Happy Fossil Friday!
Who: Atrypids!
What: Atrypidae. A group of extinct brachiopods also called "lamp shells" because of their shape
When: Late Ordovician to the Upper Devonian
Where: Found most places other brachiopods are found (including but not limited to: China, Europe, and North America).
Fun Fact!: Like all brachiopods, one thing that sets them apart from clams (bivalves) is the filter feeding apparatus called a "lophophore". Characteristic to Brachiopoda, this structure allows the organism to feed by creating water currents that run over spiral shaped structures inside the brachiopod and filter out particles of food to be digested.
Why are they cool?: Atrypids (as well as other Brachiopods) make fantastic fossils for determining the ages of assemblages, as they are restricted to very specific ranges and if you find a certain brachiopod in your fossil bed, you can easily get a good estimate of the age.
Here is a link to a video of a dissection of an extant brachiopod Lingula for those interested in the unique internal anatomy of these critters.
Science warning for information hunters!: While fact checking some of the information used in this post, I skimmed the Wikipedia article for this group and found that they say the range of the group was Ordovician to Carboniferous, following the link they cited the information to, I saw they used the ranges for a trilobite genus, rather an actual Brachiopod group. Just fair warning to all the new and experienced science lovers out there, Wikipedia is a wonderful source to jump from, to orient yourself in a sea of confusing and often bloated information, but ALWAYS check their sources yourself!)
Happy hunting!
Image Credits: (Both) A. Johnson