Northeast Pacific Cretaceous record ofPyropsis(Neogastropoda: Pyropsidae) and paleobiogeography of the genus

Abstract

The neogastropod genusPyropsisConrad, 1860 (family Pyropsidae Stephenson, 1941) is recognized for the first time from Upper Cretaceous shallow-marine siliciclastic rocks in the region extending from Vancouver Island, British Columbia southward to southern California. Four new species were detected:Pyropsis aldersoni(earliest Coniacian, southern California),Pyropsis californica(early Coniacian, northern California),Pyropsis louellae(late Coniacian or early Santonian, northern California), andPyropsis grahami(late early Campanian, Vancouver Island).A critical review of the global reports ofPyropsis, a genus that has been commonly confused with other genera (especiallyTudiclaRöding, 1798), establishes thatPyropsishad an amphitropical distribution and lived in warm-temperate waters adjacent to a broad tropical realm. It is rare to uncommon wherever found, and its geologic range is middle Cenomanian to an age near the Cretaceous/Paleogene boundary (probably earliest Paleocene). It was moderately widespread before the Maastrichtian but was predominantly restricted to the New World during the Maastrichtian.

The heterobranch subgenusTrochactaeon(Trochactaeon) in the Campanian (Late Cretaceous) of the northern Arabian Platform and its paleoenvironmental and paleobiogeographic implications

“…5). Amphitropical distribution patterns are relatively common among diverse groups of tropical realm gastropods, particularly in carbonate platforms that were extensive in geographical latitude (i.e., South Africa and North/South America or Caucasia and Africa) during the Late Cretaceous (Squires, 2011). Amphitropic Trochactaeon ( Trochactaeon ) species achieved such a distribution no earlier than the late Cenomanian (Fig.…”

“…implications.-Upper Cretaceous shallow-water carbonates from the Tethys Ocean were accreted in the Mediterranean area and constitute the best archive of the endemic or amphitropical fauna that prevailed in this vast ocean during the Late Cretaceous (Kauffman, 1973;Sohl, 1987;Christensen, 1997;Squires, 2011Squires, , 2018Steuber et al, 2016). Trochactaeon (Trochactaeon) is a widespread taxon recorded in Europe, Caucasia, Asia, America, south-southwestern Africa, and Arabia-northern Africa (Fig.…”

Northeast Pacific record of the Paleogene genusPseudoperissolax(Neogastropoda: Muricidae: Muricinae) and its paleobiogeography

“…Stewart (1927, 1930) and Wenz (1943), furthermore, were undecided if Perissolax is a synonym of various other genera. Squires (2011, p. 1202) opined that Perrisolax is probably a nomen dubium . Gabb (1861) used steinkerns (internal molds) as the basis for his genus, and he did not clearly designate a type species; thus, it is concluded herein, without equivocation, that Perissolax is a nomen dubium .…”

Checklist of California Paleogene–Neogene marine Mollusca since Keen and Bentson (1944)

“…sp., fideSaul (1988b: p. 14). Not a Pyropsis, fideSquires (2011Squires ( : p. 1204). [Perissityidae].…”