Lepetodriloidea McLean 1988

Gorgoleptis emarginatus is one of three presumed Gorgoleptis morphs we find in plankton samples at 9N. It has coarse pitted sculpture in rows that follow the curve of the shell. The most distinctive feature of these protoconchs is the scalloped edges of the aperture, with sharp points at the anterior edge and on either side. There is a narrow aperture rim, tapering toward the posterior edge. The protoconch matches that of Gorgoleptis emarginatus in size and sculpture, but the scallops are not preserved in post-larval specimens, making the identification somewhat tentative.

Gorgoleptis emarginatus is one of three presumed Gorgoleptis morphs we find in plankton samples at 9N. It has coarse pitted sculpture in rows that follow the curve of the shell. The most distinctive feature of these protoconchs is the scalloped edges of the aperture, with sharp points at the anterior edge and on either side. There is a narrow aperture rim, tapering toward the posterior edge. The protoconch matches that of Gorgoleptis emarginatus in size and sculpture, but the scallops are not preserved in post-larval specimens, making the identification somewhat tentative.

Small protoconchs with coarse pitted sculpture in closely spaced rows, giving the effect of lineate sculpture. The aperture is slightly wavy, with a distinct medium-width rim visible under the compound microscope.

Small protoconchs with coarse pitted sculpture in closely spaced rows, giving the effect of lineate sculpture. The aperture is slightly wavy, with a distinct medium-width rim visible under the compound microscope.

These are small protoconchs with fine pitted sculpture. In some individuals the pits appear to form lines, but this is not usually evident under the light microscope. The line of the aperture continues straight to the posterior edge of the shell in the apical view. There is a distinct medium-width aperture rim visible under the compound microscope.  Five species of Lepetodrilus - L. cristatus, L. elevatus, L. ovalis, L. pustulosus (all described in McLean, 1988) and L. tevnianus McLean 1993 , are present at 9°N. All these species have protoconchs that are similar in size and shape. Some individuals are nearly transparent (above left), while others are more opaque; it is possible this is a taxonomically useful trait, but the species cannot be distinguished morphologically at this time.

These are small protoconchs with fine pitted sculpture. In some individuals the pits appear to form lines, but this is not usually evident under the light microscope. The line of the aperture continues straight to the posterior edge of the shell in the apical view. There is a distinct medium-width aperture rim visible under the compound microscope.  Five species of Lepetodrilus - L. cristatus, L. elevatus, L. ovalis, L. pustulosus (all described in McLean, 1988) and L. tevnianus McLean 1993 , are present at 9°N. All these species have protoconchs that are similar in size and shape. Some individuals are nearly transparent (above left), while others are more opaque; it is possible this is a taxonomically useful trait, but the species cannot be distinguished morphologically at this time.

Gorgoleptis spiralis is one of three presumed Gorgoleptis morphs we find in plankton samples at 9N. It has coarse pitted sculpture in rows that follow the curve of the shell. The most distinctive feature of these protoconchs is the scalloped edges of the aperture, with sharp points at the anterior edge and on either side. There is a narrow aperture rim, tapering toward the posterior edge. The protoconch matches that of Gorgoleptis spiralis in size and sculpture, but the scallops are not preserved in post-larval specimens, making the identification somewhat tentative.

Gorgoleptis spiralis is one of three presumed Gorgoleptis morphs we find in plankton samples at 9N. It has coarse pitted sculpture in rows that follow the curve of the shell. The most distinctive feature of these protoconchs is the scalloped edges of the aperture, with sharp points at the anterior edge and on either side. There is a narrow aperture rim, tapering toward the posterior edge. The protoconch matches that of Gorgoleptis spiralis in size and sculpture, but the scallops are not preserved in post-larval specimens, making the identification somewhat tentative.

This protoconch closely resembles the two Gorgoleptis protoconchs in sculpture and is roughly the same size as Gorgoleptis emarginatus. It differs from the others in having only a single sharp point at the anterior edge of the aperture and the sides are sinuous rather than being scalloped. If it has an aperture rim, it is very narrow. A third species of Gorgoleptis, Gorgoleptis patulus McLean, 1988, was described from the Galápagos Rift. Its protoconch is unknown, but it could be a possible candidate for this morph. The species has not been reported from 9°N.

Ventral. Specimen ID: 9617322. Field no.: J2-162-1-1. Taxon rep.: Pseudorimula sp. Image quality: 1. Aspect ratio: 1.333.

Ventral. Specimen ID: 8722519. Field no.: S41-F72-1. Taxon rep.: Pseudorimula marianae. Image quality: 1. Aspect ratio: 1.333.

Ventral. Specimen ID: 8702983. Field no.: R1941-END07-8-1. Taxon rep.: Clypeosectus curvus. Image quality: 1. Aspect ratio: 1.333.