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Delsate, Steur, Schneider, Thuy Lower to Middle Emsian flora and fauna from Consthum and Merkholtz
porites annulatus, E. rotatus, Streelispora newportensis,
Verrucosisporites polygonalis, an assemblage
aributed to the Middle Emsian rather than to the
Lower Emsian .
2.3. New palynological data
P. Steemans (ULg) performed new tests on 3
samples from the 2 localities: Consthum level
with Porolepis scales (eastern part of the quarry),
Consthum level with specimen EIB153, about 100
m NW of the Porolepis scales point, and Merkholtz
level with Drepanaspis. The spores in the 3 samples
are rather similar, with the stratigraphically
important: Acinosporites lindlarensis Riegel 1968,
Apiculiretusispora brandtii Streel 1964, Dibolisporites
echinaceus (Eisenack) Richardson 1965 emend. Mc-
Gregor 1973, Dibolisporites weeldorfensis Lanninger
1968, Emphanisporites zavallatus Richardson et
al. 1982 var. nodosus Steemans 1989, Rhabdosporites
minutus Tiwari & Schaarschmidt 1975.
Such a miospores assembly is typical of the
Emsian. The presence of R. minutus and A.
lindlarensis leads to estimate that the 3 samples
belong at least to the interval biozone “Min” of the
Ferrantia • 36 / 2003
“FD” assembly biozone (Fig. 2). In the absence of
more recent taxa, the levels could be aributed to
this “Min” biozone. However, the palynomorphs
are poorly preserved, and their biodiversity is
low (most of the species are simple forms of
poor stratigraphical indicators like Retusotriletes,
Apiculiretusispora). This prevents to completely
exclude a somewhat younger age (Biozone “AP”)
of the samples, which however would not reach
the top of the Emsian, when very particular forms
appear, like Hystricosporites and Ancyrospora, not
observed here. In the Porolepis Consthum sample,
a very badly preserved spore might be aributed
to Acinosporites apiculatus (Streel) Streel 1967,
aributing its level to the overlying “AP” biozone,
of which this species characterizes the base.
These new observations confirm the Steemans et
al. 2000 conclusions, on a sample taken some 10
m west of the Drepanaspis level of Merkholtz. The
age is approximatively aributed to the Middle to
Upper parts of the Emsian, without reaching its
top. However, it must be noticed that the spores
biozones have not been calibrated as Lower, Middle
or Upper Emsian. Moreover, palynologists
formerly considered the appearance of Emphanisporites
annulatus, as the base of the Emsian, in the
Biozones Âges
Vel Eifélien
AP Pro
Cor sup?
Min
FD Pra moy?
Fov Emsien
AB
inf?
Su
PoW Pa
Po Praguien
W
Fig. 2 : Biozones from the Pragian to the Eifelian, after Streel et al. 1987 and 2000
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