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Tytuł:
Carapace bone histology in the giant pleurodiran turtle Stupendemys geographicus: phylogeny and function
Autorzy:
Scheyer, T M
Sanchez-Villagra, M.R.
Powiązania:
https://bibliotekanauki.pl/articles/20658.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
bone histology
Pleurodira
phylogenesis
bone analysis
Miocene
Stupendemys geographicus
Pelomedusoides
bone microstructure
giant pleurodiran turtle
Testudines
Bothremydidae
Podocnemidae
paleontology
Opis:
Stupendemys geographicus (Pleurodira: Pelomedusoides: Podocnemidae) is a giant turtle from the Miocene of Venezuela and Brazil. The bone histology of the carapace of two adult specimens from the Urumaco Formation is described herein, one of which is the largest of this species ever found. In order to determine phylogenetic versus scaling factors influencing bone histology, S. geographicus is compared with related podocnemid Podocnemis erythrocephala, and with fossil and Recent pelomedusoides taxa Bothremys barberi, Taphrosphys sulcatus, “Foxemys cf. F. mechinorum”, and Pelomedusa subrufa. Potential scaling effects on bone histology were further investigated by comparison to the Pleistocene giant tortoise Hesperotestudo (Caudochelys) crassiscutata and the Late Cretaceous marine protostegid turtle Archelon ischyros. A diploe structure of the shell with well developed external and internal cortices framing interior cancellous bone is plesiomorphic for all sampled taxa. Similarly, the occurrence of growth marks in the shell elements is interpreted as plesiomorphic, with the sampled neural elements providing the most extensive record of growth marks. The assignment of S. geographicus to the Podocnemidae was neither strengthened nor refuted by the bone histology. A reduced thickness of the internal cortex of the shell elements constitutes a potential synapomorphy of the Bothremydidae. S. geographicus and H. crassiscutata both express extensive weight−reduction through lightweightconstruction while retaining form stability of the shell. The bone histology of A. ischyros presents features likely related to an open marine lifestyle.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lower and Middle Jurassic ammonoids of the Shemshak Group in Alborz, Iran and their palaeobiogeographical and biostratigraphical importance
Autorzy:
Seyed-Amami, K
Fursich, F.T.
Wilmsen, M.
Majidifard, M.R.
Shekarifard, A.
Powiązania:
https://bibliotekanauki.pl/articles/21183.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Middle Jurassic
biostratigraphy
Lower Jurassic
Ammonitida
ammonoid
paleontology
Jurassic
Alborz Mountains
paleobiogeography
Shemshak Group
Iran
Opis:
The Shemshak Group at Shahmirzad (northern Iran) is characterized by the most frequent and extensive marine intercalations and contains the most abundant and diverse ammonite faunas hitherto known from the Lower and lower Middle Jurassic strata of the Alborz Range. So far, 62 ammonite taxa have been recorded from this area, including 25 taxa from earlier studies. The taxa belong to the families Cymbitidae, Echioceratidae, Amaltheidae, Dactylioceratidae, Hildoceratidae, Graphoceratidae, Hammatoceratidae, Erycitidae, and Stephanoceratidae with the new species Paradumortieria elmii and Pleydellia (P.?) ruttneri. The fauna represents the Late Sinemurian, Late Pliensbachian, Toarcian, Aalenian, and Early Bajocian. Palaeobiogeographically, it is closely related to the Northwest European (Subboreal) Province, and exhibits only minor relations with the Mediterranean (Tethyan) Province.
Źródło:
Acta Palaeontologica Polonica; 2008, 53, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The phylogenetic position of the ornithischian dinosaur Stenopelix valdensis from the Lower Cretaceous of Germany and the early fossil record of Pachycephalosauria
Autorzy:
Butler, R J
Sullivan, R.M.
Powiązania:
https://bibliotekanauki.pl/articles/21353.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Cretaceous
Dinosauria
ornithischian dinosaur
fossil
paleontology
Pachycephalosauria
Ornithischia
Germany
phylogenetic position
Marginocephalia
Lower Cretaceous
dinosaur
Stenopelix valdensis
Opis:
The holotype of Stenopelix valdensis is the most completely known dinosaur specimen from the “Wealden” (Lower Cretaceous) of northwestern Germany, but its phylogenetic position has remained highly controversial. Most recent authors have suggested affinities with the ornithischian clade Marginocephalia, and most commonly to the marginocephalian subclade Pachycephalosauria. A pachycephalosaurian identity would make Stenopelix the only confirmed pre−Late Cretaceous member of this clade, breaking up an extensive ghost lineage which extends to the inferred origin of Pachycephalosauria in the Middle–Late Jurassic. Based upon re−examination of the holotype we here review the characters that have previously been used to assign Stenopelix to either Pachycephalosauria or Ceratopsia. All of these characters are problematic, being based upon inaccurate anatomical interpretations, or having more widespread distributions within Ornithischia than previously realised. We conclude that although the overall anatomy of Stenopelix is consistent with marginocephalian affinities, there is insufficient evidence to support referral to either Pachycephalosauria or Ceratopsia; we consider Stenopelix ?Marginocephalia. A brief review indicates that there is no compelling fossil evidence for pachycephalosaurs prior to the Late Cretaceous.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 1; 21-34
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trochiliscus (Eutrochiliscus) cf. bulbiformis Karpinsky (Charophyta) in the Devonian limestone of Traunkammen, Spitsbergen
Trochiliscus (Eutrochiliscus) cf. bulbiformis Karpinsky (Charophyta) z dewońskich wapieni z Traunkammen, Spitsbergen
Trochiliscus (Eutrochiliscus) cf. bulbiformis Karpinsky (kharofity) devonskikh izvestnjakov Traunkammena, Shpicbergen
Autorzy:
Wrona, R.M.
Powiązania:
https://bibliotekanauki.pl/articles/23014.pdf
Data publikacji:
1977
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
paleobiology
fossil
sediment
Trochiliscus cf.bulbiformis
Charophyta
Devonian
limestone
Traunkammen mountain
Spitsbergen
Źródło:
Acta Palaeontologica Polonica; 1977, 22, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new sauropod dinosaur from the Lower Cretaceous Cedar Mountain Formation, Utah, USA
Autorzy:
Taylor, M.
Wedel, M.
Cifelli, R.
Powiązania:
https://bibliotekanauki.pl/articles/23198.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Dinosauria
Sauropoda
Camarasauromorpha
Brontomerus
Brontomerus mcintoshi
diversity
Early Cretaceous
North America
new sauropod dinosaur
Lower Cretaceous
Cedar Mountain Formation
Utah
Cretaceous
sauropod dinosaur
Opis:
Brontomerus mcintoshi is a new genus and species of sauropod dinosaur from the Hotel Mesa Quarry in Grand County, Utah, USA, in the upper part of the Ruby Ranch Member (Aptian–Albian) of the Lower Cretaceous Cedar Mountain Formation. It is known from at least two fragmentary specimens of different sizes. The type specimen is OMNH 66430, the left ilium of a juvenile individual; tentatively referred specimens include a crushed presacral centrum, a complete and well−preserved mid−to−posterior caudal vertebra, the partial centrum of a distal caudal vertebra, a complete pneumatic anterior dorsal rib from the right side, the nearly complete left scapula of a much larger, presumably adult, individual, and two partial sternal plates. Brontomerus is diagnosed by five autapomorphies of the type specimen: preacetabular lobe 55% of total ilium length, longer than in any other sauropod; preacetabular lobe directed anterolaterally at 30 to the sagittal, but straight in dorsal view and vertically oriented; postacetabular lobe reduced to near absence; ischiadic peduncle reduced to very low bulge; ilium proportionally taller than in any other sauropod, 52% as high as long. In a phylogenetic analysis, Brontomerus was recovered as a camarasauromorph in all most parsimonious trees, but with uncertain position within that clade. The large preacetabular lobe of the ilium anchored powerful protractor and abductor muscles, but precise interpretation is impossible without functionally related elements such as femora and proximal caudal vertebrae. Brontomerus is the eighth sauropod genus named from the Early Cretaceous of North America, and more remain to be described: North American sauropod diversity did not decline catastrophically at the end of the Jurassic as often assumed. The most striking differences between Late Jurassic and Early Cretaceous sauropod faunas in North America is that the former are abundant and dominated by diplodocids, whereas the latter are comparatively scarce— though still diverse—and dominated by macronarians.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A peculiar faunivorous metatherian from the early Eocene of Australia
Autorzy:
Beck, R.M.D.
Powiązania:
https://bibliotekanauki.pl/articles/945605.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Mammalia
Metatheria
Marsupialia
Sparassodonta
Archaeonothos henkgodthelpi
new species
Eocene
fossil
deposit
paleontology
Australia
Opis:
I describe Archaeonothos henkgodthelpi gen. et. sp. nov., a small (estimated body mass ~40–80 g) tribosphenic metatherian from the early Eocene Tingamarra Fauna of southeastern Queensland, Australia. This taxon, known only from a single isolated upper molar (M2 or M3) is characterised by a very distinctive combination of dental features that, collectively, probably represent faunivorous adaptations. These include: a straight, elevated centrocrista; a metacone considerably taller than the paracone; a wide stylar shelf (~50% of the total labiolingual width of the tooth); reduced stylar cusps; a long postmetacrista; a small and anteroposteriorly narrow protocone; an unbasined trigon; and the absence of conules. Some of these features are seen in dasyuromorphians, but detailed comparisons reveal key differences between A. henkgodthelpi and all known members of this clade. A. henkgodthelpi also predates recent molecular estimates for the divergence of crown-group Dasyuromorphia. Similar dental features are seen in a number of other metatherians, including the South American sparassodonts, Wirunodon chanku from the ?middle–late Eocene Santa Rosa local fauna of Peru, and Kasserinotherium tunisiense from the early Eocene Chambi fauna of Tunisia, although whether A. henkgodthelpi is closely related to any of these taxa is unclear based on available evidence. I therefore refer A. henkgodthelpi to Metatheria incertae sedis. Potential relatives of A. henkgodthelpi are unknown from any other Australian fossil deposit.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 1; 123-129
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anatomy and relationships of the Triassic temnospondyl Sclerothorax
Autorzy:
Schoch, R R
Fastnacht, M.
Fichter, J.
Keller, T.
Powiązania:
https://bibliotekanauki.pl/articles/20469.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
terrestrial vertebrate
Temnospondyli
Stereospondyli
Triassic
Buntsandstein
anatomy
Sclerothorax
Germany
Sclerothorax hypselonotus
paleontology
Opis:
Recently, new material of the peculiar tetrapod Sclerothorax hypselonotusfrom the Middle Buntsandstein (Olenekian) of north−central Germany has emerged that reveals the anatomy of the skull and anterior postcranial skeleton in detail. Despite differences in preservation, all previous plus the new finds of Sclerothorax are identified as belonging to the same taxon. Sclerothorax is characterized by various autapomorphies (subquadrangular skull being widest in snout region, extreme height of thoracal neural spines in mid−trunk region, rhomboidal interclavicle longer than skull). Despite its peculiar skull roof, the palate and mandible are consistent with those of capitosauroid stereospondyls in the presence of large muscular pockets on the basal plate, a flattened edentulous parasphenoid, a long basicranial suture, a large hamate process in the mandible, and a falciform crest in the occipital part of the cheek. In order to elucidate the phylogenetic position of Sclerothorax, we performed a cladistic analysis of 18 taxa and 70 characters from all parts of the skeleton. According to our results, Sclerothorax is nested well within the higher stereospondyls, forming the sister taxon of capitosauroids. Palaeobiologically, Sclerothorax is interesting for its several characters believed to correlate with a terrestrial life, although this is contrasted by the possession of well−established lateral line sulci.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Osteology, paleobiology, and relationships of the sauropod dinosaur Sauroposeidon
Autorzy:
Wedel, M J
Cifelli, R L
Sanders, R K
Powiązania:
https://bibliotekanauki.pl/articles/22230.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Oklahoma
pneumatic structure
Sauroposeidon proteles
Sauroposeidon
paleobiology
Cretaceous
Antlers Formation
dinosaur
sauropod
North America
paleontology
Opis:
Sauroposeidon proteles is a large brachiosaurid sauropod recently described from the Antlers Formation (Aptian-Albian) of southeastern Oklahoma. Sauroposeidon represents the culmination of brachiosaurid trends toward lengthening and lightening the neck, and its cervical vertebrae are characterized by extensive pneumatic structures. The elaboration of vertebral air sacs during sauropod evolution produced a variety of internal structure types. We propose a new classification system for this array of vertebral characters, using computed tomography (CT) of pneumatic internal structures. Comparisons with birds suggest that the vertebrae of sauropods were pneumatized by a complex system of air sacs in the thorax and abdomen. The presence of a thoraco-abdominal air sac system in sauropods would dramatically affect current estimates of mass, food intake, and respiratory requirements. Sauroposeidon was one of the last sauropods in the Early Cretaceous of North America; sauropods disappeared from the continent by the early Cenomanian. The demise of sauropods in the Early Cretaceous of North America predates significant radiations of angiosperms, so the decline and extinction of this dinosaur group cannot be linked to changes in flora.
Sauroposeidon proteles to wielki dinozaur z rodziny brachiozaurów, opisany niedawno z formacji Antlers (apt-alb) z południowo-wschodniej Oklahomy (USA). Stanowi on kulminację widocznej u brachiozaurów tendencji do wydłużania szyi i zmniejszania jej ciężaru - kręgi szyjne odznaczają się intensywną pneumatyzacją. Rozrost worków powietrznych w kręgach szyjnych doprowadził do wytworzenia rozmaitych wariantów ich budowy wewnętrznej. Autorzy proponują nowy podział owych struktur anatomicznych, oparty na obserwacji tomograficznej spneumatyzowanych kręgów. Porównania z ptakami sugerują, że kręgi zauropodów mieściły rozbudowany system worków powietrznych obejmujących też tułów. Obecność piersiowo-brzusznych worków powietrznych oznaczałaby radykalne zmiany dotychczasowych oszacowań masy ciała, zapotrzebowania pokarmowego i wydolności oddechowej zauropodów. Zauroposejdon był jednym z ostatnich zauropodów zamieszkujących Amerykę Północną we wczesnej kredzie (we wczesnym cenomanie brak już zauropodów na tym kontynencie). Zniknięcie zauropodów z Ameryki Północnej poprzedziło większe radiacje adaptacyjne roślin okrytozalążkowych, toteż nie można wiąać upadku i zaniku tej grupy dinozaurów ze zmianami flory.
Źródło:
Acta Palaeontologica Polonica; 2000, 45, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dental and tarsal morphology of the European Paleocene-Eocene 'condylarth' mammal Microhyus
Autorzy:
Tabuce, R
Antunes, M.T.
Smith, R.
Smith, T.
Powiązania:
https://bibliotekanauki.pl/articles/23184.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Paleocene
locality
mammal
Eocene
Belgium
Microhyus musculus
postcranial remains
morphology
dental remains
Europe
paleontology
Opis:
New dental and postcranial remains of the alleged louisinine hyopsodontid “condylarth” Microhyus from the European Paleocene/Eocene transition are described, and prompt a reevaluation of the genus. New specimens belonging to Microhyus musculus from Dormaal (MP7, Belgium) provide the first evidence of the lower dentition of the type species. We describe M. musculus? from Pourcy (MP7, France) and cf. Microhyussp. from Berru (MP6a, France). A rich original assemblage of M. reisi from Silveirinha (MP7, Portugal) allows a detailed description of the morphological dental variation within that species. Well−preserved astragali and calcanei from Silveirinha can be confidently attributed to Microhyus reisi. Functional analysis of these elements suggests that Microhyus was a terrestrial mammal capable of rapid running or jumping. The pedal morphology of Microhyus is very similar to that of Paschatherium. These louisinines share some derived characters with the hyopsodontids Apheliscus and Haplomylus (e.g., the occurrence of a cotylar fossa on the astragalus) but they differ from Hyopsodus. Therefore, in view of the pedal morphology alone, the hyopsodontids may be polyphyletic. Given the dental similarities between Microhyus and the early representatives of the order Macroscelidea, we compared the tarsal morphology of louisinines with that of modern macroscelidids (Paleogene tarsal remains are currently unknown for this group). Macroscelidids and louisinines present some similarities in their astragalar morphology; however, the macroscelidid astragalus appears to be too specialized to be compared with that of Microhyus and Paschatherium.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The brachyopoid Hadrokkosaurus bradyi from the early Middle Triassic of Arizona, and a phylogenetic analysis of lower jaw characters in temnospondyl amphibians
Autorzy:
Ruta, M.
Bolt, J.R.
Powiązania:
https://bibliotekanauki.pl/articles/21195.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachyopoid
Hadrokkosaurus bradyi
Early Middle Triassic
Triassic
Arizona
phylogenetic analysis
lower jaw
temnospondyl amphibian
amphibian
Temnospondyli
Chigutisauridae
evolution
paleontology
holotype
Opis:
The holotype of the brachyopoid temnospondyl Hadrokkosaurus bradyi, represented by a right lower jaw ramus, is re−examined based upon new data and revision of various morphological features. Additional fragmentary jaw material referred to this species is briefly described. Prominent features are a large postsymphyseal foramen that is anteriorly open, and prearticular and surangular buttresses for support of the articular. Brachyopoid characters include a long and robust postglenoid area formed by surangular and prearticular, anterior and posterior keels on at least some marginal dentary teeth, and subtriangular outline of the adductor fossa in dorsal view. Five features of the holotype ramus, long thought to be at odds with its brachyopoid or temnospondyl nature, are critically re−evaluated. A phylogenetic analysis of lower jaw characters in temnospondyls retrieves most of the clades found in more comprehensive data sets, but the statistical node support is low. Brachyopoids are monophyletic, with Hadrokkosaurus emerging as their most basal taxon.
Źródło:
Acta Palaeontologica Polonica; 2008, 53, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new kentriodontine dolphin from the middle Miocene of Portugal
Autorzy:
Lambert, O
Estevens, M.
Smith, R.
Powiązania:
https://bibliotekanauki.pl/articles/22701.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Portugal
Miocene
Odontoceti
Middle Miocene
Lower Tagus Basin
Kentriodontidae
new species
dolphin
Cetacea
new genus
Tagicetus joneti
paleontology
Opis:
A nearly complete skull, a partial left scapula, five lumbar vertebrae, and some fragments of ribs of a medium−sized kentriodontid dolphin (Cetacea, Odontoceti) discovered in the middle Miocene of Setúbal Peninsula, Lower Tagus Basin, Portugal, are herein assigned to a new genus and species, Tagicetus joneti. Within the grade−level family Kentriodontidae, the new taxon is referred to the specifically and ecologically diversified subfamily Kentriodontinae, essentially defined by a well−developed posterolateral projection of the nasal. The elongated rostrum, the constriction of the asymmetric premaxillae at the base of the rostrum, the anteriorly elongated palatines, and the elevated vertex of T. joneti suggest closer affinities with the larger, more derived Macrokentriodon morani, from the middle Miocene of Maryland (USA). Among other features, T. joneti differs from the latter in having more numerous maxillary teeth and shorter zygomatic processes of the squamosals. Besides providing additional indications about the evolutionary trends within the Kentriodontinae, this occurrence constitutes the first record of the subfamily from the east coast of the North Atlantic based on a nearly complete skull. Considering their morphological diversity and wide geographic range, the Kentriodontinae may have constituted one of the dominant groups of Miocene oceanic dolphins.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unique bone histology in partial large bone shafts from Upper Triassic of Aust Cliff, England: An early independent experiment in gigantism
Autorzy:
Redelstorff, R.
Sander, P.M.
Galton, P.M.
Powiązania:
https://bibliotekanauki.pl/articles/945884.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Reptilia
Dinosauria
bone
histology
large bone shaft
primary osteon
secondary osteon
osteon
Upper Triassic
Triassic
Aust Cliff
England
gigantism
Opis:
Two giant partial bone shafts, possible femora, from the Rhaetian Bone Bed (Upper Triassic) of Aust Cliff in SW England continue to conceal their origin. The most striking characteristic of these bones is their size, showing that dinosaur-like gigantism had already evolved by the Late Triassic. Based on their characteristic, columnar shaft morphology, it was previously suggested they came from a prosauropod or stegosaur. The bone histology of both specimens is very similar: the cortex is always rather thin, not exceeding 10 mm, and is of fibrolamellar type with longitudinal primary osteons. The primary osteons show a rather unusual feature, the development of a secondary osteon inside the primary one. The bone surface in both specimens shows open vascular canals, suggesting that the animals were still growing at the time of death, but an external fundamental system (EFS) is visible in the outermost cortex of specimen BRSMG Cb3870. The external cortex shows dense growth marks, but their annual nature is difficult to ascertain. The bones are probably dinosaurian, as indicated by the fibrolamellar bone, and possibly belong to an unknown basal sauropodomorph lineage. Alternatively, some very large pseudosuchians may have evolved fibrolamellar bone independently as an adaptation for reaching giant size.
Źródło:
Acta Palaeontologica Polonica; 2014, 59, 3; 607-615
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New genus of dimeropygid trilobites from the earliest Ordovician of Laurentia
Autorzy:
Adrain, J.M.
Westrop, S.R.
Powiązania:
https://bibliotekanauki.pl/articles/21221.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Dimeropygidae
Hystricuridae
Ordovician
silicified fossil
Trilobita
dimeropygid trilobite
new genus
paleontology
trilobite
fossil
Ibexian
locality
stratigraphy
ecology
systematics
Opis:
The new genus Tulepyge includes a type species, T. tulensis nov., from the Barn Canyon Member of the House Formation, western Utah, USA, and T. paucituberculata from the Broom Point Member of the Green Point Formation, western Newfoundland, Canada. Both species are earliest Ordovician in age, with occurrence immediately above the Cambrian–Ordovician boundary. Together with the hystricurid taxon Millardicurus, the new genus is likely to serve as an indicator fossil for the Cambrian–Ordovician boundary in Laurentia, as it is already known from different biofacies on opposite margins of the continent. Tulepyge is not closely comparable with contemporaneous taxa assigned to Hystricuridae but in its dorsally convex and coarsely tuberculate exoskeleton it resembles taxa which have been referred to Dimeropygidae, most of which are considerably younger in age.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reappraisal of the tribosphenidan mammals from the Trinity Group (Aptian-Albian) of Texas and Oklahoma
Autorzy:
Davis, B.M.
Cifelli, R.L.
Powiązania:
https://bibliotekanauki.pl/articles/21832.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
tribosphenidan mammal
mammal
Tribosphenida
Metatheria
Eutheria
Deltatheroida
Trinity Group
Texas
Oklahoma
paleontology
taxonomy
Oklatheridium
Pappotherium
Holoclemensia
Kermackia
Slaughteria
Early Cretaceous
Cretaceous
Opis:
The Trinity therians have long been the focus of attempts to reconstruct the evolutionary history of higher mammals, especially in the context of the development of tribospheny. In this paper, we update the taxonomy of the tribosphenidan taxa known from the Trinity Group and establish with more confidence the premolar/molar count in each. Many isolated specimens can be referred to a specific tooth locus. Additional diversity is revealed within the Deltatheroida, with the description of an additional species of Oklatheridium; Pappotherium is here considered a likely metatherian based on the inferred presence of four molars, while Holoclemensia is a basal eutherian (the opposite of some traditional interpretations). The remainder of the genera, Kermackia and Slaughteria, cannot be allied with either of the living groups of tribosphenidan mammals using the available data. We identify strong morphological diversity within this assemblage of stem taxa, including modifications to the traditional tribosphenic occlusal pattern in Kermackia. Mammalian evolution at the base of the tribosphenidan radiation was complex, and this underscores the need for caution when interpreting the morphology and relationships of taxa known by incomplete material.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strophomenide and orthotetide Silurian brachiopods from the Baltic Region, with particular reference to Lithuanian boreholes
Autorzy:
Musteikis, P
Cocks, L.R.M.
Powiązania:
https://bibliotekanauki.pl/articles/22973.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Strophomenoidea
brachiopod
Plectambonitoidea
Silurian
Orthotetoidea
Lithuania
Baltic region
Brachiopoda
paleontology
borehole
Opis:
Epeiric seas covered the east and west parts of the old craton of Baltica in the Silurian and brachiopods formed a major part of the benthic macrofauna throughout Silurian times (Llandovery to Pridoli). The orders Strophomenida and Orthotetida are conspicuous components of the brachiopod fauna, and thus the genera and species of the superfamilies Plectambonitoidea, Strophomenoidea, and Chilidiopsoidea, which occur in the Silurian of Baltica are reviewed and reidentified in turn, and their individual distributions are assessed within the numerous boreholes of the East Baltic, particularly Lithuania, and attributed to benthic assemblages. The commonest plectambonitoids are Eoplectodonta (Eoplectodonta) (6 species), Leangella (2 species), and Jonesea (2 species); rarer forms include Aegiria and Eoplectodonta (Ygerodiscus), for which the new species E. (Y.) bella is erected from the Lithuanian Wenlock. Eight strophomenoid families occur; the rare Leptaenoideidae only in Gotland (Leptaenoidea, Liljevallia). Strophomenidae are represented by Katastrophomena (4 species), and Pentlandina (2 species); Bellimurina (Cyphomenoidea) is only from Oslo and Gotland. Rafinesquinidae include widespread Leptaena (at least 11 species) and Lepidoleptaena (2 species) with Scamnomena and Crassitestella known only from Gotland and Oslo. In the Amphistrophiidae Amphistrophia is widespread, and Eoamphistrophia, Eocymostrophia, and Mesodouvillina are rare. In the Leptostrophiidae Mesoleptostrophia, Brachyprion, and Protomegastrophia are common, but Eomegastrophia, Eostropheodonta, Erinostrophia, and Palaeoleptostrophia are only recorded from the west in the Baltica Silurian. In the Eopholidostrophidae, Mesopholidostrophia is common and Eopholidostrophia rare, and within the Shaleriidae the genus Shaleria is revised and found to be the only genus within the family Shaleriidae and to contain three subgenera, S. (Shaleria), S. (Shaleriella) and S. (Janiomya). In the Strophonellidae Strophonella was widespread and Eostrophonella rare. Within the Orthotetoidea, Coolinia and Morinorhynchus(with the new Ludlow and Pridoli species M. rubeli from the Lithuanian boreholes erected) are common, and Fardenia, Saughina, and Valdaria again only known from the west Baltic. Most of the genera and many of the speciesreviewed were very widespread and many found in the adjacent Avalonia and Laurentia: a few were even more cosmopolitan.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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