UTRECHT MICROPALEONTOLOGICAL BUllETINS

Oepikodus evae emend. herein, this subzone corresponds with the rockinterval,
containing our Protopanderodus rectus/Oepikodus evae up to and
including the lower portion of our Prioniodus navis/Prioniodus crassulus
Zone (fig. 15). This interval corresponds to the upper portion of Tjernvik's
(1956) Plesiomegalaspis planilimbata Zone, together with his Megalaspides
dalecarlicus Zone and possibly part of Tjernvik's Zone of Plesiomegalaspis
estonica (fig. 19 and chapter III.2.).
From the species that would characterize Sergeeva's Subzone of Oistodus
parallelus, only Oistodus originalis (= element referred to Paroistodus parallelus
emend. herein), Triangulodus brevibasis emend. herein and Microzarkodina
flabellum emend. LINDSTROM are found in the rock-sequence of
north-western Oland, after the disappearance of Oepikodus evae emend.
herein. Another typical species, Prioniodus navis (= element of Prioniodus
navis emend. herein) occurs together with Oepikodus evae in the basal
portion of our Prioniodus navis/P. crassulus Zone. To facilitate a correlation
between Sergeeva's Subzone of Oistodus parallelus with the conodontzonation
of Oland, the base of this Subzone of Oistodus parallelus is
considered to be defined by the first appearance of Prioniodus navis emend.
herein. The upper boundary of this subzone can not be located on Oland, as
the typical species of Sergeeva's next younger Subzone of Falodus simplex,
were not encountered. Thus defined, the Subzone of Oistodus parallelus is
correlative with at least the rock-interval containing the Prioniodus navis/
P.crassulus Zone up to and including the Triangulodus brevibasis Zone
(figs. 15 and 19). If the base of the Subzone of Oistodus parallelus is defined
by the first appearance of Prioniodus navis emend. herein, the basal portion
of this subzone and the upper portion of Sergeeva's next older Subzone of
Prioniodus evae have an overlap in the Prioniodus navis/P.crassulus Zone of
Oland (fig. 19). For this reason Sergeeva's Subzone of Oistodus parallelus
may include the upper portion of Tjernvik's Zone of Megalaspides dale carlicus.
The Zone of Plesiomegalaspis estonica certainly forms part of it.
III.S. A COMPARISON BETWEEN THE OLANDIAN CONODONT ASSEMBLAGES AND SOME
CONODONT FAUNAS OF ESTONIA
Viira, Kivimagi and Loog (1970) described the conodont fauna of the
Varangu Member (= AlII V) of northern Estonia and also gave the faunal
composition of the units AIIM, BIa and BIb of the Estonian stratigraphical
scheme.
These conodont faunas are comparable with the conodont assemblages