Spirifer invalidistriatus Hyde, 1953 - fossil brachiopods in sandstone in the Mississippian of Ohio, USA.

The Byer Sandstone is one of four stratigraphic units in the Mississippian-aged, siliciclastics-dominated Logan Formation of eastern Ohio. Ascending from the base, they are the Berne Conglomerate Member, the Byer Sandstone Member, the Allensville Member, and the Vinton Member. The Byer is dominated by quartzose sandstones.

The fossils are brachiopods, a group of sessile, benthic, filter-feeding, marine invertebrates. They first appear in Cambrian rocks and were abundant in Earth's oceans throughout the Paleozoic. They were also common in Mesozoic oceans, but are scarce in modern oceanic biotas. Brachiopods have two shells, called valves, that are usually calcareous (made of calcite - CaCO3 - calcium carbonate). Each shell of a brachiopod is bilaterally symmetrical, unlike each shell of a bivalve (clam).

These brachiopods are spiriferids, preserved as molds in sandstone. They appear to be consistent with Spirifer invalidistriatus Hyde, 1953 (originally "Spirifer centronatus invalidistriata"), which was described by Hyde (1953) from the same locality as those seen here.

Classification: Animalia, Brachiopoda, Articulata (a.k.a. Rhynchonelliformea), Spiriferida, Spiriferidae

Stratigraphy: lower Byer Sandstone Member, lower Logan Formation, Waverly Group, Osagean Stage, upper Lower Mississippian

Locality: talus next to old quarry on the southern side of the Licking River at Black Hand Narrows, Licking Gorge, west of the town of Toboso, far-eastern Licking County, eastern Ohio, USA (vicinity of 40° 03' 01.65" North latitude, 82° 13' 47.09 West longitude)

For info. on Spirifer invalidistriatus, see:

Fagadau (1952) - Paleontology and Stratigraphy of the Logan Formation of Central and Southern Ohio. Ph.D. dissertation. Ohio State University, Columbus, Ohio, USA. pp. 232-233, 400, pl. 6, figs. 1-6.