#FossilFriday is an active hashtag on Bluesky. In the last 30 days, 144 people shared 341 posts with it — around 11 a day. Activity is down 80% versus the previous week, peaking on Jul 31 with 79 posts.

Posts with #FossilFriday

David Clark

@clarkeocrinus.bsky.social

about 1 year ago

This is one of the most stunning crinoids in my collection. Gennaeocrinus mourantae from the Devonian Arkona Fm. of Ontario. A large pocket of these were found decades ago and very few have been found since. #FossilFriday

90 276 3456

Tabby🪶

@findmeinthecreek.bsky.social

2 months ago

Found a nice little megalodon this evening! Probably my biggest ever, but still small for a meg! #fossilhunting #FossilFriday

A large-ish fossil shark tooth in Tabby's palm. The root is black and the blade is gray. It has some damage on the left side, but it's pretty minor.

88 147 3367

Charmouth Heritage Coast Centre

@charmouthhcc.bsky.social

about 1 month ago

It's another stunning 2026 find for July's Fossil of the Month! Tony Gill found this rock showing a hint of ammonite back in January. Some expert prep work from Kayleigh Gill has revealed this stunning, rare ammonite, an ancestor to the ones found up in Yorkshire! #FossilFriday

38 294 2442

Cam Muskelly (Explorer of Deep Time ⏰ ⚒️)

@cambriancam.bsky.social

5 months ago

Happy #FossilFriday This is a beautiful Hexagonaria (colonial horn coral) from the Middle Devonian Cedar Valley Formation from Coralville, Iowa. There is a location in Iowa City, Iowa known as the Devonian Fossil Gorge where you can see an intact coral 390 million year old coral reef like this one.

69 264 2182

Cam Muskelly (Explorer of Deep Time ⏰ ⚒️)

@cambriancam.bsky.social

8 months ago

Welcome back to #FossilFriday! Here is a Petoskey Stone which is Michigan's state stone. It is a colonial rugose coral known as Hexagonaria percarinata. This comes from the Middle Devonian (Givitian) Gravel Point Formation (Traverse Group). Each corallite that you see would have housed a polyp.

51 221 1931

Cam Muskelly (Explorer of Deep Time ⏰ ⚒️)

@cambriancam.bsky.social

6 months ago

Welcome back to another #FossilFriday Here is the molar from an American Mastodon (Mammut americanum). This comes from Pleistocene deposits in San Jacinto County, Texas. Mastodons used their bumpy molars for grinding up twigs, leaf matter, and other shrubs.

63 221 1838

Cam Muskelly (Explorer of Deep Time ⏰ ⚒️)

@cambriancam.bsky.social

6 months ago

Welcome back to #FossilFriday everyone! Here we have a beautiful chain coral known as Halysites cantenularia. This comes from the Lower Silurian Cordell Formation (Monistique Group) Door County, Wisconsin.

30 155 1572

Prof. Juan Cisneros ⚒️🐉

@cisneros.bsky.social

about 9 hours ago

Um tronco petrificado, mais antigo que os dinos, aflorando na margem do rio Poty, e prédios no fundo. Teresina é a única cidade do mundo onde você consegue tirar uma foto assim. #FossilFriday

2 13 157

Cam Muskelly (Explorer of Deep Time ⏰ ⚒️)

@cambriancam.bsky.social

7 months ago

#FossilFriday Here is a gorgeous piece of petrified wood belonging to the genus Schinoxylon. This comes from the Eocene aged Laney Shale Member of the Green River Formation from in Valley, Sweetwater Co, Wyoming. This specimen has a beautiful vein of blue Chalcedony Quartz running through it.

35 158 1545

Cam Muskelly (Explorer of Deep Time ⏰ ⚒️)

@cambriancam.bsky.social

7 months ago

Welcome to the first #FossilFriday of 2026! We kick off the new year with this beautiful colonial horn coral know as Acrocyathus floriformus. This specimen comes from the Middle Mississippian (Lower Carboniferous) St. Louis Limestone in Missouri.

36 108 1382

David Clark

@clarkeocrinus.bsky.social

3 months ago

This is a Mississippian aged crinoid, Taxocrinus, from the Indian Shale Fm. of Indiana. I've collected this site a few times and found lots of blastoids. Crinoids are much less common. #FossilFriday

62 150 1354

David Clark

@clarkeocrinus.bsky.social

about 2 months ago

A nice piece of Hexagonaria coral from Alpena, Michigan. This is a colonial rugose coral with 6 sided corallites. It's Devonian aged and about 365 million years old. Michigan's state stone is commonly called a Petoskey stone as many beach worn specimens can be found near Petoskey, MI #FossilFriday