A Cretaceous scleractinian coral with a calcitic skeleton.
It has been generally thought that scleractinian corals form purely aragonitic skeletons. We show that a well-preserved fossil coral, Coelosmilia sp. from the Upper Cretaceous (about 70 million years ago), has preserved skeletal structural features identical to those observed in present-day scleractinians. However, the skeleton of Coelosmilia sp. is entirely calcitic. Its fine-scale structure and chemistry indicate that the calcite is primary and did not form from the diagenetic alteration of aragonite. This result implies that corals, like other groups of marine, calcium carbonate-producing organisms, can form skeletons of different carbonate polymorphs.
Stolarski
Jaroslaw
J
Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, PL-00-818 Warsaw, Poland. stolacy@twarda.pan.pl
Meibom
Anders
A
Przenioslo
Radoslaw
R
Mazur
Maciej
M
D000818:Animals; D037421:Anthozoa / Q000033:anatomy & histology* / Q000737:chemistry*; D002113:Calcification, Physiologic; D002119:Calcium Carbonate; D003460:Crystallization; D005580:Fossils; D019015:Geologic Sediments; D014131:Trace Elements / Q000032:analysis
D014131:Trace Elements; D002119:Calcium Carbonate