Fostoria dhimbangunmal toe bone (left), vertebra (upper right),
The new Australian dinosaur, named Weewarrasaurus pobeni, was about the size of a large dog.
The ancient creature was an ornithopod dinosaur, part of a group of small plant-eating species that moved around on two legs and that were particularly abundant on the Cretaceous floodplains of eastern Australia.
A fragment of the jawbone of Weewarrasaurus pobeni was found deep in an underground mine at the Wee Warra locality close to the Grawin/Glengarry opal fields, approximately 25 miles (40 km) southwest of Lightning Ridge, central-northern New South Wales.
The fossil was analyzed by a team of paleontologists from the Australian Opal Centre and the Universities of New England and Queensland.
“Like all fossils from the Lightning Ridge opal mines, the lower jaw of Weewarrasaurus pobeni is preserved in opal,” said University of New England’s Dr. Phil Bell and co-authors.
“Lightning Ridge is the only place in the world where dinosaur bones routinely turn to opal.”
(Excerpt) Read more at sci-news.com ...
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The lower jaw of Weewarrasaurus pobeni. Image credit: Bell et al, doi: 10.7717/peerj.6008
It is extremely rare for conditions to be right for formation of fossils; and even more rare for opalised fossils to form. Usually, only the hard parts of living things fossilise – for example seed pods, wood, teeth, bones and shells. This often happens after the plant or animal (or a part of it) is buried in sand or other sediments that slowly turn to stone.
Opal forms in cavities within rocks. If a cavity has formed because a bone, shell or pinecone was buried in the sand or clay that later became the rock, and conditions are right for opal formation, then the opal forms a fossil replica of the original object that was buried. We get opalised fossils of two kinds:
1) Internal details not preserved: Opal starts as a solution of silica in water. If the silica solution fills an empty space left by a shell, bone etc that has rotted away – like jelly poured into a mould – it may harden to form an opalised cast of the original object.
Most opalised shell fossils are 'jelly mould' fossils – the outside shape is beautifully preserved, but the opal inside doesn’t record any of the creature’s internal structure.
2) Internal details preserved: If the buried organic material hasn’t rotted away and a silica solution soaks into it, when the silica hardens it may form an opal replica of the internal structure of the object. This happens sometimes with wood or bone.
http://www.geologypage.com/2017/04/opalised-fossils-form.html
Ammonite
Snail (gastropod)
Belemnite ("Belemnites were superficially squid-like. They possessed ten arms of equal
length studded with small inward-curving hooks used for grasping prey."[2]-Wikipedia)
Fossil Wood
Ammonite
Pine cone
PING
I have never even heard of this.
I remember a picture from an old National Geographic (1956?) of two opalized fossils from Australia, a reptile bone and part of a tree trunk. Also keep in mind that the world’s largest opal deposit is at Coober Pedy, South Australia, not too far away from this discovery.
Thanks for posting this. Opalized Dino bones. Great pics.
All you’d ever want to know and more about opal at this link...
What is Opal?
https://www.opalauctions.com/learn/opal-information/what-is-opal
FWIW, Opal is my so-called "Birthstone"
So totally nifty neato....never heard of these.
Aside: dhimbangunmal ...pretty dhim name for a dino, imho.