Gastropoda Stromboidea | Species / Latiala Heliaca

Species / Latiala Heliaca

Stromboidea

Original diagnosis:

"A slender fusiform Latiala with about 16 xial ribs on spire whorls, greatly reduced on final whorl to two or three on dorsal side of body whorl."

Original description of Latiala heliaca by Saul, 1998:

"Shell of medium size, spindle shaped, except for expanded outer lip, of about nine whorls; whorls about twice as wide as high; last whorl approximately half of shell height; pleural angle about 36°; whorl profile on spire roundly convex; profile of last whorl roundly convex except at axial nodes and with broad axial bulge on apertural face; outer lip expanded, broad, subquadrate, slightly thickened at distal edge, with short anterior and longer posterior projections. Protoconch of four or five rapidly enlarging, rounded, glossy whorls; transition to juvenile sculpture gradual, marked by spaced faint, arched, axial ribs and spiral striae; ribs rapidly strengthened, becoming crowded. Sculpture on first juvenile whorl of 26-36 arched axial ribs crossed by much weaker fine spiral cordlets; sculpture of next through penultimate whorls of about 16 arcuate axial ribs crossed by fine spiral cordlets, strongest adjacent to posterior suture, three cordlets commonly strongest; sculpture on body whorl of three to four short, sharp, strong axial ribs crossed by fine spiral cordlets. Aperture elongate; inner lip broadly callused, callus angling from posterior of aperture across mid-whorl on apertural face and wrapping halfway around anterior rostrum; rostrum narrow, straight, relatively short."

Locus typicus: north end of Sunflower Valley (=McLure Valley), Fresno County, California, USA

Stratum typicum: Panoche Formation, ? late Albian-Cenomanian, Cretaceous

Original remarks of Saul, 1998:

"No varices were recognized on the early whorls of Latiala heliaca. LACMIP 11380 consists of a protoconch of 4 polished, rounded whorls and the first teleoconch whorl. The earliest axial ribs are irregular, low, and difficult to count, but on the second quarter of the first teleoconch whorl the ribs become stronger, more distant and more regular. Rib strength varies between individuals, and on some whorls the axial ribs may be indiscernible."
"Specimens from Elder Creek (LACMIP loc. no. 24370) are from a boulder containing species suggestive of late Albian age in a conglomerate that is of Turonian age (Jones and Bailey, 1973)."

Etymology:

The species name, derived from Greek, helios, sun, refers to the type locality at the northwest end of Sunflower Valley.

Latiala heliaca in Saul, 1998

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