Stromboidea
Original Description of Tessarolax distorta by Gabb, 1864:
- "Shell elongated; spire high; whorls five or six (from casts), slightly convex in the middle, so as to produce a faint undulation on the smooth surface of the spire. Apex usually flattened and somewhat twisted; at other times bluntly rounded. Surface of body bicarinate, bearing on the upper carina, at a point about o third of the circumference from mouth, a short, clavate process, abruply truncated at the end and flattened above and below, prominent and angular at the extremity. This is placed about half-way between the first and the outer lip. Aperture small, broad above, rapidly narrowed and prolonged below into a canal, which curves obliquely forwards and to the left. Above, the mouth is continued into a canal, which runs beside the spire for about two-thirds of its height, and then curves off obliquely backwards and to the right. The outer lip is prolonged into two long, slender, channeled spines, continuations of the carinae on the whorl, which diverge rapidly, and which are not in the same plane, the lower one being directed much in advance of the upper."
Locus typicus: Tuscan Springs, Tehama County, California, USA
Stratum typicum: Campanian, upper Cretaceous
Holotype: UCMP 31394
Tessarolax distorta Gabb, 1864, pl. XX, fig. 82, 82a, b
History and Synonymy
1868
Tessarolax distorta in Gabb, 1868, pl. 14, fig. 18, 19
2015
Tessarolax distorta in Saul & Squires, 2015; Paratype; upper Cedar District Formation, upper middle Campanian, upper Cretaceous; ‘‘White House Site’’, western Denman Island, British Columbia Province, Canada; Coll. no. RBCM.EH2011.007.0011; Copyright Natural History Museum of Los Angeles County.
Tessarolax distorta in Saul & Squires, 2015; upper Cedar District Formation, upper middle Campanian, upper Cretaceous; ‘‘White House Site’’, western Denman Island, British Columbia Province, Canada; Copyright Natural History Museum of Los Angeles County.
- Upper row left; Hypotype coll. no. RBCM.EH2011.007.0012
- Upper right; Hypotype coll. no. RBCM.EH2011.007.0013
- Lower row; Hypotype coll. no. RBCM.EH2011.007.0014
Tessarolax distorta in Saul & Squires; Copyright Natural History Museum of Los Angeles County.
- Upper row; Hypotype; Chico Formation undifferentiated (possibly Ten Mile Member?), middle lower Campanian, upper Cretaceous; Tuscan Springs about 16 km northeast of Red Bluff, Tehama County, California, USA; Coll. LACMIP no. 13587
- Lower row left; Hypotype; lower Tuna Canyon Formation, upper Turonian, upper Cretaceous; Rustic Canyon/Temescal Canyon divide, Santa Monica Mountains, Los Angeles County, California, USA; Coll. LACMIP no. 13588
- Lower row right; Hypotype; Chico Formation, upper lower or upper middle Campanian, upper Cretaceous;; Rock Corral north of Folsom, east of Sacramento, Sacramento County, California, USA; Coll. LACMIP no. 13586
Specimens from institutional collection
Tessarolax distorta Gabb, 1864; (Chico Formation, Campanian, Cretaceous?), Ensenada, Baja California, Mexico; Coll. Naturkunde Museum Coburg
Specimens from private collections
Tessarolax distorta is a very strange species:
Coll. Ulrich Wieneke
Tessarolax distorta Gabb, 1864; Tuna Canyon Formation, Cretaceous; Palisades Highlands area, Santa Ynez Canyon, central Santa Monica Mountains, Los Angeles County, southern California, USA; Coll. Han Stoutjesdijk
Tessarolax distorta Gabb, 1864; Northumberland Formation, middle late Campanian, upper Cretaceous; Hornby Island, Vancouver Island area, British Columbia Province, Canada; Coll. Rick Ross
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