Moving grandfather's fossils

[GeschWhat]

14 hours ago, lildragon said:

 

 

Beautiful Xenophora (aka carrier shell)! They have always intrigued me.

[caldigger]

Your name isn't Alice is it?  Because you've been walking through Wonderland for several weeks now.

[oldtimer]

The shells at the top of this page are amazing.

Your grandfather sure had some beautiful stuff.

[TGFV]

Hello Lildragon,

 

The box of "Dinosaur poop" you have found on the attic is of much more recent date. It is an ichnofossil of Miocene age and comes from the region of Antwerp. It is believed that these concretions originated around burrows of a worm called Tasselia ordamensis (R. Van Tassel, 1965).

 

If you happen to cross a concretion that is damaged have a closer look at the cross section. You will notice a difference in colour; more light grey in the centre and more brown towards the outside of the fossil. The colour changes mark a transition from  apatite (calcium phosphate) to siderite (iron carbonate). The presence of phosphate at the centre of the fossil confirms the biological origin of these concretions.

 

Just let me know if you want more information on this type of fossils.

 

Best regards,

 

Tom