Mazon Creek Best Of The Best Octomedusa Pieckorum Johnson And Richardson, 1968

[RCFossils]

Octomedusa is a type Scyphozoan jellyfish.

It is the smallest described species of jellyfish that can be found in the Mazon Creek deposit. The bell can reach a maximum diameter of approximately 2 centimeters.

Like all Cnidaria from Mazon Creek, they are only found in the marine portion of the deposit.

In the faunal study that I have referenced in previous posts, Octomedusa made up .03% of 230,000 concretions collected.

Often times, only the bell is preserved.

Well preserved specimens will show 8 tentacles. Depending on orientation in the concretion, some specimens will show a crenulated edge around the bell. 

Most specimens show very little raised detail and often appear as just a color difference in the rock.

A large “X” shaped mouth opening is preserved in some better specimens.
This first specimen shows most of the defining features.

 

[RCFossils]

A very nice specimen preserving all 8 tentacles (rare).

[RCFossils]

[RCFossils]

This specimen shows the crenulated edging around the bell.

[RCFossils]

This amazing specimens is one of the favorites in my collection.

It is a unique association of multiple Octomedusa surrounding an unusual and rare shrimp named Kellibrooksia macrogaster.

[Tidgy's Dad]

There are eight reasons I love this species.

[Nimravis]

Very nice examples Rob, here are a few that I had handy to photograph tonight.

 

[Wrangellian]

Wonderful.

I've got one little Octomedusa specimen with only one tentacle that I can see... hardly worth taking a pic compared to these!

[RuMert]

Looks like I've found that faunal study but I couldn't locate any comprehensive statistic table. What am I doing wrong?

[RCFossils]

11 hours ago, Nimravis said:

Very nice examples Rob, here are a few that I had handy to photograph tonight.

 

Nice specimens.

Thanks for sharing them.

[deutscheben]

3 hours ago, Wrangellian said:

Wonderful.

I've got one little Octomedusa specimen with only one tentacle that I can see... hardly worth taking a pic compared to these!

I just have one specimen as well, but I love it- it is such a simple yet expressive fossil creature. These examples are so incredible, with all the delicate tentacles preserved. 

[Ruger9a]

Fantastic collection!