Австралийн Шинэ Өмнөд Уэльс мужийн тариалангийн талбайгаас 11-16 сая жилийн тэртээх эртний ширэнгэн ойн үлдэгдлийг илрүүлжээ.
Австралийн Музейн Судалгааны Хүрээлэнгийн эрдэмтэд “Gondwana Research” сэтгүүлд нийтлүүлсэн судалгаагаараа дамжуулан уг олдвор хэрхэн хадгалагдан үлдсэнийг тайлбарлажээ. Тухайн бүс нутаг сая сая жилийн өмнө халуун орны ширэнгэн ой байсан бөгөөд шавьж, аалз, загас, шувууд болон ургамлын төрөл зүйл амьдардаг байв. Өнөөдөр хуурайшиж, цөлжсөн МакГратс Флэт хэмээх уг газраас олдсон олдворууд нь төмрийн агууламж өндөртэй гөтит хэмээх ашигт малтмалын давхаргад гайхалтай нарийвчлалтайгаар хадгалагджээ.
Ихэнх палеонтологийн олдвор шаварлаг чулуулаг буюу элсэн чулуунд хадгалагддаг бол энэ тохиолдолд олдворууд “феррикрит” хэмээх төмөрлөг бодисоор бүрхэгдсэн байна. Микроскопийн түвшинд 0.005 миллиметрийн хэмжээтэй төмрийн эсгэлэн хэсгүүд эртний организмын эд эс рүү нэвтэрч, задралд орохоос нь өмнө нөхөн бүрдүүлснээр ийм нарийн бүтэц хадгалагджээ.
Энэхүү олдворуудаас загасны нүдний пигмент эс, шавьж болон загасны дотоод эрхтэн, аалзны нарийн үс, тэр ч байтугай мэдрэлийн эсүүд хүртэл тод харагдаж байгаа нь шинжлэх ухааны хувьд онцгой ач холбогдолтой юм. Судлаачдын үзэж буйгаар эртний голын эргийн нуурын ёроолд тунасан төмрийн агууламж бүхий тунадас нь амьд биесийг эсийн түвшинд хүртэл “хөлдөөж” үлдээсэн байна. Энэхүү нээлт нь хуурай газрын эртний экосистемийг судлах шинэ арга замыг нээж өгч байгаа юм.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A patch of farmland in New South Wales has turned out to be one of Australia’s most remarkable fossil sites. Hidden beneath the soil, researchers have uncovered fossils from an ancient rainforest that lived between 11 and 16 million years ago, preserved in iron-rich rock with stunning detail. The discovery is surprising for another reason: the fossils were found in what is essentially rust.
Today, McGraths Flat sits beneath a landscape better known for dust and dry conditions than tropical vegetation. Millions of years ago, though, the area looked very different. A lush rainforest covered the region, providing a habitat for insects, spiders, fish, birds, and a wide range of plants.
Researchers from the Australian Museum Research Institute have spent years studying the site and the fossils it contains. Their latest work, published in Gondwana Research, focuses on the unusual iron-rich sediments that preserved this ancient ecosystem in extraordinary detail.
A Fossil Treasure Hidden in Iron
Most famous fossil sites share something in common. They are usually found in rocks such as shale, sandstone, limestone, or volcanic ash, where organisms were buried quickly enough for delicate tissues to survive.
As stated by Australian Museum Research Institute, classic examples include Germany’s Messel Pit, where fossils around 47 million years old preserve traces of fur, feathers, and skin, and Canada’s Burgess Shale, which contains soft-bodied animals dating back roughly 500 million years.
McGraths Flat is different. The rocks here are made almost entirely of goethite, an iron-bearing mineral that gives them a striking red color. Iron-rich rocks are usually associated with ancient geological formations rather than detailed fossils of plants and animals that lived on land.
That is why the site caught researchers off guard. Finding terrestrial fossils preserved so well in iron was not something scientists expected.
Cells and Organs Found in Fossils
The secret lies in the rock itself. McGraths Flat is made of a fine-grained iron-rich material called ferricrete. Under a microscope, it consists of tiny iron-oxyhydroxide particles measuring about 0.005 millimeters across.
As explained by Gondwana Research, these microscopic particles were able to enter tissues as organisms were buried in sediment. They filled structures at an incredibly fine scale, preserving details that are usually lost during decomposition.
The fossils reveal features that sound almost impossible to preserve over millions of years. Scientists can see pigment cells in fish eyes, internal organs in insects and fish, delicate hairs on spiders, and even nerve cells. Those details are especially valuable because terrestrial fossil sites with preserved soft tissues are uncommon. Marine fossil deposits often dominate the record, while land-based ecosystems are much harder to capture in such detail.
How an Ancient Rainforest Made It Possible
Researchers also wanted to understand how such an unusual fossil deposit formed in the first place. The process began during the Miocene, when the region was warm, wet, and covered by rainforest. As basalt rocks weathered, iron was released into the environment and carried underground by acidic groundwater.
The dissolved iron eventually reached a river system containing an oxbow lake, a section of river that had become isolated from the main channel. There, the iron formed extremely fine sediments that settled onto the lake floor.
When plants and animals died, those sediments rapidly coated their remains and replicated soft tissues down to the cellular level. Over time, the iron-rich deposits hardened into the fossil-bearing rocks found today. The researchers believe understanding this process could help identify similar sites elsewhere.
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