Galeodea tuberculiformis, HANNA, 1924

Squires, Richard L., 2019, Revision of Eocene warm-water cassid gastropods from coastal southwestern North America: implications for paleobiogeographic distribution and faunal-turnover, PaleoBios 36, pp. 1-22 : 9-12

GALEODEA TUBERCULIFORMIS HANNA, 1924

FIGS. 4D–H

Morio (Sconsia) tuberculatus Gabb, 1864 . p. 104, pl. 19, fig. 57. Arnold, 1907. pl. 39, fig. 9.

[non] Cassidaria tuberculata Risso, 1826 . p. 186 (see Dall, 1909. p. 64).

Cassadaria [sic] ( Phalium ) turberculata [sic] Dall, in Diller (1896. p. 458).

Galeodea tuberculata (Gabb) . Dickerson, 1916. pl. 42, fig. 2.

Galeodea (Morio) tuberculata (Gabb) . Waring, 1917. pl. 15, fig. 17.

Galeodea tuberculiformis Hanna, 1924 . p. 167. Anderson and Hanna, 1925. p 110. Schenck, 1926. p. 83; pl. 14, figs. 12–16. Stewart, 1927. p. 380; pl. 28, figs. 11. Vokes, 1939. p. 149; pl. 19, figs. 19, 21, 23–27.

Coalingodea tuberculiformis (Hanna) . Durham, 1942. p. 186; pl. 29, figs. 5, 9. Givens, 1974. p. 78; pl. 8, fig. 7. Squires, 1977. table 1.

Cassis (Coalingodea) tuberculata (Gabb) . Abbott, 1968. p. 59; pl. 34 (three views).

Phalium tuberculiformis (Hanna) . Givens and Kennedy, 1979. pp. 86, 88.

Phalium (Semicassis) tuberculiformis (Hanna) . Squires, 1984. p. 27; figs. 7l. Squires, 1987, p. 40; fig. 50. Kappeler et al., 1984. table 2 on p. 17.

Phalium (Semicassis) louella Squires and Advocate. Squires and Demetrion, 1994 . p. 130; figs. 10–11.

Phalium (Semicassis) tuberculiformis (Hanna) . Squires, 1999. p. 19; fig. 37.

Primary Type Material— Lectotype ANSP 4343, designated by Stewart (1927: p. 380), Muir Sandstone, Bull’s Head Point, Martinez, north of Mount Diablo, Contra Costa County, northern California ( Weaver 1953).

Material examined— The thirty-six specimens include: Hypotypes LACMIP 6532 and 14835, plaster replica of lectotype ANSP 4343 , and the following unfigured specimens: eleven from LACMIP Locality 7180, two from LACMIP Locality 40371, nineteen from LACMIP Locality 40374, and one from LACMIP loc. 40764 .

Emended description— Size moderately small,height up to 34.2 mm height. Immature shell fusiform, early adults can have moderately high spire and tabulate last whorl, whereas late adults can have lower spire and somewhat “rounded-look” on periphery of last whorl or less, commonly, tabulate shoulder. Protoconch low (naticoid) or moderately high, 2.5 smooth whorls, with abrupt contact with earliest sculptured whorl. Teleoconch up to 3.5 whorls. Spire overall low, 0.23 to 0.24 of shell height, partially submerged. Radial ribs present on spire whorls. Suture impressed and somewhat wavy; bordered by sutural cord only on some upper spire whorls. Sutural ramp moderately inclined. Last whorl enlarged, posterior two-thirds of last whorl with widely spaced three (rarely four) carinae bearing spinose nodes (unaligned between carinae); anteriormost carina much weaker and with weaker nodes; carina on shoulder with 10 nodes. Sculpture on rest of shell (including short neck) consisting of many, closely spaced, spiral threads (visible to naked eye) crossed by growth lines and minutely cancellate, commonly producing “beaded” look on well preserved individuals. Parietal/columellar lip callus wide and well developed; separated from shell and forming umbilicus anteriorly. Siphonal canal moderately short, twisted, and unnotched; 7 to 8 transverse lirae on callused columellar lip with lirae becoming more closely spaced toward anterior end of aperture. Siphonal canal dorsally directed, with false umbilicus at posterior end. Episodic varix (or two varices) can be present (rarely none) but only on last whorl; location of varices variable. Terminal varix thick and with well developed denticles on inner edge of varix; posteriormost denticle can be prominent, thereby creating constriction in this region.

Stratigraphic occurrence— Lower to middle Eocene, southwestern Washington to San Diego, California. “ Meganos Stage ”: Upper Santa Susana Formation, south side Simi Valley, Ventura County, southern California ( Squires 1999). “ Capay Stage ”: Bateque Formation, San Ignacio area, Baja California Sur, Mexico ( Squires and Demetrion 1994). “ Domengine Stage ”:Domengine Formation, Coalinga area, San Benito County, central California ( Vokes 1939); Avenal Sandstone, Reef Ridge area, Kings County, central California ( Kappeler et al. 1984). Muir Sandstone, Contra Costa County, northern California ( Weaver 1953). Upper Juncal Formation, Pine Mountain area, Ventura County, southern California ( Givens 1974). Upper Juncal Formation and Matilija Sandstone?, Whitaker Peak area, Ventura County, southern California ( Squires 1987). Llajas Formation, Ventura County, southern California ( Squires 1984). Ardath Shale, San Diego County ( Givens and Kennedy 1979).

Remarks— Figure 4D shows the prominent posteriormost denticle on the interior of the outer lip. Although the anterior siphonal canal is damaged or broken on most specimens, a few specimens from the Llajas Formation show that this canal is short, twisted, not notched ( Fig. 4H ), and with an angular left-lateral edge. At one locality in the Llajas Formation of Simi Valley, southern California, four out of 16 specimens of this species have an episodic varix, and one of these specimens has two episodic varices.

The strength of the fine-beaded spiral sculpture on G. tuberculiformis is largely a function of how much a specimen is weathered. Beu (2008: p. 289) reported that G. tuberculiformis is more like a species of Cassis , but Cassis has a well developed siphonal notch, whereas tuberculiformis is unnotched.

Galeodea tuberculiformis has the most widespread latitudinal distribution of any of the cassids found in the CSWNA region ( Fig. 1 ). It is found, therefore, in numerous formations, and it is likely the earliest cassid found in this region ( Fig. 2). As noted by Durham (1942), it is very similar to Galeodea coronota ( Deshayes, 1830) of middle Eocene (Lutetian) age in England and France (see Wrigley 1934: pl. 17, figs. 36–38).

For discussions regarding whether or not Hanna (1924) was justified in renaming Gabb’s (1864) tuberculatus , see Schenck (1926), Stewart (1927), and Abbott (1968: p. 60). The renaming was necessary, however, because Dall (in Diller 1896: p. 458) used the name Cassadaria ( Phalium ) turberculata [sic] (Gabb), which created a secondary homonym of Cassidaria tuberculata Risso, 1826 .

Figures

Figure 1. Index map of the coastal southwestern North America (CSWNA) region.

Figure 4. See caption on the bottom of page 11.