Kids Feedback: How Do Jellyfish Fossilize?

on May 13, 2011

Hi! My name is Emma, and I am 12 years old. I homeschool, and when I was doing science today, I found a website saying that jellyfish have been buried in coarse sand in Mosinee Wisconsin. This confuses me. How are jellyfish supposed to be fossilized? They have no bones at all! How do jellyfish fossilize if they don't have bones?

Thank you for your time,

– Emma T., Indiana

Thanks for sending in this great question, Emma. I can understand why you are confused, because it is difficult for soft-bodied creatures, such as jellyfish, to fossilize. Normally, dead jellyfish on a sandy beach start to decompose within hours. In order for a jellyfish to fossilize in sand, there would have to be catastropic conditions, causing rapid fossilization.

Consider what happens to soft-bodied creatures like jellyfish when washed up on a beach today. Because they consist only of soft “jelly,” they melt in the sun and are also destroyed by waves crashing onto the beach. Based on this reality, the discoverer of these exquisitely preserved soft-bodied marine creatures concluded that all of them had to be buried in less than a day!1

Fossilized Jellyfish

Photo courtesy Andrew Snelling

Soft-bodied marine creatures, such as this fossilized jellyfish (Mawsonites spriggi), are finely preserved in a sandstone bed.

When we look in the Bible, where do we find a catastrophe that would cause rapid fossilization? Genesis 7:6–12 describes a world-wide Flood, where “the fountains of the great deep burst forth, and the windows of the heavens were opened.” The Flood was a violent, catastrophic event. The upheaval caused during the Flood (and potentially with local catastrophes since then) would have caused the conditions necessary for soft-bodied creatures to fossilize. These creatures would have to be buried quickly in sediment, which then hardened.

To learn more about jellyfish and some very interesting fossils, please read the following:

Parents, if your children have any questions, please submit them using the “contact us” section on our main website.


  1. Andrew Snelling, “The World’s a Graveyard”, Answers Magazine, Vol. 3, No. 2, April–June 2008,