Euspira, LOUIEMARINCOVICHI, 1837

EUSPIRA? LOUIEMARINCOVICHI View in CoL

POWELL AND DINEEN, N. SP.

FIGURES 1–4 View Figures 1–4

Zoobank ID — urn:lsid:zoobank.org:act:2969452C-D99E-45B3-8851-D726958FB5C9

Diagnosis —The fine, closely spaced, narrow radial, and spiral sculpture forming a faint checkerboard pattern set this species apart from all northeastern Pacific and Arctic Naticidae .

Holotype — UCMP 123663 View Materials from UCMP locality- IP23235.

Paratypes — UCMP 123666 View Materials from UCMP locality IP23232 and UCMP 123677 View Materials from UCMP locality IP 23248.

Referred Collections —The number of specimens and partial specimens in each collection are documented as follows: complete or nearly complete specimens followed in square brackets by partial specimens or larger identifiable fragments – i.e., 5[4] = 5 complete or nearly complete specimens (4 significantly broken or fragmented specimens). UCMP localities IP22958 (3[3]), IP23232 (5[1]), IP23233 (0[1]), IP23235 (3[0]), IP23238 (3[0]), IP23239 (3[0]), IP23248 (1[2]), IP23264 (4[0]), IP23266 (1[0]), IP23272 (2[0]), IP23279 (1[0]), IP23280 (7[0]), IP23316 (1[0]), IP23511 (3[3]), IP23555 (1[0]), IP23559 (12[3]), IP23561 (1[1]), IP23574 (7[0]), IP23576 (4[0]), IP23577 (8[0]), IP23588 (1[2]), IP23589 (6[2]), IP23590 (16[5]), IP23593 (9[1]), IP23596 (4[1]), IP23597 (1[0]), IP23602 (1[0]), IP23607 (1[0]), IP23721 (2[0]), IP23722 (5[0]), IP23724 (6[1]), IP23812 (1[0]), IP23856 (4[3]), IP23857 (3[0]), IP23868 (1[2]), IP23870 (6[1]), IP23879 (1[0]), IP23884 (5[0]), IP24104 (7[0]).

Additional collections observed: USGS localities M8151 and M8997. These collections could not be located at UCMP, but were identified for internal USGS E&R’s (Evaluation and Report documents). The information is added here for completeness as either Louie Marincovich or the senior author ( CPII) identified the specimens.

Locality information for all collections can be found in Appendix 1.

Occurrence — Known only from the Gubik Formation along the northwestern part of the Arctic Coastal Plain (North Slope) of Alaska from Skull Cliff south of Barrow in the west to along the Colville River and Kogru River/ Teshekpuk Lake areas in the east, North Slope Borough, Alaska ( Figure 6 View Figure 6 and Appendix 1). Early Pleistocene in age (see discussion for details).

Etymology — This new species is named for Louie Marincovich, Jr. who first introduced this species to the senior author and for his work on unraveling many mysteries of Paleogene–Neogene Arctic geology and paleontology.

Description — This new species has a naticiform shell about as high as wide and with a moderate thick, substantial shell. The spire is very short and consists of about four whorls and is less than a tenth the height of the entire shell. The protoconch is worn on all specimens and not available for description.With a generally smooth shell profile the whorls show a slight indentation or suture and a very fine, channel at the top of its whorls. The exterior of the shell shows very fine, closely spaced, irregular, spiral threads crossed by very fine, closely spaced, mostly continuous, radial threads forming a microscopic crosshatch pattern covering the exterior of the shell ( Figure 5 View Figure 5 ). The aperture is large, near–tear–drop shape and is about three–quarters of the shell's height with a parental callus that mirrors the inner margin of the aperture a few millimeters wide. The posterior apertural