Lepidocyclina sp.

Phylum Protozoa
Class Sarcodina
Order Foraminifera

(Scale bar is 1 cm)



Large discoidal forams are common in the Eocene and Oligocene limestones of the southeast, as they are in other parts of the world. In this area the most common genus is Lepidocyclina, though others occur as well. Identification to species requires slicing thin sections and examining the internal structure, which is difficult and time consuming. However, when specific identification is made the fossils generally make excellent tools for correlation. This particular suite of individuals is from the Bridgeboro Limestone.

In the Mediterranean region the genus Nummulites (from the latin 'nummulus', which means 'coin') is the most common taxon. Eocene and Oligocene rocks in that region have historically been included in a time-rock unit called the "Nummulitic". Rocks in Egypt are very rich in these fossils - most of the blocks of the pyramids of Giza, for example, are full of them. One species from the Arabian Peninsula reached a size of about 15-20 cm (6-8"), an amazing feat for a single celled organism! Such individuals may have lived for a century.

In Recent seas, large forams generally live in shallow, clear, nutrient poor waters. Much of their nutriment comes from the excess photosynthate produced by algae that live symbiotically in their tissues, as in the reef-building corals. Fossil lepidocyclines and nummulitids are almost always found in rocks characteristic of these types of environments, suggesting that they too lived symbiotically with algae.


AGE: LATE EOCENE and EARLY OLIGOCENE

FORMATION: OCALA and BRIDGEBORO LIMESTONES and RESIDUUM

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