Exposed Anatomy of Lower Devonian Brachiopod from New York

[Jeffrey P]

Found this small Lower Devonian brachiopod two weeks ago- Meristella laevis with part of the outer shell broken away exposing the internal anatomy. It was found near Deer Park, NY. in Orange County. A special thanks to Gordon on the Forum for showing me this small exposure.

[abyssunder]

Nice lophophore!

[Fossildude19]

Very cool, Jeff. 
Nice example, for sure. 

Thanks for showing it to us, here. 

Regards, 

[sdsnl]

Fascinating! I could not help but spend hours looking up info about it. Here's a better specimen from London's Natural History Museum:

 

This preserved structure is called a brachidium. It is a cartilage that supports the lophophore, a filter feeding organ (which is also present in bryozoans, but in bryozoans it is like a crown while in brachiopods it is U-shaped or coiled). Brachiopods are named after the U-shaped lophophore, which is also called a brachium because of its resemblance to an arm (brachium is the anatomical term for the arm minus the hand).

 

The lophophore is filled with tentacles, but unlike conventional tentacles, they are hollow like a tube. Cilia at the top of the lophophore wave around to move water through the tentacles, where planktons are trapped by mucus, then transported by cilia all the way to the brachiopod's mouth.

 

p.s. Not all brachiopods have a brachidium. For species that don't, the lophophore is solely supported by the water pressure inside the shells.

[Darktooth]

Nice find Jeff! Thanks for sharing with us!

[Ludwigia]

Nice specimen, Jeff. Thank goodness for calcite replacement.