Subj : ES Picture of the Day 06  2023
To   : All
From : Dan Richter
Date : Fri Jan 06 2023 11:00:36

 EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes
and phenomena which shape our planet and our lives. EPOD will collect and
archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


 Opalized Fossil of a Cycad Cone

   January 06, 2023


    Mila_cycad (003)

   Photographer:  Mila Zinkova

   Summary Author:  Mila Zinkova

   Shown above is an opalized  cycad cone fossil (31 x 11 x 9 mm) that
   was found in Lighting Ridge, Australia. Fossil cycads, dating from the
    Mesozoic, have been uncovered on every continent. These very
   ancient group of seed plants are thought to be a sister group to all
   other living seed plants.

   Most fossil cycads are called  cycadeoids and are classified
   scientifically in the order Bennettitales. During the  Jurassic,
   cycads and their kin, along with conifers and  ginkgos, dominated
   the plant kingdom. They remain  extant and are commonly referred to
   as living fossils.

   On occasion, cycad fossils are  opalized. If a cavity in a rocky
   surface resulted when a living organism, such as a shell or pinecone,
   was buried in sand or clay and then rotted away, an opalized cast or
   fossil replica may form of the object that was buried.  Click here
   to see a video of this fossil, which also includes clips of a modern
   cycad.


   Lighting Ridge, Australia Coordinates: -29.4278, 147.9790


Related EPODs

    Opalized Fossil of a Cycad Cone  Radial Stress Fracture  Red
   Bar Natural Bridge, Utah  Crystal Forms in Petrified Wood  Mt.
   Baker at Sunrise  Fossil Find in Sicily, Italy
    More...

Geology Links

     *  Earthquakes
     *  Geologic Time
     *  Geomagnetism
     *  General Dictionary of Geology
     *  Mineral and Locality Database
     *  Mohs Scale of Mineral Hardness
     *  This Dynamic Earth
     *  USGS
     *  MyShake - University of California, Berkeley
     *  USGS Ask a Geologist
     *  USGS/NPS Geologic Glossary
     *  USGS Volcano Hazards Program

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   Earth Science Picture of the Day is a service of the  Universities
   Space Research Association.

https://epod.usra.edu
 
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