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Two new species of Trochurinae trilobites from the
Middle Devonian (Eifelian) of Southern Morocco
Joan CORBACHO* & Francisco J. LÓPEZ-SORIANO**
*Museo Geológico del Seminario de Barcelona, Diputación 231, 08007-Barcelona (Spain)
fosilart@hotmail.com
**Departament de Bioquímica i Biologia Molecular, Facultat de Biologia,
Universitat de Barcelona, Diagonal 643, 08028-Barcelona (Spain)
flopez@ub.edu
ABSTRACT- Two new species of trilobites of the Trochurinae subfamily from the Middle Devonian
(Eifelian) of the Tafilalt region (Morocco) are described. In addition, a new genus (Basseiarges gen. nov.) is
proposed in order to include one of them (Basseiarges mellishae sp. nov.). The main characteristics that
make it different from the other members of the subfamily Trochurinae are its peculiar cephalon and
pygidium, and the saw-shape of the ridge that connects the genal spines, which is similar to that present on
the pygidium border. The second species described here is Akantharges mbareki sp. nov. from Tinejad. Both
them are compared with the previously described species of the genus Akantharges. In addition, the first
description of the hypostome of a member of the genus Akantharges is included.
KEYWORDS - Trilobita, Trochurinae, new genus, Devonian, Morocco.
RESUMEN – Se describen dos nuevas especies de trilobites de la subfamilia Trochurinae procedentes del
Devónico Medio (Eifeliense) de la región de Tafilalt (Marruecos). Asimismo, se propone un nuevo género
(Basseiarges gen. nov.) para incluir a una de ellas (Basseiarges mellishae sp. nov.). Las principales
características que la diferencian del resto de miembros de la subfamilia Trochurinae son sus peculiares
cefalón y pigidio, y la forma de sierra de los bordes de la cresta que conecta las espinas genales, y que es
similar a la del borde del pigidio. La segunda especie que se describe es Akantharges mbareki sp. nov.
procedente de Tinejad. Ambas especies son comparadas con las especies del género Akantharges
previamente descritas. Asimismo, se incluye la primera descripción del hipostoma de un miembro del género
Akantharges.
PALABRAS CLAVE - Trilobites, Trochurinae, nuevo género, Devónico, Marruecos.
INTRODUCTION
Both Lower and Middle Devonian were one of the
richest geological periods in trilobite diversity.
Particularly, Devonian trilobites from Morocco
are often articulated and exquisitely preserved,
and they represent a wide variety of ecological
niches (Chatterton & Gibb 2010). Some
researchers have been specialized on the trilobites
of the Devonian of Morocco, being Alberti who
has done most of this research (Alberti 1969). At
the present, Fortey, Gibb, Chatterton and Basse
are developping the main studies on this subject
(Feist & Orth 2000; Schraut 2000; Basse &
Müller 2004; Chatterton et al. 2006; Gibb &
Chatterton 2007; Chatterton & Gibb 2010;
Johnson & Fortey 2012).
Specimens similar to some that are presented
in this paper already appeared in the open market
approximately two years ago. Since then, these
specimens have usually been classified as
belonging to the genus Akantharges. The study of
well-preserved specimens have suggested us that,
in fact, there are two new different species. For
this reason, and because of the particular
characteristics of their cephalon and pygidium, we
BATALLERIA
18
2013
15-24 (Barcelona, febrero 2013)
ISSN0214-7831
16 J. CORBACHO & F. J. LÓPEZ-SORIANO
contacted some of the best specialists on
Devonian trilobites, and taking into account their
answers now we consider that some of these
trilobites belong to a new genus which is
described in the present paper, whereas the other
specimens belong to a new species of the genus
Akantharges. It is noteworthy that the previous
material assigned to the genus Akantharges is
usually deformed and in a poor degree of
preservation, and that the only cranidium
previously assigned to this genus from Morocco
(Thomas & Holloway, 1988) is different to those
that are presented here.
SYSTEMATIC PALAEONTOLOGY
The specimens with the abbreviation MGSB
are kept in the Museo Geológico del Seminario de
Barcelona (Barcelona, Spain), those with the
abbreviation MMB are kept in the Museo del
Mamut (Barcelona, Spain), whereas those with
the abbreviation JC are kept at th particular
collection of Joan Corbacho.
Order LICHIDA Moore, 1959
Family LICHIDAE Hawle & Corda, 1847
Subfamily TROCHURINAE Phleger, 1936
Genus
Basseiarges gen. nov.
(Plate I: Figs. 1-6, Plate II: Figs. 1-3)
Type species. Basseiarges mellishae sp.
nov., from the Eifelian of El Jorf, Tafilalt
region (southeastern Morocco).
Stratigraphical and geographical range.
Middle Devonian (Eifelian), El Jorf
(Morocco).
Geographical distribution. Restricted to
the southeast of Morocco.
Name. This genus is named after Dr.
Martin Basse (Bochum, Germany) for his
major contributions to the knowledge of
Devonian trilobites.
Diagnosis. See the description of the type-
species, because it is monotypic.
Description. See the description of the
type-species, because it is monotypic.
Figure 1.
A
: Map of Africa with the ubication of Morocco.
B
: Partial map of Morocco with the position of the
amplified section. C: Map showing the distribution of the Devonian in the Tinejad and Arfoud region; the
shading areas represent the Devonian outcrops (after Kaufmann 2006; slightly modified after own
observations).
TWO NEW SPECIES OF TROCHURINAE TRILOBITES FROM ... MOROCCO 17
Basseiarges mellishae sp. nov.
(Plate I: Figs. 1-6 and plate II: Figs. 1-3)
Taxonomic data. The holotype (Plate I, figure
4) is a complete exoskeleton kept at the Museo
Geológico del Seminario de Barcelona (Spain)
with the registration number MGSB79774. The
paratypes MMB102 (Plate I, figures 2, 5 and 6,
and Plate II, figures 1 and 2), MMB103 (Plate I,
figure 3) and MMB104 (Plate I, figure 1, and
Plate II, figure 3) are also complete exoskeletons
kept at the Museo del Mamut de Barcelona
(Spain). All these specimens come from the
Middle Devonian (Eifelian) of El Jorf, Tafilalt
(Morocco).
Name. This species is named after M. Claire
Mellish, curator of Fossil Arthropods and
Graptolites of the British Museum of Natural
History of London as acknowledgement by her
continuous help.
Geographical location. The studied outcrop
(Figure 1, map C, 1) belongs to the Eifelian
(Middle Devonian), and is located at the NW of
Jorf, in the area of Tafilalt, administrative district
of Er-Rachidia (SE of Morocco), approximately 1
km of the NW of Fezna, 8 km of the NW of El
Jorf, 17 km of the NW of Arfoud, 49 km of Er-
Rachidia, and 361 km of Rabat (Morocco’s
capital). The coordinates of the excavation were N
31º 31’ 60.4” - W 4º 28’ 07.3”, and the altitude
was 840-870 m; these data were recorded by one
of us (Joan Corbacho) in October 2012 using a
GARMIN GPS Model Foretrex 401.
Since 2011 this outcrop has not been exploited.
Several genera of trilobites have been previously
found in this locality: Drotops, Crotalocephalus,
Cyphaspides, Phacops, unclassified Harpidae,
Scutellum, Struveaspis and Thysanopeltis. In
addition, several unclassified Cephalopoda (both
Nautiloidea and Ammonoidea) and Bivalvia are
also present. The locality exposes dark reddish
micritic limestones, the fossils appearing since its
surface until a maximum of 2 meters of depth
approximately.
Material and Measurements. Four specimens
are presented (the holotype and three paratypes)
with a good preservation. The total exoskeleton
length of them are: MGSB79774 23 mm,
MMB104 30 mm, MMB102 28 mm and
MMB103 22 mm. Table 1 shows the different
exoskeleton measurements.
A = total cephalon lenght; B = total glabella length; C =
maximum width of the genal spine (without crests); D =
maximum cephalon width; E = width of the posterior margin
of the glabella; F = width of the anterior margin of the
glabella; G = occipital lobe width; H = maximum pygidial
width; I = anterior width of the pygidial rachis; J = posterior
width of the pygidial rachis; K = total pygidium lenght
(without spines).
Diagnosis. Rounded cephalon in which the
continuation of the upper part of the genal spine
edge separates the central lobe of the glabella
from the other glabellar lobes, with only a well-
defined axial pygidial ring.
Description. Trochurine macropygous trilobite
of medium size, with a carapace of elliptical
outline.
The cephalon is subtriangular, being wider (tr.)
than longer (sag.), and representing approximately
a quarter of the total exoskeleton length (without
taking into account the pygidial spines). Glabella
broad and strongly convex, slightly overhanging
the anterior border. L1 as long as the occipital
ring, the area placed at the base of median
glabellar lobe being strongly depressed.
Longitudinal glabellar furrows are not visible.
Genal angles produced backwards into long,
straight and strong blade-like genal spines
projected moderately outwards, bearing bulbous
crenulations on both edges, being bigger in the
dorsal edge than in the ventral one; a crenulated
ridge connects the two genal spines crossing the
glabella. The genal spine length is larger than the
thorax length. Longitudinal furrows fused in the
anterior part. Upright cheeks with small
tubercules and pits. Small eyes, placed low on the
fixigena rather far from the glabella and in frontal
position. Hypostome unknown.
The thorax has either ten or eleven segments.
Its length is almost a third of the total exoskeleton
length, being wider in its posterior part than in the
anterior one. The rachis is slightly vaulted and
well defined by dorsal furrows. The thoracic
pleurae do not present furrows but finish in
strong, straight and sharp pleural tips.
18 J. CORBACHO & F. J. LÓPEZ-SORIANO
The pygidium is semicircular in overall outline
and with a thick section. Pygidial axis represents
more than two-thirds of the total length (sag.) of
the pygidium, with only a well-defined axial
pygidial ring followed by four additional rings.
Pygidial edge high and with three pairs of strong
marginal spines, the two central shorther and
placed in the postrachial area; these spines have a
rounded cross-section and are attached at the
lower pygidial edge. The pygidial surface shows
small tubercles mainly on the rachis. There are
three pairs of pleural ribs well-differentiated by
deep and wide furrows which are ended into two
or three big indentated tubercles orientated
upwards; each one of these pairs contains two
semifused ribs separated by a furrow, except the
two medial ribs which do not present this furrow
because they are completely fused.
Akantharges mbareki sp. nov.
(Plate III: Figs. 1-6)
1988 Akantharges sp. Thomas & Holloway, p.
227.
Taxonomic data. The holotype (Plate III,
figure 5) is a complete exoskeleton kept at the
Museo Geológico del Seminario de Barcelona
(Spain) with the registration number
MGSB79879. The paratypes JC94 (Plate III,
figure 1), JC95 (Plate III, figures 2-4) and JC96
(Plate III, figure 6) are also complete
exoskeletons, one of them with the hypostome,
and are kept at the particular collection of Joan
Corbacho. All these specimens come from the
Middle Devonian (Eifelian) of Tinejad
(Morocco).
Name. This species is named after Mbarek
Ahachach from the Palaeontological Museum of
Arfoud as acknowledgement for his help in our
research.
Geographical location. The studied outcrop
(Figure 1, map C, 2) belongs to the Eifelian
(Middle Devonian), and is located at the SW of
Tinejad, administrative district of Er-Rachidia (SE
of Morocco), approximately 20 km of the SW of
Tinejad and 32 km of the E of Tinerhir, 96 km of
the E of Arfoud, 94 km of Er-Rachidia, and 320
km of Rabat (Morocco’s capital). The coordinates
of the excavation were N 31º 27’ 20’’- W 5º 14’
31’’, and the altitude was 1109 m; these data were
recorded by one of us (Joan Corbacho) in October
2012 using a GARMIN GPS Model Foretrex 401.
Since 2012 this outcrop has not been exploited.
Trilobite specimens from several families have
been previously found in this locality: Harpidae,
Phacopidae and Proetidae. The locality exposes
gray micritic limestones, the fossils appearing in
the surface of a plain, in the bank of a small river.
Material and Measurements. Four specimens
are presented (the holotype and three paratypes)
with a good preservation. The total exoskeleton
length of them are: MGSB79879, JC94 27 mm,
JC95 34 mm, and JC96 29 mm. Table 2 shows the
different exoskeleton measurements.
A = total cephalon lenght; B = total glabella length; C =
maximum width of the genal spine (without crests); D =
maximum cephalon width; E = width of the posterior margin
of the glabella; F = width of the anterior margin of the
glabella; G = occipital lobe width; H = maximum pygidial
width; I = anterior width of the pygidial rachis; J = posterior
width of the pygidial rachis; K = total pygidium lenght
(without spines).
Diagnosis. It is characterized by the presence
of granulations distributed along the carapace
with the exception of the thoracic rachis, and also
by the presence of the mesial tubercle.
Description. Trochurine isopygous trilobite of
medium size, with a carapace of elliptical outline.
The cephalon is subtriangular, being wider (tr.)
than longer (sag.), and representing approximately
a third of the total exoskeleton length (without
taking into account the pygidial spines). Glabella
broad and strongly convex, slightly overhanging
the anterior border. L1 as long (sag.) as the
occipital ring, the area placed at the base of
median glabellar lobe being strongly depressed.
Longitudinal glabellar furrows are not visible. It
presents mesial tubercle. Genal angles produced
backwards into long, straight and strong blade-
like genal spines projected moderately outwards,
bearing bulbous crenulations on both edges, being
bigger in the dorsal edge than in the ventral one;
the crenulation ridge is extended from the tip of
the genal spines until the outer end of the occipital
TWO NEW SPECIES OF TROCHURINAE TRILOBITES FROM ... MOROCCO 19
furrows. The genal spines are extended until the
ninth thoracic segment and present middle-sized
tubercles in their whole surface. Upright cheeks
with small tubercules and pits. Small eyes, placed
low on the fixigena rather far from the glabella
and in frontal position.
Hypostome of conterminant type. It has
subpentagonal shape, being slightly wider than
longer, and of medium size, its length
representing almost a half of the total cephalon
length. Its central part is extended until nearly the
posterior border (incomplete in the specimen),
being well-delimited by lateral furrows. Its middle
body is bulky, being two-fold wider than the
lateral border, whereas the posterior border is
narrower than the lateral one and is completely
smooth. At the posterior half part of the middle
body there are two well-defined and oblique
furrows that are weakly projected towards the
anterior part of the hypostome; these furrows limit
the posterior rectangular lobe with the anterior
lobe, this latter being of triangular shape and
similar size.
The thorax has eleven segments and is its
length is something more than a third of the total
exoskeleton length. Its width (tr.) is the same both
in its anterior and posterior part. The rachis is
slightly vaulted, with granulations but with well-
defined dorsal furrows. The thoracic pleurae
present small tubercles but do not present furrows,
and they finish in strong, straight and sharp
pleural tips.
The pygidium is semicircular in overall outline
and with a thick section. Pygidial rachis
represents more than two-thirds of the total length
(sag.) of the pygidium, being vaulted in its central
axis and with a well-defined axial pygidial ring
followed by eight additional rings, with furrows
directed backwards at their lateral ends. Pygidial
edge high and with three pairs of strong marginal
spines, the two central are shorter and placed in
the postrachial area; these spines have a rounded
cross-section and are attached at the lower
pygidial edge. Border absent. The pygidial surface
shows tubercles: those present on the rachis are
aligned at both sides of the rachis and in parallel
to the central axis, whereas those of the rest of the
surface are bigger and placed in a line on the
middle of the pleural ribs. There are three pairs of
pleural ribs very well differentiated by deep and
wide furrows which are ended into either three
(the two anterior pairs) or two (the distal pair)
tubercles orientated upwards; each one of these
pairs contains two semifused ribs separated by a
furrow, except the two medial ribs which are
completely fused and without furrow.
DISCUSSION
The differences between both the cephalon and
the pygydium of Basseiarges mellishae gen. and
sp. nov. with the other genera and species of the
subfamily Trochurinae are very clear; in fact,
there is only a similarity with the genus
Akantharges, and for this reason we present here a
comparison between it and the two known species
of the genus Akantharges. Akantharges has been
often described on the basis of isolated parts of its
exoskeleton; indeed, the diagnosis of these
trilobites has been based on the characteristics of
these parts (reviewed by Thomas & Holloway
1988; see also Holloway & Thomas 2002). In
particular, Lichas gourdoni Barrois, 1886, the
type-species of the genus Akantharges, was
described on the basis of strongly deformed and
incomplete exoskeletons from the Eifelian of
central Pyrenees (France), thus making it difficult
a correct interpretation. For this reason, there is
not a complete description of this genus in the
paleontological bibliography. The other species
assigned to this genus is Akantharges erbeni
(Meischner, 1965), from the Middle Devonian
(Eifelian-Givetian) of France, Germany and
Morocco. Again in this case, the specimens have
also been tectonically deformed, thus difficulting
the comparison with other species, although
Holloway & Thomas (2002) suggested a
resemblance of its pygidium with that of
Acanthopyge.
The cranidium of Basseiarges mellishae gen.
and sp. nov. is only partially similar to that was
described by Thomas & Holloway (1988) (plate
14, figs. 299, 300 and 303). Accordingly to that
indicated in this paper, the previous
reconstructions of the cephalon of this genus
provided by other authors (Barrois 1886; Phleger
1936) are not correct. However, the glabella of
Basseiarges mellishae gen. and sp. nov. does not
shown longitudinal gabellar furrows, whereas in
Akantharges sp. (also from the Eifelian of
Morocco), which is the most similar trilobite to
Basseiarges mellishae gen. and sp. nov., these
furrows are well-defined. In addition, Basseiarges
mellishae gen. and sp. nov. shows crests that cut
the posterior part of the glabella and which are
absent in Akantharges. The crenulations observed
on the genal spines of Basseiarges mellishae gen.
and sp. nov. are smaller and more spaced than in
Akantharges, and the granulations present in the
cephalon of the latter genus are more numerous
and bigger than in Basseiarges mellishae gen. and
sp. nov. Concerning the pygidium, the two
20 J. CORBACHO & F. J. LÓPEZ-SORIANO
posteromedial spines are thinner and also are
more closely attached in their basis, being
separated in their distal part; however, in
Akantharges gourdoni they are straightly
projected from the pygidium and in parallel to the
thoracic rachis. The rachis of the pygidium of
Akantharges gourdoni presents a terminal piece,
which is absent in Basseiarges mellishae gen. and
sp. nov.
The second species described in this paper is
Akantharges mbareki sp. nov. which at first
glance shows some similarities with Basseiarges
mellishae gen. and sp. nov., although we have
considered more aproppiate to include it in the
Akantharges genus. In fact, there are some
important differences between them. Firstly,
Akantharges mbareki sp. nov. is bigger than
Basseiarges mellishae gen. and sp. nov. and
presents tubercles distributed along its carapace,
the tubercles crossing the glabella being smaller
than in Basseiarges mellishae sp. nov.
Akantharges mbareki sp. nov. presents mesial
tubercle, whereas Basseiarges mellishae sp. nov.
does not. In addition, the genal spines are larger in
Basseiarges mellishae sp. nov. when their length
is considered in relation to the total length of the
exoskeleton. The thorax shape is also different: in
Akantharges mbareki sp. nov. is rectangular,
whereas in Basseiarges mellishae sp. nov. is
wider in its anterior part than in the posterior one.
In Basseiarges mellishae sp. nov. the pigidial
tubercles are hardly visible, whereas in
Akantharges mbareki sp. nov. they are clearly
visible. In addition, in Akantharges mbareki sp.
nov. the pygidial rachis is larger (in relation to the
pygidium) and presents more ribs. Basseiarges
mellishae sp. nov. presents two tubercles in the
posterior part of the pygidium, whereas
Akantharges mbareki sp. nov. do not. By the other
side, the pygidial spines of Akantharges mbareki
sp. nov. are notably shorter than those present in
Akantharges erbeni. Finally, concerning the
hypostome, it must to be emphasized that we
present here the first description of an hypostome
of the genus Akantharges in the bibliography.
ACKNOWLEDGEMENTS
We sincerely thank Dr. Sebastián Calzada
(director of the Museo Geológico del Seminario
de Barcelona) for his generous help. We are also
grateful to Brahim Tahiri from the Arfoud
Museum for the preparation of some of the
specimens described here, and to Abdelali
Hamdaoui for his help during the field work. In
addition, we sincerely thank Julia Slesareva
(directora of the Museo del Mamut, Barcelona,
Spain) for the loan of several specimens to study.
Finally, we also thank the company FOSILART
(Spain) for its generous grant for the purchase of
some of the specimens and the funding of the
Morocco expedition.
REFERENCES
Alberti, G.K.B. 1969. Trilobiten des jüngeren
Siluriums sowie des Unter- und Mitteldevons. I.
Mit Beiträgen zur Silur-Devon-Stratigraphie einiger
Gebiete Marokkos und Oberfrankens.
Abhandlungen der Senckerbergischen
Naturforschenden Gesellschaft 520: 1-692.
Barrois, C. 1886. Sur la faune de Hont-de-Ver (Haute-
Garonne). Annales de la Société Géologique du
Nord 12: 124-144.
Basse, M. & Müller, P. 2004. Eifel-Trilobiten III.
Corynexochida, Proetida (2), Harpetida,
Phacopida (2), Lichida. Quelle & Meyer-Verlag,
Wiebelsheim, 261 pp.
Chatterton, B.D.E., Fortey, R., Brett, K., Gibb, S. &
McKellar, R. 2006. Trilobites from the upper
Lower Devonian to Middle Devonian Timrhanrhart
Formation, Jbel Gara el Zguilma, southern
Morocco. Palaeontographica Canadiana 25: 1-
176.
Chatterton, B.D.E. & Gibb, S. 2010. Latest Early to
Early Middle Devonian trilobites from the
Erbenochile Bed, Jbel Issoumour, southeastern
Morocco. Journal of Paleontology, 84: 1188-1205.
Feist, R. & Orth, B. 2000. Trilobites de la limite
Eifélien/Givétien de la région stratotypique
(Tafilalet, Maider, Maroc). Travaux de l’Institut
Scientifique, Serie Geologie et Geographie
Physique 20: 78-91.
Gibb, S. & Chatterton, B.D.E. 2007. Timsaloproetus
new genus (Proetida: Trilobita) and included
species from Lower and Middle Devonian strata of
southern Morocco. Journal of Paleontology 81:
352-367.
Hawle A.I. & Corda, A.J.C. 1847. Prodrom einer
Monographie der böhmischen Trilobiten. J.G.
Calve, Prague. 176 pp.
Holloway, D.J. & Thomas, A.T. 2002. Hoplolichoides,
Allolichas, Autoloxolichas and Akantharges, and
the classification of lichid trilobites. Geobios 35:
111-125.
Johnson, R.G. & Fortey, R.A. 2012. Proetid trilobites
from the Lower Devonian (Pragian) Ihandar
Formation, Anti-Atlas, Morocco. Journal of
Paleontology 86: 1032-1050.
Kaufmann, B. 2006. Calibrating the Devonian Time
Scale: A synthesis of U–Pb ID–TIMS ages and
conodont stratigraphy. Earth Science Reviews 76:
175-190.
TWO NEW SPECIES OF TROCHURINAE TRILOBITES FROM ... MOROCCO 21
Meischner, D. 1965. Neue Trilobiten aus dem Devon
des Kellerwaldes. Fortschritte in der Geologie von
Rheinland und Westfalen 9: 119-150.
Moore, R. C. 1959. Order Lichida. In: Treatise on
Invertebrate Paleontology. Part O (Arthropoda 1),
(ed. R.C. Moore) pp O495-O504. Geological
Society of America – University of Kansas Press.
Lawrence.
Phleger, F.B., Jr. 1936. Lichadian trilobites. Journal of
Paleontology 10: 593-615.
Schraut, G. 2000. Trilobiten aus dem Unter-Devon des
Südöstlichen Anti-Atlas, Süd-Marokko.
Senckenbergiana Lethaea 79: 361-433.
Thomas, A.T. & Holloway, D.J. 1988. Classification
and phylogeny of the trilobite order Lichida.
Philosophical Transactions of the Royal Society of
London. B. Biological Sciences 321: 179-262.
Received: October 1, 2012
Accepted: February 14, 2013
22 J. CORBACHO & F. J. LÓPEZ-SORIANO
Plate I
Plate I. Basseiarges mellishae gen. and sp. nov., from the Middle Devonian (Eifelian) of El Jorf (Tafilalt,
southern Morocco). 1: paratype MMB104; 2: paratype MMB102; 3: paratype MMB103; 4: holotype
MGSB79774; 5: detail of the paratype MMB102; 6: frontal view of the paratype MMB102. All these
specimens were coated with ammonium chloride. Scale bar: 5 mm.
TWO NEW SPECIES OF TROCHURINAE TRILOBITES FROM ... MOROCCO 23
Plate II
Plate II.
Basseiarges mellishae gen. and sp. nov., from the Middle Devonian (Eifelian) of El Jorf (Tafilalt,
southern Morocco). 1: Left lateral view of the paratype MMB102; 2: Right lateral view of the paratype
MMB102; 3: Posterior view of the pygidium of the paratype MMB104. All these specimens were coated
with ammonium chloride. Scale bar: 5 mm.
24 J. CORBACHO & F. J. LÓPEZ-SORIANO
Plate III
Plate III. Akantharges mbareki sp. nov. from the Middle Devonian (Eifelian) of Tinejad (southern
Morocco). 1: Left lateral view of the paratype JC94; 2: Dorsal view of the paratype JC95; 3: Frontal
view of the hypostome of the paratype JC95; 4: Dorsal view of the cranidium of the paratype JC95; 5:
Dorsal view of the holotype MGSB79879; 6: Dorsal view of the paratype JC96. All these specimens
were coated with ammonium chloride. Scale bar: 5 mm.
