Hikidea osoensis, Kaim, Andrzej, Jenkins, Robert G., Tanabe, Kazushige & Kiel, Steffen, 2014

Kaim, Andrzej, Jenkins, Robert G., Tanabe, Kazushige & Kiel, Steffen, 2014, Mollusks from late Mesozoic seep deposits, chiefly in California, Zootaxa 3861 (5), pp. 401-440: 408-409

publication ID

http://dx.doi.org/10.11646/zootaxa.3861.5.1

publication LSID

lsid:zoobank.org:pub:E62DB6C3-0C5F-4898-99C4-1BEC70DD1734

persistent identifier

http://treatment.plazi.org/id/03F4372E-FFE1-6846-FF34-04A1FBE5FE18

treatment provided by

Plazi

scientific name

Hikidea osoensis
status

sp. nov.

Hikidea osoensis   sp. nov.

( Fig. 3 View FIGURE 3. A E –I)

Diagnosis. Shell turbiniform, continuously convex and weakly inflated with weakly expressed concave ramp at the adapical suture. Surface smooth apart from some weak and hardly recognizable spirals and strongly prosocline growth lines.

Holotype: GZG.INV. 84968, height H = 10.7 mm, width W = 9.6 mm.

Paratype: GZG.INV. 84969, H = 8.8 mm, W = 7.0 mm.

Type locality and strata: Bear Creek, Colusa County, California, USA; locality # 4 in Kiel et al. (2008 b). Great Valley Group, Grizzly Canyon member of Crack Canyon Formation; Valanginian (Early Cretaceous).

Other material: Five additional specimens from the type locality including a juvenile shell (GZG.INV. 84970) illustrated in Fig. 3 View FIGURE 3. A I.

Description. Protoconch unknown. Shell turbiniform with four whorls, convex with no angulations. Concave ramp at the adapical suture weakly expressed. Juvenile shell ornamented by numerous spiral ribs. Adult shell surface smooth apart from some weak and hardly recognizable spirals and strongly prosocline growth lines. Generating curve circular, aperture tangential, peristome uninterrupted. Inner lip with narrow callus, outer lip not preserved. No umbilicus.

Remarks. Hikidea osoensis   differs from H. omagariensis   and H. yasukawensis   by its much larger size and higher shell with more numerous whorls. The Recent Cantrainea nuda   is also smaller and has a slightly angulated demarcation between the flank and the base, and less convex whorl flanks. This occurrence is the earliest known record of the genus.

Distribution. Type locality only.

Etymology. From Oso, Spanish for bear, referring to the name of type locality.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Trochida

Family

Colloniidae

Genus

Hikidea