Temat: Early Cretaceous - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: A relict stem salamander: evidence from the Early Cretaceous of Siberia
Autorzy:: Skutschas, P.P.
Tematy:: relict
salamander
evidence
evolution
Early Cretaceous
Cretaceous
Siberia; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/20727.pdf Link otwiera się w nowym oknie
Opis:: The early evolution of salamanders, which are one of the three living groups of lissamphibians, is not well known. Both stem- and crown-group salamanders first appeared in the Middle Jurassic (Bathonian), but subsequently had different evolutionary histories: stem salamanders were thought to have gone extinct in the Late Jurassic, while crown salamanders persist to the present day. Here, I report the discovery of an indeterminate stem salamander in the Lower Cretaceous (Aptian–Albian) Ilek Formation of Western Siberia. This is new evidence that the most basal salamanders survived beyond the Jurassic–Cretaceous boundary and co-existed with crown-group salamanders during approximately the first 40 million years of the known history of salamanders. The recognition of stem salamanders in the Early Cretaceous of Western Siberia adds to the inventory of taxa that suggest this area was a refugium for various groups of vertebrates with Jurassic affinities.
Dostawca treści:: Biblioteka Nauki

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Tytuł:: A nearly complete ornithocheirid pterosaur from the Aptian (Early Cretaceous) Crato Formation of NE Brazil
Autorzy:: Elgin, R.A.
Frey, E.
Tematy:: ornithocheirid pterosaur
pterosaur
Aptian
Early Cretaceous
Cretaceous
Crato Formation
Brazil
Ornithocheiroidea; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/19983.pdf Link otwiera się w nowym oknie
Opis:: A partial ornithocheirid, representing a rare example of a pterosaurian body fossil from the Nova Olinda Member of the Crato Formation, NE Brazil, is described from the collections of the State Museum of Natural History, Karlsruhe. While similar in preservation and taphonomy to Arthurdactylus conandoylei, it is distinguished by slight differences in biometric ratios, but the absence of a skull prevents closer identification. Mostly complete body fossils belonging to ornithocheiroid pterosaurs appear to be relatively more abundant in the younger Romualdo Member of the Santana Formation, making the described specimen one of only two well documented ornithocheiroids known from the Nova Olinda Lagerstätte.
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Early Cretaceous symmetrodont mammal Gobiotheriodon from Mongolia and the classification of Symmetrodonta
Autorzy:: Averianov, A O
Tematy:: Gobiotheriodon infinitus
systematics
classification
Early Cretaceous
mammal
Cretaceous
Mongolia
Gobiotheriodon
paleontology; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/20946.pdf Link otwiera się w nowym oknie
Opis:: The “symmetrodont” mammal, Gobiotheriodon infinitus (Trofimov, 1980), from the Early Cretaceous (Aptian–Albian) of Mongolia, is redescribed.The species is restricted to the holotype only (dentary with three last molars), the referred maxillary fragment with M3? is considered here as cf. Gobiconodon sp.The dental formula of G. infinitusis reinterpreted as i1–3 c1 p1–3 m1–4. G. infinitus is characterized by a short dentary symphysis; long, well−developed Meckel's groove; small, triangular−shaped pterygoid fossa; weakly developed pterygoid crest; i3 enlarged; p1–3 two−rooted; lower molars acute− to obtuse−angled, labial cingulids lacking, lingual cingulids very short, well developed mesial and distal cingulid cuspules (“e” and “d”) and prominent wear surface on the paracristid. Gobiotheriodon is similar to Tinodon (Late Jurassic, USA; Early Cretaceous, Great Britain and Portugal) in postcanine dental formula and structure of the pterygoid fossa; it is provisionally assigned to Tinodontidae Marsh, 1887.Some taxa previously assigned to (or suggested as possible relatives of) “Symmetrodonta” are reviewed.Amphidontidae Simpson, 1925 is considered as nomen dubium.A new classification for “Symmetrodonta” is proposed.
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Monotreme nature of the Australian Early Cretaceous mammal Teinolophos
Autorzy:: Rich, T H
Vickers-Rich, P.
Trusler, P.
Flannery, T.F.
Cifelli, R.
Constantine, A.
Kool, L.
Van Klaveren, N.
Tematy:: Early Cretaceous
holotype
Australia
mammal
Teinolophos trusleri
Cretaceous
Teinolophos
Steropodontidae
paleontology; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/22297.pdf Link otwiera się w nowym oknie
Opis:: The morphology of the single preserved molar of the holotype of the Australian Early Cretaceous (Aptian) mammal Teinolophos trusleri shows that it is a monotreme and probably a steropodontid, rather than a 'eupantothere' as originally proposed. The structure of the rear of the jaw of T. trusleri supports the molecular evidence that previously formed the sole basis for recognising the Steropodontidae as a distinct family.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Highly derived eutherian mammals from the earliest Cretaceous of southern Britain
Autorzy:: SWEETMAN, STEVEN C.
SMITH, GRANT
MARTILL, DAVID M.
Tematy:: mammalia
eutheria
dentition
early cretaceous
purbeck group
britain
uk; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/945956.pdf Link otwiera się w nowym oknie
Opis:: Eutherian mammals (Placentalia and all mammals phylogenetically closer to placentals than to marsupials) comprise the vast majority of extant Mammalia. Among these there is a phenomenal range of forms and sizes, but the origins of crown group placentals are obscure. They lie within the generally tiny mammals of the Mesozoic, represented for the most part by isolated teeth and jaws, and there is strongly conflicting evidence from phenomic and molecular data as to the date of origin of both Eutheria and Placentalia. The oldest purported eutherians are Juramaia from the Upper Jurassic of China, and Eomaia and Acristatherium from the Lower Cretaceous, also of China. Based on dental characters and analyses of other morphological and molecular data, doubt has recently been cast on the eutherian affinities of the Chinese taxa and consequently on the date of emergence of Eutheria. Until now, the only tribosphenic mammal recorded from the earliest Cretaceous (Berriasian) Purbeck Group of Britain was the stem tribosphenidan Tribactonodon. Here we document two new tribosphenic mammals from the Purbeck Group, Durlstotherium gen. nov. and Durlstodon gen. nov., showing highly derived eutherian molar characters that support the early emergence of this clade, prior to the Cretaceous.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Early Cretaceous record of microboring organisms in skeletons of growing corals
Autorzy:: Kołodziej, Bogusław
Radtke, Gudrun
Golubic, Stjepko
Bucur, Ioan I.
Tribollet, Aline
Opis:: A spectacularly preserved assemblage of microbial euendoliths, penetrating into skeletons of growing scleractinian corals, has been recognized in Early Aptian (Early Cretaceous) reef limestone of the Rara ̆ u Mountains (East Carpathians, NE Romania). Microboring euendolithic filaments were found in five coral colonies of the suborder Microsolenina. They remained in part well-preserved, often impregnated with iron oxides, which made them visible even in strongly recrystallized parts of coral skeletons. Filaments of a wide range of sizes (2–40 l m in diameter) were concentrated within medium parts of coral septa, oriented along the septa in the direction of the coral growth. The larger filaments were tubular, occurring in bundles and branched into finer, often tapering branches. Their behaviour and organization were quite similar to the modern euendolithic siphonalean chlorophyte Ostreobium . Filament diameters exceeded those reported for the modern species, but covered a similarly wide size range. Narrower frequently branching filaments, 4–8 l m in diameter, resemble distal branching patterns of modern Ostreobium quekettii. Some very thin filaments (ca. 1–2 l m) observed within skeleton or inside the large tubular filaments, sometimes associated with globular swellings, may represent euendolithic fungi. The recrystallization of coral skeleton had limited effect on preservation of euendoliths due to their impregnation with iron oxides; microbial euendoliths were subjected to different taphonomic changes.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 7.

Tytuł:: A new deinopoid spider from Cretaceous Lebanese amber
Autorzy:: Penney, D
Tematy:: Early Cretaceous
Araneae
Palaeomicromenneus lebanensis
Cretaceous
spider
Lebanese amber
paleontology
Deinopidae
amber; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/20055.pdf Link otwiera się w nowym oknie
Opis:: Palaeomicromenneus lebanensis gen. et sp. nov. (Araneae: Deinopidae) is described from Upper Neocomian–basal Lower Aptian (ca. 125–135 Ma) Cretaceous amber from the Hammana/Mdeyrij outcrop, Lebanon. This is the oldest known, and possibly the first true fossil, deinopid. The lack of ocular modifications in the new fossil genus does not exclude it from having exhibited the same net−casting prey capture behaviour as extant deinopids. Alternatively, this prey−capture behaviour may be highly derived and whether it had evolved by the Early Cretaceous cannot be determined for sure; early deinopids (as diagnosed by pedipalp morphology rather than behaviour) may have been orb−web weavers as is their sister taxon the Uloboridae.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: $^{40}Ar^{39}Ar$ dating of alkaline lamprophyres from the Polish Western Carpathians
Autorzy:: Anczkiewicz, Robert
Lucińska-Anczkiewicz, Anna
Villa, Igor M.
Ślączka, Andrzej
Opis:: Amphiboles from two types of alkaline lamprophyres from the Silesian Nappe in the Polish Western Carpathians were dated by $^{40}Ar^{39}Ar$ stepwise heating technique. Three teschenite samples representing mesocratic type of lamprophyres yielded similar ages of 122.3±1.6 Ma, while leucocratic lamprophyre represented by a syenite dyke gave 120.4±1.4 Ma date. These ages are interpreted as the time of magmatic emplacement during Early Cretaceous extensional episode within the Silesian Basin. Ages for both types of lamprophyres are identical within error limits, which points to fast (probably ca. 5 Ma) magma evolution from meso to leucocratic stage.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 9.

Tytuł:: Reconstruction of Cretaceous rifts incorporated in the Outer West Carpathian wedge by balancing
Autorzy:: Oszczypko, Nestor
Nemčok, M.
Coward, M. P.
Ludhova, L.
Sercombe, W. J.
Cieszkowski, Marek
Paul, Z.
Ślączka, Andrzej
Wojtaszek, Marek
Nemčok, J.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 10.

Tytuł:: Primitive boreosphenidan mammal [?Deltatheroida] from the Early Cretaceous of Oklahoma
Autorzy:: Kielan-Jaworowska, Z
Cifelli, R L
Tematy:: Oklahoma
Early Cretaceous
Boreosphenida
Cretaceous
Atokatheridium boreni
primitive mammal
Deltatheroida
boreosphenidan mammal
Aegialodontidae; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/21171.pdf Link otwiera się w nowym oknie
Opis:: We describe a new boreosphenidan mammal, Atokatheridium boreni gen. et sp. n., from the Early Cretaceous of Oklahoma, based on an upper molar and a tentatively referred lower molar. The upper molar is characterized by a small protocone and unwinged conules, broad stylar shelf, paracone taller than metacone, and lack of pre- and postcingula. Comparisons with relevant Early and Late Cretaceous boreosphenidans suggest closest similarity to Deltatheroida, including one character (extreme development of the distal stylar shelf, which projects labially and lacks cusps) interpreted as derived. The tentatively attributed lower molar shows similarity to Deltatheridium and the ?aegialodontid genus Kielantherium in having the paraconid higher than the metaconid, but differs from Kielantherium in having a differently shaped talonid. From Aegialodon it differs in having a vertically oriented (rather than semi-procumbent) paraconid and a larger talonid. We figure also two isolated trigonids, differing in size, which show some resemblance to that of ?Atokatheridium. Deltatheroidans, despite their generally primitive dental morphology, are otherwise surely known only from the Late Cretaceous, and are largely restricted to the Old World. If a deltatheroidan, the new taxon implies a significant temporal range extension for the group, and provides another biogeographic link between Cretaceous mammals of Asia and North America.
W pracy opisano nowy gatunek i rodzaj prymitywnego ssaka o zębach trybosfenicznych - Atokatheridium boreni, z wczesnej kredy stanu Oklahoma w Stanach Zjednoczonych. Nowy takson oparty jest na dobrze zachowanym górnym zębie trzonowym i na dolnym trzonowcu, zaliczonym z zastrzeżeniem. Atokatheridium zostal zaliczony do podgromady Boreosphenida, obejmującej ssaki o zębach trybosfenicznych, które powstały na Półkuli Północnej zapewne we wczesnej kredzie. Do Boreosphenida należą wszystkie współcześnie żyjące ssaki właściwe - torbacze i łożyskowce, ich kopalni przedstawiciele, oraz formy wymarłe o zębach trybosfenicznych, których stanowisko systematyczne jest nieustalone. Atokatheridium jest jednym z najstarszych znanych przedstawicieli boreosfenidów. Górny trzonowiec nowego taksonu charakteryzuje się małym protokonem, konulami pozbawionymi skrzydełek, bardzo szeroką półką stylarną, oraz brakiem przednich i tylnych wałeczków (cingulum). Porównanie z zębami wczesno- i późnokredowych boresosfenidów wskazuje, że Atokatheridium najbardziej jest zbliżony do przedstawicieli późnokredowego rzędu Deltatheroida, który należy do Metatheria i stanowi grupę siostrzaną torbaczy. Cechą wspólną jest obecność bardzo rozszerzonej części dystalnej półki stylarnej, kt6ra wystaje w kierunku dowargowym i jest pozbawiona guzków stylarnych. Z drugiej strony, dolny trzonowiec zaliczony z zastrzeżeniem do Atokatheridium wykazuje podobieństwo zarówno do trzonowców deltateroidów, jak i do słabo poznanej grupy wczesnokredowych boreosfenidów - egialodontów, szczególnie do rodzaju Kielantherium. W pracy zilustrowano takze dwa niekompletne dolne trzonowce (trygonidy) pochodzące z tej samej formacji co Atokatheridium, które wykazują pewne podobieństwo do trzonowca zaliczonego z zastrzeżeniem do Atokatheridium. Rząd Deltatheroida, który charakteryzuje się ogólnie prymitywną budową zębów i ma wzór zębowy taki jak torbacze, znany był dotąd tylko z późnej kredy i tylko z Pólkuli Północnej. Jeżeli Atokatheridium należy rzeczywiście do Deltatheroida, to wskazywałoby to że deltateroidy pojawiły się we wczesnej kredzie.
Dostawca treści:: Biblioteka Nauki

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