Stromboidea
Original Diagnosis of Tessarolax alaskana by Saul & Squires, 2015
- ” Mature last whorl bicarinate, carinae with many small nodes; callus over ventral face becoming massively thick at ablabral edge, crossing carinae, and extending up spire and along edge of apical digitation. ”
Original Description of Tessarolax gabbi by Saul & Squires, 2015:
- "Shell up to 44 mm high (apical and rostral digitations incomplete) and 58 mm wide (only posterior outer lip digitation complete). Pleural angle approximately 40 degrees. Protoconch unknown. Teleoconch of at least six whorls (tip missing). Suture moderately impressed. Immature shell: Turriculate, consisting of five whorls, unicarinate; numerous spiral threads on whorls, threads more widely spaced on ramp. Penultimate whorl carina with weak nodes. Mature shell: Consisting of very wide last whorl, strongly bicarinate, carinae with many small nodes, posterior carina stronger, interspace covered with spiral ribs. Aperture wide. Outer lip thickened with callus, expanded into four slender canaliculate digitations. Apical digitation extending along spire at angle to shell axis and crossing below tip of shell. Posterior and anterior outer lip digitations extending from their respective carinae. Rostral digitation apparently straight. Callus deposit over ventral face of shell becoming massively thick on ablabral edge, forming thick ridge that crosses carinae and continuing up spire along edge of apical digitation; tip of spire free of callus, but tipmissing from specimens withmost callus. Base of last whorl free of callus, flattish, with spiral threads immediately anterior to anterior carina. Apertural side of neck with some light callus glaze."
Locus typicus: Cottonwood Creek, Shasta County, Ono, northern California, USA
Stratum typicum: Shasta Group, Hauterivian, Cretaceous
Holotype: ANSP 4282
Helicaulax bicarinata Gabb, 1869, pl. 27, fig. 47
Tessarolax gabbi Saul & Squires, 2015; Budden Canyon Formation, Ogo Member, upper Hauterivian, Cretaceous; North Fork Cottonwood Creek area, Ono, Shasta County, California; left hypotype LACMIP 13568, middle and right hypotype LACMIP 13569
Tessarolax gabbi Saul & Squires, 2015; Budden Canyon Formation, Ogo Member, upper Hauterivian, Cretaceous; North Fork Cottonwood Creek area, Ono, Shasta County, California; left hypotype LACMIP 13570, middle and right hypotype LACMIP 13572
Tessarolax gabbi Saul & Squires, 2015; Budden Canyon Formation, Ogo Member, upper Hauterivian, Cretaceous; North Fork Cottonwood Creek area, Ono, Shasta County, California; left hypotype LACMIP 13570 , right hypotype CAS 62534.01
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