Humptulipsia macsotayi, Kiel & Campbell & Gaillard, 2010

Kiel, Steffen, Campbell, Kathleen A. & Gaillard, Christian, 2010, New and little known mollusks from ancient chemosynthetic environments, Zootaxa 2390 (1), pp. 26-48 : 31-32

Humptulipsia macsotayi sp. nov.

( Fig 3 )

1972 Mesogasteropoda genus indet. Thieuloy, p. 19, pl. 1, figs. 3–9.

1980 Busnardoa thieuloyi Macsotay, p. 146.

1982 Busnardoa thieuloyi Macsotay; Lemoine et al., p. 645.

Diagnosis: Shape, size and sculpture typical for genus, whorls with subsutural constriction and ridge, upper sinus below that ridge; lower slit narrow, at or below basal margin, with sinuous growth lines below slit.

Holotype: The specimen figured by Thieuloy et al. (1972, pl. 1, fig. 5) and here in Figure 3B , deposited in the collection of Grenoble University ( ID 10112 ).

Paratype: FSL 286 451, specimen showing the basal slit.

Type locality: Hauterivian (Early Cretaceous) presumed seep carbonates near Rottier, southeastern France, 44°28’N, 5°25’E .

Description: Large, high-spired shell with six or more whorls, whorl profile with subsutural constriction and ridge, deep sinus below ridge, especially on last whorl, periphery convex; early whorls sculptured by sinuous axial ribs that are strongest on periphery, weaker towards suture, ribs fade on later whorls, twelve or more spiral ribs present on early and later whorls; slit at or below basal margin formed by strongly backwards sloping growth lines; no sculpture below slit; growth lines distinct, of varying strength. Aperture unknown.

Remarks: Humptulipsia macsotayi n. sp. can be distinguished from the type species H. raui by its subsutural constriction and ridge, and its very narrow lower sinus. Thieuloy (1972) noticed similarities between Humptulipsia macsotoyi n. sp. and ‘ Chemnitzia ’ eucosmeta Ascher, 1906, from Hauterivian strata in eastern Czech Republic that also bear the brachiopod Peregrinella and other seep-related taxa. Ascher’s illustrations show a species, which indeed has similarly sinused ribs, but she neither figured nor described a strong sinus at the base of the aperture ( Ascher 1906). By lacking this apertural sinus, her species seems more similar to Abyssochrysos giganteum Kiel, Campbell, Elder & Little, 2008 from Early Cretaceous methane seeps in the Great Valley Group in California, USA (Kiel et al. 2008). Neither Humptulipsia macsotoyi , H. raui , nor Abyssochrysos giganteum have the callus on the inner lip of the aperture as strongly developed as the Czech ‘ Chemnitzia ’ eucosmeta. Unfortunately, the material of ‘ Chemnitzia ’ eucosmeta at the Bavarian State Collection in Munich is lost (A. Nützel pers. comm. 2007) and thus cannot be examined.

Distribution: Type locality only.

Etymology: For Oliver Macsotay, Valencia ( Venezuela), who described this species as Busnardoa thieuloyi in his by IZCN criteria unpublished PhD thesis. This name was later listed but not validated by Lemoine et al. (1982).

Figures

FIGURE 3. Humptulipsia macsotayi n. sp. from alleged Hauterivian (Early Cretaceous) seep carbonates at Rottier, southeastern France. A. Paratype, rubber cast of a specimen showing the basal slit (arrow, FSL 286 451). B. Holotype, specimen showing the subsutural constriction and ridge (Grenoble ID 10112). C. Paratype, early teleoconch with well developed sinuous axial ribs (Grenoble ID 10113). D. Paratype, large specimen; arrow indicates the deep sinus in the outer lip of the aperture (Grenoble ID 10111). Figs. B-D from Lemoine et al. (1982).