BULLETIN DE L'INSTITUT ROYAL
DES SCIENCES NATURELLES
DE BELGIQUE
BULLETIN VAN HET KONINKLIJK
BELGISCH INSTITUUT VOOR
NATUURWETENSCHAPPEN
SCIENCES DE LA TERRE
AARDWETENSCHAPPEN
VOL. 81
BULLETIN DE L'INSTITUT ROYAL
DES SCIENCES NATURELLES
DE BELGIQUE
BULLETIN VAN HET KONINKLIJK
BELGISCH INSTITUUT VOOR
NATUURWETENSCHAPPEN
SCIENCES DE LA TERRE
AARDWETENSCHAPPEN
VOL. 81
BRUXELLES 2011 BRUSSEL
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Michael A. KAMINSKI (London, U K )
Jordi M A R T I N E L L (Barcelona, Spain)
David B. W E I S H A M P E L (Baltimore, U S A )
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Gloria ARRATIA, Arnaud B I G N O N , André B O R N E M A N N , Denise BRICE,
C l a u d i a D O J E N , J e a n G A U D A N T , M i r e i l l e G A Y E T , R o d o l f o G O Z A L O , C h r i s KlNG,
L e o n a K O P T I K O V A , R o s s A . M c L E A N , Jeffrey O V E R , A d r i a n R U N D L E ,
E t i e n n e S T E U R B A U T , J a m e s T Y L E R , T o m U Y E N O , A n t h o n y J. W R I G H T
BULLETIN
DE L'INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE
SCIENCES DE LA TERRE
BULLETIN
VAN H E T KONINKLIJK BELGISCH INSTITUUT V O O R
NATUURWETENSCHAPPEN
AARDWETENSCHAPPEN
Vol. 8 1 - 2 0 1 1
ISSN 0374-6291
P u b l i é , v e r s c h e n e n , published:
30.XI.2011
© Edition de
© Uitgave van het
l'Institut Royal d e s Sciences Naturelles
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de Belgique
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CONTENTS
TABLE DES MATIÈRES
t W A L L I S E R , O . & P. B U L T Y N C K — E x t i n c t i o n s ,
TAVERNE,
survival a n d innovations o f conodont species
during the Kacâk Episode (Eifelian-Givetian) in
south-eastern M o r o c c o
Catervariolus
(Teleostei, "Pholidophoriformes")
du Jurassique m o y e n de Kisangani (Formation
de Stanleyville) en République Démocratique du
Congo
175
T A V E R N E , L.
- Osteologie et relations de
Ligulella
(Halecostomi, Ligulelliformes nov.
ord.\ poisson du Jurassique m o y e n d e Kisangani
(Formation d e Stanleyville) en République
Démocratique d u C o n g o
213
COEN-AUBERT,
Middle
M.
Devonian
investigated
by
LE
Reassignment
of
some
rugose
MAÎTRE
(1934)
Chalonnes Formation from
Armorican Massif (France)
to
5
- - Osteologie
et
relations
de
the
corals
in
L.
the
the Southeastern
27
VAN V I E R S E N , A . P . & H. P R E S C H E R — T w o n e w
species of scutelluid trilobites formerly k n o w n
as Scutellum costatum from Frasnian bioherms
in Belgium
BOGAN,
55
C A S I E R , J.-G., D E V L E E S C H O U W E R , X . , P E T I T C L E R C , E. & A . P R E A T — O s t r a c o d s , rock facies
and magnetic susceptibility o f the Hanonet
Formation /Trois-Fontaines Formation boundary
interval (Early Givetian) at the M o n t d ' H a u r s
(Givet, France)
63
S.,
TAVERNE,
L.
&
FL.
AGNOLIN
Description of a n e w aspidorhynchid
fish, Belonostomus
lamarquensis
sp. nov.
(Halecostomi, Aspidorhynchiformes), from the
continental Upper Cretaceous o f Patagonia,
Argentina
235
S T E U R B A U T , E. — N e w calcareous nannofossil
taxa from the Ypresian (Early Eocene) of the
North Sea Basin and the Turan Platform in West
Kazakhstan
247
C A S I E R , J.-G., D E V L E E S C H O U W E R , X . , M O R E A U ,
J., P E T I T C L E R C , E. & A. P R É A T —
Ostracods,
B R Z O B O H A T Y , R . & D. N O L F —
rock facies and magnetic susceptibility records
from the stratotype of the Terres d ' H a u r s
Formation (Givetian) at the Mont d ' H a u r s
(Givet, France)
97
T A V E R N E , L. — O s t e o l o g i e et relations p h y l o g é n é t i q u e s d e Steurbautichthys
("Pholidophorus")
aequatorialis
g e n . nov. (Teleostei,
" P h o l i d o p h o r i f o r m e s " ) du Jurassique m o y e n
de K i s a n g a n i , en R é p u b l i q u e D é m o c r a t i q u e d u
Congo
129
Fish otoliths
from the Middle Eocene (Bartonian) of Yebra d e
Basa, province o f Huesca, Spain
279
BULLETIN DE L'INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE
BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN
SCIENCES DE LA TERRE, 81: 5-25, 2011
AARDWETENSCHAPPEN, 81: 5-25, 2011
Extinctions, survival and innovations of conodont species during the Kacak
Episode (Eifelian-Givetian) in south-eastern Morocco
by Otto W A L L I S E R t & Pierre B U L T Y N C K
WALLISER, O. & BULTYNCK, P., 2011 - Extinctions, survival and
innovations of conodont species during the Kacâk Episode (Eifelian-
Introduction
Givetian) in south-eastern Morocco. Bulletin de l'Institut royal des
The Global Stratotype Section and Point ( G S S P ) for
Si j , m es naturelles de Belgique, Sciences de la Terre, 81: 5-25,4 figs,
4 pis. Brussels, November 30, 2011 - ISSN 0374-6291.
Abstract
For the first time the complete conodont fauna from the GSSP
for the base of the Givetian at Jebel Mech Irdane in the Tafilalt
(SE Morocco) is described. The conodont faunas described by
BULTYNCK in 1987 from the Bou Tchrafine ridge in the same area
and from the Jebel Ou Driss (Mader, SE Morocco) in 1989 are
updated. Many new morphotypes of Polygnathus linguiformis and
other conodont species are described. Polygnathus amphora, P.
psciutoeiflius and Icriodus hollardi are established as new species.
Keywords: Conodonts, Kacak, Eifelian-Givetian,
Morocco.
Résumé
L'entière faune à conodontes trouvée au GSSP pour la base du
Givetien et localisée dans le Jebel Mech Irdane du Tafilalt (SudEst du Maroc) est décrite pour la première fois. Les identifications
des faunes à conodontes du Bou Tchrafine dans la même région
décrites par BULTYNCK (1987) ainsi que celles du Jebel Ou Driss
dans le Mader (Sud-Est du Maroc) décrite en 1989 sont mises à
jour. Des nouveaux morphotypes de Polygnathus linguiformis et
d'autres espèces de conodontes sont décrits. Polygnathus amphora,
P. pseudoeiflius et Icriodus hollardi sont décrits comme nouvelles
espèces.
Mots-clefs: Conodontes, Kacâk, Eifelien-Givetien,
Maroc.
the base o f the Givetian is located in the Jebel Mech
Irdane in the Tafilalt of SE M o r o c c o . T h e position of
the boundary w a s designated by the S u b c o m m i s s i o n
on Devonian Stratigraphy ( S D S ) a n d is based on the
first occurrence o f the conodont species
Polygnathus
hemiansatus
considered to be a direct descendant o f
Polygnathus
pseudofoliatus.
T h e boundary level is
within the K a c a k E p i s o d e ( W A L L I S E R el al,
1995).
M a n y samples from the M e c h Irdane section contain
abundant a n d very diverse c o n o d o n t faunas, hundreds
of specimens p e r k i l o g r a m m e . At the time o f the
discussion o f the G S S P for the base of the Givetian
the study o f the conodont faunas w a s limited to the
evolutionary lineage/?pseudofoliatus-P.
hemiansatus,
as well as Polygnathus ensensis, the species considered
important for the b o u n d a r y definition. T h e s e species
groups w e r e figured in the guide-book for the field
meeting o f the S D S in the Tafilalt-Mader area in 1 9 9 1
( W A L L I S E R , ed.,
1991).
The conodont faunas are not only rich by the
n u m b e r of specimens but the species also demonstrate
a large variability. This allows recognition of different
morphotypes in k n o w n species o r new species that are
useful for establishing lineages a n d for biostratigraphy.
T h e description of these morphotypes and n e w species
is the main purpose of the present paper. T h e study o f
the Mech Irdane conodonts is c o m b i n e d with an update
of earlier described conodonts from the same time
interval in the same region: the Bou Tchrafine section
in the N Tafilalt ( B U L T Y N C K , 1 9 8 7 ) a n d the O u Driss
section in the M a d e r ( B U L T Y N C K , 1 9 8 9 ) . T h e position
t Otto WALLISER passed away late December 2010. The present
paper is dedicated to his memory. He was a brilliant geologistpalaeontologist. The last two years we worked together on the
conodont faunas described herein.
of the three studied sections is shown in Fig. 1.
6
Fig. 1 -
Otto W A L L I S E R & Pierre B U L T Y N C K
M a p o f the Tafilalt and M a d e r region with indication o f p a l e o g e o g r a p h y d u r i n g the late Eifelian and early G i v e t i a n .
T h e three studied sections, Jebel M e c h Irdane, B o u Tchrafine and Jebel O u Driss East are indicated with a r r o w s .
T h e L a t e Eifelian E v e n t s ( K a c a k E p i s o d e )
Kacak Episode with the Late Eifelian 1 Event and the
Late Eifelian 2 Event.
T h e G S S P for the base of the Givetian is placed in a
stratigraphic succession s h o w i n g a sharp facies change
due to an hypoxic perturbation ( W A L L I S E R el al, 1995).
The terminology for this hypoxic interval caused s o m e
confusion in earlier literature. H O U S E (1985) introduced
the name Kacák Event, after the Kacák M e m b e r or Shale
in the Bohemian Massif. It is a black and calcareous
shale in which the index tentaculite Nowakia
otomari
occurs. In the uppermost part of the Choteé Limestone
just below the Kacák M e m b e r the index conodont
Tortodus kockelianus
occurs ( C H L U P A C et al, 2000).
At the same time W A L L I S E R (1985) proposed the
otomari Event based on the onset of the dacryoconarid
lineage of the species Nowakia otomari. S o m e authors
considered that the Kacák Event and the otomari Event
covered the same period and were s y n o n y m o u s . It
w a s also demonstrated that the Kacák Event w a s not
instantaneous but represents a polyphased biotic crisis
( G A R C I A - A L C A L D E et al., 1990). In order to solve
this confusing situation W A L L I S E R (2000) proposed a
In the Mech Irdane section (Fig. 2) the base o f the
Late Eifelian 1 Event corresponds with the sudden onset
of dark shales and can be assigned to the otomari Event.
During the late Eifelian 2 Event the dark shales b e c o m e
progressively lighter and contain marly and nodular
limestones. The Kacak Episode is 0.50 m thick.
In the Bou Tchrafine section (Fig. 3) the base of the
Late Eifelian 1 is drawn at a level s h o w i n g a c h a n g e o v e r
from light b r o w n shales to gray shales with nodules and
two thin limestone beds at the base, samples 15 and
15a. In these limestones occur dark spots with organic
matter and concentrations of dacryoconarids, including
Nowakia otomari. In the Late Eifelian 2 Event the
shales and limestone nodules as well as bed 15b show
brownish spots due to the presence of hematite and
also yield a hematitic fauna. T h e Kacak Episode is
represented by about 2 m of strata.
T h e Jebel Ou Driss Eastern section (Fig. 4) s h o w s
m o r e neritic influences than the t w o other sections. T h e
base of the Late Eifelian 1 Event can be recognized
Jebel Mech Irdane Section
Polygnathus pseudofoliatus
group
P. angusticost. gr.
Tortodus
P. linguiformis group
Icriodus
0O,
>
3
Conodont
zones
c
t
timorensis
>
hemiansatus
139
138
137
135
133
131
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Fig. 2 -
1
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Table s h o w i n g t h e r a n g e s o f c o n o d o n t species a n d their m o r p h o t y p e s in t h e Jebel M e c h Irdane section, from t h e kockelianus
timorensis Z o n e . N o c o n o d o n t s recovered from t h e interval b e t w e e n s a m p l e s 116 and 118.
Z o n e t o t h e base o f t h e
Polygnathus
Bou Tchrafine Section
pseudofoliatus
S
•2
o
Conodont
zones
o
group
P. angusticost. gr.
ca.
£
o
T3 -O
a
È
P. linguiformis group
Tortodus
È
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11
kockelianus
it
Q.
Q.
aff.
australis
9 = Sample number of first
occurrence in the Bou Tchrafine section
Chotee event
Fig. 3 -
4
10
Frequency:
• 1 to 5 specimens
+ 6 to 20 specimens
# 21 to 100 specimens
Sample BT1» Bultynck 1985 m 0
T a b l e s h o w i n g t h e r a n g e s a n d f r e q u e n c y o f c o n o d o n t s p e c i e s a n d t h e i r m o r p h o t y p e s in t h e B o u T c h r a f i n e s e c t i o n f r o m t h e t o p o f t h e australis
b a s e o f t h e timorensis
Zone.
Z o n e to the
Conodont evolution at the Eifelian/Givetian boundary in SE Morocco
by the sudden colour change of brown-reddish marls
to dark gray shales and limestones at the level of bed
O D E - 8 - 1 9 and continuing upward to bed O D E - 7 - 1 . Just
above occurs a level with four compact limestone beds
that forms a characteristic ridge in the Jebel Ou Driss
and that is considered to represent the Late Eifelian 2
Event. T h e total Episode is represented by 2.50 m of
strata.
In the three sections the Late Eifelian 1 Event and the
lower part of the Late Eifelian 2 Event are assigned, in
part or entirely, to the ensensis Zone. The uppermost part
of the Late Eifelian 2 Event belongs to the hemiansatus
Zone. T h e onset of the Kacak Episode m a y be related
to the basal sea level rise of cycle If of J O H N S O N et al.
(1985) that also belongs to the ensensis Z o n e .
E x t i n c t i o n levels
T h e species of the Polygnathus
angusticostatus
group show a more or less simultaneous extinction
level in the three sections (Figs 2-4). However, in the
Mech Irdane section and in the Ou Driss E section
the extinction level is below the Kacak Episode.
In the Bou Tchrafine section it is slightly above the base
of the Kacak Episode and also more simultaneous for
the different species than in the two other sections. The
discrepancy between the M e c h Irdane section and the
Bou Tchrafine section can be explained by the presence
of the interval with dark shales without a conodont
record at the base of the Kacak Episode in the former
section.
O n e should also consider that the changeover to
dark shales is less pronounced in the Bou Tchrafine
section than in the t w o other sections.
Most Icriodus
species of the c o m m o n Eifelian
Icriodus type (the /. corniger-struvei
group) that have
a rather broad spindle and a rather short posterior
extension of the median row denticles behind the
spindle, disappear below the K a c a k Episode. T h e last
representative, Icriodus
struvei,
disappears slightly
below the Kacak Episode after probably giving
rise to the Icriodus arkonensis
group in the Kacak
Episode ( W E D D I G E , 1977); Icriodus walliserianus
is
the earliest representative. The innovative
Icriodus
regularicrescens, first occurs in the costatus Zone and
ranges into the Kacak Episode and above, is ancestral
to the Icriodus
obliquimarginatus
group in which
w e recognize three morphotypes a, 0 and y. T h e a
m o r p h o t y p e seems to be restricted to the pelagichemipelagic facies, the (3 and y morphotypes occur also
in the neritic facies.
9
Survival and innovations
The Polygnathus pseudofoliatus
group
In the kockelianus
Z o n e , below the Kacak Episode,
the P. pseudofoliatus
group is represented in the three
sections by P. pseudofoliatus,
P. pseudoeiflius
n. sp.,
P. eiflius and P. amphora n. sp. T h e last mentioned
species also occurs in the Plum Brook Shale of O h i o
(US), described by SPARLING (1995) as P.
pseudofoliatus
subsp. A. T h e Plum Brook Shale was assigned by
SPARLING to the upper part of the ensensis Z o n e .
The
most
characteristic
innovation
in
the
P. pseudofoliatus
group took place during the Late
Eifelian Event 2 by the initiation of the
Polygnathus
hemiansatus lineage, characterized by the modification
of the anterior trough margins. In the earlier species
of the P. pseudofoliatus
group the anterior trough
margins are steep and relatively symmetric on the
inner and outer side. In the hemiansatus
lineage the
anterior trough margins b e c o m e strongly asymmetric.
The outer anterior through margin is characterized by
the development of an outward b o w i n g spoon-like
structure and a pointed or linear constriction in the
outer platform margin just posterior to the geniculation
point. T h e inner anterior trough margin is only slightly
outward b o w i n g and is steep.
In the M e c h Irdane section the platform surface o f
P. hemiansatus
is strongly ribbed in the interval from
b e d 123 to bed 129. From bed 131 on, the surface
of the platform can be also punctuated and b e c o m e s
m o r e elongated.
The Polygnathus linguiformis
group
Three new morphotypes of Polygnathus
linguiformis
linguiformis,
y,, y and y,, appear in the upper part
of the kockelianus
Zone. T h e y m o r p h o t y p e has a
short stratigraphic range and disappears slightly
above the Kacak Episode and does not reach the top
of the hemiansatus
Zone. Notable is the presence
of Polygnathus
conradi
in the upper part of the
hemiansatus
Z o n e in the M e c h Irdane section. It was
decribed by C H A T T E R T O N (1978) from the EifelianGivetian boundary interval from a section in the
Canadian Northwest Territories. Until n o w it w a s not
recognized outside this area.
2
3
Systematic Paleontology
The different species, based on P, elements, are
described or discussed in the same order as in the three
range charts (Figs 2-4). We distinguish a
Polygnathus
1(1
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snnjieopnasd
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Table s h o w i n g t h e ranges a n d frequency o f c o n o d o n t species a n d their m o r p h o t y p e s in t h e Jebel O u Driss Eastern
section from t h e ? kockelianus Z o n e to t h e b a s e o f the timorensis Z o n e . S e e Fig. 3 for the m e a n i n g o f the frequency
symbols.
11
Conodont evolution at the Eifelian/Givetian boundary in SE Morocco
pseudofoliatus
group, a Polygnathus
angusticostatus
group, the genus Tortodus, the Polygnathus
linguiformis
group and the genus Icriodus. S y n o n y m y lists are only
established for a few taxa. T h e reader is cautioned that
except otherwise mentioned, the stratigraphic ranges o f
the described species are only based on the data from
the Moroccan sections described herein.
Polygnathus
Polygnathus
pseudofoliatus
pseudofoliatus
group
WITTEKINDT, 1 9 6 6
Derivatio
nominis
The n a m e refers to the species'
Polygnathus
eiflius.
Description
Two morphotypes are recognized. T h e morphotype a
conforms perfectly to the holotype of the species. T h e
P, element o f the ß morphotype is more elongated.
Alpha morphotype. - T h e slightly asymmetric
platform is relatively flat, broad oval-shaped and the
anterior termination is narrow. T h e anterior part o f
the platform s h o w s a weak rostrum. Posterior of the
rostrum the platform margins widen gradually on both
sides, the outer margin distinctly m o r e than the inner,
and describes a convex curve to the posterior end of the
platform. T h e carina is slightly curved and reaches the
posterior end o f the platform. Except for the anterior
trough margins, the platform is covered with nodes
and irregular ribs and the adcarinal troughs are narrow.
T h e inner side o f the anterior trough margins shows a
few short ribs and the anterior margins decline steeply
downward.
Beta m o r p h o t y p e . - T h e platform of the beta
m o r p h o t y p e is m o r e slender and the rostrum m o r e
distinct than in the alpha m o r p h o t y p e . T h e adcarinal
troughs are m o r e developed than in the alpha
m o r p h o t y p e and ribs predominate in the platform
ornamentation.
Holotype
Geoscience Center, Gottingen University, specimen n°
1 6 0 1 - 4 8 7 - Y 1 1 3 - 8 9 , figured on PI. 1 , Fig. 5 .
Paratypes
Geoscience Center, Gottingen University, specimens n°
1 6 0 1 - 4 8 7 - Y 1 0 8 - 1 0 and n° 1 6 0 1 - 4 8 7 - Y 1 1 5 - 1 2 ,
figured
Locus typicus
Jebel Mech Irdane section.
Stratum
typicum
Bed 1 1 3 .
Diagnosis
The n e w species is characterized by a short rostrum
with parallel margins and representing about o n e third
or less of the total platform length. T h e outer margin
forms a strong nearly half-circular expansion and
the inner margin a weakly convex curve. T h e outer
margin of the rostrum can be slightly diagonal and
for that reason these forms w e r e mostly assigned to or
compared with P. eiflius.
Range
T h e species occurs from within the kockelianus
to within the timorensis Z o n e .
Polygnathus
Range
T h e a m o r p h o t y p e occurs from within the kockelianus
Z o n e to the ansatus Zone. T h e ß morphotype first
occurs at the base of the australis Z o n e and ranges into
the ansatus Z o n e .
n.sp.
1 9 7 I _ Polygnathus aff. eiflius BlSCHOFF & ZlEGLER - KLAPPER,
pi. 2, figs 14, 15, 20.
1987 — Polygnathus eiflius, BlSCHOFF & ZlEGLER, 1957 -
Zone
eiflius BlSCHOFF & ZlEGLER, 1 9 5 7
PL 1 , Fig. 6
nan 1980 — Polygnathus eiflius
BULTYNCK, pi. 8, only figs 16, 18.
with
on PI. 1 , Figs 3 and 4 .
PI. 1 , Figs 1-2
Polygnathuspseudoeiflius
PI. 1 , Figs 3 - 5
similarity
BlSCHOFF & ZlEGLER, 1957 -
BULTYNCK & HOLLARD, p. 45, pi. 5, fig. 15; pi. 6,
fig. 5 (= Polygnathus amphora n. sp.).
n o
„ 1987 — Polygnathus eiflius BlSCHOFF & ZlEGLER, 1957
- BULTYNCK, pi 8, figs. 1 5 - 1 8 (figs. 15, 17 = P.
amphora n. sp.; figs 16, 18 = P. pseudoeiflius n. sp.).
Description
Platform typically with short anterior s y m m e t r i c
rostrum. T h e m a i n part o f platform is a s y m m e t r i c a n d
widest at mid-length. O u t e r p l a t f o r m - h a l f is w i d e r
than inner and its margin is m o d e r a t e l y to strongly
c o n v e x . T h e surface is c o v e r e d with fine n o d e s or
irregular ribs. T h e m a r g i n s o f the anterior rostrum a r e
relatively high and m o s t l y serrated. T h e y continue a s
a diagonal ridge or r o w o f n o d e s on t h e m a i n part o f
12
Otto WALL1SER & Pierre B U L T Y N C K
the platform, in the direction o f the carina or ± parallel
to the carina.
Range
T h e species is less c o m m o n than P. pseudofoliatus.
It
appears also slightly later (within kockelianus
Zone)
and disappears in t h e lower part o f t h e timorensis
Zone.
Polygnathus
ensensis ZlEGLER & K.LAPPER, 1976
PI. 1, Figs 2 1 - 2 2
1980 —
Polygnathus eiflius BlSCHOFF & ZlEGLER, 1957 -
Remarks
A c c o r d i n g to the holotype and paratypes of the species,
typical ensensis
specimens should have a slightly
constricted anterior platform with denticulated/serrated
margins. T h e posterior part of t h e platform shows
convex platform margins, especially on the outer side.
S o m e of the specimens d o not show clearly these
characteristics and their identification is indicated with
" ? " . It is stressed herein that t h e outer platform margin
can b e distinctly c o n v e x in t h e p o s t e r i o r half. T h i s is
also t h e case in t h e h o l o t y p e a n d o n e p a r a t y p e o f t h e
BULTYNCK & HOLLARD, pi. 5, fig. 15; pi. 6, fig.5.
1987 —
Polygnathus eiflius BlSCHOFF & ZlEGLER, 1957 -
s p e c i e s ( Z l E G L E R & K L A P P E R in Z l E G L E R et al,
Polygnathus
amphora
n.sp.
PI. 1, Figs 18-20
BULTYNCK, pi. 8, figs 15, 17.
1 9 9 5 — Polygnathus pseudofoliatus,
WITTEKINDT subsp. A -
SPARLING, pi. 3, figs 10-22.
1976,
pi. 3 , figs 4 , 8 ) . It is also noted that t h e g e n i c u l a t i o n
p o i n t s a r e not a l w a y s o p p o s i t e ( i b i d e m , p i . 3 , fig. 8;
B U L T Y N C K & H O L L E V O E T 1 9 9 9 , p i . 1, fig. 4 ; U Y E N O
1998, pi. 14,fig.2 3 ) .
Derivatio
nominis
T h e outline o f the platform is similar to a Greek vase
with the n a m e amphora.
Range
P. ensensis ranges from t h e base o f the ensensis
into the major part of the timorensis Z o n e .
Holotype
Geoscience Center, Gottingen University, specimen n °
1601-487-Y131-49, figured on PI. 1, Fig. 19.
Polygnathus
aff. P
Zone
pseudofoliatus
W I T T E K I N D T , 1966
Paratype
I R S c N B n ° b l 9 6 8 , figured in Bulfynck 1987, pi. 8, fig.
15.
PI. I , Figs 7-10
Diagnosis
Locus
typicus
Jebel Mech Irdane section.
Strongly ribbed platform, with typically ± parallel
platform borders. Anteriorly there m a y b e a weak t o
more strong constriction on the outer side. T h e anterior
adcarinal trough margins are steep.
Stratum
typicum
Bed 131.
M a y include transitional
hemiansatus.
Diagnosis
T h e n e w species can b e easily distinguished from t h e
a and (3 morphotypes o f / pseudofoliatus
by t h e long
rostrum with parallel margins a n d representing o n e
third to half o f the total platform.
5
Remarks
The specimen figured on P l . l , Fig. 18 is a transitional
form between P. aff. P. pseudofoliatus
to P. amphora.
Range
The species has been recognized from the upper part of
the kockelianus Zone to the lower part of the timorensis
Zone, based on data from Morocco and N . America
( S P A R L I N G , 1995, Polygnathus pseudofoliatus
subsp. A )
Polygnathus
hemiansatus
forms
to
Polygnathus
B U L T Y N C K , 1987
PI. 1, Figs 11-17
Description
T h e main characteristics o f Polygnathus
hemiansatus
are the constriction in the outer platform margin j u s t
posterior to t h e geniculation point a n d t h e strongly
outwards b o w i n g of the outer anterior trough margin
forming a spoon-like structure. T h e degree o f
development o f these t w o characteristics allows to
distinguish three m o r p h o t y p e s .
In the a m o r p h o t y p e the platform posterior t o t h e
geniculation points is rounded and short a n d mostly
s h o w i n g strong ribs.
Conodont evolution at the Eifelian/Givetian boundary in SE Morocco
In the p morphotype the platform is elongated and
the constriction in the outer platform margin rises to a
distinct point in the margin and the spoon-like structure
is short.
In the y morphotype the platform is elongated and
the constriction in the outer platform margin forms a
high shoulder-like structure. The spoon-like structure
is well developed.
Range
T h e a morphotype is restricted to the lower part of the
hemiansatus
Z o n e and the 0 and y morphotypes range
into the ansatus Zone.
Polygnathus angusticostatus
group
Polygnathus angusticostatus
WlTTEKINDT, 1966
PI. 2, Figs 3-4
Diagnosis
Relatively long oval-shaped to triangular platform with
wide, shallow adcarinal troughs. Short, conspicuous ribs
at margin of platform. Carina low, slightly extending
behind platform.
Range
First occurrence in costatus Z o n e ( B U L T Y N C K , 1985, pi.
7, fig. 21) and may range into the hemiansatus
Zone.
Polygnathus
angustipennatus
BlSCHOFF & ZlEGLER,
1957
PI. 2, Figs 5a-5b
Diagnosis
Short platform, with deep adcarinal troughs, high
upturned, denticulated platform margins. Blade long
with n u m e r o u s slender denticles, high in the anterior
part. High carina, clearly longer than platform with
wider denticles than denticles of the blade, and ±
triangular in lateral view. Large pit.
Range
From australis
Z o n e to ensensis
Polygnathus
Zone.
robusticostatus
BlSCHOFF & ZlEGLER,
1957
PI. 2, Figs 1-2
Diagnosis
Anterior half of platform rounded to oval-shaped with
13
strong ribs and narrow adcarinal troughs. Posterior part
of platform triangular with pointed end ( a morphotype).
S o m e specimens are more elongated with a weak
constriction or rostrum in the anteriormost part of the
platform (= ß morphotype). The latter is s o m e w h a t
similar to P. angusticosatus,
but the platform of the
ß morphotype of P. wbusticostatus
is more flat with
narrow, shallow adcarinal troughs. T h e a m o r p h o t y p e
corresponds to the holotype.
Range
T h e species has been recorded from the costatus
to the top of the kockelianus Zone.
Polygnathus
Zone
trigonicus
BlSCHOFF & ZlEGLER,
1957
PI. 2, Fig. 6
Diagnosis
Platform
triangular, slightly narrowing
in the
anteriormost part, covered with nodes or short ridges.
Anterior platform margins ± straight. T h e anterior part
of the platform is characterized by an inner and outer
row of nodes diverging in the anterior direction and
delimiting a triangular surface on the platform without
ornamentation. Free blade short with denticles of
nearly equal size. Platform surface clearly arched, and
pit located on anteriormost part of lower surface.
Range
T h e species was only found from the australis
the ensensis Zone.
Z o n e to
G e n u s Tortodus W E D D I G E , 1977
Tortodus? intermedins (BULTYNCK, 1966)
PI. 2, Figs 11-12
Diagnosis
T h e slender denticles of the anterior half of the P,
element, contrast with the wider, ± triangular in lateral
view, denticles of the posterior half. There is a lateral
thickening ("wulst") in the posterior half, but n o
platform. In lateral view the lower margin is straight
in the anterior half, concave in the posterior part.
Conspicuous pit with oval to drop-like outline and with
small lips, located in the anterior half of the element.
T h e assignment to the genus Tortodus is questioned
because the posterior end is not twisted.
14
Otto W A L L I S E R & Pierre B U L T Y N C K
Range
From austräte
Z o n e to ensensis
Polygnathus
linguiformis
Polygnathus linguiformis
HlNDE, 1879
Zone.
Tortodus Sardinia ( M A W S O N & T A L E N T , 1989)
PI. 2, Fig. 15
Remarks
N u m e r o u s , tightly packed, rather slender denticles.
In lateral view the lower margin is straight in the
anterior half, concave in the posterior half. N o platform
development. Oval shaped pit, approximately at
midlength of the P, element. T h e figured specimen is
very similar to the specimens figured by M A W S O N &
T A L E N T 1989, pi. 7, figs 5 and 6.
Range
Was only found in hemiansatus
Tortodus variabilis
Zone.
(BlSCHOFF AND ZlEGLER, 1957)
PI. 2, Figs 13-14
Description
In lateral view the outline of the upper margin, formed
by the tips of the denticles, is typically undulating,
culminating in the anterior third and posterior 2/3 of
the P, element. C o n s p i c u o u s platform development or
thick " wulst" with nodes or irregular ribs in posterior
2/3 of the element. Posterior part curved or twisted.
Range
Was found from ensensis
Z o n e to timorensis
Zone.
Tortodus n. sp. A
PI. 2, Fig. 10
Remarks
In Tortodus n. sp. A the outline of the denticles are
more uniform than in Tortodus? intermedius in which
the denticles of the anterior half contrast with those of
the posterior half; in T. n. sp. A the posterior part of the
P, element is slightly twisted which is not the case in
Tortodus?
intermedius.
Range
Was found in ensensis
and hemiansatus
Zones.
group
linguiformis
Remarks
ZlEGLER and K L A P P E R 1976 regarded the Polygnathus
linguiformis
y morphotype
(BULTYNCK,
1970)
as identical with the holotype of that species
and consequently indicated the y m o r p h o t y p e as
P. linguiformis
linguiformis.
A n e w analysis of
P, elements of the P. linguiformis
material from
M o r o c c o , mainly from the Mech Irdane, Ou Driss and
Bou Tchrafine sections allows recognition of minor
and more important differences in the morphology
of P, elements that w e r e previously assigned to
P. linguiformis linguiformis. M o r e important differences
permit recognition of three major morphotypes:
y l , y2 and y 3 . On the basis of minor differences
the y l morphotype is subdivided into y l a and y l b .
T h e s e n e w m o r p h o t y p e s can be recognized in figured
material from different geographical areas in Europe,
N . A m e r i c a and Australia and are useful in biostratigraphy. According to NARKIEWICZ & BULTYNCK
(2010) the last occurrence of P. linguiformis
is at the
top of the hermanni Z o n e . It should be stressed that
the
holotype
of
Polygnathus
linguiformis
linguiformis
is from
the " C o n o d o n t
b e d " of
HlNDE 1879 with m a n y reworked
conodonts,
especially P. linguiformis
linguiformis
and Latericriodus
latericrescens
latericrescens
(HUDDLE,
1981).
Some
authors
extend
the
range
of
P. linguiformis linguiformis into the top of the Givetian
or the base of the Frasnian (e.g. O R R & K L A P P E R , 1968
and SANDBERG el al, 1994) but in the sections they
describe there are discontinuity surfaces and there can
be reworking. UYENO (1998) reported it in the Middle
varcus (ansatus)
Z o n e in the Northwest Territories
(Canada).
Polygnathus
linguiformis
linguiformis
HlNDE, 1879 y 1 m o r p h o t y p e
PI. 3 , Figs 1-2
Description
The tongue represents about one-third of the total
platform-length and its surface is crossed by strong,
continuous transversal ridges. T h e margin of the outer
platform, anterior to the tongue (further indicated as
"platform") is high, flange-like and its rim is nearly
rectilinear. T h e adcarinal trough is deep and wide. T h e
margin of the narrower inner platform is only slightly
Conodont evolution at the Eifelian/Givetian boundary in SE Morocco
15
raised and can be straight or slightly concave or convex.
The inner platform is ornamented with nodes and/or
straight or irregular ribs.
In the y l a m o r p h o t y p e (PL 3 , Fig. 1) the width o f
the tongue decreases progressively from the end of the
anterior platform to the end o f the tongue. In the B o u
Tchrafine section it occurs from the costatus Z o n e to
the top of the hermanni Zone. It is the dominant and
longest ranging morphotype of the species.
Range
In the M o r o c c a n sections it occurs mainly from the
kockelianus Z o n e to the hemiansatus Zone, it b e c o m e s
rare in the timorensis Z o n e and the youngest occurrence
is in the lowest part of the ansatus Z o n e .
In the y l b morphotype (PI. 3 , Fig. 2) there is a
pronounced constriction in the outer platform margin,
just anterior of the onset of the narrow tongue. This
morphotype is most c o m m o n in the kockelianus and
ensensis Zones, but less than morphotype y 1 a; it b e c o m e s
more rare from the hemiansatus Z o n e on and it is nearly
absent in the timorensis and the ansatus Zones.
PI. 3 , Figs 7-8
Polygnathus
linguiformis
linguiformis
H I N D E , 1879 y2 m o r p h o t y p e
PI. 3, Fig. 3
Description
In the y2 morphotype the outer platform is characterized
at about mid-length by a pronounced widening and b y
the development of a high flange, especially in the
posterior part o f the platform.
Range
This m o r p h o t y p e occurs in the studied M o r o c c a n
sections from the kockelianus Z o n e to the base o f the
ansatus Z o n e .
Polygnathus linguiformis
linguiformis
HINDE, 1879 y3 m o r p h o t y p e
PI. 3 , Figs 4 - 6
Description
T h e general outline of the y3 morphotype is slender. In
comparison with the y 1 and y2 m o r p h o t y p e s the relative
length of the tongue is clearly longer and m a y represent
about the half-length o f the P, element. T h e inner and
outer margins o f the platform are upturned, both at the
same level a n d are parallel in the anteriormost part.
In upper view, the transition from the outer platformmargin to the tongue describes a curve. T h e tongue
is pointed. This morphotype is somewhat similar to
Polygnathus
linguiformis
bultyncki WEDDIGE, 1977.
However, the latter subspecies is more robust a n d the
transition from the outer platform margin to the tongue
does not describe a regular curve.
Polygnathus
linguiformis
klapperi
C L A U S E N , L E U T E R I T Z & Z I E G L E R , 1979
Description
The relatively flat anterior platform with strong ridges
and sometimes nodes on the inner platform, the curved
transition from the outer platform margin to the well
developed tongue with m a n y strong transversal ribs
and clearly bent d o w n w a r d are the m a i n characteristics
of the subspecies.
In Polygnathus
linguiformispinguis
W E D D I G E , 1977
the tongue is less developed, less bent d o w n w a r d and
the inner platform margin is slightly convex in front of
the tongue.
Range
In the M o r o c c a n sections the subspecies ranges from
within the kockelianus
Z o n e to the semialternans
I
latifossatus Zone.
Polygnathus
linguiformis
subsp. A
U Y E N O & BULTYNCK, 1993
PI. 3, Fig. 9
Description
T h e platform is rather short a n d squat. T h e anterior
platform is more or less square shaped. T h e inner and
outer platform halves are separated from the carina b y
an adcarinal trough, the outer o n e being wider than
the inner. T h e outer platform margin is m u c h higher
than the inner a n d serrated, b u t without d e v e l o p m e n t
of a prominent flange. T h e transition from the outer
platform margin to the tongue is rounded a n d the
tongue is deflected inward a n d d o w n w a r d , moderately
long with strong to w e a k e r transverse ridges that can b e
slightly interrupted by the carina.
Range
In the M o r r o c a n sections the subspecies occurs from
the ensensis Z o n e to the hemiansatus
Zone.
16
Otto W A L L I S E R & Pierre B U L T Y N C K
Polygnathus
linguiformis
weddigei
C L A U S E N , L E U T E R I T Z & Z I E G L E R , 1979
PI. 3 , Figs 10-11
Description
T h e surface of the platform is flat, the posterior half
is turned inward a n d bent slightly d o w n w a r d . T h e
carina is curved a n d can be mostly recognized until
the pointed posterior e n d . T h e posterior part o f the
platform is characterized by the presence o f w e a k ±
transversal ribs. A c c o r d i n g to the holoype the outer
platform margin is regularly curved over the total
length. T h e ribs on the outer platform show a radial
pattern.
Range
In the Morrocan sections the species occurs from the
hemiansatus Zone to the ansatus Zone.
Polygnathus
conradi C H A T T E R T O N , 1978
PI. 3 , Figs 12-14
Remarks
T h e main characteristic o f this species is the twisted
tongue-like posterior end o f the platform with strong
transversal ribs that can b e continuous or interrupted
by the carina. T h e species shows similarities with
Polygnathus
linguiformis
theta
m o r p h o t y p e in
J O H N S O N , K L A P P E R & T R O J A N , 1980 (pi. 4 , fig. 3 5 )
that in Nevada occurs in the costatus
Zone.
Range
T h e Moroccan specimens occur in the
hemiansatus
Zone. C H A T T E R T O N (1978) mentions that the species
occurs slightly below a n d above the Eiflian-Givetian
boundary in the Canadian Northwest Territories.
Polygnathus
parawehhi C H A T T E R T O N , 1974
PI. 3 , Figs 15-16
Remarks
The outline of the platform of Polygnathus
parawebbi
is similar to the platform outline o f
Polygnathus
linguiformis linguiformis y l a morphotype as described
herein. However, in P. parawebbi the ribs on the tongue
are interrupted by the carina, reaching the posterior end
of the platform.
Range
In the Moroccan sections the species ranges from the
kockelianus Z o n e to the timorensis Zone. However, in
other areas the species occurs from the australis Z o n e
to the ansatus Zone.
G e n u s Icriodus
B R A N S O N & M E H L , 1938
Icriodus hotiardi n. sp.
PI. 4 , Figs 1-6
V 1987 —
V
Icriodusplatyobliquimarginatus n. sp. BULTYNC k. pi.
5, figs 8-9 only.
1 9 8 7 — ? Icriodus struvei
fig. 10 only.
WEDDIGE,
1977-
BULTYNCK,
pi. 5.
Derivatio
nominis
In honour o f Henri Hollard for his t r e m e n d o u s work o n
the Devonian of the Anti-Atlas ( M o r o c c o ) .
Holotype
I R S c N B n° b 6 3 7 2 , figured on PI. 4 , Fig. 2.
Paratypes
I R S c N B n° b 6 3 7 1 , b 6 3 7 3 , b 6 3 7 4 , figured on PI. 4 , Figs
1, 3 , 4 ; Gottingen specimens n°s 1601-487-J-109-5
(PI. 4 , Fig. 5) and 1601-487-J-104-5 (PI. 4 , Fig. 6 ).
Locus
typicus
Jebel O u Driss, eastern section.
Stratum
typicum
T a b o u m a k h l o u f Formation, sample O D E - 8 - 1 9 .
Diagnosis
Spindle concavo-convex to slightly biconvex, pointed,
elongated anterior part, with a typically individualized
middle denticle r o w ; t w o to three last middle row
denticles on the spindle are higher than lateral r o w
denticles; posterior extension o f middle r o w with
mostly three to four denticles, typically slightly higher,
can h o w e v e r be at same level of last M R (middle r o w )
denticles on spindle. About five denticles in inner
and outer lateral denticle r o w with rounded sections.
Posterior expansion of cavity relatively broad,
asymmetric, more expanded on outer side.
Remarks
The n e w species partly corresponds to
Icriodus
struvei in B U L T Y N C K , 1987 (pi. V, fig. 10 only) and
/. platyobliquimarginatus
ibidem (pi. V, figs 8-9 only).
T h e spindle of Icriodus struvei is m o r e elongated a n d
curved and the denticles o f the posterior extension of
the middle denticle r o w are m o r e slender. In Icriodus
platyobliquimarginatus
the posterior extension o f the
Conodorit evolution at the Eifelian/Givetian boundary in SE Morocco
middle row is longer and the last denticle is strongly
reclined.
Range
In the Moroccan sections the species occurs in the
kockelianus and in the ensensis Zones.
B and y morphotypes appear at the base or slightly above
the base of the hemiansatus
Zone. T h e a m o r p h o t y p e
appears in the upper half of the hemiansatus Z o n e . The
different morphotypes occur to the top of the timorensis
Zone.
Icriodus
Icriodus
obliquimarginatus
BlSCHOFF & ZlEGLER, 1957
PI. 4, Figs 16-19
Description
Three main morphotypes are recognized.
T h e a morphotype
(Figs 17-19) corresponds to
the holotype. The spindle is narrow, and even m o r e
narrowing to its posterior end and showing an irregular
denticulation pattern. The posterior middle row
extension is long ( m i n i m u m five to six denticles) and is
slightly curved in upper view. In lateral view the outline
of the upper margin of the posterior M R extension is
slightly convex, the highest point being close to the
posterior end. In lateral view the posterior margin is
moderately to strongly reclined. The outer margin of
the basal cavity widens progressively from the anterior
to the posterior end.
The p morphotype
(Fig. 16) differs from the a
m o r p h o t y p e by the regular denticulation pattern. The
MR denticles are slightly anterior to the corresponding
lateral row denticles or alternate.
T h e y morphotype
(See BULTYNCK, 1987, pi. 4,
fig. 16). Nearly straight longitudinal axis. Very regular
denticulation pattern, middle row and lateral row
denticles alternating or middle row denticles slightly
anterior to corresponding lateral row denticles. T h e
denticles of the posterior extension of the middle row
are ± of equal size. T h e cusp is not m u c h higher than the
neighboring denticles and in lateral view the posterior
margin is straight.
Remarks
Typical transitional specimens between
Icriodus
regularicrescens
and /. obliquimarginatus
(PI. 4, Fig.
2 0 a-b) are characterized by a long spindle showing a
regular denticulation pattern and by a middle denticlerow posterior extension with at least 4 denticles. T h e
spindle is widest at about mid-length.
Range
In the Moroccan sections transitional specimens
between /. regularicrescens
and /.
obliquimarginatus
first occur in the upper part of the kockelianus Z o n e . T h e
17
struvei WEDDIGE, 1977
PI. 4, Figs 9-10
Diagnosis
T h e anterior half of the spindle is narrow and elongated
and its outline is triangular. T h e middle row and lateral
row denticles slightly alternate. T h e short posterior
extension of the medial-row denticles is slightly
curved.
Range
In the Moroccan sections the species was found from
the lower part of the costatus Z o n e to the base of the
ensensis Zone.
Conclusions
T h e K a c a k Episode cannot be considered as an event.
In the SE M o r o c c a n Tafilalt and M a d e r it m a y start in
the uppermost part of the kockelianus
Z o n e , occupies
the entire ensensis Z o n e and ends in the lower part of
the hemiansatus Z o n e . It is best qualified as an hypoxic
interval. Extinctions are limited to five species/
morphotypes of the Polygnathus angustíeos tatus group
in the Bou Tchrafine section and to 4 in the Mech
Irdane section. T h e Episode is better characterized as
an innovation period of the Polygnathus
pseudofoliatus
group with the appearance of Polygnathus
amphora
n.sp., P. ensensis and P. hemiansatus.
The outline
of the anterior trough margins of P.
hemiansatus
represents an innovation in comparison with earlier
Polygnathus species, e.g. P. costatus, P.
pseudofoliatus
and P. eiflius. These species have rather steep anterior
through margins. In P. hemiansatus,
on the other
hand, the outer anterior through margin develops to an
expanding spoon-like structure. Also the morphology
of the P, element of the Icriodus
obliquimarginatus
group changes drastically in comparison
with
the earlier species of the corniger-struvei
group.
It should also be mentioned that the base of the
timorensis Z o n e shown in BULTYNCK, 1987 is m o v e d
upward, from bed B T 1 8 to B T 2 0 . T h e
Polygnathus
timorensis specimen from bed 18, figured on pi. 7, fig.
11 of the 1987 paper is no longer considered as a good P.
IS
Otto W A L L I S E R & Pierre B U L T Y N C K
timorensis representative because the platform margins
are not nodose as mentioned in the original diagnosis
of K L A P P E R , P H I L I P & J A C K S O N , 1970.
CHATTERTON, B.D.E., 1974. Middle Devonian conodonts
from the Harrogate Formation, Southeastern British
Columbia. Canadian Journal of Earth Sciences, 11: 1461¬
1484.
Acknowledgements
Firstly 1 would like to thank the Walliser family for having made the
photographic material of the conodonts of the Mech Irdane section
available to me. Also I wish to thank Helga Groos-Uffenorde
(Gottingen) who provided me with the necessary information for
using this material. This paper contributes to IGCP 596 on MidPaleozoic climate and biodiversity. Jeffrey Over (SUNY-Geneseo)
and Tom Uyeno (Geological Survey of Canada, Calgary) are
very much thanked for the critical reading of the manuscript with
valuable comments and linguistic corrections. The conodont plates
were made by W. Miseur, the four figures by E. Dermienec and
the manuscript typewriting by A. Vandersypen (Department of
Palaeontology).
References
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Correlation
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19
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Pierre BULTYNCK
Department of Paleontology
Royal Belgian Institute of Natural Sciences
Vautierstraat 29, B-1000 Brussel, Belgium
Typescript submitted: April 2 8 , 2011
Revised typescript received: July 2 6 , 2011
20
Otto W A L L I S E R & Pierre B U L T Y N C K
E x p l a n a t i o n of p l a t e s
Most figured specimens are from the Mech Irdane (MI) section. They are deposited in the collections of the Museum of the
Geoscience Center, Goettingen University (GZG). They bear a tripartite registration number e.g. 1601-487-Y104-7. The
number 1601 is the collection number, 487 is the locality number of the Mech Irdane section and Y104-7 is the number
of a figured specimen, 104 is the sample number and 7 refers to the specimen. Other figured specimens are from the Bou
Tchrafine section (BT) and from the eastern part of the Jebel Ou Driss (ODE). They are deposited in the micropaleontological
collections of the Department of Palaeontology of the Royal Belgian Institute of Natural Sciences (IRScNB n° b6305-b6381)
Magnifications are x50 unless otherwise noted. The figured specimens are upper views of P, elements except where otherwise
stated.
PLATE 1
Fig. 1
Fig. 2
Figs 3-5
— Polygnathus pseudofoliatus WlTTEKINDT, 1966, alpha morphotype, n. 1601 -487-Y104-7.
— Polygnathus pseudofoliatus WlTTEKINDT, 1966, beta morphotype, n. 1601 -487-Y 107-3.
— Polygnathus pseudoeiflius n. sp., holotype and two paratypes, n°s 1601 -487-Y 108-10. 115-12 and 113-39;
Fig. x60.
Fig. 6
— Polygnathus eiflius BlSCHOFF & ZlEGLER, 1957, n° 1601-487-Y 115-5.
Figs 7-10
— Polygnathus aff. P. pseudofoliatus WlTTEKINDT, 1966, transitional forms to Polygnathus
hemiansatus
BULTYNCK, 1987,n°s 1601-487, Y122-3, Y122-15 and 16,Y122-6; Fig. 10x60.
Fig. 11
— Polygnathus hemiansatus BULTYNCK, 1987, alpha morphotype, n° 1601 -487-Y 123-7; x60.
Figs 12-15 — Polygnathus hemiansatus BULTYNCK, 1987, gamma morphotype, n°s 1601 -487-Y 123-15, Y-123-2, Y-125¬
17, Y127-6; Figs 12, 14, 15x60.
Fig. 16
— Polygnathus hemiansatus BULTYNCK, 1987, beta morphotype, n° 1601-487-Y 131-42.
Fig. 17
— Polygnathus hemiansatus BULTYNCK, 1987, gamma morphotype, n° 1601 -487-Y 132-5; x60.
Fig. 18
— Polygnathus aff. P. pseudofoliatus WlTTEKINDT, 1966, transitional form to Polygnathus amphora n. sp., n°
1601-487-Y 118-28; x60. '
Figs 19-20 — Polygnathus amphora n. sp., holotype and a juvenile form, n°s 1601-487-Y 131 -49, Yl 18-7.
Figs 21-22 — Polygnathus ensensis ZlEGLER & KLAPPER, 1976, n°s 1601-487-Y 123-19 and Y123-14, oblique-lateral
view.
PLATE 2
Figs 1 -2
Figs 3-4
Fig. 5a,b
Fig. 6
Fig. 7
— Polygnathus robusticostatus BlSCHOFF & ZlEGLER, 1957, n°s 1601 -487-X109-2 and X108-5.
— Polygnathus angusticostatus WlTTEKINDT, 1966, n°s 1601 -487-X 112-3 and X104-3.
— Polygnathus angustipennatus BlSCHOFF & ZlEGLER, 1957, n°s 1601-487-X 104-29; fig. 5b is an oblique
lateral view.
— Polygnathus trigonicus BlSCHOFF & ZlEGLER, 1957, n° 1601-487-X104-22.
— Polygnathus hemiansatus BULTYNCK, 1987, beta morphotype, sample ODE 7-5. n° IRSNB b6305.
Fig. 8a-b
—
Polygnathus
timorensis
KLAPPER, PHILIP & JACKSON, 1970, sample BT20, n°s IRSNB b6366; 8b is an
outer lateral view.
Fig. 9a-b
— Polygnathus timorensis KLAPPER, PHILIP & JACKSON, 1970, sample BT20, n°s IRSNB b6367; 9b is an
outer lateral view.
Fig. 10
— Tortodus n. sp. A, n° 1601-487-139-X, inner lateral view; x60.
Figs 11-12 — Tortodus ? intermedins (BULTYNCK, 1966), n°s 1601-487-X 104-12 and X104-13; fig. 12 is an inner lateral
view.
Figs 1 3 - 1 4 — Tortodus variabilis (BlSCHOFF & ZlEGLER, 1957), n° 1601-487-X 157-X and ODE-8-21; fig. 14b is an outer
lateral view; the anterior part is broken; Fig. 14 a, b x60.
Fig. 15
— Tortodus Sardinia MAWSON & TALENT, 1989, n° 1601-487-X 128-19, inner lateral view.
ab
Figs 16-17
—
Polygnathus
timorensis KLAPPER, PHILIP & JACKSON, 1970, n°s 1601-487-X 139-1 and XI39-6; Fig. 17 is
an inner lateral view.
Conodont evolution at the Eifelian/Givetian boundary in SE Morocco
21
PLATE 3
Fig. 1
Fig. 2
Fig. 3
Figs 4-6
Figs 7-8
Fig. 9
Figs 10-11
— Polygnathus linguiformis linguiformis HlNDE, 1879, y l a morphotype, n° 1601-487-L108-2.
— Polygnathus linguiformis linguiformis HlNDE, 1879, y 1 b morphotype, n° 1601 -487-L 107-2, inner oblique
lateral view.
Polygnathus linguiformis linguiformis HlNDE, 1879, y2 morphotype, n° 1601-487-L 108-1.
Polygnathus linguiformis linguiformis HlNDE, 1879, y3 morphotype, n°s 1601-487-L 122-13, LI22-8 and
L122-7.
— Polygnathus linguiformis klapperi CLAUSEN, LEUTERITZ & ZlEGLER, 1979, n°s 1601-487-L 123-54 and
LI 18-1; Fig. 8 is an oblique inner lateral view.
Polygnathus linguiformis sp. A UYENO & BULTYNCK, 1993, n° ODE-8-10, n° IRScNB b6368; x60.
Polygnathus
linguiformis
weddigei CLAUSEN, LEUTERITZ & ZIEGLER, 1979, n°s 1601-487-L 141-21 and
L130-ob-4.
Polygnathus conradi CHATTERTON, 1978, n°s 1601 -487-X123-1, X127-1 and L141 -31.
Polygnathus parawebbi CHATTERTON, 1974, n°s 1601-487-L 104-13 and L103-2; oblique inner lateral
views, Fig. 15x60.
Figs 12-14
Figs 15-16
PLATE 4
Magnification x45, except where otherwise stated.
Figs 1-4
—
Figs 5-6
Figs 7 -8
—
—
ab
Figs 9 - 1 0
ab
Figs 11-12
Figs 13-15
Fig. 16
ah
Figs 17-19
Fig. 20^
b
—
—
—
Icriodus hollardi n. sp., holotype and three paratypes, 1, 2 sample ODE-8-19 and 3, 4 sample BT-15, n°s
IRScNB b6369, b6370, b6371 and b6372; Fig. 4 is an inner lateral view.
Icriodus hollardi n. sp., two paratypes n°s 1601 -487-J109-5 and J104-5.
Icriodus amabilis BULTYNCK & HOLLARD, 1980, sample ODE-8-9, n° IRScNB b6373, Fig. 7b is a lower
view and 8 is an outer lateral view.
Icriodus struvei WEDDIGE, 1977, sample ODE-8-9 and ODE-8-21, n° IRScNB b6374 and b6375; Fig. 10b
is an inner lateral view.
Icriodus walliserianus WEDDIGE, 1988, n°s 1601-487-J219-2 and J123-52.
Icriodus regularicrescens BULTYNCK, 1970, samples ODE-8-23, ODE-8-19, ODE-X-X, n°s IRScNB
b6376, b6377 and b6378; Fig. 15 is a transitional form to Icriodus obliquimarginatus BlSCHOFF & ZlEGLER,
1957.
Icriodus obliquimarginatus BlSCHOFF & ZlEGLER, 1957, beta morphotype, sample ODE-7-11, n° IRScNB
b6379 ; Fig. 16b is an inner lateral view of the same specimen; x62.
Icriodus obliquimarginatus BlSCHOFF & ZIEGLER, 1957, alpha morphotype n°s 1601-487-J 125-9, J125-7
and J129-20.
Icriodus regularicrescens BULTYNCK, 1970, transitional form to Icriodus obliquimarginatus, n° 1601 -487J104-2; Fig. 2b is an inner lateral view.
22
Otto W A L L I S E R & Pierre B U L T Y N C K
PLATE 1
Conodont evolution at the Eifelian/Givetian boundary in SE Morocco
PLATE 2
23
24
Otto W A L L I S E R & Pierre B U L T Y N C K
PLATE 3
Conodont evolution at the Eifelian/Givetian boundary in SE Morocco
25