Nucleolaria cowlitziana, GROVES, 1994

Groves, Lindsey & Squires, Richard L., 2023, Revision of northeast Pacific Paleogene cypraeoidean gastropods, including recognition of three new species: implications for paleobiogeographic distribution and faunal turnover, PaleoBios 40 (10), pp. 1-52 : 8-9

NUCLEOLARIA COWLITZIANA GROVES, 1994 A

FIGS. 4A–C

Nucleolaria cowlitziana Groves, 1994a, p. 247 –248, figs. 6, 7. Nesbitt, 1995. p. 1066. Groves, 1997. p. 7. Groves, 2000. p. 120. Dolin and Lozouet, 2004. p. 73. Lorenz, 2017. p. 220. Lorenz, 2018. p. 664, pl. 328, fig. 5.

Jenneria cowlitziana (Groves) . Fehse, 2001. p. 37.

Holotype and Type Locality — UCMP 39837 ( Figs. 4A–C ), length 27.2 mm, width 17.3 mm, height 11.3 mm. UCMP Locality D-8040, Cowlitz Formation , south-central Lewis County, Washington.

Occurrence— Middle to upper Eocene (“Tejon Stage”), south-central Lewis County, Washington .

Etymology— Originally named for the Eocene Cowlitz Formation, Lewis County, southwest Washington.

Description— Shell of size medium size. Shape ovoid. Spire covered. Maximum height slightly posterior of midpoint. Dorsal groove faint; dorsal nodules smooth, circular, connected by fine threads that extend onto basal surface and form prominent denticulation. Marginal callus slight. Aperture curved slightly posteriorly toward columella. Denticulation prominent with smooth interstices, labial lip with 19 teeth, and columellar lip with 18 teeth. Fossula with strong denticulation. Anterior and posterior canals prominently lengthened by terminal teeth. ( Groves 1994a: p. 247).

Remarks— The holotype of this Cowlitz Formation species is the only known record of this genus in the eastern Pacific. Fehse (2001: pp. 18, 37) assigned N. cowlitziana erroneously to the ovulid genus Jenneria Jousseaume, 1884 , but later, following an examination of the holotype, Fehse acknowledged his error (personal communication, July 2004). Dolin and Lozouet (2004: p. 73) inexplicably questioned the provenance of this specimen and compared it to the living species N. nucleus ( Linnaeus, 1758) . In the same publication they described Nucleolaria bezoyensis and mistakenly claimed that their species (now reassigned to the genus Naria by Lorenz, 2017) was the earliest record of Nucleolaria . However, N. cowlitziana remains the earliest record of the genus and its provenance is certain.

This earliest known occurrence of Nucleolaria in the NEP region is an enigma. It is likely indicative of an eastward-directed faunistic influx during the Paleogene between the warm waters of the central Pacific Ocean and the NEP region. Nucleolaria today is a tropical Indo-Pacific genus. Like most other extant cypraeoideans, its larvae are planktonic ( Groves 1994a). Emerson and Chaney (1995) documented 15 species of Indo-Pacific cypraeid species from the eastern Pacific, three of which are based on single specimens. Lorenz (2017) recognized only a single Indo-Pacific species established in the eastern Pacific. Lindberg et al. (1980) documented the only other fossil Indo-Pacific species [ Naria cernica (G.B. Sowerby II,1870) ] in the eastern Pacific from the Pleistocene of Isla de Guadalupe, Baja California, México.

Figures

Figure 4 (previous page). A–C. Nucleolaria cowlitzensis Groves, 1994, Cowlitz Formation (middle Eocene, upper “Tejon Stage”), Vader area, south-central Lewis County, Washington. Basal (A), dorsal (B), and left (columellar) side (C) views, 1.9x, length 27.2 mm, width 17.3 mm, height 11.3 mm, of holotype UCMP 39837, UCMP Locality D-8040. D–H. Propustularia kemperae (Nelson, 1925), Santa Susana Formation, (Paleocene, Selandian Stage), north side Simi Hills, Ventura County, southern California. Basal (D), dorsal (E), and right (labral) side (F), and views, 2.2x, length 21 mm, width 17.3, height 12 mm, of holotype CASG 391.01 [ex CASG 987], Locality CASG 391. Dorsal (G) view, 2.6x, length 18.2 mm, width 14.9, height 11.2 mm, of hypotype LACMIP 22307.6, LACMIP Type 14918 (LACMIP Locality 22307). Basal (H) view, 2.2x, length 21 mm, width 17.3, height 12 mm, of paratype UCMP 30541, UCMP Locality 3764. I–N. Subepona goedertorum (Groves and Squires, 1995), Crescent Forma- tion (Eocene, “Capay Stage”), Black Hills, Thurston County, Washington. Basal (I), dorsal (J), left (columellar) lateral (K), and right (labral) (L) views, 2.8x, length 19.4 mm, width 12.3, height 10.8 mm, of holotype LACMIP 16655.23, LACMIP Type 12375, LACMIP Locality 16655 [=LACMIP Locality 41563; ex CSUN Locality 1563]. M–N, Juncal Formation, Canton Canyon, Whitaker Peak area, Ventura County, southern California. Basal (M) and dorsal (N) views, both 2.4x, length 19.4 mm, width 13.9, height 9.4 mm, of hypotype LACMIP 40807.1, LACMIP Type 14935 (LACMIP Locality 40807 [= LACMIP Locality 16191, ex CSUN Locality 807]). O–Q, Subepona leahae n. sp., Llajas Formation (Eocene, “Domengine Stage”), north side Simi Valley, Ventura County, southern California. Basal (O), dorsal (P), and left (labral) side (Q) views, 1.6x, length 29.5 mm, width 13.9, height 15.1 mm, of holotype LACMIP 40374.79, LACMIP Type 14936, (LACMIP Locality 40374).