Subepona goedertorum, (GROVES AND SQUIRES, 1995)

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 : 11

SUBEPONA GOEDERTORUM

( GROVES AND SQUIRES, 1995)

FIGS. 4I–N

Proadusta goedertorum Groves and Squires, 1995 . pp. 113–116, figs. 2–5 [fig. 4 is a right-lateral view, not a left-lateral view as stated in the caption; fig. 5 is a left-lateral view, not a right-lateral view as stated in the caption]. Fehse, 2009. pp., 16, 19; fig. 32.

Subepona goedertorum (Groves and Squires) . Dolin and Lozouet, 2004. p. 62. Pacaud, 2018a. p. 10 (table 2).

Eopustularia goedertorum (Groves and Squires) . Fehse, 2010. p. 5 (as Proadusta goedertorum ). Lorenz, 2017. p. 210. Lorenz, 2018. p. 662, pl. 327, fig. 11.

Holotype and Type Locality— LACMIP 16655.23 , LACMIP Type 12375 ( Figs. 4I–L ), length 19.4 mm, width 12.3 mm, and height 10.8 mm. LACMIP Locality 16655 [= LACMIP Locality 41563; ex CSUN Locality 1563], upper part of Crescent Formation , Larch Mountain area , Black Hills , Thurston County, southwestern Washington.

Paratype — LACMIP 16655.24 , LACMIP Type 12376, length 17.1 mm, width 10.4 mm, and height 8.9 mm. Locality same as holotype .

Referred Specimens—Hypotype LACMIP 40807.1 , LACMIP Type 14935, ( Figs. 4M, N ), length 19.0 mm, width 13.8, and height 9.4 mm . LACMIP Locality 16191 [= LACMIP Locality 40807; ex CSUN Locality 807), Juncal Formation, Canton Canyon, Whitaker Peak area, Los Angeles County, southern California. A poorly preserved specimen from LACMIP Locality 16848 [ex CSUN Locality 1564], from the Rock Candy Mountain area, Thurston County, Washington, also exhibits original shell material. Two additional poorly preserved specimens, LACMIP 41599.1 , from the Crescent Formation, LACMIP Locality 41599 (ex CSUN Locality 1599), Middle Fork Satsop River, Dry Lakes quadrangle, Mason County, Washington are noted.

Occurrence— Lower to late early Eocene, Washington to southern California. “Capay Stage ”: Upper part of Crescent Formation, Larch Mountain area, Black Hills, Thurston County, southwestern Washington ( Groves and Squires 1995) at LACMIP Locality 16848 [ex CSUN Locality 1564], Thurston County, in the general vicinity of the type locality (for more details, see Groves and Squires 1995: p. 116). Juncal Formation, Canton Canyon, Whitaker Peak area, Ventura County, southern California at LACMIP Locality 40807 [= LACMIP Locality 16191; ex CSUN Locality 807] (new information). The Juncal Formation specimen, which is from the middle lower Eocene (“Capay Stage” = “ Turritella uvasana infera ” fauna) in the Juncal Formation, was originally believed by Squires (1987: p. 35, unfigured) to be a questionable (juvenile) specimen of Gisortia clarki Ingram, 1940 .

Etymology— Originally named for colleagues James L. (Jim) and the late Gail H. Goedert [1940-2017] (Gig Harbor, Washington).

Description— Shell small to medium in size (holotype largest known specimen). Shell ovate, slightly elongate, smooth, dorsum medium to highly arched, maximum height near midpoint. Rostrate (can be beaklike) extremities present on both sides of exhalant canal, with labrial extremity large and more curved relative to much shorter and much straighter columellar extremity. Slight depression (shallow pit) can be present above submerged spire on more mature specimen. Marginal border on shell sides very weak but noticeable near ends of shell. Basal surface of shell wide and slightly convex to flattened (on less mature specimen). Aperture generally narrow and straight throughout most of its length but posteriorly labral side noticeably curved slightly toward columella. Mature specimen labial lip (outer lip) with 26 strong teeth. Mature specimen columellar lip with 17 slightly weaker teeth. Terminal fold (on each lip) long, thin, extended, and bladelike. Siphonal canal long, wide, deep and clearly distinct from curve of shell margin. Basal marginal callus (border) on both sides of shell but strongest on left side; callus produced at both extremities, especially on anterior extremity. ( Groves and Squires, 1995: pp. 114, 115).

Remarks— This species is rare. The six known speci mens of Subepona goedertorum range range in preservation from poor to excellent. It is characterized by its smooth shell, unequal-strength rostrate posterior terminae, inflated dorsum, presence of a slight depression in the submerged-spire area, strong but short dentition on both lips, and prominent terminal folds (one on each anterior end of shell). Subpeona goedertorum closely resembles S. herrerensis Dolin and Lozouet (2004 : pl. 27, figs. 3a–3c), the type species of Subepona from France. The holotypes are near each other in size: the holotype of S. goedertorum is 19.4 mm length; the holotype of S. herrerensis is 14 mm.

Pacaud (2018a: table 2) listed Subepona goedertorum ( Groves and Squires, 1995) as occurring in France, as well as the United States, and no geologic nor paleontologic details were provided. The “occurrence” of this species in France is likely a typographic error.

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).