Rugosa

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The Rugosa Rose is also sometimes just called "Rugosa"

Rugosa Fossil range: Ordovician–Permian
"Tetracoralla" from Ernst Haeckel's Kunstformen der Natur, 1904
Scientific classification
Kingdom: Animalia Phylum: Cnidaria Class: Anthozoa Subclass: Zoantharia Order: Rugosa
Suborders
Columnariina† Cystiphyllina† Streptelasmatina†

The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permian seas.

Solitary rugosans (e.g., Caninia, Lophophyllidium, Neozaphrentis, Streptelasma) are often referred to as horn corals because of a unique horn-shaped chamber with a wrinkled, or rugose, wall. Some solitary rugosans reached nearly a meter in length. However, some species of rugose corals could form large colonies (e.g., Lithostrotion). When radiating septa were present, they were usually in multiples of four.

Rugose corals have a skeleton made of calcite that is often fossilized. Like modern corals (Scleractinia), rugose corals were invariably benthic, living on the sea floor or in a reef-framework. Although there is no direct proof, it is inferred that these Palaeozoic corals possessed stinging cells to capture prey. They also had tentacles to help them catch prey. Technically they were carnivores, but prey-size was so small they are often referred to as microcarnivores.

The Rugosa is one of the most well-known of corals for its fossilized character. It's almost always in a cast because of its dead body sinking into sand and being filled in with clay and other inorganic particles.

Horn coral are extremely common fossils in some areas, such as the outer Bluegrass of Kentucky. They are easily picked out of creek rock in stream beds, but tend to be worn smooth, as shown in the photo.

[edit] External links

• Color reconstruction of the Devonian coral Heliophyllum halli at www.emilydamstra.com