Cambrian Scyphozoan Jellyfish Fossils Mass Mortality

Four Jellyfish Stranded on a Cambrian Shoreline

Scyphozoa Jellyfish Ichnofossil

Phylum Cnidaria, Class Scyphozoa

Geological Time: Middle Cambrian

Size: Matrix: 12 by 8 inches

Fossil Site: Krukowski Quarry, Mount Simon Sandstone Outlier, Mosinee,Wisconsin

Code: DD426

Price: $375.00


Here we have a mass mortality plate of Cambrian Scyphozoan jellyfish, from the Krukowski quarry in Central Wisconsin that has been under currently intense scientific study since 2000. The Krukowski quarry yields ichnofossils that are the earliest evidence of terrestrialization of animals in the fossil record

The plate contains four tentacled jellyfish, which are rare in the quarry. The fossils are actually body cavity infillings that formed as the animal's ingested sand while pumping their bodies in a futile attempt to escape their stranding on the intertidal zone of a Cambrian shoreline. Because these jellyfish body fossils are incredibly subtle in vertical relief, the specimen has been subtly stained. Some Blackberry Hill jellyfish fossils approach two feet in diameter.

Being comprised entirely of soft tissue (living jellyfish are about 95 % water), unlike animals with exoskeletons (e.g., trilobites) or skeletons (vertebrates), jellyfish fossils are body fossils that are impressions of the jellyfish. Such fossil impressions are rare throughout the fossil record. Appearing during the Ediacaran, jellyfish were some of the most ferocious predators of the Cambrian marine environment. The Blackberry Hill scyphozoan fossils are almost surely the result of a mass stranding on an ancient Cambrian beach, possibly caused by a storm surge.

Phylum Cnidaria (anemones, corals, jellyfish and sea pens) are among the most ancient animals and has one of the longest fossil histories of metazoans. Though simple in body form, they remain ubiquitous and widespread in modern marine environments. The earliest forms in the fossil record appear in Ediacarian fauna of Southern Australia, which dates to the Precambrian some 600 million years ago. Their persistence is clear testament that old and simple animals can be enormously successful, and that the clique' "climbing the evolutionary ladder" is a misnomer; rather, life either adapts to the current and changing environment, or perishes.

Reference: Hagadorn, JW., Dott, RH., Damrow, D, Stranded on a Late Cambrian shoreline: Medusae from central Wisconsin, Geology (39) No. 2.


Fossils Purchase Information

Click pix to enlarge

Fossil Mall Navigation:
l Home l Fossils for Sale Map l Museum and Rare Fossils l How to Buy Fossils l

Navigate by Fossil Category:
l Trilobites
l Ammonites l Fish Fossils l Invertebrate Fossils l
l Crinoids and Echinoderms l Insect Fossils l Dinosaur and Reptile Fossils l
l Cambrian Explosion Fossils l Plant Fossils l Stromatolites l
l Vertebrate Fossils l Fossil Amber l Trace & Ichnofossils l

l Fossils and Paleotological Science Information l