Trilobita

Le Sud du Maroc recèle un incomparable ensemble d'archives paléontologiques sur les premiers développements de la Vie durant près de 180 millions d'années. Au travers d'illustrations somptueuses, servies par un texte remarquablement documenté, l'auteur met en scène de véritables "pépites paléontologiques" patiemment exhumées par les collecteurs locaux et les paléontologues. Ce splendide ouvrage nous entraîne dans un monde extraordinaire, véritable repaire "d'aliens fossiles" aux morphologies les plus improbables ! Plus de 950 photos et illustrations pour un périple paléontologique dans le Sud du Maroc. Morocco contains an incomparable collection of palaeontological archives on the early development of life for nearly 180 million years. Through sumptuous illustrations, served by a remarkably documented text, the author describes and illustrates true "paleontological nuggets" patiently exhumed by local collectors and palaeontologists. This splendid work leads us into an extraordinary world, a true haunt of "fossil aliens" with the most improbable morphologies! More than 950 photos and illustrations for a palaeontological journey in Southern Morocco Southern. « My compliments on the massive and impressive work. This will surely be a book discussed and loved by many. I am excited to be among the first people to read it. » Allart van Viersen (Natuurhistorisch Museum Maastricht) « Un ouvrage de référence remarquablement documenté et superbement illustré sur les fossiles du Paléozoïque marocain : le "paradis des géologues" possède désormais sa Bible! » Bertrand Lefebvre (CNRS, Université Lyon 1)

Trilobiten sind eine ausgestorbene, rein auf das Erdaltefium (Paläozoikum) beschränkte Gruppe mariner Arthropoden (Gliedertiere). Heute noch lebende Arthropoden sind die Crustacea (Krebstiere), die Chelicerata (Spinnentiere), die Myriapoda (Tausendfüßler) und die lnsecta (Insekten). Trilobiten sind vom unteren Karnbrium (520 Mio. Jahre vor heute) bis in das obere Perm (255 Mio. Jahre vor heute) nachgewiesen. Ihr Panzer besteht, wie auch bei anderen Gliedeftieren, aus Chitin und Proteinen, allerdings werden bei den Trilobiten Calciumsalze in die Cuticula eingelagert (sie wird ,,calcifizieti"), wodurch sich ihre fossi le Erhaltungsftihigkeit wesentlich erhöht. Die Trilobiten bilden folglich die weitaus wichtigste und am besten überliefefte Gruppe paläozoischer Arthropoden. Durch ihren großen Formenund Individuenreichtum, zusalnmen mit hoher Evolutionsrate und meist guter Bestimmbarkeit stellen sie wichtige Leitfossilien in Kambrium und Ordovicium dar, später sind sie nur mehr von lokal-stratigraphischer Bede utung. MoRpnolocrn DES DoRs¡.lpaNznRs Calcifizierte Panzerteile sind die gesamte Dorsalseite (Rückenseite), der sogenannte Urnschlag (ventrale randliche Foftsetzung des Panzers) und das Hypostom (präorale Mundplatte). Die weichhäutigen Ventralstrukturen (Antennen, Spaltbeine, ventrale Körperdecke) sind paläontologisch nur äußerst selten überliefeft.

The middle Cambrian succession of Utah’s West Desert offers an outstanding record of one of the most important periods in Earth history, and in recent decades it has provided one of the most important faunal records of this time interval in the world. A total of 18 formations comprise the middle Cambrian (Series 3) succession of the West Desert and, together, they span the entirety of the series, with the Eokochaspis through Cedaria trilobite zones represented. For more than a century the middle Cambrian strata of the area have been well-known for their abundant, diverse, and well-preserved trilobites, which are especially prominent in the Wheeler, Marjum, and Weeks formations. The paleoenvironmental conditions that promoted the preservation of articulated trilobites and other mineralized organisms also contributed to soft-bodied preservation of Burgess Shale-type biotas in those units. The particularly rich fossil record from this area includes endemic taxa that are unique to the region as well as those found elsewhere in Laurentia and on other paleocontinents. In recent years, understanding of the middle Cambrian biotas from western Utah has increased as new taxa, including many soft-bodied forms, have been discovered. In the past year alone, species diversity from the Wheeler, Marjum, and Weeks formations has been expanded considerably. Taxa new to the Wheeler Formation include the protomonaxonid Lenica cf. hindei, the vetulocystid Thylacocercus ignota, the hemichordate Sphenoecium wheelerensis, and the conulariid Cambrorhytium sp.  Those from the Marjum Formation include the arthropod Dytikosicula desmatae, the cambroernid Eldonia ludwigi, and the new pterobranch hemichordate, Sphenoecium wheelerensis. The new arthropod Falcatamacaris bellua from the Weeks Formation joins two other new arthropod taxa described since 2013. The steady increase in taxonomic diversity of these units has contributed greatly to understanding the complex ecosystems that thrived in this region during the middle Cambrian. Recent work has also shed light on the living environments and circumstances surrounding exceptional preservation of the fossil assemblages. The House Range embayment, a deep water trough that first developed at the onset of Wheeler deposition, gradually filled through time, resulting in an overall shallowing upwards sequence and a general decrease in the frequency of soft-bodied preservation.

Despite previous investigations, the function of the forked morphology of asaphid trilobite hypostomes is enigmatic. The focus of this study is the large and robust forked hypostome of the largest known genus of trilobite, Isotelus, and the independently-derived forked hypostome of Hypodicranotus, the longest hypostome relative to body size of any trilobite. Although the trilobite hypostome is analogous to the labrum in other arthropods, forked hypostomes lack an obvious modern functional counterpart. The Isotelus hypostome is distinguished from other trilobite hypostomes by closely-spaced terrace ridges on a greatly thickened inner surface of the forked posterior margin, with the scarp of the terrace facing antero-ventrally. This is compatible with a grinding function, suggesting possible limb differentiation to complement this structure. The inner face of the tine (one of the two, prominent, sub-parallel posterior projections) is also unique in that it has a microstructure which is evident in section, running perpendicular to the surface. Macropredatory and filter-feeder roles are ruled out, and previous characterizations of the hypostome as knife-like or serrated are rejected. Its function is incompatible with that of other non-asaphid trilobites with forked hypostomes, like the remopleuridid Hypodicranotus, which lack similar terrace ridges and thickened inner-edge cuticle. □Arthropoda, Asaphida, ecology, functional morphology, Trilobita.

The illaenid trilobite Vysocania is widely represented in the Upper Ordovician of the Czech Republic, Portugal and Spain, and is one of the most characteristic taxa in the high-latitude peri-Gondwana palaeobiogeographical region to which it is endemic. Three species of the genus that were formerly assigned to Stenopareia and Zetillaenus, from the Czech Republic and Spain respectively, are herein revised, and a new species is described from the Czech Republic. The genus Octillaenus, of which a new species is described from the Upper Ordovician of Morocco, is considered to have arisen from Vysocania through paedomorphic (neotenic) processes. The relationships between Vysocania, Octillaenus, Stenopareia and Zetillaenus are reviewed and the criteria used in the definition of these taxa discussed. Species assigned to Vysocania are V. vaneki (type-species), V. iberica, V. moraveci sp. nov. and V. panderi; species assigned to Octillaenus are O. hisingeri (type-species) and O. marocanus sp. nov. Vysocania appears for the first time in the lower Berounian (Sandbian) and has its last undoubted record in the upper Berounian (upper Katian); Octillaenus is presently restricted to the Kralodvorian (upper Katian). •

Puji dan syukur penulis panjatkan kehadiran Tuhan Yang Maha Esa, karena atas berkat dan karunia-Nya penulis dapat menyelesaikan makalah ini dengan judul " Kelas Trilobita " untuk memenuhi tugas pada mata kuliah Paloentologi. Dalam penulisan makalah ini, penulis banyak mendapatkan bantuan dan bimbingan serta dorongan dari berbagai pihak. Penulis menyadari bahwa dalam penulisan ini masih terdapat banyak kesalahan maupun kekurangan, baik dalam susunan kata – kata, kalimat maupun bahasannya karena terbatasnya

Aconsolidated list of available generic names introduced since the beginning of the binomial
nomenclature system for trilobites is presented for the first time. Each entry is accompanied
by the author and date of availability, by the name of the type species, by a lithostratigraphic
or biostratigraphic and geographic reference for the type species, by a family assignment and
by an age indication of the type species at the Period level (e.g. MCAM, LDEV). A second
listing of these names is taxonomically arranged in families with the families listed
alphabetically, higher level classification being outside the scope of this work. We also
provide a list of names that have apparently been applied to trilobites but which remain
nomina nuda within the ICZN definition.

Contributions to the knowledge of Phacopina (Trilobita). The giant phacopids From Maider, SE-Moroccan Pre-Sahara.

The giant trilobites from the Middle Devonian of the Maider area - which attain a total length of 12-17 cm. and occasionally up to 20 cm. - are here assigned to the Tribus Geosopini STRUVE 1984 of the Subfamilia Phacopinae WAWLE & CORDA 1847. They belong to the "North African" genus Drotops STRUVE 1990, represented by the taxa megalomanicus megalomanicus STRUVE 1990, megalomanicus subornatus n. subsp., and armatus n. sp. as well by the "Central European" (sub-)genus Pedinoparops (Hypsipariops) STRUVE 1982, represented by the species vagabundus STRUVE 1990. - The introductory part of this paper treats with the marketing behavior of collectors and dealers, first attempts at determination, and with the problem of falsifications and/or "artifacts". The taxonomic-systematic part is introduced by a discussion of morphological features essential for generic determination. The descriptions are supported by a key for (sub-) generic assignment of Rhenish "aspect" phacopids and by a very simplified key for discrimination of "Maider Giants". - The evaluative part of the paper deals with the biostratinomic and palaeoecologic interpretation of the "Maider Giants" beds. Establishment  of geological age(s) of the collecting site(s) is attempted by conodont and brachiopod evidence, as well as by the evaluation of the developmental stage of the species vagabundus within the phylogeny of Pedinopariops (Hypsipariops). Placozoogeographical affinities are discussed - The appendix treats with the subgeneric sub-division of Phacops EMMRICH 1839 [cited tn the key], with Atryparia eta n. sp. [Zone brachiopod, mentioned in the stratigraphic discussion] and with Chondrites praetargionii n. ichnosp.  [facies indicator, metioned in the palaeoecological-palaeobathymetrical discusson].

The digestive system of trilobites is rarely preserved. As a result, many aspects of its organization remain unknown. Fortunately, the exoskeleton sometimes preserves evidence of soft-tissue attachment sites that can be used to infer internal anatomy. Among them are the frontal auxiliary impressions (FAIs), probable soft-tissue insertion sites located on the fronto-median glabellar lobe of some trilobites. FAIs are herein described in the Carboniferous trilobite Phillipsia belgica Osmolska 1970 – representing the only known example of such structures in the Proetida and their youngest occurrence. A taphonomic scenario is proposed to explain their variable preservation. Although particularly common in the Phacopina, FAIs or FAI-like structures are also found in several orders that differ greatly. Comparisons with modern analogues suggest that FAIs might represent attachment sites for extrinsic muscles associated with a differentiated crop within the foregut. A review of purported remains of the trilobite digestive system indicates that it usually consisted of a tube-like tract flanked by a variable number of metamerically paired diverticulae. Its anterior portion is not particularly individualized, except in a few specimens that might hint at the presence of a crop. This differentiation of a crop might have constituted a secondarily evolution of the foregut in trilobites, occurring independently in different clades. Accompanied by a strengthening of associated extrinsic muscles, this modification of the foregut might explain the presence of more conspicuous muscle insertion sites on the glabella. Study of FAIs might therefore provide new data on the anatomy of the foregut in trilobites and evidence of diverse feeding habits.

The new ellipsocephaloid trilobite species Kingaspidoides spinirecurvatus has a spectacular morphology because of a unique set of two long and anteriorly recurved spines on the occipital ring and the axial ring of thoracic segment 8. Together with the long genal spines this whimsical dorsally directed spine arrangement is thought to act as a non-standard protective device against predators. This is illustrated by the body posture during different stages of enrolment, contrasting with the more sophisticated spinosities seen in later trilobites, which are discussed in brief. Kingaspidoides spinirecurvatus from the lower–middle Cambrian boundary interval of the eastern Anti-Atlas in Morocco has been known for about two decades, with specimens handled as precious objects on the fossil market. Similar, but far less spectacular, spine arrangements on the thoracic axial rings are known from other ellipsocephaloid trilobites from the Anti-Atlas of Morocco and the Franconian Forest region of Germany. This suggests that an experimental phase of spine development took place within the Kingaspidoides clade during the early–middle Cambrian boundary interval.

A new genus of Lichidae (Parvilichas n. gen., with the type species P. marochii n. sp.) is described from the Floian of the Tinzouline (Zagora region, Morocco). Its closest relative is Uralichas Delgado, 1892, but Parvilichas n. gen. differs from Uralichas mainly in its smaller size, its larger eyes and longer genal spines. Parvilichas n. gen. extends the range of the Subfamily Lichinae down to the Floian.

Trilobites are often considered exemplary for understanding the Cambrian explosion of animal life, due to their unsurpassed diversity and abundance. These biomineralized arthropods appear abruptly in the fossil record with an established diversity, phyloge-netic disparity, and provincialism at the beginning of Cambrian Series 2 (∼521 Ma), suggesting a protracted but cryptic earlier history that possibly extends into the Precambrian. However, recent analyses indicate elevated rates of phenotypic and genomic evolution for arthropods during the early Cambrian, thereby shortening the phylogenetic fuse. Furthermore, comparatively little research has been devoted to understanding the duration of the Cambrian explosion, after which normal Phanerozoic evolutionary rates were established. We test these hypotheses by applying Bayesian tip-dating methods to a comprehensive dataset of Cambrian trilobites. We show that trilobites have a Cambrian origin, as supported by the trace fossil record and molecular clocks. Surprisingly, they exhibit constant evolutionary rates across the entire Cambrian, for all aspects of the preserved phenotype: discrete, meristic, and continuous morphological traits. Our data therefore provide robust, quantitative evidence that by the time the typical Cambrian fossil record begins (∼521 Ma), the Cambrian explosion had already largely concluded. This suggests that a modern-style marine biosphere had rapidly emerged during the latest Ediacaran and earliest Cambrian (∼20 million years), followed by broad-scale evolutionary stasis throughout the remainder of the Cambrian.

Seventeen species from 14 genera of Tremadocian and Darriwilian trilobites, plus two taxa recognizable only down to family level, have been
documented from the Lower to Middle Ordovician succession of the Deh-Molla area, southeast of Shahrud in northern Iran. Two species,
Asaphellus intermedius and Conophrys multituberculatus, are new to science. Unlike previously documented Iranian faunas, the early
Tremadocian trilobite assemblage is characterized by proliferation of the olenid Chungkingaspis sinensis, which is also known as the eponymous
taxon of the basal Ordovician trilobite biozone in South China. This is the first record of the occurrence of the olenid biofacies in the Ordovician
of Iran. Overall, both the Tremadocian and Darriwilian trilobite assemblages show distinct similarity to the contemporaneous faunas of South
China down to species level. Trilobite-based correlation with the Ordovician succession of South China confirms the existence of a hiatus at the
base of the Ordovician succession in the eastern Alborz and a significant gap, with the upper Tremadocian, Floian and Dapingian parts of the
succession completely missing in Deh-Molla.

Remains of a digestive system from a slightly damaged articulated specimen of the comparatively rare bathycheilid trilobite Prionocheilus vokovicensis (Šnajdr, 1956) are described for the first time. The specimen comes from the Middle Ordovician Šárka Formation of the Prague Basin and contains the midgut region of the digestive system preserved through the axial region of glabella and six anterior thoracic segments. The anterior-most part of the digestive system is unknown as the anterior glabellar lobes are not preserved in the studied specimen. In the cephalic shield, the remains of two pairs of gut diverticulae are seen in the posterior region of the glabella. Remains of five pairs of small cavities developed in the axis of the first six thoracic segments represent the remains of thoracic gut diverticulae. The discussed specimen possess the first undoubted remain of digestive structures established within the family Bathycheilidae (PŘibyl, 1953).

The sub-surface section of the Middle Ordovician Sueve Formation of the Cantabrian
Zone, studied during the construction of a tunnel in the A-8 free highway of northern
Spain, provided abundant fossiliferous horizons rich in trilobites of Darriwilian age. Finegrained mudstones of the Cofino Member delicately preserve a number of early stages of ~
the calymenacean trilobite Prionocheilus mendax (Vanek), from protaspides to meraspid
degree 2, including in situ exuviae with disarticulated librigenae. From the upper part of
the Bayo Member, small clusters of pyrite spheres ca. 0.5 mm in diameter are recorded,
and may represent eggs of trilobites, being associated with the pliomerid Placoparia
(Coplacoparia) tournemini. (Rouault) in the same beds. The sphaeroids may represent the
pyrite infilling of the internal cavity of possible eggs, and the covering is replaced by phyllosilicates. Differences in shape and size from presumed olenid eggs may be caused by the
particular environmental adaptations of the latter group. The relatively large size of both
the calymenid larvae and the pyritized eggs suggests a lecithotrophy development related
to higher latitudes and/or with scarce organic matter.

A lack of well resolved biostratigraphic data has prevented robust regional and global correlation of lower Cam-brian successions from South Australia. A new early Cambrian biostratigraphy, based on data derived from 21 measured stratigraphic sections and drill cores (11 described herein) reveals the abundance and diversity of shelly fauna from the Arrowie Basin, and the value of early Cambrian "small shelly fossils" (SSF) for biostrati-graphic studies. Here we examine shelly fauna associated with the youngest of three recently established biozones, the Dailyatia odyssei Taxon Range Zone (hereafter D. odyssei Zone), and their correlative potential. The D. odyssei Zone features a diverse suite of tommotiids, organophosphatic brachiopods, bradoriid arthropods, molluscs and phosphatic problematica. This fauna permits strong correlation (often at species-level) with other major early Cambrian terranes, particularly Antarctica, South China and Laurentia, and suggest a Cambrian Series 2, Stages 3-4 age for the D. odyssei Zone. Bradoriids have proven to be useful biostratigraphic tools. Four new species and three new genera are described herein: Acutobalteus sinuosus gen. et sp. nov., Eozhexiella adnyamathanha gen. et sp. nov., Manawarra jonesi gen. et sp. nov. and Mongolitubulus descensus sp. nov. The description of Eohadrotreta sp. cf. zhenbaensis represents the first occurrence of the acrotretoid brachiopod Eohadrotreta from Australia.

The new ellipsocephaloid trilobite species Kingaspidoides spinirecurvatus has a spectacular morphology because of a unique set of two long and anteriorly recurved spines on the occipital ring and the axial ring of thoracic segment 8. Together with the long genal spines this whimsical dorsally directed spine arrangement is thought to act as a non-standard protective device against predators. This is illustrated by the body posture during different stages of enrolment, contrasting with the more sophisticated spinosities seen in later trilobites, which are discussed in brief. Kingaspidoides spinirecurvatus from the lower–middle Cambrian boundary interval of the eastern Anti-Atlas in Morocco has been known for about two decades, with specimens handled as precious objects on the fossil market. Similar, but far less spectacular, spine arrangements on the thoracic axial rings are known from other ellipsocephaloid trilobites from the Anti-Atlas of Morocco and the Franconian Forest region of...

Trilobiten sind eine ausgestorbene, rein auf das Erdaltertum (Paläozoikum) beschränkte Gruppe mariner Arthropoden (Gliedertiere). Heute noch lebende Arthropoden sind die Crustacea (Krebstiere), die Chelicerata (Spinnentiere), die *Myriapoda* (Tausendfüßler) und die Insecta (Insekten). Sie sind vom unteren Kambrium (560 Mio. Jahre vor heute) bis in das obere Perm (250 Mio. Jahre vor heute) nachgewiesen. Ihr Panzer besteht, wie auch bei anderen Gliedertieren, aus Chitin und Proteinen, allerdings werden bei den Trilobiten Calciumsalze in diese Cuticula eingelagert (sie wird "calcifiziert"), wodurch sich ihre fossile Erhaltungsfähigkeit wesentlich erhöht. Die Trilobiten bilden daher die weitaus wichtigste Gruppe paläozoischer Arthropoden. Durch ihren großen Formen-und Individuenreichtum, zusammen mit hoher Evolutionsrate und meist guter Bestimmbarkeit stellen sie wichtige Leitfossilien in Kambrium und Ordovicium dar, später sind sie nur mehr von lokal-stratigraphischer Bedeutung. Morphologie des Dorsalpanzers Calcifizierte Panzerteile sind die gesamte Dorsalseite (Rückenseite), der Umschlag (ventrale randliche Fortsetzung des Panzers) und das Hypostom (präorale Mundplatte). Die weichhäutigen Ventralstrukturen (Antennen, Spaltbeine, ventrale Körperdecke) sind paläontologisch äußerst selten überliefert. Der Dorsalpanzer ist durch die beiden Dorsalfurchen (Rückenfurchen; b.4; im folgenden beziehen sich alle Buchstaben-und Nummernverweise auf die Bildtafel, Fig.

Trilobites are an iconic group of extinct arthropods that lived in Palaeozoic oceans for c. 270 Ma, before their demise at the end of the Permian Period. Despite their considerable diversity (> 22 000 species) and abundance, particularly in Cambrian and Ordovician rocks, as well as intensive study for well over 200 years, trilobite systematics remains in a state of flux. In this contribution, the complex history of trilobite classification over the last century is briefly reviewed, including the seminal scheme published by Henry Swinnerton in 1915. The cryptogenesis problem, which relates to the supposedly obscure phylogenetic links between major post-Cambrian trilobite clades and their Cambrian sister taxa, is also discussed. Previous studies have suggested that the cryptogenesis problem is largely a taxonomic artefact, but the Cambrian origins of some post-Cambrian groups, such as the orders Proetida and Odontopleurida, are still unclear. Future directions for research on trilobite systematics are outlined, from taxonomic studies involving comprehensive documentation and extensive illustration of morphology at the species level, through to broad-scale phylogenetic analyses that initiate or test hypotheses about relationships across the major groups. Other ongoing issues to be addressed include identifying the sister group of Trilobita, and determining whether certain taxa, such as the suborder Agnostina and Cambrian family Burlingiidae, represent trilobites.

A REVISION OF THE UNIVERSITY OF VIENNA’S TRILOBITE COLLECTION: A COMPILING CATALOGUE WITH ADDITIONAL INFORMATION ON THE PHYLOGENETIC POSITION OF THE TRILOBITA.
Trilobites have been known some 15.000 years. Although the group is not as important in a cultural sense as for example, molluscs, trilobites have been used as cultic objects by certain Indian tribes of North and South America, as amulets and jewellery by Europeans; they are even mentioned  in literature and poetry.
WALCH introduced the name ”Trilobites” in 1771; since then highly different views concerning their zoological position have been discussed, and even at present their exact phylogenetic position remains an unsolved problem. In 1939 and in the following years STØRMER reconstructed the morphology of the trilobite biramous limb: he believed in the presence of a precoxa on the protopodite, to which the outer branch of the biramous appendage is attached. If this is true, the trilobite exite should be a pre-epipodite and therefore cannot be homologous to the crustacean exite, which is a true exopodite originating from the basis. In STØRMER’s view this trilobite-type limb is an important characteristic uniting Trilobitomorpha and Chelicerata (the ”Arachnomorpha” or ”Arachnata” concept), the latter having primary biramous appendages, as indicated by xiphosuran limbs with a small remaining exite. None of the following studies, however, was able to prove the existence of STØRMER’s precoxa. According to new findings in stem-lineage crustaceans it is highly probable that neither Lamellipedia (= new appropriate name for ”Trilobitomorpha”) nor Chelicerata possess a true coxa (in the crustacean sense), their protopodite therefore being homologous to the basis of Crustacea. The important characteristics of the trilobite-type appendage are that the exopodite (exite of basis) bears long, flattened setae; these setae are directed away from the endopodite. Trilobite-type and crustacean-type biramous limbs are clearly homologous structures, originating from a simple construction of schizoramous appendage as shown in the proschizoramian Fuxianhuia. Neither do additional characteristics like cephalisation, pygidium and facial sutures prove a closer relationship of Lamellipedia and Chelicerata. At present the Lamellipedia are best treated as an independent subphylum of the phylum Arthropoda, with no closer connection to the Chelicerata than to the Crustacea. Rejecting the Uniramia-hypothesis the Arthropoda as a whole are considered to be monophyletic.
During the work on the trilobite collection, every fossil was cleaned, classified, and labelled. The specimens are now housed adequately in sealed plastic bags or showcases. The trilobite collection consists of 1411 fossils mainly from the Czech Republic (1091 specimens), but also from other countries such as Germany, Austria, Sweden, Great Britain, the United States of America, Russia, Estonia, Italy, Morocco and France. These objects were brought together by a variety of different people, some of them important palaeontologists: Othenio ABEL, Ignaz HAWLE, Jaroslav J. JAHN, Rudolf KNER, Valerian von MÖLLER and Ottomar P. NOVÁK; a separate chapter deals with the historical origin of some specimens. Being a collection for educational purposes various indices are added to the systematic catalogue in order to find objects according to specific criteria important for teaching at the university.

A new otarionine trilobite Otarionella rastrum sp. nov., from the late Emsian Mont Peyroux Formation (Montagne Noire, France), is described. Silicified remains, recovered from the underlying Bissounel Formation (early to late Emsian), are also attributed to this new species. These isolated silicified sclerites represent metaprotaspid to young holaspid growth stages, which enables the almost complete ontogeny of an otarionine trilobite with a spinose adult morphology to be described for the first time. Comparison with associated larval and juvenile growth stages of Cyphaspis reveal that the pattern of juvenile cranidial spine distribution in Otarionella rastrum sp. nov. differs from all patterns described so far in the Otarioninae, in particular that characterizing the tribe Otarionini. A second species, Otarionella lkomalii sp. nov., known only from a complete articulated specimen discovered in the early Eifelian of southern Morocco, is also described. Like the middle Eifelian Otarionella chamaeleo (Basse, 1997), this new species has only ten thoracic segments, with the fourth and the sixth segments each bearing a long axial spine. In the light of the new elements provided by the ontogenetic sequence of O. rastrum sp. nov. and the adult specimens of this species and O. lkomalii sp. nov., the putative synonymy of Otarionella and Otarion is rejected and a restricted concept of the genus Otarionella is defined.

Abundant trilobite remains were recovered from late mid−Famennian marlstones from various sites in Eastern Tafilalet, southeast Morocco. All belong to a single taxon previously identified as Cyrtosymbole (Waribole) prima. This taxon is designated the type species of Osmolskabole gen. nov. A redefinition of this species, including the description of newly discovered, disarticulated exuviae both in limestone and silicified state of preservation, is given. In particular, silicified sclerites of various sizes allow the first complete growth series of a cyrtosymboline proetid to be presented. The close morphological resemblance of its protaspid stages to known proetoid larvae emphasizes the homogeneity of the early ontogeny in this superfamily. The Famennian proetoid anaprotaspis is also of comparable size to that of other Devonian proetoid larvae. However, their size−range is much less than that observed in Carboniferous larvae. This suggests that the survival of proetoid trilobites at the Frasnian - Famennian Kellwasser crisis did not result from a modification of the developmental strategy, as it might have been the case at the terminal Devonian extinction event. Moreover, O. prima possesses a plectrum from the metaprotaspid to the mid meraspid periods. This implies that the natant hypostomal condition is not steadily acquired early in the ontogeny of the Proetida. Thus we preclude the use of this character in the diagnosis of this order.

Estudios Geológicos [online] http://dx.doi.org/10.3989/egeol http://estudiosgeol.revistas.csic.es Manuscrito aceptado Accepted manuscript Autor(es) Author(s): Esteve, J. Título (original, ES): Title (original, ES): Revisión del enrollamiento en los trilobites del Cámbrico español y su implicación en la evolución de los trilobites Título (traducido, EN): Title (translated, EN): Puede citar este artículo como: You may cite this article as: Esteve, J. (2013). Revisión del enrollamiento en los trilobites del Cámbrico español y su implicación en la evolución de los trilobites. Estudios Geológicos [en línea], manuscrito aceptado, doi: 10.3989/egeol.41215.259 Esteve, J. (2013). Revisión del enrollamiento en los trilobites del Cámbrico español y su implicación en la evolución de los trilobites. Estudios Geológicos [online], accepted manuscript, doi: 10.3989/egeol.41215.259 NOTA: Este documento es un artículo inédito que ha sido aceptado para su publicación.

"Members of Ceratarges Gürich are known from Devonian strata in various countries but they have not yet
been formally described from Morocco. Ceratarges ziregensis sp. nov., Ceratarges koumalii sp. nov. and Ceratarges aries
sp. nov. are herein described from the El Otfal Formation (Eifelian) in Morocco on the basis of complete specimens.
Supplementary material is illustrated of Ceratarges cognatus van Viersen from the Jemelle Formation (Eifelian) in France.
The relationships between Ceratarges, Mephiarges Richter & Richter and Asawikwanabe Basse in Basse & Müller are
briefly elaborated on."

Trilobites are a minor component of Permian benthic marine faunas, which explains why they remain poorly known. For example, only two specimens have been found in the highly fossiliferous and extensively studied Middle-Upper Permian Pamucak Formation (Antalya Province, Turkey). These two complete enrolled trilobites of Wordian age are described herein. The diagnosis of the subgenus Pseudophillipsia (Nodiphillipsia) Kobayashi & Hamada 1984a is emended and its occurrence outside of eastern Asia is reported for the first time. The second specimen represents a new species, Pseudophillipsia (Carniphillipsia) kemerensis sp. nov. Its discovery in the Wordian of Turkey suggests that Pseudophillipsia (Carniphillipsia) is no less diversified in the Middle Permian than in the Early Permian. Both specimens exhibit a particular enrollment posture, with the anterior part of the pygidium located within the cephalic cavity, while its posterior part is adpressed against the anterior cephalic doublure. The advantages of this style of enrollment are discussed, especially with regards to resistance of the enrolled body to external pressures, and rare examples of similar postures in older trilobites are reported. These two specimens are the first Permian trilobites from Turkey to be described, thus complementing the poor fossil record of these organisms in the Permian of southwestern Asia.

Quantitative data reveal a complex evolution of late trilobite diversity. In the Mid- to early Late Devonian, a series of extinction events led to a drastic taxonomic impoverishment. In the Famennian, while only two orders remained, originations started to compensate still high extinction rates marking the onset of a remarkable diversification. Though interrupted by the major Hangenberg turnover, the general diversification trend accelerated in the Tournaisian whilst extinctions became modest. Originations notably diminished during the Viséan and the Serphukovian, making the diversity to step down at the level of the Frasnian. It has never been much higher thereafter, despite a profound restructuring of trilobite communities in the early Pennsylvanian permitting the progressive domination of ditomopygines. After another drop in the Kasimovian a period of stasis occurred with very low diversity levels and almost no renewal. The last diversification burst took place in the Wordian, but it ceased rapidly in the Capitanian when the degradation of environmental conditions started to inhibit originations. Thus, the extinction of the Trilobita at the end of the Permian resulted from the disappearance of merely a handful of genera.

The presence of bollandiine trilobites is reported for the first time in the early Carboniferous of Moravia, the Czech Republic. Bollandia persephone (Hahn & Hahn, 1970) and B. cf. megaira (Hahn & Hahn, 1970) were recovered from pelitic shales of late Tournaisian age within the Březina Formation exposed in Mokrá quarry, near Brno. Along with other taxa, these two species constitute a trilobite assemblage with few affinities to other Carboniferous associations known from the Czech Republic, but resemble an assemblage from the late Tournaisian of the Harz Mountains. Morphological characters of Bollandia species are interpreted as being indicative of an epibenthic mode of life, with possible adaptations for digging and for predatory/scavenging feeding habits.