Martin Stein

IT University of Copenhagen, København, Capital Region, Denmark

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Publications (13)64.32 Total impact

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    ABSTRACT: Large, actively swimming suspension feeders evolved several times in Earth's history, arising independently from groups as diverse as sharks, rays and stem teleost fishes, and in mysticete whales. However, animals occupying this niche have not been identified from the early Palaeozoic era. Anomalocarids, a group of stem arthropods that were the largest nektonic animals of the Cambrian and Ordovician periods, are generally thought to have been apex predators. Here we describe new material from Tamisiocaris borealis, an anomalocarid from the Early Cambrian (Series 2) Sirius Passet Fauna of North Greenland, and propose that its frontal appendage is specialized for suspension feeding. The appendage bears long, slender and equally spaced ventral spines furnished with dense rows of long and fine auxiliary spines. This suggests that T. borealis was a microphagous suspension feeder, using its appendages for sweep-net capture of food items down to 0.5 mm, within the size range of mesozooplankton such as copepods. Our observations demonstrate that large, nektonic suspension feeders first evolved during the Cambrian explosion, as part of an adaptive radiation of anomalocarids. The presence of nektonic suspension feeders in the Early Cambrian, together with evidence for a diverse pelagic community containing phytoplankton and mesozooplankton, indicate the existence of a complex pelagic ecosystem supported by high primary productivity and nutrient flux. Cambrian pelagic ecosystems seem to have been more modern than previously believed.
    Nature 03/2014; 507(7493):496-9. DOI:10.1038/nature13010 · 41.46 Impact Factor
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    ABSTRACT: Cycloneuralians form a rich and diverse element within Cambrian assemblages of exceptionally preserved fossils. Most resemble priapulid worms whereas other Cycloneuralia (Nematoda, Nematomorpha, Kinorhyncha, Loricifera), well known at the present day, have little or no fossil record. First reports of Sirilorica Peel, 2010 from the lower Cambrian Sirius Passet fauna of North Greenland described a tubular lorica covering the abdomen and part of a well developed introvert with a circlet of 6 grasping denticles near the lorica. The introvert is now known to terminate in a narrow mouth tube, while a conical anal field is also developed. Broad muscular bands between the plates in the lorica indicate that it was capable of movement by rhythmic expansion and contraction of the lorica. Sirilorica is regarded as a macrobenthic member of the stem-lineage of the miniaturised, interstitial, present day Loricifera. Like loriciferans, Sirilorica is now known to have grown by moulting. Evidence of the life cycle of Sirilorica is described, including a large post-larval stage and probably an initial larva similar to that of the middle Cambrian fossil Orstenoloricusshergoldii.
    PLoS ONE 08/2013; 8(8):e73583. DOI:10.1371/journal.pone.0073583 · 3.23 Impact Factor
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    Martin Stein · Graham E Budd · John S Peel · David At Harper
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    ABSTRACT: Background Exceptionally preserved Palaeozoic faunas have yielded a plethora of trilobite-like arthropods, often referred to as lamellipedians. Among these, Artiopoda is supposed to contain taxa united by a distinctive appendage structure. This includes several well supported groups, Helmetiida, Nektaspida, and Trilobita, as well as a number of problematic taxa. Interrelationships remain unclear, and the position of the lamellipedian arthropods as a whole also remains the subject of debate. Results Arthroaspis bergstroemi n. gen. n. sp., a new arthropod from the early Cambrian Sirius Passet Lagerstätte of North Greenland shows a striking combination of both dorsal and ventral characters of Helmetiida, Nektaspida, and Trilobita. Cladistic analysis with a broad taxon sampling of predominantly early Palaeozoic arthropods yields a monophyletic Lamellipedia as sister taxon to the Crustacea or Tetraconata. Artiopoda is resolved as paraphyletic, giving rise to the Marrellomorpha. Within Lamellipedia, a clade of pygidium bearing taxa is resolved that can be shown to have a broadly helmetiid-like tergite morphology in its ground pattern. This morphology is plesiomorphically retained in Helmetiida and in Arthroaspis, which falls basally into a clade containing Trilobita. The trilobite appendages, though similar to those of other lamellipedians in gross morphology, have a unique outward rotation of the anterior trunk appendages, resulting in a ‘hard wired’ lateral splay, different to that observed in other Lamellipedia. Conclusions The combination of helmetiid, trilobite, and nektaspid characters in Arthroaspis gives important hints concerning character polarisation within the trilobite-like arthropods. The distinctive tergite morphology of trilobites, with its sophisticated articulating devices, is derived from flanged edge-to-edge articulating tergites forming a shield similar to the helmetiids, previously considered autapomorphic for that group. The stereotypical lateral splay of the appendages of lamellipedians is a homoplastic character shown to be achieved by several groups independently.
    BMC Evolutionary Biology 05/2013; 13(1):99. DOI:10.1186/1471-2148-13-99 · 3.37 Impact Factor
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    ABSTRACT: Stein, M., Peel, J.S., Siveter, D.J. & Williams, M. 2009: Isoxys (Arthropoda) with preserved soft anatomy from the Sirius Passet Lagerstätte, lower Cambrian of North Greenland. Lethaia, Vol. 43, pp. 258–265.Isoxys volucris is the most commonly occurring species in the lower Cambrian Sirius Passet Lagerstätte of North Greenland. Newly identified material allows a first, limited, account of the ventral morphology of this species, hitherto known only by the morphology of its shield. The antennula is large and robust, composed of about seven articles armed with spines, and was probably not sensorial. The postantennular limbs are serially similar, biramous with a large paddle-shaped exopod fringed with setae. It is possible that the animal possessed a furca. The inner lamella, lining the ventral surface of the shield is recognised in Isoxys for the first time. Comparisons with other congeneric species of which aspects of the ventral morphology are known, show similarities with Isoxys auritus from China, reconsidered here, but indicate differences in antennular morphology with other species as currently understood. □Cambrian, Greenland, Isoxys, soft anatomy, Sirius Passet, palaeoecology.
    Lethaia 05/2010; 43(2):258 - 265. DOI:10.1111/j.1502-3931.2009.00189.x · 1.45 Impact Factor
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    ABSTRACT: Kiisortoqia soperi gen. et sp. nov. is an arthropod species from the Early Cambrian Sirius Passet Lagerstätte of North Greenland. A head, incorporating four appendiferous segments and biramous limbs, with an anteroposteriorly compressed basipod with a spine bearing median edge, support the euarthropod affinities of K. soperi gen. et sp. nov. Similarities with ‘short great appendage’ arthropods, or megacheirans, like the nine-segmented endopod, and the flap- or paddle-like exopod, may be symplesiomorphies. The antennula, however, resembles in composition and size the anteroventral raptorial appendage of anomalocaridids. Thus, the morphology of K. soperi gen. et sp. nov. provides additional support for the homologization of the anomalocaridid ‘great appendage’ with the appendage of the antennular or deutocerebral segment of extant Euarthropoda.© 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158, 477–500.
    Zoological Journal of the Linnean Society 02/2010; 158(3):477 - 500. DOI:10.1111/j.1096-3642.2009.00562.x · 2.72 Impact Factor
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    John S. Peel · Martin Stein
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    ABSTRACT: Aaveqaspis inesoni gen. et sp. nov., is described from the lower Cambrian Sirius Passet Fossil-Lagerstätte of Peary Land, North Greenland. It has a semicircular head shield and a thorax with 5 tergites. The tail shield carries 2 pairs of spines, the most anterior of which is enormous and dominates the trunk. A. inesoni lacks any preserved trace of eyes, as is also the case with several other Sirius Passet arthropods, suggesting that the fossils accumulated in deeper water than the contemporaneous Chengjiang Fossil-Lagerstätte of China or the middle Cambrian Burgess Shale assemblages of British Columbia.
    Bulletin of Geosciences 12/2009; 84(4). DOI:10.3140/bull.geosci.1158 · 1.52 Impact Factor
  • Linda Lagebro · Martin Stein · John S. Peel
    Journal of Paleontology 09/2009; 83(5):820-825. DOI:10.1666/09-011.1 · 1.28 Impact Factor
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    Martin Stein
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    ABSTRACT: Fossil collections from the lower Cambrian (Cambrian Series 2) Bastion Formation at Albert Heim Bjerge in North-East Greenland acquired during 1950 and 1951 contain some 60 specimens of olenellid trilobites. Although morphologically variable, the material can be attributed to a single species, Fritzolenellus lapworthi (Peach and Horne, 1892), previously known from the 'Fucoid' Beds of north-west Scotland. Immature specimens allow a first, limited, description of the ontogeny of Fritzolenellus. The presence of F. lapworthi in North-East Greenland offers an important tie point for correlation of Olenellus-bearing strata (Cambrian Series 2, Stage 4) across eastern Laurentia.
    Bulletin of the Geological Society of Denmark 12/2008; 56. · 1.44 Impact Factor
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    ABSTRACT: The arthropod Oelandocaris oelandica from the upper Middle Cambrian “Orsten” of Sweden was recently recognized as a member of the early phase of crustacean evolution based on additional morphological detail from new specimens. Here we present a detailed investigation of all available material. It includes the description of a 400 µm long specimen probably representing an early developmental stage. Variation in size correlated with variation of trunk-segment numbers allowed recognition of different instars. The largest specimens do not exceed an estimated length of about 1 mm, indicating that our material may consist only of immature specimens. The characteristic, extremely long antennula of O. oelandica branches into three long rods. It may have served as the major structure to sweep in food, aided by the two subsequent appendages. These and the more posterior limbs were also responsible for locomotion. Minute pores on the outer edges of the posterior limbs and on the trunk tergites possibly contained sensilla originally, which may have served as water-current detectors. The presence of a minute proximal endite only on the third head appendage suggests a rather basal position of this species within Crustacea, because comparable developmental stages of other known stem crustaceans have such an endite on more of their appendages. Reconstruction of O. oelandica and its life attitudes (referred to the largest instar known) benefited from the application of 3D modelling. These helped, e.g., in identifying the combination of the plesiomorphic feeding function of the antennulae and the specialisation of the exopods of the next two appendages as a step toward the development of a sweep-net mode of feeding, one of the key novelties in the evolution of Crustacea. Such a mode of feeding coupled with locomotion of the three anterior appendages is still practiced in the naupliar and metanaupliar phases of many extant eucrustaceans, and even some adults.
    Acta Palaeontologica Polonica 09/2008; 53(3). DOI:10.4202/app.2008.0308 · 1.87 Impact Factor
  • Martin Stein · John S. Peel
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    ABSTRACT: The distinctive trilobite Perissopyge phenax was originally described from the Henson Gletscher Formation (Cambrian Series 2, Stage 4) of central North Greenland and reported from the Sekwi Formation of Yukon Territory, Canada. This latter material is illustrated herein for the first time. Perissopyge phenax is also currently described from the Paralleldal Formation of Peary Land, North Greenland, some 100 km east of the type locality, where overlying strata correlate with the middle-upper Toyonian Stage of Siberia (Cambrian Stage 4). Perissopyge triangulata, from the Harkless Formation (Cambrian Stage 4) of Nevada, is also discussed and tectonic deformation of the type suite is recog- nized. An indeterminate species of Perissopyge is identified in the Ella Island Formation of North-East Greenland. The Ella Island Formation yields Olenellus hanseni, which is possibly synonymous with O. cf. truemani from the Henson Gletscher Formation. Together, these occurrences enhance stratigraphical correlation between central North Greenland and North-East Greenland and suggest some utility for Perissopyge in correlation of the lower half of the Laurentian Cambrian.
    Gff -Uppsala- 06/2008; 130(2-2):71-78. DOI:10.1080/11035890801302071 · 1.31 Impact Factor
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    Dieter Waloszek · Andreas Maas · Junyuan Chen · Martin Stein
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    ABSTRACT: Focusing on structural and functional changes during the evolution of Arthropoda, we based our approach on evidence provided by two major Cambrian lagerstätten yielding exceptional preservation: the Lower Cambrian Chengjiang lagerstätte, Yunnan Province, China, and the Lower to Upper Cambrian ‘Orsten’-type lagerstätten with their 3D-preserved fossils. We established a model of major steps in the evolution of the arthropod feeding system, with emphasis on the head region. Using fossils, we identify two major gaps in our knowledge about this evolutionary process to be filled in the future. One of them is how development progressed from the stem arthropod level toward that of Arthropoda s. str. The latter stage is known now from three Chengjiang taxa, which possess, besides other features, a head composed of only two segments, i.e. those bearing the compound eyes and the limb-shaped antennulae. The post-antennular trunk limbs are very simple and lack any feeding structures, spines or setae. With this, only the antennula could have been involved in food gathering. Another uncertainty concerns the transition from the Arthropoda s. str. level to that of the Euarthropoda. Euarthropoda embraces all those well-sclerotized arthropods with extant descendants, and its ground pattern includes a larger head tagma with four appendage-bearing segments and post-antennular limbs made of a rigid, but flat gnathobasic basipod carrying two rami. At this stage, feeding had become more elaborate than before, yet all post-antennular appendages remained serially designed. Crustacea changed their feeding system initially by modifying the anterior three cephalic appendages, and the mouth area and by developing a specific setation on various body parts. Subsequently, more appendages became involved within certain in-group taxa. Our model elucidates that changes of the functional system occurred at the macroscopic and the microscopic level. Although many allied features, such as the gut system or the appendage morphology, remained remarkably conservative over longer periods, feeding was most likely a significant driving force for evolutionary changes in the morphology of arthropods, particularly of the head region.
    Palaeogeography Palaeoclimatology Palaeoecology 10/2007; 254(1-2-254):273-287. DOI:10.1016/j.palaeo.2007.03.027 · 2.34 Impact Factor
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    ABSTRACT: The large number of soft-part preserved fossils from the Lower Cambrian Maotianshan Shale (Chengjiang) Lagerstätten suggests particularly favourable conditions for a rich life on the shelf-zone sea bottom of the Yangtze Plate, China. This high degree of biodiversity opens an excellent window into the early radiation phase of Metazoa and represents a significant data source for the study of adaptive strategies among early animals. Feeding and locomotion are the main life strategies of organisms we investigated with regard to two major benthic macrofaunal components of the Maotianshan Shale biota, the nemathelminths and the arthropods. Our attempt was to test whether food, feeding and locomotory strategies of the benthic Lower Cambrian shallow-water communities were as diversified as it appears from the morphological diversity of the organisms present. Two major types of feeders can be discerned: suspension/micro-particle feeders – mostly epibenthic sedentary taxa – and larger-particle feeders, living in benthic to bentho-pelagic realms. Scant evidence exists for exclusive vegetarians, fungi eaters, biomat utilizers and for in-faunal vertical burrowers or grazers (bioturbators). Predation, in a wider sense, seems to be a, if not the, major feeding mode among metazoans. Nemathelminths and arthropods are amongst the best examples. In the benthic shallow-water regime, as exposed by the Maotianshan Shale biota, animals and their ontogenetic stages were the most suitable and readily available food source. At least for arthropods, we propose that improvement of predatory strategies was paralleled by the enhancement of locomotory and food manipulation structures. Accumulating evidence of late Precambrian to Early Cambrian metazoans exposing diverse morphologies and life styles indicates that, on the large scale, phylogenesis progressed gradually in the Late Precambrian. This renders an “explosive” radiation of Metazoa unlikely.
    Palaeogeography Palaeoclimatology Palaeoecology 10/2007; 254(1-2-254):250-272. DOI:10.1016/j.palaeo.2007.03.018 · 2.34 Impact Factor
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    ABSTRACT: In several areas of southern Sweden, limestone nodules, locally called Orsten occur within bituminous alum shales. These shales and nodules were deposited under dysoxic conditions at the bottom of what was most likely a shallow sea during the late Middle to Upper Cambrian (ca. 500 million years ago). Subsequently, the name ‘Orsten’ has been referred to particular, mainly arthropod, fossils from such nodules, and, in a wider sense, to the specific type of preservation of minute fossil through secondarily phosphatization. This preservation is exceptional in yielding uncompacted and diagenetically undeformed three-dimensional fossils. ‘Orsten’-type preservation resulted from incrustation of a thin external layer and also by impregnation by calcium phosphate and, therefore, mineralization of the surface of the former animals during early diagenesis. Primarily, this type of preservation seems to have affected only cuticle-bearing metazoans such as cycloneuralian nemathelminths and arthropods. ‘Orsten’ preservation in this sense seems to be limited by size, in having yielded no partial or complete animals larger than 2mm. On the other end of the scale, even larvae 100μm long are preserved, often more complete than larger specimens, and details such as setules and pores smaller than 1μm can be observed. Fossils preserved in such a manner are almost exclusively hollow carcasses, but can be filled secondarily; less common are completely phosphatized compact specimens. The high quality of preservation makes the Swedish ‘Orsten’ a typical Konservat-Lagerstätte. Yet, its special type of preservation is more widespread in time and geographical distribution than assumed initially, and the origin of the phosphate is not necessarily restricted just to one source. Subsequent to the first discoveries of limb fragments of Cambrian arthropods in 1975, animals in this special preservational type have been discovered in several continents and across a broad stratigraphic range including even Proterozoic strata. The latter have yielded early cleavage and metazoan embryonic stages, expanding knowledge on the preservational capacities of the ‘Orsten’. Here, we report the recent status of our research on the ‘Orsten’ and give perspectives for future exploration on a worldwide scale, particularly in light of a recently formed international research group named Center of Orsten Research and Exploration (C.O.R.E.).
    Palaeoworld 08/2006; 15(3):266-282. DOI:10.1016/j.palwor.2006.10.005

Publication Stats

280 Citations
64.32 Total Impact Points


  • 2014
    • IT University of Copenhagen
      København, Capital Region, Denmark
  • 2013
    • Naturhistorisk Museum - Aarhus
      Års, North Denmark, Denmark
  • 2006–2010
    • Uppsala University
      • Department of Earth Sciences
      Uppsala, Uppsala, Sweden
  • 2008
    • Universität Ulm
      • Institute of Biosystematic Documentation
      Ulm, Baden-Wuerttemberg, Germany