinct. The team found an extraordinary range of 15 to 25-million-year-old beetles, ants, flies, springtails, mites, pseudoscorpions, cicadas, plant hoppers, midges, sandflies, bark lice, roundworms, spores, fungi, and the wing scales of moths or butterflies, trapped in the kauri amber – even spiders with insects trapped in their webs. The blood-sucking sandflies presumably fed on penguins and seals. All specimens have been deposited in the University of Otago's geological museum.
The findings are extremely interesting as New Zealand is the only place in world with a continuous record of amber going back 70 million years. The amber gives us the only insight into the ecology, food webs and evolutionary history of a community of soft-bodied, fragile animals in a Gondwana forest.
I must apologise for a blue I made in my column of February 5, where I mistakenly claimed that Moroccan phosphate deposits were the guano made by ancient reptiles. That, it seems, is a myth. Rather, the deposits developed in ancient shallow marine sediments.