Receptaculites oweni Algae Fossil

This picture is of a Receptaculites oweni (Hall, 1861) algae colony fossil. It was found in Minnesota USA. It dates to the Middle Ordovician Period.

The picture was taken in June 2023 on the first floor of the Smithsonian Museum of Natural History in Washington D.C. USA.

Fisherites Chlorophytes Fossil

These pictures show a fossil of calcareous green algae (chlorophytes) from the Ordovician Period. They are called Fisherites sp. of the order Dasyclads and family Receptaculites. The fossil was found in the Galena Formation of Minnesota.   Second picture shows a cross section of the fossil.
Thanks to Herb for the images.