Pb. Hamilton et Kr. Laird, Nitzschia pseudosinuata sp nov., a new holocene diatom from the sediment of Moon Lake, North Dakota, USA, DIATOM RES, 16(2), 2001, pp. 317-324
Nitzschia pseudosinuata Hamilton & Laird sp. nov. is described from the sed
iments of Moon Lake, North Dakota, U.S.A. The new species is a small (lengt
h <20 <mu>m), weakly silicified, tabelloid diatom observed in the sediments
from 1840 to 2220 yr BP. A modem analogue, Nitzschia sinuata var. tabellar
ia (Grunow) Grunow, is superficially similar, but exhibits significant diff
erences in fibular and canal raphe construction as well as in the density o
f striae and fibulae. In addition, according to conventional systematic con
siderations, these similar taxa belong to two different subgeneric groups (
Sections Lanceolatae and Grunowia, respectively). Based on co-occurences wi
th Cyclotella quillensis Bailey and Chactoceros sp. [cf. muellerial elmorei
(resting spores)], it appears that N. pseudosinuata is a mesohaline specie
s indicative of shallow saline waters of the past.