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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
Tytuł:
Hypsodonty in the Pleistocene ground sloth Megalonyx: Closing the 'diastema' of data
Autorzy:
Fields, S E
Powiązania:
https://bibliotekanauki.pl/articles/22782.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
sloth
paleontology
hypsodonty
Pleistocene
Megalonyx
statistical analysis
ground sloth
Opis:
Hypsodonty in Pleistocene ground sloths was reported by Bargo et al. (2006), but no data was provided for megalonychids. Herein, hypsodonty indices (HI) are presented for 22 Megalonyx specimens (mean = 1.06, SD = 0.10), and statistical analysis suggests that there were no significant changes in HI during the ontogeny or phylogeny of the genus during the Pleistocene.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 1; 155-158
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new short-bodied salamander from the Upper Jurassic-Lower Cretaceous of China
Autorzy:
Wang, Y
Evans, S.E.
Powiązania:
https://bibliotekanauki.pl/articles/20232.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Lower Cretaceous
Cretaceous
China
Upper Jurassic
Pangerpeton sinensis
deposit
Jurassic
salamander
paleontology
Opis:
Abundant well−preserved salamander fossils have recently been recovered from localities across northeastern China. Pangerpeton sinensis gen. et sp. nov. is represented by a nearly complete skeletal impression of a postmetamorphosed salamander from the Late Jurassic/Early Cretaceous locality of Wubaiding, Liaoning Province. It is characterised by a short wide skull and only 14 presacral vertebrae. Associated soft tissue impressions suggest a warty skin and a broad body outline. Phylogenetic analysis indicates a basal position within Caudata, either just within or just outside crown−group Urodela.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The scapulocoracoid of an Early Triassic stem-frog from Poland
Autorzy:
Borsuk-Bialynicka, M
Evans, S.E.
Powiązania:
https://bibliotekanauki.pl/articles/20856.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
scapulocoracoid
Triassic
Polska
pectoral girdle
Anura
Triadobatrachus
stem-frog
Salientia
Early Triassic
paleontology
Czatkowice
Opis:
The scapulocoracoid of Czatkobatrachus polonicus Evans and Borsuk−Białynicka, 1998, a stem−frog from the Early Triassic karst locality of Czatkowice (Southern Poland), is described. The overall type of scapulocoracoid is plesiomorphic, but the subcircular shape and laterally oriented glenoid is considered synapomorphic of Salientia. The supraglenoid foramen is considered homologous to the scapular cleft of the Anura. In Czatkobatrachus, the supraglenoid foramen occupies an intermediate position between that of the early tetrapod foramen and the scapular cleft of Anura. The cleft scapula is probably synapomorphic for the Anura. In early salientian phylogeny, the shift in position of the supraglenoid foramen may have been associated with an anterior rotation of the forelimb. This change in position of the forelimb may reflect an evolutionary shift from a mainly locomotory function to static functions (support, balance, eventually shock−absorption). Laterally extended limbs may have been more effective than posterolateral ones in absorbing landing stresses, until the specialised shock−absorption pectoral mechanism of crown−group Anura had developed. The glenoid shape and position, and the slender scapular blade, of Czatkobatrachus, in combination with the well−ossified joint surfaces on the humerus and ulna, all support a primarily terrestrial rather than aquatic mode of life. The new Polish material also permits clarification of the pectoral anatomy of the contemporaneous Madagascan genus Triadobatrachus.
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Volgian and Santonian–Campanian radiolarian events of the Russian Arctic and Pacific Rim
Autorzy:
Vishnevskaya, V.S.
Kozlova, G.E.
Powiązania:
https://bibliotekanauki.pl/articles/23102.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Volgian
Santonian
Campanian
radiolarian event
Russian Arctic
Pacific Rim
Radiolaria
Cretaceous
paleontology
Opis:
Radiolarians are widely distributed in two siliceous intervals that coincide with the Tithonian–Berriasian and Santonian–Campanian boundaries in the Mesozoic of the Russian Arctic and Pacific Rim. The first level is rich in organic matter and typical of Jurassic–Cretaceous boundary strata from the Russian North European Margin (Barents−Pechora, Volga−Urals, and Siberian hydrocarbon provinces, as well as western Kamchatka). Abundant and diverse representatives of the family Parvicingulidae provide a basis for establishing the new genus Spinicingula (uppermost Middle Volgian–Lower Berriasian); another new genus, Quasicrolanium (Upper Volgian–Upper Berriasian) is also described. A Santonian– Campanian siliceous interval with radiolarians is documented from the margins of northern Asia (eastern Polar Ural, Kara Basin, Kamchatka). The Boreal genus Prunobrachium makes its first appearance at the Santonian–Campanian boundary and reaches an acme in Campanian strata. Radiolarian data can be used for basin biostratigraphy and correlation, as well as palaeogeographical interpretation of these hydrocarbon−rich facies. The Arctic and northern Pacific rims are well correlated on the basis of parvicingulids, while in Sakhalin these are absent and calibrations are based on Unitary Associations zones of the Tethys. In addition to the two new genera noted above, five new species (Parvicingula alata, Parvicingula papulata, Spinicingula ceratina, Lithostrobus borealis, and Spongurus arcticus) are erected, while 60 radiolarian species typical of the Russian Arctic and Pacific rims are illustrated.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Middle Cambrian gogiid echinoderms from Northeast Spain: Taxonomy, palaeoecology, and palaeogeographic implications
Autorzy:
Zamora, S
Gozalo, R.
Linan, E.
Powiązania:
https://bibliotekanauki.pl/articles/21902.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Middle Cambrian
gogiid echinoderm
Spain
taxonomy
paleoecology
paleogeography
Gogia parsleyi
echinoderm assemblage
Echinodermata
Murero Formation
Eocrinoidea
Gogia
Gogiida
Opis:
Gogia parsleyi Zamora sp. nov. and Gogia sp. are described from two different echinoderm assemblages, both from the middle Cambrian of the Murero Formation (Iberian Chains, NE Spain). Gogia parsleyi is reconstructed and described on the basis of fifteen complete or partial specimens and numerous isolated plates. It is characterised by spiralled brachioles, simple epispires, sometimes covered by stereomic domes or tiny cover plates, and by thecal plates arranged in subregular circlets. This gogiid population comprises juveniles, advanced juveniles and mature individuals. The material was found in the upper part of the Murero Formation (upper Caesaraugustian–lower Languedocian). Gogia sp. is represented by two almost complete specimens and several isolated plates from the lower part of the Murero Formation (lower Caesaraugustian). The genus Gogia was first described in Western Gondwana from the Languedocian (upper middle Cambrian) of France, but the material from Spain is older and represents the oldest record of this genus in Gondwana, suggesting an early migration from Laurentia. The gogiids are well preserved in two echinoderm Lagerstätten, which, together with other echinoderms, comprise the majority of the fossil fauna. Both levels are derived from obrution deposits produced in calm and open marine conditions, sometimes affected by sporadic storms. Their holdfast morphology suggests that these gogiids were low−tier suspension feeders, living attached to trilobite fragments in a soft, muddy environment.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 2; 253-265
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A basal archosauriform from the Early Triassic of Poland
Autorzy:
Borsuk-Bialynicka, M
Evans, S.E.
Powiązania:
https://bibliotekanauki.pl/articles/22940.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Osmolskina czatkowiensis
Polska
bone
Middle Triassic
Early Triassic
Czatkowice
basal archosauriform
geographic distribution
Early Olenekian
Archosauriformes
deposit
distribution
paleontology
Opis:
Basal Archosauriformes had a wide geographic distribution through the Lower to Middle Triassic. Osmolskina czatkowiensis gen. et sp. nov. from Early Olenekian karst deposits at Czatkowice, west of Cracow, provides the first record from Poland. The reconstructed skull and attributed postcranial elements show a morphology closely resembling that of the Early Anisian African genus Euparkeria Broom, 1913, while differing at generic level. Both genera display the same mosaic of plesiomorphic and apomorphic character states, but share no unique apomorphic character state. They might thus be combined in the family Euparkeriidae Huene, 1920, but could also constitute two plesions of the same grade lying just below the Archosauria + Proterochampsidae node. Currently, Euparkeriidae remains monotypic because no other genus can be assigned to it with confidence. Until this problem is resolved, the term “euparkeriid” essentially denotes a grade of Lower to Middle Triassic non−archosaurian archosauriforms that are more derived than proterosuchid grade taxa, but lack the specializations of either erythrosuchids or proterochampsids. They were probably Pangaean in their distribution.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New lizards and rhynchocephalians from the Lower Cretaceous of Southern Italy
Autorzy:
Evans, S E
Raia, P.
Barbera, C.
Powiązania:
https://bibliotekanauki.pl/articles/20920.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
predation
Italy
Cretaceous
Rhynchocephalia
Squamata
new lizard
Lepidosauria
lizard
paleobiogeography
paleontology
Opis:
The Lower Cretaceous (Albian age) locality of Pietraroia, near Benevento in southern Italy, has yielded a diverse assemblage of fossil vertebrates, including at least one genus of rhynchocephalian (Derasmosaurus) and two named lizards (Costasaurus and Chometokadmon), as well as the exquisitely preserved small dinosaur, Scipionyx. Here we describe material pertaining to a new species of the fossil lizard genus Eichstaettisaurus (E. gouldi sp. nov.). Eichstaettisaurus was first recorded from the Upper Jurassic (Tithonian age) Solnhofen Limestones of Germany, and more recently from the basal Cretaceous (Berriasian) of Montsec, Spain. The new Italian specimen provides a significant extension to the temporal range of Eichstaettisaurus while supporting the hypothesis that the Pietraroia assemblage may represent a relictual island fauna. The postcranial morphology of the new eichstaettisaur suggests it was predominantly ground−living. Further skull material of E. gouldi sp. nov. was identified within the abdominal cavity of a second new lepidosaurian skeleton from the same locality. This second partial skeleton is almost certainly rhynchocephalian, based primarily on foot and pelvic structure, but it is not Derasmosaurus and cannot be accommodated within any known genus due to the unusual morphology of the tail vertebrae.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On a small Cochleosaurus described as a large Limnogyrinus [Amphibia, Temnospondyli] from the Upper Carboniferous of the Czech Republic
Autorzy:
Milner, A R
Sequeira, S.E.K.
Powiązania:
https://bibliotekanauki.pl/articles/21039.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Carboniferous
Temnospondyli
Limnogyrinus
Czech Republic
Amphibia
Limnogyrinus elegans
Cochleosaurus
paleontology
Upper Carboniferous
Opis:
Limnogyrinus elegans (Fritsch) is the most primitive micromelerpetontid temnospondyl from the Upper Carboniferous of Nýřany, Czech Republic. Arecent revision of the taxon by Werneburg (1994) attributed to this species a skull in dorsal aspect which was significantly larger than any previously reported and showed evidence of snout elongation. Restudy of this specimen demonstrates it to be a skull, visible in ventral aspect, of a juvenile of Cochleosaurus bohemicus, a more primitive edopoid temnospondyl, which is frequent in the Nýřany assemblage. Werneburg’s diagnosis of Limnogyrinusis revised and the problems of constructing ontogenetic series are discussed.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Revision of the amphibian genus Limnerpeton [Temnospondyli] from the Upper Carboniferous of the Czech Republic
Autorzy:
Milner, A R
Sequeira, S.E.K.
Powiązania:
https://bibliotekanauki.pl/articles/22128.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Temnospondyli
Carboniferous
Amphibia
Czech Republic
amphibian
Limnerpeton
paleontology
Dissorophoidea
Upper Carboniferous
Opis:
The Late Carboniferous amphibian genus Limnerpeton Fritsch, 1881 is revised on the basis of the type specimens of the eight original species described by Fritsch using material from Nýřany, Třemošná and Kounov, now in the Czech Republic. The type species Limnerpeton modestum is a nomen dubium restricted to a mandible that almost certainly belongs to an amphibamid temnospondyl but is not critically diagnostic. “Limnerpeton” laticeps and “Limnerpeton” macrolepis lectotypes are both small individuals of the same taxon as the later described Mordex calliprepes Steen, 1938 and thus form part of the hypodigm of Mordex laticeps comb. nov. “Limnerpeton” elegans is now Limnogyrinus elegans and is a member of the temnospondyl family Micromelerpetontidae. “Limnerpeton” obtusatum is a specimen of the microsaur Microbrachis pelikani. “Limnerpeton” dubium is an indeterminate tetrapod, probably either a temnospondyl or a pelycosaur. “Limnerpeton” difficile is a nomen dubium but the type is probably a small specimen of the tuditanomorph microsaur Crinodon limnophyes. “Limnerpeton” caducum is almost certainly a specimen of the ophiderpetontid aïstopod Oestocephalus granulosus. Several other described small temnospondyls from Nýřany are discussed and shown to be specimens of either Limnogyrinus elegans, Mordex laticeps or Amphibamidae incertae sedis. The tetrapod fauna at Nýřany includes four dissorophoid temnospondyls as proposed by Milner (1986) but with two changes in nomenclature. They comprise the branchiosaurid Branchiosaurus salamandroides, the micromelerpetontid Limnogyrinus elegans, the amphibamid Platyrhinops cf. lyelli and the primitive trematopid Mordex laticeps. These represent four of the five major dissorophoid families and demonstrate that the group had already diversified by the late Westphalian.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The choristoderan reptile Monjurosuchus from the Early Cretaceous of Japan
Autorzy:
Matsumoto, R
Evans, S.E.
Manabe, M.
Powiązania:
https://bibliotekanauki.pl/articles/19928.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Reptilia
Early Cretaceous
Japan
Choristodera
fossil
Cretaceous
Monjurosuchus
Kuwajima Formation
paleontology
choristoderan reptile
Tetori Group
Opis:
The choristoderan reptile Monjurosuchus is described from the Lower Cretaceous Tetori Group of Japan on the basis of an associated specimen from the Kuwajima Formation, Ishikawa Prefecture, and more fragmentary remains from the contemporaneous Okurodani Formation, Gifu Prefecture. This is the first report of Monjurosuchus from Japan, but a long−necked choristodere, Shokawa, has already been recorded from these deposits. Monjurosuchus was first described from the Lower Cretaceous Jehol Biota of China, although it has only recently been recognised as a choristodere. As reconstructed, the Japanese Monjurosuchus differs from the type species, Monjurosuchus splendens, in the structure of the postorbital region, reduction of the quadratojugal, a slender parietal with a deep groove along the interparietal suture, and elongation of the jugal. As in M. splendens, the lower temporal fenestrae are closed. A cladistic analysis was performed in order to place Japanese and Chinese taxa, including the incompletely described Chinese long−necked Hyphalosaurus lingyanensis, into choristoderan phylogeny. The results support the monophyly of Neochoristodera and of a Sino−Japanese clade of long necked choristoderes. The placement of the European Tertiary Lazarussuchus remains problematic, but the analysis supports its placement within Choristodera rather than on the stem. The identification of Monjurosuchus from Japan provides an additional link between the fossil assemblages of the Tetori Group and those of the slightly younger Jehol Biota of China.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New albanerpetontid amphibians from the Early Cretaceous of Morocco and Middle Jurassic of England
Autorzy:
Gardner, J D
Evans, S.E.
Sigogneau-Russell, D.
Powiązania:
https://bibliotekanauki.pl/articles/21595.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Early Cretaceous
Middle Jurassic
Cretaceous
England
Albanerpetontidae
amphibian
albanerpetontid amphibian
Ramonellus
Morocco
Jurassic
paleontology
Lissamphibia
Opis:
A third albanerpetontid genus, Anoualerpeton gen. nov., is erected for two new species: An. unicussp. nov. (type species) from the Early Cretaceous (Berriasian) of Morocco and An. priscus sp. nov. from the Middle Jurassic (late Bathonian) of England. Anoualerpeton differs from the exclusively Laurasian albanerpetontid genera Albanerpeton (Early Cretaceous– Paleocene, North America; Miocene, Europe) and Celtedens (?Late Jurassic and Early Cretaceous, Europe) in a unique combination of primitive and derived character states of the jaws and azygous frontals. Monophyly of Anoualerpeton is supported by two synapomorphies of the maxilla and dentary (occlusal margin convex in labial outline and teeth strongly heterodont in size anteriorly) that are convergent with an unrelated, relatively derived Late Cretaceous species of Albanerpeton from North America. The two species of Anoualerpeton differ in character states of the premaxilla and azygous frontals. Cladistic analysis of 20 characters scored for ten albanerpetontid taxa postulates Anoualerpeton as the sister−taxon of Albanerpeton + Celtedens. The sister−pair of Albanerpeton + Celtedensis founded on one or, perhaps, two premaxillary synapomorphies. Anoualerpeton unicus documents the only known Gondwanan occurrence for the Albanerpetontidae and provides a minimum age of basal Cretaceous for the establishment of the clade in Africa. Characters of the mandible, vertebrae, and limbs support the interpretation that Ramonellus (Aptian; Israel) is a caudate, not an albanerpetontid.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New craniodental material of the typotherian notoungulates from the upper Oligocene of Mendoza, central-western Argentina and their taxonomical importance
Autorzy:
Hernandez Del Pino, S.
Seoane, F.D.
Cerdeno, E.
Powiązania:
https://bibliotekanauki.pl/articles/31341361.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
new material
craniodental material
typotherian notoungulate
notoungulate
Notoungulata
fossil mammal
Mammalia
Archaeohyracidae
Hegetotheriidae
Interatheriidae
Agua de la Piedra Formation
Deseadan
Mendoza province
Oligocene
Upper Oligocene
Mendoza
Argentina
taxonomy
Źródło:
Acta Palaeontologica Polonica; 2022, 67, 4; 983-997
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fused and vaulted nasals of tyrannosaurid dinosaurs: Implications for cranial strength and feeding mechanics
Autorzy:
Snively, E.
Henderson, D.M.
Phillips, D.S.
Powiązania:
https://bibliotekanauki.pl/articles/21688.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Carnosauria
computer tomography
Theropoda
Tyrannosauridae
biomechanics
computer modelling
dinosaur
feeding mechanism
paleontology
theropod dinosaur
tyrannosaurid dinosaur
cranial strength
Opis:
Tyrannosaurid theropods display several unusual adaptations of the skulls and teeth. Their nasals are fused and vaulted, suggesting that these elements braced the cranium against high feeding forces. Exceptionally high strengths of maxillary teeth in Tyrannosaurus rex indicate that it could exert relatively greater feeding forces than other tyrannosaurids. Areas and second moments of area of the nasals, calculated from CT cross−sections, show higher nasal strengths for large tyrannosaurids than for Allosaurus fragilis. Cross−sectional geometry of theropod crania reveals high second moments of area in tyrannosaurids, with resulting high strengths in bending and torsion, when compared with the crania of similarly sized theropods. In tyrannosaurids trends of strength increase are positively allomeric and have similar allometric exponents, indicating correlated progression towards unusually high strengths of the feeding apparatus. Fused, arched nasals and broad crania of tyrannosaurids are consistent with deep bites that impacted bone and powerful lateral movements of the head for dismembering prey.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
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

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