GeolCarp_Vol52_No5_301

GEOLOGICA CARPATHICA, 52, 5, BRATISLAVA, OCTOBER 2001

301 — 318

NON-MARINE CALCAREOUS ALGAE OF UPPER JURASSIC TO

LOWER CRETACEOUS SEQUENCES FROM THE

WESERBERGLAND (NORTHWEST GERMANY)

OVIDIU DRAGASTAN

and DETLEV K. RICHTER

This paper is dedicated to the Dr. Hans Füchtbauer, Professor Emeritus of the Institute of Geology, Ruhr University Bochum
(Germany) with the occasion of 80

years anniversary.

University of Bucharest, Faculty of Geology and Geophysics, Laboratory of Paleontology, Bd. N. Balcescu 1, 70111 Bucharest, Romania

Ruhr-University Bochum, Institute of Geology, Mineralogy and Geophysics, Universitätsstraße 150, 44780 Bochum, Germany

(Manuscript received January 11, 2001; accepted in revised form June 13, 2001)

Abstract: The Upper Jurassic/Lower Cretaceous brackish carbonate sequences of the Weserbergland area (NW Ger-
many) contain numerous calcareous algae and cyanobacteria closely associated with layers dominated by serpulids and
ooids. Algae are an essential tool for the interpretation of brackish environments. Several new taxa of Chlorophyta
(Pseudopenicillus weseri n.sp., Springerella bifurcata n.gen. n.sp., S. fuchtbaueri n.sp., Brachydactylus reisi n.sp.) and
one new species of Cyanobacteria (Ponsella freyteti n.sp.) are described.

Key words: Germany, Jurassic—Cretaceous, non-marine, calcified, cyanobacteria, algae.

Introduction

Little is known about fossil fresh or brackish water algae (e.g.
Toomey & Nitecki 1985). Furthermore, specific data about
chlorophytes and cyanobacteria of the serpulid containing se-
ries of Upper Jurassic to Lower Cretaceous age in NW Germa-
ny do not exist. This seems surprising because the series often
contain deposits of non-marine environments within the wide-
spread area of the so-called Portland Trough (Fig. 1).

Recently, Freytet (1997, 1998, 2000) and Freytet et al.

(1999) reviewed the record of non-marine algae from the Per-
mian to the present-day – some of them found in travertine
and tufa – establishing 16 new genera and 56 new species.

The study of the fossil non-marine algae has long been ne-

glected, altough Reis (1923) published and described new taxa
from  the  Miocene  of  Rheinpfalz  (Donnerberg  Sheet)  as  fol-
lows: Ternithrix compressa – a girvanelloid cyanobacterium
(Oscillatoriaceae),  Dimorphostroma  palatinum,  D.  diffusum
(Rivulariaceae),  Chlorellopsis  coloniata,  Microchorton  clav-
iger, Dendractis brevis, D. compacta, Brachydactylus radia-
lis, Cladophorites incrustans and C. dubius (Chlorophyta).

More recently, Chlorellopsis coloniata was also found in the

Miocene of the northern Rhine Valley by Stapf (1988) and in
the Ries Crater by Arp (1995). Cladophorites incrustata was
decribed from the Miocene of the Ries Crater by Riding
(1979) and Arp (1995).

Geological setting

Uppermost Jurassic to Lower Cretaceous sequences con-

taining serpulids are typical of the final carbonate facies of the
E-W striking Portland Trough in northwestern Germany

(Fig. 1). This facies characterizes the more or less marine parts
of  the  so-called  Malm  group  (Fig. 2)  until  the  non-marine
Wealden  facies  extends  with  the  Bückeberg  Formation  far
over  the  coastline  of  the  Upper  Jurassic  basin  (Gramann  et
al.  1997). Compilations (Gramann et al. 1997) emphasize that
the  < 100  m  thick  Serpulit  Formation  correlates  with  the
youngest bed (OM 6) of the Malm group. Biostratigraphically,
the Serpulit Formation is assigned to ostracod zones 22/23 and
charophyte  zones  7/8  (Berriasian  of  Gramann  et  al.  1997).
The “Serpulit” sensu stricto corresponds with the Upper Ser-
pulid Limestone of Casey et al. (1975) and Schonfeld (1979).
The Münder Marl ranges from Tithonian (OM 3 and OM 4) to
Lower Berriasian (OM 5) (Gramann et al. 1997).

The first description of serpulid limestones from the south-

ern  coast  of  the  Portland  Trough  (Fig. 1)  was  published  by
Blumenbach (1803). Hoyer (1965) interprets these as a near-
coastal  facies  with  serpulid  biostromes,  while  Huckriede
(1967) explains the same sedimentary succession by transpor-
tation and sedimentation of tubes of the phytal living Serpula
coacervata.  According  to  the  Huckriede  (1967),  serpulid  fa-
cies of Hannover reflects meio- to pleiomesohaline conditions
of brackish water (3—18 ‰ salinity) and only the marly inter-
calations were oligohaline (0.5—3 ‰). For the Upper Serpulid
Limestone  in  the  area  south  of  Hannover,  Schonfeld  (1979)
supposes a predominant alternation of limnic (partly subaerial
with desiccation) and brackish/marine (10—18 ‰) conditions,
whereas some local celestine intercalations probably indicate
episodically  higher  salinity  environments.  Based  upon  well-
known anhydrite and halite layers in the deepest parts of the
sedimentary  basin  (Brand  1954),  Gramann  et  al.  (1997)  as-
sume a salinity stratification during sedimentation of the ser-
pulid (OM 6) sensu Schott (1951) and Jordan (1971). Due to
increasing  humidity  of  the  climate  the  limnic  to  terrestrial

302 DRAGASTAN

and RICHTER

Wealden facies finally overlaps the dominantly carbonate ma-
rine facies with variable salinity within the Portland Trough of
northwestern Germany.

The paleoecology of serpulid outcrops in northwestern Ger-

many are described by Jahnke & Ritzkowski (1980), focusing
on the uppermost Jurassic deposits, and by Ten Hove & Van
Den Hurk (1993) dealing with lowermost Cretaceous.

The localities of our study represent the serpula-dominated

facies of the southern coastal zone of the Portland Trough situ-
ated southwest/south to Hannover (Fig. 1). The bulk of the
samples was taken from three disused quarries in the Deister
Mountains north of Springe:

Locality 1 – Lower Serpulid Limestone (samples Bre 1—2)

overlain by marls and fine-grained siliciclastic sediments con-
taining thin and partly nodular limestone intercalations (sam-
ple A3); map and Gauss-Krüger coordinates – MTB 3723
Springe, H 5789800, R 3538160; the locality corresponds to

Loc. 142 of Hoyer (1965), Loc. 1 of Schönfeld (1979) and
Loc. 132 of the geological tourist map of the rural district of
Hannover (1977).

Locality 2 – Upper Serpulid Limestone (samples 835 and

38/1—5); MTB 3723 Springe, H 5790210, R 3538480; the lo-
cality corresponds to Loc. 143 of Hoyer (1965) and Loc. 38 of
Schönfeld (1979).

Locality 3 – Upper Serpulid Limestone (samples 37/1—5);

MTB 3723 Springe, H 5790370, R 3538070; the locality cor-
responds to Loc. 141 of Hoyer (1965) and Loc. 37 of Schön-
feld (1979).

A minor part of the samples was taken from an active quarry

(Schütte Company) situated ESE of Thüste village (about 20
km SSE of Springe):

Locality 4 – Oolitic Serpulid Limestone (samples F1—3);

MTB 3923 Salzhemmendorf, H 5765650, R 3545100; the lo-
cality corresponds to Loc. 21 of Herrmann (1968 – calcare-

Fig. 1. Sketch map showing the position of the localities 1—4. A – Paleogeographic distribution of the Portland Trough in northwestern
Germany according to Betz et al. (1987). B – Geological map for the eastern part of the Deister area, north of Springe (Geologische
Wanderkarte 1:100,000-Landkreis Hannover, 1977).

NON-MARINE CALCAREOUS ALGAE OF JURASSIC TO CRETACEOUS SEQUENCES 303

Fig. 3. Schematic facies pattern for the Upper Jurassic to Lower Cretaceous coastal area, south of Hannover following the models of Logan
et al. (1970) and Jahnke & Ritzkowski (1980) – with supplements. The positions of the localities 1—4 correspond to the horizontal and verti-
cal facies pattern but not to the stratigraphical position.

Fig. 2. Stratigraphic column for the Jurassic to Lower Cretaceous
in the investigated area (Jordan 1979; Gramann et al. 1997).

ous facies of the Münder Marl) and Loc. 57 of Jordan (1979 –
Upper Jurassic “Serpulit”). According to Jahnke & Ritzkowski
(1980) all sampled limestones can be assigned to the middle
part of the Münder Marl (OM 4) below a stromatolitic horizon

and,  consequently,  they  are  assumed  to  be  stratigraphically
lower  than  the  Serpulit  Formation.  Gramann  et  al.  (1997)
place  the  serpulid  limestones  from  the  Hils  Syncline  near
Thüste in ostracod zone 19, which corresponds to lithostrati-
graphic position OM 4.

Microfacies and diagenesis

In order to understand microfacies and diagenesis of the

samples some information is necessary concerning the envi-
ronmental and stratigraphic situation at the southern coast of
the Portland Trough (Fig. 3). We assume a restricted sea with
tidal  effects  influenced  by  deltaic  sedimentation.  Normally,
the  supratidal  flats  were  followed  in  a  seaward  direction  by
stromatolitic  to  oncolitic  facies,  mud  facies  (wacke/mud-
stones), bar facies (grain/packstones) and mud facies wacke/
mudstones).  Furthermore,  we  assume  channels  as  a  connec-
tion between river and basin areas (Fig. 3). This sedimento-
logical scenario moves with transgression and regression cor-
responding to the rule of Walther (see Jahnke & Ritzkowski
1980). This simple paleogeographic situation was complicat-
ed  by  changing  salinities  caused  by  deltaic  influence  and
evaporation.

Grain/packstones

The Lower Serpulid Limestone at Loc. 1 and the limestone

facies of the Münder Marl at Loc. 4 consist predominantly of
grain/packstones rich in bioclasts and/or ooids (bar facies in
Fig. 3). In some cases elongated clasts of serpulids, bivalves
and algae trace plane and cross bedding. At the top the Ser-

304 DRAGASTAN

and RICHTER

pulid Limestone of Loc. 1 a remarkable velocity of flow is im-
pressively indicated by current ripples. This typical feature for
near coastal sedimentary environments is in good agreement
with the paleogeographic position of the investigated localities
at the margin of the Portland Trough (see Fig. 1).

More or less broken tubes of serpulids (Serpula coacervata

according to Schönfeld 1979 and Ten Hove & Van Den Hurk
1993)  are  the  main  bioclasts.  Often,  these  tubes  show  tele-
scope-like  interlocking  (Fig.  8.3)  so  that  using  only  a  band-
lens they can be misinterpreted as ooids. In addition, there are
thalli and fragments of green algae and cyanobacteria (see pa-
leoalgological description) as well as different types of shells.
Monolayered prismatic shells and doublelayered shells – pri-
marily calcitic as well as formerly aragonitic layers – can be
assigned  to  bivalves,  whereas  shells  which  are  completely
composed of calcitic fibres or formerly aragonitic shells can-
not be clearly identified. Particularly the samples from Loc. 4
(Thüste)  contain  gastropods  and  ostracods  in  addition  to  bi-
valves. Foraminifers and ostracods in the samples from Loc. 4
seem to be reworked from older beds (see paleogeographic
situation  in  Fig. 1)  because  of  their  distinctive  diagenetic
composition – e.g. Fe-calcites in skeletons and intraparticle
pores  which  differ  from  those  of  the  surrounding  particles
and cements.

Ooids are common in all studied microfacies types from Ti-

thonian to Berriasian and in some layers they can be regarded
as rockforming (Fig. 8.4). This is especially the case at Loc. 2
and Loc. 4 as well as in the marly beds between the Lower and
Upper Serpulid Limestones (Loc. 1) according to Schönfeld
(1979).

Aside from normally structured ooids with spherical nucleus

and cortex (Fig. 8.4), more complex ooids (Fig. 8.5) and hiatus
ooids  (broken  and  regenerated  ooids;  Fig.  8.4)  occur  (see
Richter  1983).  Within  the  beds  of  Loc.  4  with  its  relatively
high proportion of formerly aragonitic bioclasts, “eggshell di-
agenesis”  (Wilkinson  &  Landing  1978 – dissolution  of  ara-
gonitic nuclei before compaction of the sequence) can be ob-
served  in  some  cases  (Fig.  8.6).  Generally,  all  ooids  of  the
studied localities have a radialcalcitic structure which is typi-
cal for marine ooids in the “calcite time” from Lower Jurassic
to Upper Cretaceous sensu Sandberg (1983). Fe-calcitic ooid
cortices point to a primary composition of radially structured
Mg-calcite (according to Richter & Füchtbauer 1978; Richter
1984).  However,  an  exact  value  of  the  primary  Mg  portion
cannot be determined. But, taking into account the abundant
non-marine green algae and cyanobacteria, and the (brackish)/
marine serpulids, brackish conditions with oscillating salinity
(fine cathodoluminescence zonation in the ooid cortices indi-

Fig. 4. Distribution of algae and the paleocommunities during the Upper Jurassic and Lower Cretaceous in Weserbergland, NW Germany.

NON-MARINE CALCAREOUS ALGAE OF JURASSIC TO CRETACEOUS SEQUENCES 305

cating a primary geochemical fluctuation) seems likely. This
interpretation is further supported by the distribution of radial-
calcitic  ooids  in  the  Neogene/Quaternary  sequences  of  the
Isthmus of Corinth (Richter & Neuser 1998) where ooids oc-
cur within a Neogene/Quaternary cyclic sequence of glacial-
eustatic origin – marine conditions with seawater highstands
and  lacustrine-brackish  conditions  with  sea-level  lowstands
and isolation of seas neighbouring the Mediterranean (in this
case, the Gulf of Corinth). Ooids with aragonitic cortices (re-
placed  by  secondary  isometric  calcite)  are  limited  to  marine
episodes  whereas  radial  Mg-calcitic  cortices  (often  replaced
by Fe-calcite) occur in lacustrine-brackish periods.

The groundmass of the grain/packstones is predominantly

formed by cement, whereas matrix – a. micritic, b. pelmicrit-
ic  (clotted  limestone  sensu  Bathurst 1971,  peloidal  structure
due to crystallization with participation of bacteria according
to  Chafetz  1986) – can  be  exclusively  observed  in  pack-
stones.  The  first  cement  generation  consists  of  calcitic  pali-
sades, which can be observed, mostly in intraparticle pores –
especially in serpulids. This was probably an early cement, but
it is impossible to reconstruct the primary Mg content or the
salinity. The normal sequence of cements is formed by isomet-
ric calcite with an ideal succession calcite I, Fe-calcite, calcite
II. The same cement succession can also be observed in disso-
lution pores of formerly aragonitic particles if they were not
previously calcitized in situ (compare Fig. 8.7).

Wacke/mudstones

Wacke/mudstones are common especially in the Upper Ser-

pulid Limestone of localities 2 (Fig. 8.2) and 3, and also in the
marly  sequences  between  Lower  and  Upper  Serpulid  Lime-
stone at locality 1 and in the upper part of the calcareous facies
of the Münder Marl at locality 4 (mud to stromatolite facies in
Fig. 3). The wacke/mudstones occur as beds and as intraclasts.
With  respect  to  ooids  and  biogenic  components  the  wacke/
mudstones are similar to the grain/packstones, but the predom-
inantly micritic facies contains a distinctly higher proportion
of  green  algae  and  cyanobacteria  (see  paleoalgological  de-
scription).  Partly,  the  wacke/mudstones  have  a  strongly  in-
creased  proportion  of  intraclasts  and  oncoids.  At  locality  3
these oncoids can reach diameters in the range of decimeters
(Fig. 8.1) and in some cases are composed of a complex algal
community.  Detrital  quartz  grains  complete  the  component
spectrum of the wacke/mudstones. Few of these grains show
authigenic rims of quartz.

The groundmass is dominated by a micritic to peloidal,

sometimes  microsparitic  matrix  (according  to  Füchtbauer  &
Richter  1988).  Often  the  calcareous  content  of  the  matrix  is
more  or  less  substituted  by  clay  and  silt,  so  that  the  petro-
graphical composition corresponds to marls or marly clays.

Residual spaces of interparticle pores, intraparticle pores (es-

pecially in serpulid tubes) and shrinkage cracks were mostly ce-
mented by calcite. Normally, a sequence of calcite I, Fe-calcite
and calcite II can be observed corresponding to the cementation
sequence in the grain/packstones. Rarely, in some intraparticle
pores (serpulid tubes, completely preserved ostracod shells) an
initial palisade-shaped cement generation may occur.

Figs. 5—6. Springerella bifurcata nov. gen. nov. spec., thallus with
long Y-shaped dichotomously branched tubes and swellings in the
area of branching, also rare swellings between the successive di-
chotomies.

Fig. 5.

Fig. 6.

306 DRAGASTAN

and RICHTER

In thin sections of the Upper Serpulid Limestone of locali-

ties 2 and 3 the blocky calcite cement is often pigmented by
opaque material and exhibits internal zones of calcite and Fe-
calcite. The presence of lentil-shaped calcite pseudomorphs
after gypsum in the matrix, showing the same features as the
calcite mentioned above, a pseudomorph origin also seems to
be probable for the blocky calcite areas in the inter- and intra-
particle pores. This blotchy distribution of calcite can be ex-
plained by changes of the redox conditions in the pore fluid
during calcification of gypsum.

Paleoecology of non-marine algae

The communities recorded at the Jurassic-Cretaceous

boundary within the Weserbergland region, NW Germany, in-

cluded marine and non-marine algae, serpulids, bivalves, gas-
tropods, ostracods and coprolites. These occurred in shallow
basins at coast lines with a varied morphology: subtidal, inter-
tidal with limnic pools and supratidal, crossed by tidal or fluvi-
atile channels (Fig. 3).

In an attempt to reconstruct the paleoecological conditions

of this time interval, correlated with the depositional environ-
ments, three characteristic communities can be recorded:

a) Community dominated by Halimedaceae (Pseudopeni-

cillus weseri) confined to the subtidal, marine realm, corre-
sponding to the depositional environment of the Oolitic Ser-
pulid Limestone (locality 4) of the Münder Marl Formation
(= OM 4), Upper Tithonian in age.

The occurrence of broken algal segments, as elongate, paral-

lel bioclasts, indicates that they were transported by “tidal
streams” especially within the channel facies where they accu-

Fig. 7. Reconstruction of a stromatolitic nodule built by various algae and microbes: in the basal part algal-micrite, microbialite, covered by
Chlorellopsis coloniata Reis composed of spherical cells, then Broutinella arvernensis Freytet, mainly represented by monostrata crust, in-
terlayered with Ponsella freyteti nov. spec. and in the upper part, laminated layers with protuberances of Brachydactylus reisi nov. spec. and
Broutinella arvernensis.

NON-MARINE CALCAREOUS ALGAE OF JURASSIC TO CRETACEOUS SEQUENCES 309

mulated during slow sedimentation, as a function of their
shape, dimensions and weight. They produced bioclastic accu-
mulations as micro-rhythmites.

The marine deposits with normal salinity reached the interi-

or by repeated marine “invasions” along the tidal channels,
generating “micro-rhythmitic” deposits of thallus fragments
(only cortical parts), together with rare serpulid tubes, benthic
foraminifers (Lenticulina, Epistomina, Nautiloculina) and bi-
valve shells (Fig. 4).

Small oncoids, 0.2—0.4 mm in diameter occur rarely and al-

gal pellets were deposited in “quiet” environments, after their
transport.

b) Community dominated by Serpula coarcervata, tubes

embedded in micrites (locality 1) (Ten Hove & Van Den Hurk
1993).

The matrix is made of pure micrites and biogenic micrites

resembling algal pellets and stromatolites, fine quartz grains
(0.010—0.10 mm) and clasts (clay, marls or micrite).

In addition to serpulid tubes, the community includes shells

and shell fragments of bivalves, ostracods and rare charophyte
gyrogonites, together with coprolites deposited in shallow in-
tertidal, bar and limnic pool areas. In these “ponds” oncoids
formed with dimensions of 2—10 mm.

From a paleoalgological point of view, 4 morphospecies are

identified: Chlorellopsis coloniata Reis, Broutinella arvernen-
sis Freytet, Ponsella freyteti n.sp. and Brachydactylus reisi
n.sp. (Fig. 7).

Two types of stromatolites can be observed: homogenous

and heterogenous sensu Freytet (2000). Both categories are
abundant, reflecting the growth of flat laminae, hemispheres,
small domes and columns, like Broutinella arvernensis.

The microbial encrustation B. arvernensis is initially micrit-

ic, followed by radial sparite palissades type in laminated mi-
cro-build-ups. The microlaminations are interpreted as a result
of bacterial activity with a daily rhythm and a fabric made of
cyanobacterial filaments.

The homogenous stromatolites have nodular-ellipsoidal

shapes, 2.5—3.0 mm in diameter, enclosing gastropod shell
fragments and, in the outer part, microbial crusts of Broutinel-
la arvernensis.

The heterogenous stromatolites are larger (4.5—10.0 mm in

diameter) and have nodular-ellipsoidal shapes bearing external
protuberances with a vertical growth tendency, initially tempo-
rarily fixed to the substrate, finally generating in place build-
ups.

There are oval-ellipsoidal algal nodules with cerebroid ex-

ternal surfaces and diameter of 3.0—4.0 mm. They include a
core of Chlorellopsis coloniata, covered by microbial laminae
and an external succession of crusts made by Broutinella arv-
ernensis and small protuberances of Brachydactylus reisi.

These compound nodules are typically formed by the super-

position of 2—4 algal-microbial generations. At the base of the
nodular  build-ups,  Chlorellopsis  coloniata  is  common  fre-
quent,  composed  of  isolated,  spheroidal  cells  embedded  in  a
bacterial  micritic  mass,  generating  microlaminations.  In  the
middle part of the nodules, crusts of Broutinella arvernensis
occur coated by or intermingled with Brachydactylus reisi. To-
wards the exterior, the successive microlaminations contain a
biocoenosis of Broutinella arvernensis, Ponsella freyteti and,

at the outer margin, many small protuberances made by
Brachydactylus reisi (Fig. 7).

The occurrence of these algal-stromatolite structures with-

in the Lower Serpulid Limestone is recorded here for the first
time.

They represent lacustrine stromatolites accumulated on the

lacustrine shores. The stromatolitic nodules incorporate ser-
pulid  tubes,  disrupted  ostracod  valves,  gastropod  coprolites
(0.3—0.4 mm in length), and microbial pellets. At the top, or
between  the  algal  nodules,  occur  clay  and  limestone  clasts,
3.0—4.0 mm in length, elongated and flattened in shape, to-
gether  with  abundant  detritic  quartz,  0.010—0.10  mm  in  di-
ameter.

The Lower Serpulid Limestone (LSL) includes tubes of

Serpula selectively transported and deposited in monospecif-
ic banks, some of them being incorporated in stromatolite
nodules or serving as substrates for other algal-microbial
nodules.

The community belonging to the LSL indicates a fluctuat-

ing salinity, from hypersaline to limnic, in the peritidal envi-
ronment (Fig. 4).

c) Stromatolite community (localities 2, 3) of the inter-

tidal and proximal supratidal zones.

This community was dominated by algae and represented

by spheroidal or ellipsoidal nodules with or without a core of
1—2 tubes of serpulids on which were fixed thalli crossed by
dichotomous tubes with swellings of Springerella bifurcata
n.sp. or rarely S. fuchtbaueri n.sp.

The majority of these algal nodules were free on the sub-

stratum or were temporarily anchored when larger.

The spheroidal thalli of Springerella bifurcata (Figs. 5—6),

with or without a core, never surpassed 2.5—3.0 mm. The
thalli had ellipsoidal shapes, when the substratum or the core
was made of two serpulid tubes, and dimensions larger than
4.0—5.0 mm.

The majority of the nodules of the Upper Serpulid Lime-

stone can be regarded as homogenous, monospecific stromat-
olites.  Nodules  larger  than  6.0—10.0  mm,  with  an  irregular
outline,  with  small  external  protuberances,  occur  rarely.
They are constructed by Springerella bifurcata to the central
part  followed  externally  by  laminated  crusts  of  Broutinella
arvernensis.  In  most  cases,  the  serpulid  tubes  provided  the
better substratum for algae, such as dichotomously ramified
tubes of Springerella. The Springerella nodules incorporate
serpulid tubes, and angular quartz grains with a diameter of
0.05—0.06 mm.

In addition to Springerella and Broutinella, the community

includes bivalve shells, ostracod valves and microgastropods
(4.0—5.0 mm). The gastropod shells were filled with numer-
ous small serpulid tubes. Ooids also occur with cores of an-
gular quartz (0.05—0.06 mm in diameter) or of well rounded
quartz grains with a diameter larger than 0.80—1.0 mm.

Clusters of dead serpulids provided the initial substrates

for the nodules and laminated crusts. These crusts incorpo-
rate empty tubes of serpulids, algal pellets, ostracods, gastro-
pod shells, and quartz grains with a reduced diameter.

This community belonging to the Upper Serpulid Lime-

stone can be compared with the spirorbid algal stromatolites
and Recent stromatolites in hypersaline (50—70 ‰) lagoons

310 DRAGASTAN

and RICHTER

near  Shark  Bay,  W.  Australia  (Ten  Hove  &  Van  Den  Hurk
1993). The algal nodules of the Upper Serpulid Limestone in-
corporated  re-deposited  tubes  of  serpulids  generated  in  la-
goons  fringing  an  inland  sea,  within  the  intertidal  and  lower
supratidal zones.

Paleoalgological description

Phylum Chlorophyta

Class Bryopsidophyceae

Order Bryopsidales

Family Udoteaceae Endlicher 1834 emend. Agardh 1887

Genus Pseudopenicillus Dragastan, Richter, Kube, Popa,

Sârbu et Ciugulea 1997

Pseudopenicillus weseri nov. spec.

(Fig. 9.1—8)

Derivatio nominis: from the Weser River, Germany.
Holotype: Fig. 9.1, Coll. L.P.B. V, No. 1120, Upper Titho-

nian, sample F3A, Oolitic Serpulid Limestone (Münder Marl
= OM 4) Salzhemmendorf.

Isotypes: Fig. 9.4—8, Coll. L.P.B. V, No. 1121, No. 1122, No.

1123, No. 1124, Upper Tithonian, Oolitic Serpulid Limestone.

Diagnosis: Thallus composed by cylindrical segments sepa-

rated by constrictions. The segments have a central medullary
hollow, without preserving siphons, and a thin cortex crossed
by cylindrical primary, secondary and tertiary siphons. Prima-
ry siphons have in the proximal part an inflated swollen “vesi-
cle”, and the secondary siphons also have small “vesicles” in
the distal parts. Tertiary siphons, dichotomic, are very short
and narrow.

Description: Thallus formed by small narrow, cylindrical

segments separated by deep constrictions (Fig. 9.1,6). The
segments, entire or broken, have an axial cavity with an un-
even and sinous contour. The central cavity is narrow and cor-
responds to the medullary zone, in which the siphons are not
preserved. The cortex is not thick, and partially is only incom-
plete preserved. It was not strongly calcified and sometimes is
broken (Fig. 9.4—8).

The cortical zone is crossed by very fine, cylindrical, prima-

ry siphons continued by secondary siphons, both dichoto-
mously branched. The vesiculiferous inflated proximal part of
primary, and of the distal part of secondary siphons, are clearly
visible on the Fig. 9.4 (see arrow).

Dimensions in mm: length of thallus: 2.0—3.0; diameter of

thallus: 0.90—0.95; diameter of thallus between segments:
0.70—0.75; diameter of the axial cavity or medulla: 0.50—0.55;
thickness of cortex: 0.15—0.20; length of primary cortical si-
phons: 0.080—0.10; length of secondary cortical siphons:
0.040—0.060; length of tertiary siphons: 0.020—0.030; diameter
of primary cortical siphon: in the proximal part 0.030 and in
the median and distal part: 0.020; diameter of secondary corti-
cal siphons in the distal part 0.010—0.015; diameter of tertiary
siphons: 0.010.

Discussion: Pseudopenicillus weseri n.sp. differs from P.

jurassicus (Dragastan), P. orientalis (Dragastan), P. elongatus
(Dragastan), P. texana (Johnson) and P. dragastani (Bucur) of
Late Jurassic—Early Cretaceous age, by the small size of the
segments and by the presence of “vesicle” in the proximal
parts of the primary siphons and in the distal parts of the sec-
ondary cortical siphons.

P. peloponnesiacus Dragastan et Richter from Tithonian,

Corinth area (Grecee), is similar in the small segment size and
presence of cylindrical primary and secondary cortical si-
phons, but lacks “vesicle” in the proximal and distal parts of
the siphons.

Phylum Chlorophyta

Springerella nov. gen.

Derivatio nominis: from Springe locality and from the

ending “rella”.

Type species: Springerella bifurcata nov. gen. nov. spec.
Diagnosis: Nodular thallus crossed by only one kind of

long tube, open or Y-shaped, dichotomously branched, hav-
ing a strong calcified swelling in the area of branching. Due
to the reduced number of swellings (1—2) between the suc-
cessive dichotomies and in the branching area, the thallus is
slightly moniliform.

Discussion: The new taxon is comparable with non-ma-

rine genera Purserella Freytet 1997 (Oligocene), Ponsinella
Freytet 1998 (Ludian—Recent) and Sarfatigirella Freytet
1998 (Campanian—Oligocene—Recent).

Purserella has erect filaments, regular, flexuously sinuous,

dichotomous branches diverging at 30°, but lacks swellings
in the branching area and along the filament tubes.

Ponsinella has two types of filaments, prostrate, then in-

clined and erect, rarely branched with a lateral tube making
an angle of 60° (Freytet 1998, p. 21).

Sarfatigirella shows intricate filaments, arcuate, flexuous,

having a “pinch and swell” aspect, forma torulata, which dif-
fers in shape and thickness from the new taxon.

The new taxon is also comparable with the Jurassic species

of  the  marine  Mitcheldeania  Wethered  1886  and  with
Pseudomitcheldeania  Schlagintweit  1990  (Jurassic—Creta-
ceous)  and  Perachoraella  Dragastan,  Richter,  Gielisch  et
Kube  1998  (Late  Jurassic—Early  Cretaceous).  These  genera
also  have  dichotomously  branched  tubes  (siphons)  with  a
small  angle  of  divergence  (mainly  10°)  and  variable  swell-
ings,  occurring  in  number,  higher  than  two,  and  another
shape of swellings, which differ from the new genus.

The taxonomic attribution of the new genus within the

Chlorophyta remains open. The presence of swellings in the
tube siphons is a characteristic feature of Bryopsidophyceae.

Posinella is considered close to modern Scytonemataceae

(Cyanobacteria) and Purserella still remains in an open tax-
onomy (Freytet 1997 and 1998).

The genera Mitcheldeania, Pseudomitcheldeania and Per-

achoraella belong the Family Avrainvilleaceae, Class Bry-
opsidophyceae, Chlorophyta.

NON-MARINE CALCAREOUS ALGAE OF JURASSIC TO CRETACEOUS SEQUENCES 313

Springerella bifurcata nov. spec.

(Fig. 10.1—3, Fig. 11.1—4)

Derivatio nominis: from the open dichotomously branched

tubes.

Holotype: Fig. 10.1, Coll. L.P.B. V, No. 1125, Lower Berri-

asian, sample No. 835, Upper Serpulid Limestone, locality
Springe.

Isotypes: Fig. 10.2—3, Coll. L.P.B. V, No. 1126, No. 1127;

Fig. 11.1—4, Coll. L.P.B. V, No. 1128, No. 1129, No. 1130, No.
1131, Lower Berriasian, Upper Serpulid Limestone.

Diagnosis: Nodular thallus composed of Y-shaped, open,

dichotomously branched tubes, having in the area of branching
a strongly calcified swelling and 1—2 swellings along the tubes
in the area between two successive dichotomous branches.

Description: Nodular spheroidal or ellipsoidal thallus. The

shape of the thallus reflects the shape of the core or substra-
tum.  If  the  alga  is  attached  on  a  serpulid  tube,  the  shape  of
thallus  is  spheroidal  (Fig.  10.2).  When  it  is  attached  on  an
elongate ooid, the shape of thallus becomes ellipsoidal or if is
embedded on a double serpulid tubes, the shape of thallus is
also ellipsoidal (Fig. 11.4). The thallus is crossed by long, Y-
shaped open dichotomously branched tubes, which present an
angle of divergence of 30°—40°. In vertical (Fig. 10.1—2) and
horizontal  sections  (Fig.  10.3)  the  Y-shaped,  dichotomous
tubes present in the branching area a strong swelling and also
1—2 swellings along the tubes, between two successive dichot-
omously  branched  areas  (Fig.  10.2;  Fig.  11.3).  The  shape  of
swellings  is  ovoidal  to  ellipsoidal  between  the  dichotomies
and subtriangular in the branching area (Figs. 5—6).

The pattern of distribution of the tubes is another character-

istic feature of this species. In cross-section, the tubes are dis-
posed in a regular network, round, quadrangular or polygonal
in shape, separated from each other by coarsely crystalline cal-
cite (Fig. 10.3). The distribution of tubes is in a more or less
regular sparitic “muff”, represented by 4 (quadrangular) or 8
tubes, when the shape of “muff” is round to polygonal, the
tubes having a petaloid disposition (Fig. 10.3). Sometimes in
horizontal section, the swellings appear circular with a large
diameter, like white sparitic spots (Fig. 10.3).

Dimensions in mm: maximum diameter of thallus: 3.5—4.0;

normal diameter of thallus: 2.20—3.0; diameter of tube in the
dichotomous branching area: 0.075—0.080; diameter of tube
after the dichotomous branching area: 0.035—0.040; diameter
of swellings along the tube: 0.040—0.050; angle of divergence:
30°—40° (50°).

Discussion: Springerella bifurcata n.sp., differs from Purse-

rella gracilis Freytet (Oligocene) by the presence of swellings
in the branching area and in other kinds of dichotomy. From
Ponsinella rupestris Freytet (Recent), it differs in the absence
of two kinds of filaments, prostate and then erect.

Sarfatigirella fallacia Freytet from the Campanian differs in

its small diameter of more or less erect filaments, that are not
undulose. In common with the new species swellings are
present, but these are not distributed in the branching area, and
they also have a spheroidal shape.

The marine species Mitcheldeania americana (Johnson)

from the Jurassic differs from the new taxon by the presence of
siphons, dichotomously branched after an angle of divergence

of less than 10°, and by the presence of many swellings along
the siphons.

The marine species of Pseudomitcheldeania such as P. dra-

gastani Schlagintweit (Upper Aptian), P. akrokorinthica Dra-
gastan et Richter (Tithonian) and P. sp. (Valanginian) are dif-
ferent from S. bifurcata, in their shape and in the number of
swellings along the tube. The first of these species has many
swellings along the tube and the second species has long, large
swellings arranged at different levels. The third species has el-
lipsoidal swellings, distributed at irregular intervals along the
tubes. The species of Pseudomitcheldeania belongs to the
Family Avrainvilleaceae, Class Bryopsidophyceae.

Springerella fuchtbaueri nov. spec.

(Fig. 11.5—7)

Derivatio nominis: Species dedicated to Dr. Hans Fücht-

bauer, Professor Emeritus of the Institute of Geology, Ruhr
University Bochum, who first studied the algal-microbial nod-
ules of Weserbergland, NW Germany.

Holotype: Fig. 11.5, Coll. L.P.B. V, No. 1132, Lower Berri-

asian, sample No. 38/1, Upper Serpulid Limestone, Springe
locality.

Isotypes: Fig. 11.6—7, Coll. L.P.B. V, No. 1133 and No.

1134, Lower Berriasian, Upper Serpulid Limestone.

Diagnosis: Thallus ellipsoidal, composed of several fan-

shaped  bushes.  Each  bush  crossed  by  short,  dichotomously
branched tubes with strongly calcified sub-triangular or clavi-
form  swellings,  before  the  branching  zone  (Fig.  11.5c).  The
tubes show many spheroidal swellings between successive di-
chotomies  (Fig.  11.5,  see  arrows).  The  angle  of  divergence
varies from 10° to 40°.

Description: Thallus irregular ellipsoidal, formed by sever-

al spheroidal or fan-shaped bushes fixed on the serpulid tubes
(Fig.  11.6).  Thallus  is  crossed  by  dichotomously  branched
tubes,  having  a  subtriangular  or  claviform  swellings  (Fig.
11.5).  In  the  horizontal  and  oblique-horizontal  sections  (Fig.
11.6—7), the arrangement of tubes is subpolygonal, composed
of over 8 circular tubes (Fig. 11.7). The swellings before the
branching area have a large diameter.

Dimensions in mm: height of thallus: 0.30—0.70; width of

thallus: 0.40—0.90; tube diameter, in the dichotomic branching
area: 0.040—0.060; tube diameter after dichotomic area:
0.020—0.030; diameter of basal swelling before branching:
0.080—0.10.

Discussion: Springerella fuchtbaueri nov. spec. differs from

the non-marine species, Purserella gracilis Freytet, Ponsinella
rupestris Freytet and Sarfatigirella fallacia Freytet by the
presence of dichotomic tubes which in the branching area have
a strong calcified swelling and many small swellings separated
by constrictions along the tubes crossing the thallus. S. bifur-
cata nov. spec. is different in the shape of thallus, pattern dis-
tribution of tubes, angle of divergence and pattern of distribu-
tion of swellings along the thallus.

In comparison with marine species, the new species is com-

parable with Mitcheldeania americana (Johnson) of the Upper
Jurassic, but differs in having a different kind of branching and
fewer swellings along the tubes. It differs from Pseudomitch-
eldeania dragastani Schlagintweit (Upper Aptian), in the

314 DRAGASTAN

and RICHTER

shape of the thallus and the shape and distribution of swellings
crossing the thallus.

Genus Chlorellopsis Reis 1923

Chlorellopsis coloniata Reis 1923

(Fig. 12.1—2)

1923 Chlorellopsis coloniata n.gen. n.sp., Reis, p. 107, Tafel III,

Figs. 1

—

2, 9; Tafel IV, Figs. 3,6; Tafel V, Figs. 2

—

6 and Fig.

Text 1, p. 105

1997 Chlorellopsis coloniata, Freytet, p. 13, Pl. 1, Figs. a

—

2000 Chlorellopsis coloniata, Freytet, p. 9, Pl. I, Fig. c

Paratype: Fig. 12.2, Coll. L.P.B. V, No. 1135, Lower Berri-

asian, sample A3, Lower Serpulid Limestone, Deister Mts,
Weserbergland, NW Germany.

Description: Thallus small, nodular, in biomicritic masses

or included in laminations. Thallus is composed of spherical
bodies  (cells),  0.060—0.110  mm  in  diameter.  The  spherical
“cells” are preserved in coarsely crystalline calcite surrounded
by  microcrystalline  calcite,  polygonal  in  shape  (Fig.  12.2).
The microcrystalline calcite “layer” is covered by coarse crys-
talline  calcite  like  a  “muff”  which  preserves  the  polygonal
shape of the cells (Fig. 12.1/c—2).

Dimensions in mm: diameter of thallus: 1.0—2.0; diameter

of spherical bodies or cells: 0.060—0.110.

Remarks: Chlorellopsis coloniata is a frequent alga in the

brackish and freshwater facies mainly associated with stroma-
tolitic build-ups.

A discussion and interpretation of Ch. coloniata was well

presented by Freytet (2000) who shows that Chlorellopsis is
never free in the sediment when building stromatolitic masses
showing diverse aspects and morphologies.

The systematic position of Ch. coloniata is and remains

controversial:

– Reis (1923) considered that the species belongs to Chlo-

rophyta, Order Protococcales and compared it with the Recent
marine genus Halosphaera and with freshwater genera Eremo-
sphaera and Chlorella;

– Lindqvist (1994) considers that these thalli with spheres

are “endogonaceous fungal spores” and

– Freytet (1997) shows that a precise attribution of Chlo-

rellopsis coloniata remains open.

Genus Brachydactylus Reis 1923

Brachydactylus reisi nov. spec.

(Fig. 12.1, Fig. 13.1—6)

Derivatio nominis: Species dedicated to Otto M. Reis, who

was the first to discover and describe the Miocene non-marine
algae.

Holotype: Fig. 13.1, Coll. L.P.B. V, No. 1138, Lower Berri-

asian, sample A3, Lower Serpulid Limestone, Deister Mts,
Weserbergland, NW Germany.

Isotypes: Fig. 13.4—6, Coll. L.P.B. V, No. 1139, No. 1140

and No. 1141, Lower Berriasian, Lower Serpulid Limestone,
Weserbergland, NW Germany.

Diagnosis: Thallus crossed by a bunch of filaments grouped

in fascicles composed of finger-like, short dichotomic fila-
ments. The fascicles grow over each-other. They have a fan-
shape, being cauliflower-like in structure, and minidigitate at
the distal part of the fascicles.

Description: Thallus nodular with many small, spheroidal

protuberances. The thallus is crossed by grouped filaments
with microdigitate distal ends of the fascicles (Fig. 13.1—6).
Each filament fascicle is strongly calcified with a fan-shaped
aspect and comprise many, small, dichotomic filaments at the
distal part (Fig. 13.3—6). The fascicle filaments form spherical
nodules (Fig. 13.1,4) or planar laminated crusts (Fig. 13.6).

Dimensions in mm: diameter of the thallus nodule: 2.0—

2.5; diameter of isolated protuberances: 1.0—1.5; width of the
filament fascicles: 0.70—0.75; height of the filament fascicles:
0.40—0.50; diameter of minidigitate filaments in the distal part:
0.035—0.040.

Discussions: Brachydactylus reisi n.sp. differs from the Mi-

ocene B. radialis Reis in the shape and size of filament fasci-
cles, which contain dichotomic filaments at the distal parts of
the fascicles.

B. reisi n.sp. is one the most important builders of the stro-

matolitic  nodules,  being  associated  with  and  a  generator  of
crusts  (protuberances),  together  with  Chlorellopsis  coloniata
Reis,  Broutinella  arvernensis  Freytet  and  Ponsella  freyteti
n.sp. (Fig. 7).

Cyanobacteria

Genus Ponsella Freytet 1997

Ponsella freyteti nov. spec.

(Fig. 12.3—5)

Derivatio nominis: Species dedicated to Dr. Pierre Freytet

for his contributions in the field of non-marine algae.

Holotype: Fig. 12.3, Coll. L.P.B. V, No. 1136, Lower Berri-

asian, sample A3, Lower Serpulid Limestone, Deister Mts,
Weserbergland, NW Germany.

Isotype: Fig. 12.5, Coll. L.P.B. V, No. 1137, Lower Berri-

asian, Lower Serpulid Limestone, Weserbergland, NW Ger-
many.

Diagnosis: Thallus laminated, crustose, composed of fila-

ments grouped in fascicles at the base, inclined, then erect, be-
ing slightly dichotomously branched; adjacent fascicles form-
ing layers or lamination.

Description: Thallus crustose, laminated, not very thick,

formed by fascicles. The filaments disposed at the base, pros-
tate short, then erect (Fig. 12.4—5). The fascicles are wide, cy-
lindrical, composed of 2 or 4 slightly dichotomic branched fil-
aments.

Dimensions in mm: thickness of thallus: 0.30—0.50; width

of the fascicles: 0.070—0.10; diameter of filament tubes:
0.015—0.020.

Discussion: Ponsella freyteti nov. spec. is close to P. castel-

landonica Freytet 1997 from Ludian, in filament size, but dif-
fers in the shape and the size of the fascicles, which are not so
wide. The species P. sezanensis Freytet 1997 and P. cupulata
Freytet 1997 from the Eocene have different size and shape of

NON-MARINE CALCAREOUS ALGAE OF JURASSIC TO CRETACEOUS SEQUENCES 317

fascicle, and also are different from the new taxon in filament
diameter.

Genus Broutinella Freytet 1998

Broutinella arvernensis Freytet 1998

(Fig. 12.1/br, Fig. 7)

1998 Broutinella arvernensis n.gen. n.sp. Freytet, p. 11, Pl. XII,

Figs. a

—

i, Oligocene—Recent

Paratype: Fig. 12.1/br, Coll. L.P.B. V No. 1142, Lower

Berriasian, sample A3, Lower Serpulid Limestone, Weserber-
gland, NW Germany.

Description: Thallus crustose, laminated, formed by only

one layer (forma monostrata) with fascicles various in shape,
including diverse shapes of coarse crystalline calcite (sparite
radial, palisadic). The crust shows frequent intervals of micro-
laminations. Filaments very thin, 3—5

m in diameter.

Remarks: Broutinella arvernensis is the main organism of

the stromatolitic build-ups, forma monostrata, and it is fre-
quently associated with Chlorellopsis coloniata, Ponsella
freyteti nov. spec. and Brachydactylus reisi nov. spec.

Freytet (2000) shows that the three discriminating charac-

ters of B. arvernensis are the scarce presence of erect, more or
less radiating filaments; lamination of radial, palisadic sparite;
and the frequent presence of microlaminations in the light lam-
inae. The presence of radial palisadic type of calcite in fresh-
water facies suggests travertines or sinter crusts with periodic
proliferation of population of cyanobacteria or other bacteria.

Acknowledgments: The authors wish to express their grati-
tude to Dr. P. Freytet (France) and to Dr. R. Riding (England)
for their valuable comments and criticism.

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