Fusilinids are a group of single-celled animals belonging to the Phylum Protozoa. They secreted a protective skeleton, called a test. These animals come in many shapes and sizes. Some look like columns, blobs, or snails. Common in the Pennsylvanian of Texas are Triticites. Their tests spiral around a center axis giving it a cigar or rice shape. One species of Triticites grew to over an inch long.

These animals have two distinct cycles of maturity. When its size limit is reach, the animal’s many nuclei leave the skeleton. Each then secretes a smaller version of the skeleton around itself. The single nuclei subdivide into flagellated zoospores, which leave the small skeleton. A union of two zoospores produced multiple nuclei and another large skeleton. This is why two sizes of the same species are found together.

Triticites ventricosus (loose shells)

Common Name: fusilinids or "rice fossil"

Period: Pennsylvanian

Location: north of Cisco, Texas

Collection: Jo Cox

Size: 9 mm long (longest)

Triticites ventricosus

Common Name: fusilinids or "rice fossil"

Period: Pennsylvanian

Location: Brownwood, Texas

Collection: Jo Cox

Size: ? mm long block

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Triticites secalicus

Common Name: fusilinids or "rice fossil"

Period: Pennsylvanian

Location: Brownwood, Texas

Collection: Judie Ostlien

Size: 143 mm long block