Species: Foerstephyllum vacuum (Foerste, 1909)
Formerly: Columnaria vacua, Columnaria halli (Holland, UGA Strat Lab)
Map point data provided by iDigBio.
- C6 Sequence (Otter Creek Coral Bed – See red book: includes Saluda, Upper Whitewater & Elkhorn)
- C5 Sequence (Saluda, Lower Whitewater, Liberty)
Identification in Hand Sample
- Massive colonies
- Very short to no septa
- Highly polygonal corallites
- Corallites with tabulae and short setal spines
Foerstephyllum vacuum from Liberty formation of Nelson County, Kentucky (MUGM 5301)
Holland (UGA Strat Lab, 2013):
- Note highly polygonal corallites with short septal spines; polygonal corallites averaging 4 mm, with tabulae and short septal spines.
- According to Jull (1976), the early septal arrangement in Foerstephyllum vacuum (Foerste) is similar to the septal development in rugose corals and pores are lacking. Consequently, I consider Foerstephyllum to be a rugose coral. The evolutionary development of favositids from Foerstephyllum as suggested by Flower (1961) seems questionable.
Simmons & Oliver, Jr. (1967)
- This species is referred to as Columnaria vacua in the pre-1950 literature. Colonies are massive; 35 Otter Creek specimens range from 1 to 19 cm in maximum diameter. Average corallite size in colonies ranges from 3 to 5 mm or more. This species differs from Favistina stellata by having no septa, or very short ones; locally these may be amplexoid, extending nearly to the axis on the upper surfaces of tabulae.
- Confusion between the two horizons has undoubtedly resulted from confusion between the two principal species of corals. Foerstephyllum vacuum appears to have been mistaken for Favistellla alveolata because septa appear to extend almost to the center of some corallites in occasional specimens. Examination and sectioning show that this is the case in the bottom of calices of budding corallites where the aborted septa start.