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Tytuł:
Phosphatised olenid trilobites and associated fauna from the Upper Cambrian of Vastergotland, Sweden
Autorzy:
Ahlberg, P
Szaniawski, H.
Clarkson, E.N.K.
Bengtson, S.
Powiązania:
https://bibliotekanauki.pl/articles/19975.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
trilobite
Trilobita
Vastergotland
Olenidae
Sweden
Upper Cambrian
Cambrian
phosphatization
paleontology
Opis:
Secondarily phosphatised olenid trilobites from organic−rich limestones (orsten) in the Furongian (Upper Cambrian) of Västergötland, south−central Sweden, are described and illustrated. All trilobites originate from the Peltura scarabaeoides Zone and were collected on the western slope of Kinnekulle. Only the dorsal exoskeletons have become secondarily phosphatised, and the ventral appendages are not preserved. Yet the material is otherwise remarkably well preserved and reveals the morphology of the olenid trilobites in greater detail than hitherto known. Species belonging to the genera Ctenopyge, Sphaerophthalmus, Parabolina, and Peltura are identified, and several juvenile specimens are present in the material. The material is disarticulated and fragmentary, and it has only been possible to identify a few specimens to species level. In addition to chaetognaths and conodonts, the trilobites are associated with pelmatozoan columnals, a possible camaroid, and fossils of uncertain affinities. These fossils, along with a probable conulariid fragment from the Peltura minor Zone, are also described and discussed. The presence of a benthic fauna of pelmatozoans, and possible conulariids and camaroids, indicates that at least parts of the Peltura zones were deposited during dysoxic rather than anoxic periods. Moreover, the sea floor must have been firm enough to allow colonisation by sessile organisms.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Upper Cambrian trilobite biostratigraphy and taphonomy at Kakeled on Kinnekulle, Vastergotland, Sweden
Autorzy:
Terfelt, F
Powiązania:
https://bibliotekanauki.pl/articles/20589.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
depositional environment
trilobite
Trilobita
Sweden
Upper Cambrian
biostratigraphy
Cambrian
paleontology
Opis:
A section through the Upper Cambrian black shales and limestones at Kakeled on Kinnekulle, Västergötland, Sweden, extends from the lower–middle part of the Agnostus pisiformis Zone into the Peltura scarabaeoides Zone. Fossils are usually preserved only in the stinkstones, but in the A. pisiformis Zone trilobites can be found also in the shales. Lithologically, the stinkstones can be subdivided into primary coquinoid limestone, which include the majority of the fossils, and early diagenetically formed limestone. The orientation of cephala and pygidia of A. pisiformis were measured on four shale surfaces and one stinkstone surface. The majority of the shields were deposited with the convex side up and showed a preferred orientation, suggesting that their positions were affected by currents. Above the A. pisiformis Zone the section comprises the Olenus/Homagnostus obesus Zone (0.30 m), the upper part of the Parabolina spinulosa Zone (0.05 m), the Peltura minor Zone (1.15 m), and the Peltura scarabaeoides Zone (2.50 m). The Leptoplastus and Protopeltura praecursor zones are missing. The Olenus/H. obesus Zone is represented only by the O. gibbosus and O. wahlenbergi subzones, whereas the O. truncatus, O. attenuatus, O. dentatus, and O. scanicus subzones are missing.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The lobopod Onychodictyon from the Lower Cambrian Chengjiang Lagerstatte revisited
Autorzy:
Liu, J
Shu, D.
Han, J.
Zhang, Z.
Zhang, X.
Powiązania:
https://bibliotekanauki.pl/articles/21235.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Yunnan
antenna
paleontology
Chengjiang Lagerstatte
Lobopodia
Arthropoda
lobopod
Cambrian
Lower Cambrian
Opis:
Onychodictyon ferox, from the Lower Cambrian Chengjiang Lagerstätte, is a worm−like armored lobopod with 10 pairs of dorsal plates and a pair of probable sensory appendages (“antennae”). Newly discovered complete specimens show that Onychodictyon is represented by two species: O. ferox with a “head” bearing a pair of dorsal “antennae” and a trunk with 11 pairs of limbs, whereas O. gracilis has a blunt anterior end without any appendages and a trunk with 12 pairs of limbs. Because of the close resemblance of the “antennae” of O. ferox and those of the lobopod Miraluolishania, they are considered to be homologous structures. The “antennae” of Cambrian lobopodians are proposed to be homologous with the arthropod antennulae.
Źródło:
Acta Palaeontologica Polonica; 2008, 53, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cambrian microfossils from glacial erratics of King George Island, Antarctica
Autorzy:
Wrona, R
Powiązania:
https://bibliotekanauki.pl/articles/22565.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
skeletal fossil
Antarctic
Australia
Middle Cambrian
Early Cambrian
microfossil
Cape Melville Formation
Cambrian
paleontology
Early Miocene
King George Island
Opis:
Limestone erratics in the Early Miocene glacio−marine Cape Melville Formation of King George Island, West Antarctica, have yielded Early and Middle Cambrian small skeletal fossils (SSF) accompanied by calcified cyanobacteria, archaeocyath and spiculate sponges, trilobites and echinoderms. The SSF assemblage comprises disarticulated sclerites of chancelloriids, halkieriids, tommotiids, lapworthellids, palaeoscolecids, hyolithelminths, lingulate brachiopods, helcionelloid molluscs, hyoliths, and bradoriids. All 24 described species are common to Antarctica and Australia. Most are recorded here from Antarctica for the first time, including Shetlandia multiplicata gen. et sp. nov. and two new species Byronia? bifida and Hadimopanella staurata. The lithological and fossil contents of the boulders are almost identical with autochthonous assemblages from the Shackleton Limestone in the Argentina Range and Transantarctic Mountains. Cambrian outcrops around the Weddell Sea are a plausible source of the erratics. The fauna is closely similar to that from the uppermost Botomian Wilkawillina Limestone in the Flinders Ranges and Parara Limestone on Yorke Peninsula, and Toyonian Wirrealpa and Aroona Creek Limestones in the Flinders Ranges, as well as the Ramsay Limestone on Yorke Peninsula, all in the Arrowie and Stansbury Basins of South Australia. These very similar faunal and facies successions for Antarctica and Australia strongly support their common biotic and sedimentary evolution on the same margin of a greater Gondwana supercontinent throughout the Early Cambrian.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trunk ornament on the palaeoscolecid worms Cricocosmia and Tabelliscolex from the Early Cambrian Chengjiang deposits of China
Autorzy:
Han, J
Liu, J.
Zhang, Z.
Zhang, X.
Shu, D.
Powiązania:
https://bibliotekanauki.pl/articles/23260.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Tabelliscolex hexagonus
Palaeoscolecida
Priapulida
Chengjiang deposit
Cricocosmia jinningensis
trunk ornament
fossil worm
China
Early Cambrian
Cambrian
Lower Cambrian
paleontology
Opis:
Cricocosmia jinningensis, one of the most abundant palaeoscolecid worms from the Lower Cambrian Chengjiang deposits of south China, was originally described as bearing double longitudinal rows of lateral conical sclerites on the trunk. New observation reveals that the ventral trunk bears an additional set of ventral sclerites while the lateral sclerites display a tubercle−bearing (inner surface) and net−like (outer surface) microstructure similar to that of Tabelliscolex hexagonus. These findings mean that: (1) Cricocosmia shows a dorso−ventral and antero−posterior differentiation in trunk ornament; (2) as seen from the microstructure, Cricocosmia is close to Tabelliscolex hexagonus, supporting the idea that lobopodians and arthropods, both of which show an upper capping layer in the outer sclerites, are more closely related than the palaeoscolecidans; and (3) the similarities among the scalids, pharyngeal teeth and the trunk spines of palaeoscolecidans are superficial. Tabelliscolex maanshanensis sp. nov., characterized by an inner concentric circlet of laminae in each tubercle of the lateral trunk plate, is proposed herein. Element mapping reveal that four known pathways of preservation can be found co−occurring in a single specimen of Cricocosmia or Tabelliscolex, which sheds new light on the preservation of the Chengjiang fossils.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Early Cambrian origin of thylacocephalan arthropods
Autorzy:
Vannier, J
Chen, J.Y.
Huang, D.Y.
Charbonnier, S.
Wang, X.Q.
Powiązania:
https://bibliotekanauki.pl/articles/23320.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
fauna
thylacocephalan arthropod
Lagerstatte
Zhenghecaris shankouensis
China
arthropod
Arthropoda
Early Cambrian
Cambrian
paleontology
Opis:
Zhenghecaris shankouensis gen. et sp. nov. is one of the largest “bivalved” arthropods of the Lower Cambrian Maotianshan Shale fauna. Its non−mineralized carapace was dome−like, laterally compressed, armed with rostral features, and probably enclosed the entire body of the animal. Zhenghecaris was provided with elliptical stalked lateral eyes. The carapace design, external ornament and visual organs of Zhenghecaris suggest affinities with the Thylacocephala, an extinct (Lower Silurian to Upper Cretaceous) group of enigmatic arthropods whose origins remain poorly understood. The bivalved arthropodsIsoxys and Tuzoia (Lower and Middle Cambrian) are two other potential thylacocephalan candidates making this group of arthropods a possible new component of Cambrian marine communities. Zhenghecaris, Isoxys, and Tuzoia are interpreted as nektonic animals that probably inhabited the lower level of the water column in shallow shelf settings at depths of perhaps 100–150 m or less. Their feeding mode either in the water column (e.g., mesozooplankton) or on the substrate (e.g., small epibenthos, detritus) is uncertain, although some of these arthropods were possibly mid−water predators (e.g., Isoxys with raptorial appendages).
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The fine structure of zooidal tubes in Sabelliditida and Pogonophora with reference to their affinity
Ultrastruktura szkieletu Sabelliditida i Pogonophora oraz problem ich związków filogenetycznych
Ul’trastruktura trubok Sabelliditida i Pogonophora i problema ikh filogeneticheskikh svjazejj
Autorzy:
Urbanek, A.
Mierzejewska, G.
Powiązania:
https://bibliotekanauki.pl/articles/21125.pdf
Data publikacji:
1977
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
ultrastructure
zooidal tube
tube wall
Sabelliditida
Pogonophora
morphology
fauna
paleontology
Lower Cambrian
Cambrian
Źródło:
Acta Palaeontologica Polonica; 1977, 22, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Candle wax shells, morphodynamics, and the Cambrian explosion
Autorzy:
Seilacher, A
Powiązania:
https://bibliotekanauki.pl/articles/20029.pdf
Data publikacji:
1993
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
stratigraphy
paleobiology
sedimentology
Cambrian
paleontology
Źródło:
Acta Palaeontologica Polonica; 1993, 38, 3-4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shell microstructures in Early Cambrian molluscs
Autorzy:
Kouchinsky, A
Powiązania:
https://bibliotekanauki.pl/articles/23294.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
skeletal fossil
microstructure
shell
biomineralization
mollusc
Early Cambrian
mollusc-like organism
taxonomy
Cambrian
paleontology
Opis:
The affinities of a considerable part of the earliest skeletal fossils are problematical, but investigation of their microstructures may be useful for understanding biomineralization mechanisms in early metazoans and helpful for their taxonomy. The skeletons of Early Cambrian mollusc-like organisms increased by marginal secretion of new growth lamellae or sclerites, the recognized basal elements of which were fibers of apparently aragonite. The juvenile part of some composite shells consisted of needle-like sclerites; the adult part was built of hollow leaf-like sclerites. A layer of mineralized prism-like units (low aragonitic prisms or flattened spherulites) surrounded by an organic matrix possibly existed in most of the shells with continuous walls. The distribution of initial points of the prism-like units on a periostracurn-like sheet and their growth rate were mostly regular. The units may be replicated on the surface of internal molds as shallow concave polygons, which may contain a more or less well-expressed tubercle in their center. Tubercles are often not enclosed in concave polygons and may co-occur with other types of textures. Convex polygons seem to have resulted from decalcification of prism-like units. They do not co-occur with tubercles. The latter are interpreted as casts of pore channels in the wall possibly playing a role in biomineralization or pits serving as attachment sites of groups of mantle cells. Casts of fibers and/or lamellar units may overlap a polygonal texture or occur without it. They may reflect an inner layer consisting of aragonitic fibers fused into more or less well-developed lamellar units. It seems that nacreous and crossed-lamellar aragonitic microstructures evolved in the Cambrian from such lamellar aragonitic microstructures independently in different groups of molluscs.
Źródło:
Acta Palaeontologica Polonica; 2000, 45, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Burgess Shale-type microfossils from the middle Cambrian Kaili Formation, Guizhou Province, China
Autorzy:
Harvey, T.H.P.
Ortega-Hernandez, J.
Lin, J.-P.
Yuanlong, Z.
Butterfield, N.J.
Powiązania:
https://bibliotekanauki.pl/articles/23425.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
microfossil
Middle Cambrian
Cambrian
Kaili Formation
Guizhou province
China
Priapulida
acritarch
palynology
taphonomy
Opis:
Diverse carbonaceous microfossils, including exceptionally preserved remains of non−biomineralizing metazoans, are reported from a basal middle Cambrian interval of the Kaili Formation (Guizhou Province, China). The application of a gentle acid maceration technique complements previous palynological studies by revealing a larger size−class of acritarchs, a richer assemblage of filamentous microfossils, and a variety of previously unrecovered forms. Metazoan fossils include Wiwaxia sclerites and elements derived from biomineralizing taxa, including chancelloriids, brachiopods and hyolithids, in common with previously studied assemblages from the early and middle Cambrian of Canada. In addition, the Kaili Formation has yielded pterobranch remains and an assemblage of cuticle fragments representing “soft−bodied” worms, including a priapulid−like scalidophoran. Our results demonstrate the wide distribution and palaeobiological importance of microscopic “Burgess Shale−type” fossils, and provide insights into the limitations and potential of this largely untapped preservational mode.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Upper Cambrian trilobite ichnocoenosis from Wielka Wisniowka (Holy Cross Mountains, Poland)
Górnokambryjska ichnocenoza trylobitowa z Wielkiej Wiśniówki w Górach Świetokrzyskich
Verkhne-kembrijjskijj trilobitovyjj ikhnocenoz iz Vel'kojj Vis'njuvki v Sventokrzhiskikh Gorakh (Pol'sha)
Autorzy:
Radwanski, A.
Roniewicz, P.
Powiązania:
https://bibliotekanauki.pl/articles/21862.pdf
Data publikacji:
1963
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Cambrian
Upper Cambrian
trilobite
ichnocoenosis
fauna community
deposit
Wisniowka Wielka village
Holy Cross Mountains
Polska
Źródło:
Acta Palaeontologica Polonica; 1963, 08, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Cambrian acritarch Lusatia: Taxonomy, palaeogeography, and biostratigraphic implications
Autorzy:
Albani, R.
Bagnoli, G.
Ribecai, C.
Raevskaya, E.
Powiązania:
https://bibliotekanauki.pl/articles/21158.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Acritarcha
Cambrian
Furongian
Late Cambrian
Lusatia
acritarch
biostratigraphy
marine phytoplankton
paleogeography
paleontology
taxonomy
phytoplankton
systematics
distribution
Opis:
Intraspecific variability of the herein emended diacrodian acritarch Lusatia dendroidea is described based on late Cambrian (Furongian) well preserved material from Spain, the High Arctic of Russia, and the East−European Platform. L. dendroidea, displays bipolar asymmetric morphology and, as originally defined, consists of three long major processes originating from the “corners” of its vesicle. Specimens with one, two and four major processes are considered to represent morphological variations of the most common three process form. Based on its narrow stratigraphic range, widespread palaeogeographic distribution, and distinctive morphology, L. dendroidea is an excellent guide fossil for the Furongian.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Soft-part preservation in two species of the arthropod Isoxys from the middle Cambrian Burgess Shale of British Columbia, Canada
Autorzy:
Garcia-Bellido, D.C.
Vannier, J.
Collins, D.
Powiązania:
https://bibliotekanauki.pl/articles/20887.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
arthropod
Isoxys
Middle Cambrian
Cambrian
Burgess Shale
British Columbia
Canada
Arthropoda
Isoxys acutangulus
Isoxys longissimus
paleontology
fossil
Opis:
More than forty specimens from the middle Cambrian Burgess Shale reveal the detailed anatomy of Isoxys, a worldwide distributed bivalved arthropod represented here by two species, namely Isoxys acutangulus and Isoxys longissimus. I. acutangulus had a non−mineralized headshield with lateral pleural folds (= “valves” of previous authors) that covered the animal’s body almost entirely, large frontal spherical eyes and a pair of uniramous prehensile appendages bearing stout spiny outgrowths along their anterior margins. The 13 following appendages had a uniform biramous design—i.e., a short endopod and a paddle−like exopod fringed with marginal setae with a probable natatory function. The trunk ended with a flap−like telson that protruded beyond the posterior margin of the headshield. The gut of I. acutangulus was tube−like, running from mouth to telson, and was flanked with numerous 3D−preserved bulbous, paired features interpreted as digestive glands. The appendage design of I. acutangulus indicates that the animal was a swimmer and a visual predator living off−bottom. The general anatomy of Isoxys longissimus was similar to that of I. acutangulus although less information is available on the exact shape of its appendages and visual organs. I. longissimus is characterized by extremely long anterior and posterior spines. There are now seven Isoxys species known with soft−part preservation, I. acutangulus, I. longissimus from the Burgess Shale, I. auritus and I. curvirostratus from the Maotianshan Shale of China, I. communis and I. glaessneri from the Emu Bay Shale of Australia and I. volucrisfrom Sirius Passet in Greenland. The frontal appendages of Isoxys strongly resemble those of other Cambrian arthropods, characterized by a single pair of “great appendages” with a shared prehensile function yet some variability in length and shape.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fossil chaetognaths from the Burgess Shale: A reply to Conway Morris [2009]
Autorzy:
Szaniawski, H
Powiązania:
https://bibliotekanauki.pl/articles/21244.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
chaetognath
fossil
new genus
new species
Middle Cambrian
Chaetognatha
Oesia disjuncta
polychaete annelid
Cambrian
Amiskwia sagittiformis
Opis:
Walcott (1911) erected the new genus and species Oesia disjuncta and assigned them to the polychaete annelids, based on a small collection of similar fossils from the famous Middle Cambrian Burgess Shale. In 2002 I suggested that the species is “possibly related to chaetognaths” (Szaniawski 2002: 405). Later, after obtaining new photos of the specimens and making comparative investigations with the extant chaetognaths, I was able to describe many significant similarities, and came to the conclusion that O. disjuncta indeed is an ancestral chaetognath (Szaniawski 2005). This interpretation already has been accepted in several publications (Vannier et al. 2005; Ball and Miller 2006; Hu et al. 2007. Giribet 2008). Ball and Miller (2006: 594) confirmed not only its “... remarkable resemblance to modern chaetognaths” but also correctness of recognition of all its organs. They even reproduced a part of my illustration showing them (Ball and Miller 2006: fig. 2). Vannier et al. (2006: 629) combined the problem with the open question of the systematic position of another Burgess Shale fossil Amiskwia sagittiformis Walcott, 1911, and expressed their reservation based on “...the lack of clear evidence of a grasping apparatus...”. Only Conway Morris (2009) firmly disagreed with this diagnosis and even devoted a special “discussion” article addressing the issue. However, that article contains several ambiguities and misunderstandings which need clarification.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 2; 361-364
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trachyplax arctica, a new multiplated problematic fossil from the Lower Cambrian of North Greenland
Autorzy:
Larsson, C M
Peel, J.S.
Hogstrom, A.E.S.
Powiązania:
https://bibliotekanauki.pl/articles/20953.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Trachyplax arctica
fossil
paleontology
Lower Cambrian
Cambrian
North Greenland
Greenland
Trachyplax
Problematica
sclerite
scleritome
Multiplacophora
Paralledal Formation
Opis:
A new scleritome−bearing organism with eight sclerite types, Trachyplax arctica gen. et sp. nov., is described from the lower Cambrian Paralledal Formation of North Greenland. The originally calcareous sclerites are now silicified; no microstructures are preserved. The dominant sclerite type (A; maximum dimension 19.3 mm) is bilaterally symmetrical, strongly arched, with an oval shield showing co−marginal growth lines and a projecting rostrum with prominent radial ornamentation. A similar sclerite morphology can be identified in Silurian–Carboniferous multiplacophoran molluscs but the remaining sclerite types, which also display a combination of concentric and radial ornamentation, find no clear equivalents. Two models for scleritome reconstruction are presented, based on the relative abundance of the sclerites, but neither promotes a satisfactory assignment to a higher taxon. Despite the morphological dissimilarities, possibly reflecting the age discrepancy, reference to the Multiplacophora is most attractive and entails a substantial extension of the known geological range of that group.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 3; 513-523
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
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