Allart Van Viersen

Musée national d'histoire naturelle de Luxembourg | MNHN · Department of Palaeontology

Abstract Well-preserved specimens of the phacopine trilobites Morocops Basse (= Barrandeops McKellar & Chatterton) and Adrisiops gen. nov. are recorded from upper Emsian strata in Morocco. Morocops is a problematic taxon; the close similarities of its stratigraphically youngest members to the earliest members of Geesops Struve are indicative of gr...

A group of asteropygine trilobites with 10 thoracic segments from the lower Emsian to lowermost Eifelian of western Europe and northwest Africa is deemed monophyletic. Available names for this clade are Hollardops Morzadec, 1997, Philipsmithiana Lieberman & Kloc, 1997, Modellops Lieberman & Kloc, 1997 and Pennarbedops Bignon & Crônier, 2013, the fi...

Species of the odontopleurine trilobites Leonaspis Richter & Richter, 1917 and Kettneraspis Prantl & Přibyl, 1949 from the Silurian and the Devonian have been studied. Dorsal tubercle and spine patterns are highly variable and deemed of restricted use. The pygidial segmentation of Leonaspis is consistent among species in the development of a rudime...

A mixed Rhenish-Hercynian trilobite fauna is recorded from lower Emsian (Lower Devonian) strata in the Reideschbaach locality near Heiderscheid, Luxemburg, Ardenno-Rhenish Mountains. Previous investigations have led to the identifications of 12 distinct species of trilobites; our material is inclusive of several of these. Newly described taxa are A...

In the heart of the Fagne, halfway between Chimay and Couvin, lies Lompret, one of the most beautiful villages in Wallonia. This village with its seemingly modest appearance, bordering the meanders of the 'Eau Blanche' river, boasts a very rich cultural and historical past. beyond its status as a landmark of the region's cultural and historical her...

Published in Gea magazine, March 2022, No. 1.

Phacopids are common trilobites in early Middle Devonian strata in the Ardennes and Eifel, contrary to the Lower Devonian where they are rare or absent. The Eifel has a long tradition of Devonian trilobite research. It is the type area of many classic species and some of these are the type species of large genera. Unfortunately, many taxa are inade...

The classification and nomenclature of Devonian members of the lichid trilobite subfamily Trochurinae are reviewed. Previously claimed subjective synonymies of Lobopyge Přibyl & Erben, 1952 with Belenopyge Pek & Vaněk, 1991 and Akantharges Phleger, 1936 with Rhenarges Basse in Basse & Müller, 2004 are rejected. Basseiarges Corbacho & López- Soriano...

A new cornuproetine trilobite with nine thorax segments from upper Emsian strata in the NE Draa Valley (southern Morocco) is described as Timsaloproetus alissae sp. nov. Morphological evidence is reviewed to suggest a semi-endobenthic life mode, possibly with a carnivorous feeding habit.

High quality photographic figures of VAN VIERSEN, A.P. (2021): Type and other species of Gerastos and allied genera (Trilobita, Proetinae) from the Siluro-Devonian. – N. Jb. Geol. Paläont. Abh., 299/2: 185-217.

Silurian to Middle Devonian members of Proetinae with in particular taxa that are morphologically similar to Gerastos are reviewed. Gerastos is widely distributed in Lower and Middle Devonian strata in the Rhenohercynian Basin (southern Laurussia), peri-Gondwana and northern Gondwana. Evolution of the group during the late Lower to Middle Devonian...

Kurzfassung: Mit Arduennella hainauensis n. sp. wird eine neue Art der bisher monotypischen Trilobitengattung Arduennella WENNDORF, 1990 beschrieben. Im Zusammenhang damit erfolgt auch eine Neufassung der Typusart Arduennella maillieuxi (ASSELBERGHS, 1923) sowie eine emendierte Gattungsdiagnose. Abstract: With Arduennella hainauensis n. sp. a new...

Published in: The Trilobite Papers, vol. 23.

A poorly diversified trilobite association is recorded from an outcrop near the village of Breitfeld, Sankt Vith area, East Belgium. The co-occurrence of Arduennella maillieuxi (Asselberghs, 1923) and Burmeisterella quadrispinosa Wenndorf, 1990 in the Breitfeld locality is suggestive of an early lower Emsian age. The outcropping rocks are provision...

Viersen, A.P. van, 2020 - Nouveaux trilobites dévoniens du Mur des douaniers (Nord de la France) et quelques associations connexes de Belgique. Fossiles, Rev. Franç. Pal., 42 : 42-50.

Viersen, A.P. van & Lelubre, D., 2020 - Découverte d'une faune de trilobites de type "Vieux Moulin" dans le Dévonien Moyen d'Hargimont, Sud-Est de la Belgique. Fossiles, Rev. Franç. Pal., 44 : 42-47.

The majority of cornuproetine taxa known from articulated specimens have ten thoracic segments. Here we record rare, well-preserved specimens with nine segments in the Early and Middle Devonian of Morocco, Germany and the Czech Republic. These encompass the genera Lepidoproetus Erben, Sculptoproetus Erben, Macroblepharum Alberti, Koneprusites Přiby...

Odontopleurid trilobite remains from the latest Eifelian to earliest Givetian Hanonet Formation in the Resteigne quarry, southern Belgium, are described and assigned to a new species Radiaspis taghonorum. Although the pygidium of R. taghonorum is similar to that of some Eifelian congeners, its cephalon is markedly different. The Hanonet Formation b...

Published in the Augustus 2019 edition of The Trilobite Papers.

Well-preserved trilobite specimens are recorded from Eifelian strata between the villages of Nismes (southern Belgium) and Vireux-Molhain (northern France). In the area of study the lower Eifelian Vieux Moulin Member of the Jemelle Formation crops out. The diversified trilobite associations of this unit occur in dark shales and siltstones during a...

De groeve van Steffeshausen kwam rond 2013 in de belangstelling na de vondst van één van de oudste Belgische ammonoïden. De groeve is anno 2019 echter toe aan een grondig overzicht van de paleo-ecologie en een synthese van geologische observaties na vele decennia van sporadisch onderzoek. In dit artikel hebben we getracht om een overzicht te geven...

Published in: Spirifer, 43 (2): 2-23.

Trilobites are recorded from Frasnian strata in Belgium on the basis of old museum collections and contemporary fieldwork. Of the four third-order Transgressive-Regressive (T-R) cycles recognised here in the latest Givetian to late Frasnian, the last three are each associated with a version of a largely coherent, acastid–scutelluid dominated trilob...

Phacopids with reduced sculpture are recorded from Emsian to Givetian strata in the Ardenno-Rhenish Mountains and Brittany. Austerops couvinensis sp. nov. and Austerops hottonensis sp. nov. are described from Eifelian strata in the Ardennes and represent the first known occurrences of members of this genus outside Gondwana. Loreleiops suffeleersi g...

New species of the otarionine trilobite Cyphaspis are recorded from Pragian to Givetian localities in Morocco and Belgium. The material carries a wealth of new insights into the diversity of Cyphaspis during the Devonian. In an attempt to bring structure to the vast assortment of species, selected taxa are clustered into three informal groups that...

Belgische blauwe hardsteen, ook wel “Petit Granit”, of “Pierre Bleue Belge” genaamd, is één van de voornaamste Belgische bouw- en decoratieve kalkstenen, die overal ter wereld gebruikt en geprezen worden om hun hoogstaande kwaliteit en karakteristiek uitzicht. In het dorpje Naast (deelgemeente van de stad Soignies) wordt deze hardsteen al sinds mee...

Trilobites make up a major component of the Devonian macrofauna in the Ardennes (Belgium, northern France). This has been properly described for the first time through a recently commenced revision. While the Lochkovian and early half Pragian were dominated by classic Rhenish Homalonotidae and Acastidae, the extensive offshore environments that dev...

Kettneraspis? prescheri sp. nov. is described from the Ihandar Formation at Jbel Issoumour, SE Morocco. Relationships of the morphologically similar Kettneraspis Prantl & Přibyl and Leonaspis Richter & Richter are discussed. Previous diagnoses in the literature are no longer considered to be valid.

Three new species of Middle Devonian otarionine trilobites are described: Cyphaspis walteri sp. nov. from the Bou Dib Formation in Morocco, Cyphaspis rommersheimensis sp. nov. from the Freilingen Formation in Germany, and Cyphaspis heissae sp. nov. from the Ahbach Formation in Germany. Cyphaspis cf. heissae sp. nov. is described from the Hanonet Fo...

Several species of acastid trilobites are recorded from shallow-water deposits at two localities in the eastern part of the Dinant Synclinorium, Ardennes, Belgium. The species are Acastava? lerougei sp. nov., Treveropyge sp. and Delocare sp. in the Hierges Formation (upper Emsian) near Marche-en-Famenne, and Jaylopygiella debruni sp. nov. in the Ri...

Proetid trilobites are described from Middle Devonian strata in the Dinant Synclinorium, Belgium. Astycoryphe arduinnae sp. nov., Dohmiella cf. dohmi (richter & richter), Longiproetus cf. tenuimargo (richter), Gerastos sp. C, and Quadratoproetus sp. A are recorded from the Jemelle Formation (Eifelian) in Boutonville. These taxa provide the first co...

Scutellum decipulum n. sp. and Scutellum protrusifrons n. sp. are described from the Frasnian Moulin Liénaux and Grands Breux Formations respectively in the Couvin area. Until recently, scutelluids from this time interval in Belgium were commonly identified as the Polish species Scutellum costatum Pusch but these assignments are now revised. Scutel...

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. Supplementa...

The Frasnian representatives of Asteropyginae in the Frasnes area (south Belgium) have long been relatively well-documented when compared to other trilobites in the Devonian of the Ardennes (Belgium, northern France). However, examination of the type material and new collecting by the authors indicate that a taxonomic review has become necessary. T...

Trilobites have long been known to occur in Belgium in strata of Ordovician, Devonian and Carboniferous age. Devonian rocks are the most widespread of Palaeozoic outcrops there, yet the trilobites that they yield are the least known by far. Records (usually lists of species without illustrations or type numbers) frequented the old literature until...

Proetids are common trilobites in the Middle Devonian of the Ardennes and Eifel. They are known from ample material and so provide an excellent basis for taxonomic and biostratigraphic studies. Seven new species are recorded from the Ardennes, Belgium (Gerastos arcus n. sp., Gerastos couvinensis n. sp., Gerastos snellingsi n. sp., Astycoryphe exili...

Scutelluids are rare trilobites in the Devonian of the Ardennes (Belgium, France). Goldius angusticalix sp. nov. and Scabriscutellum sp. A are recorded from the Couvin Formation (lower Eifelian) in Nismes, Belgium. An overview is given of the regional distribution in the Eifelian of Goldius de Koninck (= Brontes Goldfuss; Bronteus Goldfuss; Goldfus...

Opercula and corallites of Calceola sandalina from the late Eifelian and early Givetian (Middle Devonian) Hanonet Formation of Belgium are illustrated. The few previous illustrations of calceoloid corals from the Devonian of Belgium did not include opercula showing the generically diagnostic morphological features, so for the first time the presenc...

Trilobites of "Rhenish" and "Bohemian" type are recorded from the Longlier Formation (Pragian to possibly Lower Emsian) at several localities in the Neufchâteau Synclinorium (southeast Belgium) on the basis of material currently kept at the Royal Belgian Institute of Natural Sciences. The occurrences of Belenopyge sp. (= Lobopyge PŘIBYL & ERBEN), P...

Two trilobites, Pedinopariops hoelleri n. sp. (Phacopidae) and Tropidocoryphe bassei n. sp. (Proetidae), are recorded from middle Eifelian strata at the "Trilobitenfelder" near the village of Gees, Germany. Lithology of the Gees Subformation (Ahrdorf Formation) at Gees is briefly elucidated. The holotype of Tropidocoryphe barroisi (MAILLIEUX) from...

New data are presented on trilobites of the family Proetidae (subfamilies Proetinae, Dechenellinae, Cornuproetinae) from the Devonian of the Ardennes Massif and the Eifel Hills (Rhenohercynian zone). Preliminary stratigraphic distributions of the Proetidae from the southern border of the Dinant Synclinorium are introduced. Eight taxa are recorded,...

The ‘Mur des douaniers’ biota at the former French/Belgian border contains a rich and diversified Lower Eifelian benthic fauna, and especially trilobites. Palaeobiodiversity and sedimentological analyses have led to the interpretation of the general palaeoenvironmental/palaeoecological context. This trilobite-rich locality is an exceptionally well-...

Koneprusia sp. A is recorded from the lower Eifelian (Jemelle Formation) of Vireux-Molhain, northern France. The taxon is exceedingly rare and was hitherto not known to occur here. Two articulated carapaces as well as a fragmentary specimen are described. Koneprusia sp. A is closely related to several Eifelian Koneprusia species from the Rhenohercy...

Specimens of Cyphaspis Burmeister are recorded from Eifelian and Frasnian strata in Belgium as well as from Eifelian strata in Germany, and are assigned to six taxa. Scant information has hitherto been available onCyphaspis from the Ardennes. From this region Cyphaspis unguloides belgica n. ssp., Cyphaspis sp. B, Cyphaspis sp. C, and Cyphaspis sp....

Trilobite occurrences and biodiversity from Devonian sections of the Ardennes Massif are presented. Fluctuations in diversity reflect environmental changes and event-stratigraphic turnovers throughout the Devonian. Peak diversity is attained during the Eifelian (Middle Devonian) when the carbonate system is developed. Six trilobite associations hav...

The macrofauna of the Hanonet Formation is well documented with the exception of trilobites. Recent investigation of the basal layers of this formation (Polygnathus ensensis conodont Zone) at Resteigne has allowed identification of six trilobite taxa, comprising Calycoscutellum goolaertsi n. sp., Nyterops hollandi n. sp., Hypsipariops? sp., Gerasto...

The Middle Eifelian trilobite fauna of the Belgian Ardennes shows close affinities with that of the German Eifel. Two trilobite taxa are recorded from Middle Eifelian strata near the town of Jemelle, on the southern border of the Dinant Synclinorium, Belgium. Kettneraspis bayarti sp. nov. is closely related to Kettneraspis elliptica (Burmeister) fr...

Dohmiella is recorded from Belgium for the first time. The genus is represented here by at least three distinct species that occur in strata of early to latest Eifelian age, namely Dohmiella dewildei n. sp., Dohmiella sp. 1 and Dohmiella sp. 2. Dohmiella preschen n. sp. is recorded from the lower Eifelian of the Eifel, Germany. Relationships of Ger...

Lower Eifelian (Middle Devonian) strata cropping out in the vicinity of Vireux-Molhain, Ardennes, France, have yielded a rich trilobite fauna. Four trilobite species are recorded, namelyCeratarges cognatus n. sp.,Rhenocynproetus catervus n. sp.,Cyphaspis n. sp. A andThysanopeltella (Septimopeltis) magnispina (Maillieux 1938).Ceratarges cognatus n....

Belgian Devonian trilobites have long been known, although they remain comparatively poorly documented. A revision of the obsolete nomenclature seems long overdue, and added to that, critical evaluations of listings of trilobite taxa by MAILLIEUX over sixty years ago are called for. The present note is the first part in a revision of Devonian trilo...

Article in Dutch published by the Dutch Geological Society. This paper describes trilobites from boulders in Limburg, the southernmost province of the Netherlands. The boulders were found in fluvial deposits and were probably sourced from Germany by the proto-Rhine. Trilobites include Digonus, Treveropyge, Acastoides, Scabriscutellum and Dechenella...

Article in Dutch published by the Dutch Geological Society. This work attempts to eliminate some of the confusion surrounding Phacops latifrons, a notorious species name which was used rather indiscriminately in the old literature, for various trilobite species of different phacopid genera.

Article in Dutch describing the discoveries of mostly Eifelian trilobites from the Belgian Ardennes.