Lamellipecten, Dijkstra & Maestrati, 2010

Dijkstra, Henk H. & Maestrati, Philippe, 2010, Pectinoidea (Mollusca, Bivalvia, Propeamussiidae, Entoliidae and Pectinidae) from the Austral Islands (French Polynesia), Zoosystema 32 (2), pp. 333-358 : 344-345

Genus Lamellipecten n. gen.

TYPE SPECIES. — Lamellipecten aduncus n. sp.

ETYMOLOGY. — A Pectinidae with strongly developed commarginal lamellae.

DIAGNOSIS. — Thin Pectinidae with a fasciolar pseudoctenolium ( Waller 1984: 213) throughout ontogeny, functional ctenolium lacking, narrow byssal fasciole, byssal notch shallow, strong resilial teeth and very weak dorsal teeth on right valve, intermediate teeth lacking ( Waller 1991: 8), strong radial and commarginal macrosculpture exteriorly, irregularly radially undulated interiorly, short auricles, internal ribs lacking.

REMARKS

A fasciolar pseudo-ctenolium had been described by Waller (1984: 213) in species of the families Propeamussiidae ( Parvamussium sayanum ( Dall, 1886) and Cyclopecten culebrensis ( Smith, 1885) , from the [sub] tropical western Atlantic),and Entoliidae ( Syncyclonema sigsbeei ( Dall, 1886) , also from the tropical western Atlantic, and an undescribed species from the Pacific, subsequently described as Pectinella aequoris Dijkstra, 1991 ). This character was also reported by Dijkstra (1995a: 37) in Parvamussium undisonum Dijkstra, 1995 , and is now found for the first time in a species of Pectinidae , Lamellipecten aduncus n. sp.

The external sculpture of the left valve of Lamellipecten n. gen. somewhat resembles that of the deepwater Pseudohinnites from the Atlantic and Pacific.However, all other shell characters are different ( Table 2):

The propeamussiids P.sayanum and P.undisonum also resemble Lamellipecten n. gen. in sculpture of the left valve, but by all other characters (interior ribs, dissimilar sculpture of both valves, lack of a true ctenolium) they are typical species of Propeamussiidae , whereas Lamellipecten n. gen. lacks interior ribs and has a similar sculpture on both valves.It is remarkable that this pectinid genus lacks a true ctenolium and only has a fasciolar pseudoctenolium. Some pectinid genera that also lack a functional ctenolium like Anguipecten , Pecten Müller, 1776 and Hyalopecten Verrill, 1897 , do not have a pseudo-ctenolium. Although Lamellipecten n. gen. has a similar pseudo-ctenolium as in two genera of Propeamussiidae ( Parvamussium and Cyclopecten ), other characters (strongly developed resilial teeth, similar macrosculpture on both valves, undulating inner surface) are typical of Pectinidae .