Two Related Genus’s of Star Coral

Elliptical Star Coral

Elliptical Star Coral Fossil (Click to view large for fine details, then arrow back)

 

 

 

 

 

 

 

 

Because the variety of corals is so vast, it can be difficult  to identify species which requires a discreet eye. After close examination and research, I believe I have targeted its identity!

Elliptical star coral is named for its oval elongated shaped corallites or the calcareous cups from which the polyps protrude. Scientifically named Dichocoenia, stokesi, shown above, is a massive colonial coral that forms round humps up to 16 inch (40 centimetres) in diameter. These two characteristics coincide with my fossil quite well.

It is a fairly uncommon species, and has been placed on the Red List for Endangered Species. In 1995 off the Florida Keys, Dichocoenia, stokesi suffered from a disease called white plague which killed 95% of its colonies. It’s a slow growing variety for which the struggle to come back is fast diminishing, unless we humans do something about its plight and that of many other coral varieties.

Kingdoms : Animalia

Phylum:  Cnardia (Marine group with stinging cells)

Class:  Anthozoa (Flower Animal)

Order:  Scleratinia  (Modern species of Stony Coral)

Family:  Meandrinidae (meandering  form)

Genus: Dichocoenia (hump-forming or flattened corals with irregular calyces)

Species: stokesi (elliptical or pineapple star coral)

Blushing Star Coral Fossil

Blushing Star Coral Fossil (View Large)

Blushing Star Coral Fossil Side view showing flat plate form)

Blushing Star Coral Fossil
(Side view showing flat plate form)

 

 

 

 

 

Stephanocoenia, intersept  have tentacles that are commonly extended during daylight, unlike most coral. When touched, it rapidly retracts them causing a slight color change, which gives this coral its common name of “Blushing Star Coral”. It can be found in Florida, the Caribbean and Central American regions and as far south as Brazil. It’s found in a number of reef habitats including channels and lagoons. It grows massive encrusting colonies forming flattened domes. Corallites can be circular to polygonal. The two characteristics of flattened domes and corallite shapes are in line with my coral fossil shown above.

Nutrition: Like all coral, it has a symbiotic relationship with algae zooxanthellae. Through photosynthesis, the algae provides energy to the coral which in turn homes the algae. Food is caught as it passes by the coral tentacles whereby stinging cells called nematocysts stun and hold onto it.

Its earliest fossil record dates back to the Eocene period between 55 and 33 million years ago.

The Blushing Star Coral is also susceptible to white plague type II which exposes the skeleton by rapid tissue destruction and is also on the Red List of Threatened species.

star coral blushing 3

Blushing Star Cora. (View Large)
Source:
http://reefguide.org/carib/pixhtml/blushingstarcoral2.html

Kingdoms : Animalia

Phylum:  Cnardia (Marine group with stinging cells)

Class:  Anthozoa (Flower Animal)

Order: Scleratinia (Modern species of Stony Coral)

Family:  Astrocoeniid  (small family made up of  both reef building and non reef building  genus, both with and without symbiotic zooxanthellae as well as both branching and encrusting species.

Genus: Stephanocoenia (Colonies are flattened usually with regular, smooth surfaces. Corallites are small and the wall between them may be relatively wide.)

Species: intersepta

 

Winkie’s Pillar Coral Fossil

Pillar Coral (Dendrogyra, cylindricus)  Source: en.wikipedia.org

Pillar Coral (Dendrogyra, cylindricus)
Source: en.wikipedia.org

Pillar Coral is one of the most spectacular stony corals found in the western Atlantic Ocean and Caribbean Sea.  It derives its name for obvious reasons with its finger like branches. They can reach a height of nearly 3 meters.

Pillar Coral Fossil (Dendrogyra, cylindricus)

Pillar Coral Fossil (Dendrogyra, cylindricus)

This pillar coral fossil is another sample given to me by my late mother-in-law, Winifred (Winkie). She gathered her coral fossil collection along Florida coasts during an era when it was okay to do so.  Colonies were once more common along the Florida reef, but commercial collections has greatly reduced its occurrence. Otherwise, pillar coral (Dendrogyra, cylindricus) is found commonly along coasts of Jamaica and Bahamas.

Dendrogyra, cylindricus is unusual in that the polyps with their tentacles are expanded in the daytime unlike most other stony coral.  The tentacles sway with the current and if one portion of the colony is disturbed by touching so that the polyps contract, a wave of contractions of the other polyps can be seen to pass over the entire colony in a period of a few seconds.     

Pillar Coral (link to clear photo)

CLASSIFICATION OF PILLAR CORAL

Kingdom: Animalia

Phylum: Cnidardia (large marine group characterized with stinging cells, tentacles and no skeletons or organs)

Class: Anthozoa (Flower Animal)

Order: Scleratinia (Stony Coral)

Suborder: Faviidae (General Spherical Shape)

Family: Meandrinidae (Meandering valleys between corallites)

Genus: Dendrogyra

Species: Cylindricus

What’s being done to bring back the threat of coral? Coral farming, see video to find out about this effort to restore the reef along Florida Keys.

 

Hope you enjoyed this display of pillar corals and learned some things along the way.  I feel privileged to have inherited this sample as part of a collection from my beautiful mother-in-law Winkie.

1983 Ft. Lauderdale Florida Winky and Joe

1983 Ft. Lauderdale Florida
Winkie and Joe

Winifred (Winkie)

Winifred (Winkie)

Mystery Fossils Found Wintertime Lake Michigan Beach

HPIM2894

Winter 2010/2011

Most years, Lake Michigan’s wave action and chilling temperatures pushes ice and snow into huge mounds over the shoreline as high as twenty feet (shown above). In order to actually see the big lake you have to climb the mounds without falling in. Danger lurks around those edges where people can and have fallen through.

It’s January 2013 and the second consecutive season where the sand is left bare of winter’s icy layers; which I can’t stress enough how extremely rare that is. Looking towards the horizon over Lake Michigan, you would normally see a frozen tundra of stillness. Not this year. Compare the photo above taken winter 2010/2011 from the photo below taken winter 2012/2013.

Lake Michigan 2013

Lake Michigan Unfrozen January 2013

Case in point; due to the season’s whirling winds, minus the layers of snow, and less tourist traffic, fossils are more exposed from the continuous movement of sand. Below, are several interesting samples of fossils I found on Oval Beach, Saugatuck, MI (USA) winter 2012/2013. I haven’t been able to fully identify these species partly due to their smoothed surfaces, so please feel free to make suggestions. I have provided a few best guesses.

Coral Fossil, Geode or both?  Mystery Fossil 1

Coral with embedded crinoids

Crinoids embedded in coral or chunk of seafloor, Mystery Fossil 2

Fossil Coral

Sponge or Coral? Mystery Fossil 3

Fossil Coral

(reverse side of fossil above)