Taiyutyla Chamberlin 1952

Taiyutyla Chamberlin 1952

Taiyutyla Chamberlin 1952:1. Type species, Taiyutyla jonesi (Chamberlin, 1951) by original designation of its synonym (see below for full details), T. corvallis Chamberlin, 1952. Hoffman, 1961:270; Shear, 1971:86, 1976:6, 2004:15.

Diagnosis: Taiyutyla species may be distinguished from sympatric conotyline genera of western North America by a T-shaped process on the posterior surface of the posterior gonopod coxites (see species descriptions and illustrations below). The stem of the T (which may be very short) connects the branch to the coxite, and the ventral and dorsal limbs of the T-cap may have various modifications. This definition restricts Taiyutyla to the following described and new species: jonesi (Chamberlin, 1951), napa Shear, 1971, francisca Shear, 1971, benedictae Shear, 1976, prefemorata Shear, 1976, variata Shear, 1976, clarki Shear, 1976, T. amicitia n. sp., T. acuphora, n. sp., and T. tillamook n. sp., the last three described below. See Shear (1971, 1972, 1974, 1976, 2004) and Shear and Krejca (2011) for more detailed morphological data. The remaining previously described species and new species described here are grouped in new genera.

The anterior gonopods of Taiyutyla species are usually simple and erect, but sometimes with elaborations at the tips. The posterior gonopod coxites carry an anterior part that may be terminally blunt, abruptly acute, or with processes. The posterior part consists of the T-shaped branch, the ventral process of which is covered in fine, short, unbranched cuticular fimbriae. The dorsal process may be either smooth, or bear long, branched fimbriae. Near the point where the T-shaped branch joins the body of the coxite, a pore may be seen, often with exudate preserved, and subtended by one or two fimbriate branches or regions. These branches may serve as a sheath or groove in which the ventral process of the T-shaped branch is carried. The T-shaped branch may be homologous to what we are calling the pseudoflagellar branch of species of Bifurcatella, n. gen. (see below).

Distribution: From the San Francisco Bay region north through northern California, including the Sierra Nevada, to Oregon, Washington and British Colombia, Canada. Females of a probable Taiyutyla species yet to be described have been taken in the Alexander Archipelago and continental southern Alaska (Shelley et al. 2009). The inclusion of T. amicitia n. sp. extends the range of the genus east to Idaho.

New records of previously described species