New Neritidae from southwestern North America

Three new genera and six new species of shallow-marine gastropods are named from Upper Cretaceous strata found mainly in California. The trochidsCidarina cretaceanew species andCidarina betanew species, the ficidBulbificopsis garzanew genus and new species, and the cancellariidMataxa aridanew species are from the Maastrichtian part of the Moreno Formation of north-central California. This is the earliest record ofCidarina, whose previous chronologic range was middle Eocene to Recent.Bulbificopsisis the first record of a Cretaceous ficid from the Pacific slope of North America, andMataxawas previously known only from Upper Cretaceous strata in the southeastern United States and northeastern Brazil. The buccinidEripachya jalamanew species and the fasciolariidCalkota daileyinew genus and new species are from the lower upper Campanian Jalama Formation in southern California.Calkotais also recognized herein as occurring in upper Maastrichtian strata of North Dakota and South Dakota. The new melongenid genus,Pentzia, established forFulgur hilgardiWhite, 1889, is from Campanian strata throughout California; middle Campanian strata on Sucia Island, Washington; and upper Campanian to lower Maastrichtian strata in northern Baja California, Mexico.

Section: Stratigraphymentioning

confidence: 98%

New late Cretaceous (Campanian and Maastrichtian) marine gastropods from California

Squires

Saul

2003

“…This is a reduced number because several neritid genera have been synonymized in recent years. Corsania , an Old World taxon, and its recognized subgenera C. (Corsania) and C. (Januncia) (Woods and Saul, 1986) as well as Nerita (Bajanerita) (Squires 1993) have been synonymized with Otostomia and Neritoplica , respectively, as discussed by Bandel and Kiel (2003) and Kiel and Aranda-Manteca (2002).…”

Section: Systematic Paleontologymentioning

confidence: 99%

“…Fossil specimens of neritid gastropods are noted to reveal color patterns more often than many other gastropod groups (Woods and Saul, 1986; Squires, 1992, 1993; Dockery, 1993; Squires and Saul, 1993) without use of chemical agents or fluorescent photography to retrieve the pattern (Hendricks, 2018). As Squires (1993, p. 1086) pointed out after a study of 114 specimens of the Late Cretaceous neritid Neritoplica californiensis, nearly half showed a color pattern.…”

Section: Biostratinomymentioning

confidence: 99%

“…At low tide, they cluster in crevices or shady spots where they will not be overheated in the sun. It is probable that neritids have occupied the intertidal zone since the Jurassic (Woods and Saul, 1986; Bandel and Kiel, 2003), making them a reliable proxy for a restricted habitat that is otherwise difficult to identify with certainty. The Fox Hills specimens are believed to reflect intertidal conditions because of their morphology, their color patterns, and their association with oysters and other bivalve shells found predominantly in stable position and because their shells show abrasion patterns interpreted as produced from the friction generated by hermit crabs dragging them over subaerially exposed tidal flats.…”

Section: Interpretation Of the Neritoptyx Hogansoni Habitatmentioning

confidence: 99%

See 1 more Smart Citation

Neritoptyx hogansoninew species (Gastropoda, Mollusca) from the Upper Cretaceous Fox Hills Formation on the Dakota Isthmus, western United States

Erickson

2018

In midcontinent North America, the Fox Hills Formation (Upper Cretaceous, upper Maastrichtian) preserves the last marine faunas in the central Western Interior Seaway (WIS).Neritoptyx hogansoninew species, a small littoral snail, exhibited allometric change from smooth to corded ornament and rounded to shouldered shape during growth. Specimens preserve a zig-zag pigment pattern that changes to an axial pattern during growth.Neritoptyx hogansoninew species was preyed on by decapod crustaceans, and spent shells were occupied by pagurid crabs. Dead mollusk shells, particularly those ofCrassostrea subtrigonalis(Evans and Shumard, 1857), provided a hard substrate to which they adhered on the Fox Hills tidal flats. This new neritimorph gastropod establishes a paleogeographic and chronostratigraphic proxy for intertidal conditions on the Dakota Isthmus during the late Maastrichtian. Presence of a neritid extends the marine tropical/temperate boundary in the WIS northward to ~44° late Maastrichtian paleolatitude. Late Maastrichtian closure of the isthmus subsequently altered marine heat transfer by interrupting northward flow of tropical currents from the Gulf Coast by as much as 1 to 1.5 million years before the Cretaceous ended.UUID:http://zoobank.org/3ba56c07-fcca-4925-a2f0-df663fc3a06b

“…Remarks. -Shell height in specimens of Velates is measured parallel to the axis of coiling, as shown by Woods and Saul (1986, fig. 4).…”

Section: Gastropods Discussed In This Paper Were Found Between 96 Andmentioning

confidence: 99%

New early Eocene marine gastropods from Baja California Sur, Mexico

Squires

Demetrion

1990

Three gastropod species are described from a previously unknown shallow-marine molluscan fauna in the lower Eocene Bateque Formation, southwest of San Ignacio, Baja California Sur, Mexico. Velates batequensis n. sp., a commonly occurring neritid in the Bateque, is the only ribbed Velates known from the Western Hemisphere. The fairly rare Platyoptera pacifica n. sp. is the earliest record of this strombid genus and its first occurrence on the west coast of North America. The very rare Cypraedia sp. is also the first occurrence of this cypraeid-like genus on the west coast of North America.