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Wyszukujesz frazę "taxonomy;" wg kryterium: Temat


Tytuł:
Ankle structure in Eocene pholidotan mammal Eomanis krebsi and its taxonomic implications
Autorzy:
Horovitz, I
Storch, G.
Martin, T.
Powiązania:
https://bibliotekanauki.pl/articles/21524.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
pholidotan mammal
Eomanis krebsi
mammal
Eocene
taxonomy
paleontology
Opis:
Georges Cuvier (1798) established the classical concept of Edentata which included sloths, anteaters, armadillos, aardvarks, and pangolins. With the growing body of comparative morphological data becoming available during the nineteenth century, it was evident that Cuvier's “Edentata” was an artificial group (e.g., Huxley 1872). In his classical textbook, Weber (1904) excluded aardvarks and pangolins from the Edentata and put them in separate orders, Tubulidentata and Pholidota. Later on, fossil taxa were repeatedly added to and removed from Edentata, such as various xenarthran groups, taeniodonts, palaeanodonts, and gondwanatheres, but the South American Xenarthra always was considered as their core group. Even the living order Pholidota has been cited again as ?Edentata incertae sedis many years after Weber’s work (Romer 1966). The validity and extent of a higher taxon Edentata are still in dispute. In this discussion, the Middle Eocene pholidotan Eomanis and the putative xenarthran Eurotamandua from Grube Messel near Darmstadt (Germany) play an important role (Storch 1978, 1981, 2003; Rose and Emry 1993; Gaudin and Branham 1998; Rose 1999). Eomanis krebsi and Eurotamandua joresi have been subject to some discussion regarding their taxonomic distinction. It has been suggested that the only specimen known of Eo. krebsi might actually be a juvenile representative of the senior species E. joresi. A reexamination of the type specimen of Eo. krebsi has yielded some new observations regarding the identity of some of its ankle elements. An element that was previously identified as a navicular, is here reidentified as a partial distal tibia, whereas a partially exposed calcaneus had gone unnoticed. These two elements display several differences in morphology between Eo. krebsi and E. joresi, indicating that these are in fact distinct species.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The PhyloCode, or alternative nomenclature: Why it is not beneficial to palaeontology, either
Autorzy:
Monsch, K.A.
Powiązania:
https://bibliotekanauki.pl/articles/23327.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
nomenclature
paleontology
Phylocode name
phylogenesis
systematics
taxonomy
Opis:
Methodological stability in biological nomenclature is being upset recently, with potential consequences for palaeontology. Some systematists, inspired mainly by de Queiroz and Gauthier (1990, 1992, 1994), reject traditional nomenclature in favour of an alternative “Phylogenetic Nomenclature” (PN). Following de Queiroz (2006) I consistently call this Phylogenetic Nomenclature, rather than Phylogenetic taxonomy, as it is often done. Important tenets of PN are the abandonment of hierarchic ranks and binomial names, and establishing name definitions based on cladogram shape (node−, stem−, and stem−modified node−based definitions), apomorphies (apomorphy−based definitions), or a combination of apomorphies and tree topology (apomorphy−modified node−based definition). For an explanation of such definitions, see Cantino and de Queiroz (2003) and Sereno (2005). The practice of Phylogenetic Nomenclature is laid out in an Internet document, the PhyloCode (Cantino and de Queiroz 2003). PN is seen as the natural next step in the evolution of taxonomy: from Linnaeus’ (1753, 1758) “creationist taxonomy” to Hennig’s (1966) cladistic taxonomy. Hence, Linnaeus’ ideas should be removed from nomenclature, which will then reflect phylogeny. Despite the dominance of cladistics as a framework for taxonomy, the validity of its philosophies and methodologies are still questioned (e.g., Szalay 2000). I encourage everyone, independently of school of taxonomy adhered to, to take interest in PN, because: (1) we are all creators or users of taxonomies and classifications, (2) PN is radically different from the current standard, (3) the Preface to the PhyloCode suggests it should ultimately replace the current Codes of Nomenclature (of bacteria, LaPage et al. 1992; of Zoology, ICZN 1999; of Botany, Greuter et al. 2000). I argue herein, why palaeontologists should not follow PN.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Agastograptus from the mulde beds of Gotland
Agastograptus z warstw mulde Gotlandii
Autorzy:
Kozlowska-Dawidziuk, A.
Powiązania:
https://bibliotekanauki.pl/articles/21121.pdf
Data publikacji:
1991
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Agastograptus
graptolite
Heloretiolites lawsoni
Retiolites balticus
taxonomy
paleontology
Gotland
Opis:
Agastograptus lawsoni (Holland, Rickards et Warren 1969), known previously as Holoretiolites (Balticograptus) lawsoni Holland, Rickards et Warren 1969 from upper Wenlock of Shropshire is described from Mulde Beds of Gotland. A new diagnosis of the species, basing on abundant and well preserved fossils, has been formulated. Former Retiolites balticus Eisenack is removed from the genus Agastograptus.
Zbadano około 70 dobrze zachowanych okazów retiolitidów, pochodzących z warstw Mulde (górny wenlok) Gotlandii, co umożliwiło zbadanie astogenezy i wyróżnienie cech diagnostycznych gatunku. Stwierdzono też kilkanaście anormalnie wykształconych rabdosomów. Gatunek ten opisany był z górnego wenloku Shropshire przez Holanda, Rickardsa i Warrena (1969) jako Holoretiolites (Balticograptus) lawsoni, jednak zły stan zachowania materiału nie pozwolił im ustalić liczby wyrostków aperturalnych. Zdaniem autorki należy on do rodzaju Agastograptus Obut et Zaslavskaya 1983. Jednocześnie autorka proponuje wyłączyć z rodzaju Agastograptus dawny gatunek Retiolites balticus Eisenack z uwagi na występowanie pojedynczego wyrostka aperturalnego oraz brak beleczek pleuralnych i zygzakowatego wzoru klatrium ścian lateralnych.
Źródło:
Acta Palaeontologica Polonica; 1991, 36, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Agastograptus, a synonym of Plectograptus [Retiolitidae, Graptolithina]
Autorzy:
Kozlowska-Dawidziuk, A
Powiązania:
https://bibliotekanauki.pl/articles/22767.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Agastograptus robustus
synonym
Retiolitidae
Graptolithina
Silurian
Agastograptus
taxonomy
Plectograptus
paleontology
Opis:
Agastograptus robustus Obut and Zaslavskaya, 1983, the type species of the genus Agastograptusis herein recognized as a species of Plectograptus. Large proximal lateral orifices are one of the significant characters of Plectograptus. P. robustus differs from the type species, Plectograptus macilentus Törnquist, 1887, in possessing paired apertural processes. Other species of Agastograptus have been assigned to three different genera: Spinograptus, S. clathrospinosus (Eisenack, 1951), S. munchi (Eisenack, 1951), Neogothograptus, N. balticus (Eisenack, 1951), and Cometograptus, C. nevadensis (Berry and Murphy, 1975). The main diagnostic feature used for Agastograptus, the spinoreticular paired apertural processes, is recognized as a species feature, characteristic mostly for Spinograptus, whereas the generic features are the arrangement of the proximal end, ventral walls, and ancora sleeve of the rhabdosome. Therefore the genus Agastograptus is a synonym of Plectograptus.
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Permian vertebrate tracks from the Tumlin Sandstone, Holy Cross Mountains, Poland
Autorzy:
Ptaszynski, T
Niedzwiedzki, G.
Powiązania:
https://bibliotekanauki.pl/articles/21416.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
footprint
Polska
Permian
Holy Cross Mountains
vertebrate
taxonomy
paleontology
Opis:
This paper describes the vertebrate ichnofauna from the Tumlin Sandstone (Buntsandstein) of the Holy Cross Mountains in Poland. The footprint assemblage has previously been regarded as Early Triassic in age; however, ichnogenera characteristic of the Late Permian are now recognized. Lack of representatives of the ichnofamily Chirotheriidae, characteristic of continental Triassic sediments worldwide, also indicates a Permian rather than a Triassic age for the studied assemblage. Three ichnogenera (Batrachichnus, Limnopus, and Amphisauropus) produced by amphibians are recognized, the remainder (Varanopus, Chelichnus, Dimetropus, Rhynchosauroides, Palmichnus, Paradoxichnium, and Phalangichnus) being of reptilian origin. Batrachichnus cf. salamandroides (Geinitz, 1861), Limnopus cf. zeilleri (Delage, 1912), Amphisauropus cf. latus Haubold, 1970, Varanopus aff. microdactylus (Pabst, 1896), Chelichnus cf. duncani (Owen, 1842), and Dimetropussp. are recorded in the Lower Buntsandstein for the first time. The following new ichnospecies are erected: Rhynchosauroides kuletae ichnosp. nov., Palmichnus lacertoides ichnosp. nov., Paradoxichnium tumlinense ichnosp. nov., Phalangichnus gradzinskii ichnosp. nov., and Phalangichnus gagoli ichnosp. nov.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New sharks and rays from the Cenomanian and Turonian of Charentes, France
Autorzy:
Vullo, R
Cappetta, H.
Neraudeau, D.
Powiązania:
https://bibliotekanauki.pl/articles/20707.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Turonian
Neoselachii
marine environment
Cenomanian
rajiform
Cretaceous
Rajiformes
taxonomy
Chondrichthyes
paleoenvironment
orectolobiform
Orectolobiformes
lamniform
new taxonomy
France
deposit
Lamniformes
Charente department
coastal environment
paleontology
Opis:
New or so far poorly known neoselachians from the Cenomanian and Turonian of SW France are described. The material studied herein comes from nine localities in the Charentes region, comprising palaeoenvironments ranging from coastal to open marine environments, and consists of two orectolobiforms, six lamniforms, and four rajiforms. The new taxa are Squalicorax coquandi sp. nov. and Roulletia bureaui gen. et sp. nov. within lamniforms, and Hamrabatis bernardezi sp. nov., Archingeayia sistaci gen. et sp. nov., and Engolismaia couillardi gen. et sp. nov. within rajiforms. New specimens of Odontaspis rochebrunei Sauvage, 1880 from the type area allow redescription of this taxon, assigned herein to the genus Cenocarcharias. Occurrences of Squalicorax baharijensis, S. cf. intermedius, and Archaeolamna sp., previously unrecorded from this region, and Almascyllium, a genus generally described from younger strata, are also noted, and improve knowledge of mid−Cretaceous selachian faunas from Western Europe.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bradoriid arthropods from the lower - middle Cambrian of Scania, Sweden
Autorzy:
Dies Alvarez, M.E.
Gozalo, R.
Cederstrom, P.
Ahlberg, P.
Powiązania:
https://bibliotekanauki.pl/articles/20703.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
bradoriid arthropod
arthropod
Cambrian
Scania
Sweden
paleontology
Arthropoda
Bradoriida
taxonomy
biostratigraphy
Opis:
Three species of bradoriid arthropods from the lower to middle Cambrian transitional interval of Scania, southern Sweden, are described and illustrated: Beyrichona tinea from the top of the traditional lower Cambrian (Gislöv Formation; Ornamentaspis? linnarssoni Zone), and Hipponicharion eos and Alutella sp. from the basal portion of the traditional middle Cambrian (lowermost part of the Alum Shale Formation). The bradoriid fauna compares most closely with others previously described from western and eastern Avalonia (New Brunswick and England). The record of B. tinea suggests a correlation between the “Protolenus Zone” (Hupeolenus Zone) of western Avalonia and the O.? linnarssoni Zone of Scandinavia. Hipponicharion eos appears to be a fairly long−ranging species as it has previously been recorded from upper lower Cambrian or lower middle Cambrian strata in New Brunswick, Poland, and probably Sardinia. The record of H. eos from the lowermost part of the Alum Shale Formation suggests that this largely unfossiliferous interval in the Scanian succession is not younger than the Acadoparadoxides oelandicus Superzone. The genus Alutella has not previously been recorded from the Acado−Baltic Province.
Źródło:
Acta Palaeontologica Polonica; 2008, 53, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Ordovician brachiopods from the Selety River basin, North Central Kazakhstan
Autorzy:
Nikitin, I F
Popov, L.E.
Bassett, M.G.
Powiązania:
https://bibliotekanauki.pl/articles/22739.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachiopod
Ordovician
Late Ordovician
biogeography
Selety River
taxonomy
Kazakhstan
Brachiopoda
paleontology
Opis:
A medium−diversity fauna of late Ordovician rhynchonelliformean brachiopods occurs in the Tauken Formation (upper Caradoc–lowermost Ashgill) of north Central Kazakhstan.It demonstrates close similarity to the approximately contemporaneous faunas characteristic of shallow clastic shelves (BA 2–3) of the Chingiz and Chu−Ili ranges (both in Kazakhstan) and South China, but is characterized by a high proportion of endemic new species, including Tetraphalerella bestiubensis sp.nov., Glyptomena kaskolica sp.nov., Dinorthis taukensis sp.nov., Rhynchotrema seletensis sp.nov., and Nalivkinia (Pronalivkinia)zvontsovisp.nov.The abundance of Rhynchotrema is somewhat unusual by comparison with faunas from other Kazakhstanian terranes, where rhynchonellides of the family Ancistrorhynchidae are usually dominant in near−shore biofacies.The occurrence of the atrypides Sulcatospira and early Nalivkinia demonstrates a clear biogeographical linkage with approximately contemporaneous faunas of South China.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Taxonomic notes on Phoebodus heslerorum and Symmorium reniforme [Chondrichthyes, Elasmobranchii]
Autorzy:
Ginter, M
Powiązania:
https://bibliotekanauki.pl/articles/23345.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Carboniferous
Symmorium reniforme
Paleozoic
tooth
Elasmobranchii
Phoebodus heslerorum
taxonomy
paleontology
Chondrichthyes
Opis:
The revision of shark teeth from the Pennsylvanian black shales of central USA, ascribed to “Phoebodus heslerorum” Williams, 1985 and Symmorium reniforme Cope, 1893, shows that “Ph. heslerorum” is a junior synonym of “Cladodus” divergens Trautschold, 1879. This species belongs neither to Phoebodus nor to Cladodus, so a new genus Heslerodus is proposed. Very common, robust cladodont teeth with a deep labio−basal depression and two buttons, often referred to as S. reniforme, do not belong to the latter species, but to “Cladodus” occidentalis Leidy, 1859. The generic affinity of “C.” occidentalis is yet undetermined, but it is possible that it represents ctenacanthoids.
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-ray microtomography (XMT) of fossil brachiopod shell interiors for taxonomy
Autorzy:
Blazejowski, B.
Binkowski, M.
Bitner, M.A.
Gieszcz, P.
Powiązania:
https://bibliotekanauki.pl/articles/23513.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
x-ray microtomography
fossil
brachiopod
shell
taxonomy
remains
paleontology
Terebratula terebratula
Opis:
The ability to see and understand the three−dimensional structure of an investigated object plays a key role in studying fossil remains. All living organisms are formed in threedimensions, but unfortunately fossilization processes often reduce overall shape, making it difficult to gather information about real overall appearance, functionality, and inner structure. Here, using a specimen of the brachiopod Terebratula terebratula we demonstrate a non−destructive technique for exploring the 3−D internal structure of fossil remains. The use of tomography allows the construction of a set of transverse serial sections in the manner used by brachiopod researchers for decades.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new periodical on mammals
Autorzy:
Archibald, J.D.
Powiązania:
https://bibliotekanauki.pl/articles/23287.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
ecology
fauna
new journal
mammal
theriology
evolution
morphology
taxonomy
zoogeography
paleontology
journal
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The bivalve Pinna cretacea [Schlotheim, 1813] from the Cretaceous of Brazil
Autorzy:
Seeling, J
Bengtson, P.
Powiązania:
https://bibliotekanauki.pl/articles/20577.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Sergipe Basin
Cretaceous
Bivalvia
Brazil
biogeography
Pinna cretacea
rock
macroinvertebrate
taxonomy
bivalve
paleontology
Opis:
The bivalve Pinna cretacea (Schlotheim, 1813) is described from the Cenomanian–Coniacian Cotinguiba Formation of the Sergipe Basin, north−eastern Brazil, and its mode of life and palaeobiogeographic distribution discussed. The specimens are generally found in life position with their articulated anterior (umbonal) end embedded vertically in the substrate, in analogy with Recent forms. Two representatives of the family Pinnidae Leach, 1819, are recognized in the Cretaceous of Brazil; besides P. cretacea, which is also known from the Albian of the Camamu Basin (Bahia), Atrina reginamaris (Maury, 1930) occurs in the Maastrichtian of the Pernambuco−Paraíba Basin.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First report on the occurrence of Neseuretinus and Ovalocephalus trilobites in the Middle Ordovician of Iran
Autorzy:
Ghobadi, Pour M
Popov, L.E.
Powiązania:
https://bibliotekanauki.pl/articles/21343.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
trilobite
taxonomy
Trilobita
paleontology
Shirgesht Formation
Ovalocephalus
Neseuretinus
Ordovician
paleobiogeography
Middle Ordovician
Iran
Opis:
In the Derenjal Mountains of east Central Iran, the upper part of the Shirgesht Formation (uppermost Darriwilian) contains a distinct trilobite assemblage that includes Neseuretinus birmanicus and Ovalocephalus aff. obsoletus among others. Both genera were previously unknown in Iran. The occurrence of Ovalocephalus represents the earliest sign of westward taxon migration from China towards higher latitudes along the West Gondwanan margin, which may be related to global warming, after a short episode of cooler climate in the early to mid Darriwilian. Patterns of biogeographical distribution of Ovalocephalus and Neseuretinussuggest that Central Iran was part of an “overlap zone” where tropical and high latitude benthic taxa mingled.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 1; 125-133
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The last Frasnian Atrypida [Brachiopoda] in southern Belgium
Autorzy:
Godefroid, J
Helsen, S
Powiązania:
https://bibliotekanauki.pl/articles/21597.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachiopod fauna
fauna
Frasnian
Devonian
Belgium
Atrypida
mass extinction
biostratigraphy
taxonomy
paleontology
Brachiopoda
Opis:
The last representatives of the order Atrypida on the southern flank of the Dinant Synclinorium (Vaulx-Nismes area) in Belgium belong to Costatrypa, Spinatrypa, Spinatrypina (?Spinatrypina), Spinatrypina (Exatrypa), Iowatrypa, ?Waiotrypa, Desquamatia (Desquamatia) and Desquamatia (?Seratrypa). Among the thirteen described taxa, five are new: Spinatrypa tumuli sp. n., Iowatrypa circuitionis sp. n., ?Waiotrypa pluvia sp. n., Desquamatia (Desquamatia) quieta sp. n. and Desquamatia (?Seratrypa) derelicta sp. n. Supposed lissatrypid 'Glassia drevermanni' Maillieux, 1936 from the late Frasnian Matagne shales is assigned to the Rhynchonellida. On the southern flank of the Dinant Synclinorium and in the Philippeville Massif, the Atrypida become extinct in the Palmatolepis rhenana Zone, significantly below the Frasnian-Famennian (F-F) boundary. Their extinction coincides with the first appearance of the green and black shales of the late Frasnian Matagne Formation, recording a transgressive-hypoxic event. Based on conodont data, this event takes place earlier on the southern flank of the Dinant Synclinorium than in the Philippeville Massif.
Źródło:
Acta Palaeontologica Polonica; 1998, 43, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The bivalve Pholadomya gigantea in the Early Cretaceous of Argentina: taxonomy, taphonomy, and paleogeographic implications
Autorzy:
Lazo, D G
Powiązania:
https://bibliotekanauki.pl/articles/23388.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Argentina
Early Cretaceous
Pholadomya gigantea
Cretaceous
Bivalvia
Anomalodesmata
paleoecology
paleogeography
taxonomy
bivalve
paleontology
Opis:
Pholadomya gigantea is a widely distributed Early Cretaceous bivalve mollusc. It has been recorded in the North Temperate, Tethyan, and South Temperate Realms. Based on recent field work and newly collected material from the Neuquén Basin, the taxonomy, mode of occurrence and palaeobiogeography of this species is reviewed. In the Agrio Formation (Valanginian–Barremian) P. gigantea is neither abundant nor dominant, but occurs throughout the unit. It was facies−dependent being restricted to well−oxygenated waters and soft to firm, sandy and bioclastic substrates of shoreface to inner shelf environments. The life habit of P. gigantea was similar to that of Recent Pholadomya candida, deep burrowing and sedentary, but it has not a pedal gape and accessory muscle scars related to valve closure. Thus a suspension−feeding habit, not a pedal−feeding system, may be inferred as is commonly suggested in other Jurassic and Cretaceous Pholadomya species. Pholadomya agrioensis is a valid taxon that is recorded in the Berriasian–Valanginian of Neuquén. It is similar in outline to P. gigantea and had probably the same basic palaeoecology, even though it has a blunt anterior margin, deep umbonal−ventral sulcus and distinct anterior ornamentation. Once in life position this species was capable of further digging in the sediment. This species probably burrowed in muddy substrates in the offshore zone. Pholadomya sanctaecrucis from the Valanginian of Europe and also recorded in Argentina is ornamented only with commarginal lines and should be removed to the genus Homomya.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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