Wednesday, May 19, 2010

Fossil of the Week

5/19/10 – Eocene Coral (3769.jpg)

Coral is a colonial “animal” made up of many individual flower-shaped polyps protected by a hard skeleton. In this specimen from the Upper Eocene of Cuba, each tiny depression was a chamber for one of these fragile polyps. There are two kinds of corals living today: colonial and solitary*. This one is a colonial coral. Living coral colonies are one of the world’s most protected and most threatened groups of animals. They require warm, clear, shallow water within the “photic” zone of the ocean, that is, shallow enough for sunlight to penetrate. This is because their tissues contain algae that live symbiotically with the coral, metabolizing carbon dioxide discarded by the coral and producing energy that helps the coral grow. Unfortunately, warm, shallow water, usually near the coast, is also where people like to play and work – for commercial and recreational fishing and boating, swimming, scuba diving, etc., - and which is also susceptible to run-off from septic systems and fertilized golf courses.

Anyway, back to our fossil. This is Astrocoenia calixtoensis (paratype** no. PRI 3769), named by John W. Wells*** (a Cornellian and student of Gilbert Harris) in 1934. The species was named for its locality, Loma Calixto near Nuevitas, Camaguey Province, Cuba. The ending “-ensis” on the name tells us that the word is a patronym named after a place. The original paper (in Bulletins of American Paleontology, vol. 20, no. 70B) says that the specimens were collected by Norman Weisbord another Cornellian and Harris student. [Harris students were a very strong force in PRI’s early days, and one academic “grandchild” of Harris (a student of one of his students) is still a member and Trustee of the organization.] Astrocoenia is apparently so far still known only from Cuba. As such, it is called an “endemic” species, that is, restricted to only one place. Endemic species are often the most fragile ecologically – we assume that something in their physiology or mode of life prevents them from spreading further geographically. So if anything happens to that particular environment, the species could be in real trouble.

PRI honors the author of this species, John Wells, by its student grant called the John W. Wells Grants-in-Aid of Research Program. This annual award supports collections-based research in any field of paleontology with up to $500 to assist with the student’s visit to PRI to use the collections. PRI has one of the largest collections of invertebrate fossils, including corals, in North America.

*For other corals, see Fossils of the Week 8/26/09 - Heliophyllum halli and 8/6/09 – Coral.
**See 10/14/09 - Atrypa aperanta Crickmay for a definition of paratype specimens.
***For more about John W. Wells, see Fossil of the Week 12/22/09 – Ichthyodorulite (Fish Spine).

Text by Paula Mikkelsen

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