Sinuites cancellatus

• Most common Bellerophontid from the Ordovician
• Evenly rounded dorsum
• Symmetrically and spirally coiled
• Rounded apertural lobes
• U-shaped sinus
• Concentric and longitudinal striae, with concentric being more visible

• Planispirally coiled; entire Cincinnatian

Fossils of Ohio (1996) :

• Medium sized. Classified by many paleontologists as monoplacophorans on the basis of the presence of multiple, bilaterally arranged muscle scars.

McFarlan (1931):

• The most common of the Ordovician Bellerophontids characterized by the evenly rounded dorsum, rounded apertural lobes, and moderately deep sinus which is U- rather than V-shaped. Surface marked by fine lines of growth crossed by fine revolving striae. The surface features are seldom preserved. Diameter up to about 25 mm., height about 4/5 diameter. Trenton to Richmond.

Ruedemann (1926):

• Sinuites cancellatus has been described by Hall (1847) and fully discussed in the various aspects owing to its great range, by Ulrich and Scofield (1897). By these authors and our material it is brought out that S. cancellatus is of medium to large size, reaching its largest size in the Lorraine formation. Its general form is subglobose, owing to its rather close coiling and the well-rounded back of the volutions. Its aperture is transverse, about twice as wide as high, its width equalling the height of the entire share. The apertural lobes posses a rounded outline and the sinus in the outer lip is broadly rounded. Shell composed of several layers, the outermost of which, rarely preserved, carries a beautiful pattern of fine transverse and revolving lines, so fine that they are barely visible to the naked eye; six of the revolving lines being counted within 1 mm in the Lorraine material. This pattern is near the umbilicus replaced by one of irregular or wavy revolving lines. Usually only the inner layer is preserved and the shell smooth.

Foerste (1924):

• Aperture without an abruptly expanding flaring flange; dorsum rounded, not carinated, without a slit-band; umbilicus closed; surface markings rather obscure and not likely to attract attention.
• Locality and Horizon. Originally described from Lorraine, New York, from the Pulaski member of the Lorraine formation. Widely distributed from the Trenton to the Richmond in Canada and New York; throughout the middle United States, chiefly in the Trenton. Typical specimens, 2- to 25 mm. in diameter, occur in the Sheguiandah at Tamarack pint, north of Honora, and at the same horizon 3 miles south of Little Current, at the top of the hill on the eastern road to Sheguiandah. In Quebec, it occurs in the Lorraine, throughout both the Leptaena and Proetus zones in the Nicolet River section. In the Proetus zone it occurs also at Chambly Canton. In the Waynesville zone it occurs in those fragments thrown out by the waves on the southeastern shore of Snake island.

Hall (1847):

• (Under Bellerophon cancellatus) Involute, subglobose; aperture expanded, bilobate; dorsal line subcarinated ?; surface cancellated by fine concentric and longitudinal striae ; concentric striae arching on the side, and meeting at a sharp angle upon the dorsal line; aperture with a sinus in the dorsal margin.
• The concentric striae are usually the more conspicuous, the others being scarcely visible, except under a magnifier. The only entire specimen seen is crushed, so that the original form cannot be clearly defined; but the marking of the surface is sufficient to distinguish it from any other species in the lower strata

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