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Tytuł:
Comodon Kretzoi and Kretzoi, 2000 replaces Phascolodon Simpson, 1925 [Mammalia], not Phascolodon Stein, 1859
Autorzy:
Cifelli, R L
Powiązania:
https://bibliotekanauki.pl/articles/20482.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Mammalia
Phascolodon gidleyi
Comodon
paleontology
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Counting premolars in early eutherian mammals
Autorzy:
Cifelli, R L
Powiązania:
https://bibliotekanauki.pl/articles/21321.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
premolar
Eutheria
mammal
Late Cretaceous
Cretaceous
eutherian group
fossil mammal
North America
paleontology
Opis:
The primitive number of premolars for most eutherian groups is four. A growing number of Cretaceous taxa, however, had five. Regardless of the hypothesis used to explain the discrepancy, or what the primitive condition was, it is generally agreed that the middle (third) tooth of five-premolared taxa is the one not represented in mammals that have only four premolars. Hence the current practice of labeling the teeth as the first through fifth and the first through fourth, depending on how many teeth are observed in the jaw, results in incorrect implied homologies for the last two premolars of the series. Given the long-standing tradition of referring to the premolars as the first through fourth, for most eutherian groups, together with the uncertainties involved in interpreting the difference, the most practical solution is to refer to the disputed tooth by a neutral term, 'Px', as advocated several decades ago.
Źródło:
Acta Palaeontologica Polonica; 2000, 45, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New data on the dentition of the scincomorphan lizard Polyglyphanodon sternbergi
Autorzy:
Nydam, R L
Cifelli, R.L.
Powiązania:
https://bibliotekanauki.pl/articles/22344.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Polyglyphanodontinae
dentition
Polyglyphanodon sternbergi
Late Cretaceous
scincomorphan lizard
Squamata
lizard
North America
paleontology
Opis:
Polyglyphanodon sternbergi Gilmore, 1940 is a large−bodied lizard from the Late Cretaceous of North America distinguished by its transversely oriented, interlocking teeth. Initially the teeth of P. sternbergi were described as smooth and blade−like, but recent discoveries of new specimens from the type locality and re−examination of the original material indicate that the chisel−like teeth of P. sternbergi have small, irregular serrations along the blades. These serrations are similar in size to those found on the teeth of the modern herbivorous lizard Iguana iguana and were likely used in a similar manner to crop vegetation, but was also capable of a degree of oral food processing due to the transverse orientation and interlocking arrangement of the dentition of P. sternbergi. Additionally, the presence of transversely oriented teeth with V−shaped blades in the anterior portion of the tooth row of P. sternbergi represents an additional shared characteristic in tooth structure between P. sternbergi and Dicothodon moorensis, Bicuspidon numerosus, and Peneteius aquilonoius; all transversely−tooth polyglyphandontine lizards from the Cretaceous of North America. It appears that the unique dentitions of Polyglyphanodon sternbergi (large teeth with transverse, serrated blades) and Peneteius aquilonius (small teeth with mammal−like specializations) present by the end of the Cretaceous were derived from a bicuspid, transversely oriented precursor tooth with a V−shaped blade.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multituberculate mammals from near the Early-Late Cretaceous boundary, Cedar Mountain Formation, Utah
Autorzy:
Eaton, J G
Cifelli, R.L.
Powiązania:
https://bibliotekanauki.pl/articles/20067.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
multituberculate
Utah
mammal
Cretaceous
Cedar Mountain Formation
Multituberculata
North America
multituberculate mammal
paleontology
Cimolodonta
Opis:
Herein we describe the oldest well-sampled multituberculate assemblage from the Cretaceous of North America. The fauna is dated at 98.37 Ma and thus approximates the Albian-Cenomanian (Early-Late Cretaceous) boundary. The multituberculate fauna is diverse. Two of the multituberculates (Janumys erebos gen. et sp. n. and an unidentified taxon) are provisionally placed among 'Plagiaulacida'. Another taxon, Ameribaatar zofiae gen. et sp. n., is of uncertain subordinal affinities. The remaining multituberculates appear to represent the advanced suborder Cimolodonta and fall within the 'Paracimexomys group'. We rediagnose Paracimexomys on the basis of the type species, P. priscus, and refer to other species as cf. Paracimexomys (including cf. P. perplexus sp. n.). A revised diagnosis is also provided for Cenomanian Dakotamys. A previously-described species from the Cedar Mountain Formation is placed in Cedaromys gen. n. as C. bestia, together with C. pawus sp. n. Bryceomys is represented in the fauna by B. intermedius sp. n. Relationships of Paracimexomys-group to later taxa remain obscure. However, Bryceomys and Cedaromys share a number of features with Cimolodontidae. Given these resemblances, together with the fact that Cimolodontidae retain certain plesiomorphies (stout lower incisor, gigantoprismatic enamel) with respect to Ptilodontoidea (to which they are commonly referred), we suggest that Cimolodontidae may have arisen from a clade within the 'Paracimexomys group', independent of ptilodontoids.
W pracy opisano najstarszy dobrze opróbowany zespół zębów wieloguzkowców (Multituberculata) z kredy Ameryki Północnej. Fauna formacji Cedar Mountain jest datowana na 98,37 mln lat temu, a więc pochodzi mniej więcej z granicy albu i cenomanu (a więc przełomu wczesnej i późnej kredy). Fauna wieloguzkowców jest zróżnicowana. Dwa z nich (Janumys erebos gen. et sp. n. oraz nieoznaczony takson) tymczasowo zaliczono do ,,Plagiaulacida". Kolejny takson, Ameribaatar zofiae gen. et sp. n., ma niejasną przynależność na szczeblu podrzędu. Wydaje się, że pozostałe wieloguzkowce reprezentują, zaawansowany podrząd Cimolodonta i należałoby je umieścić w ,,grupie Paracimexomys". Diagnoza Paracimexomys została zrewidowana na podstawie gatunku typowego, P. priscus, toteż inne gatunki potraktowano jako cf. Paracimexomys (w tym cf. P. perplexus sp. n.). Zrewidowaną diagnozę uzyskał także cenomański Dakotamys. Opisany juz wcześniej z formacji Cedar Mountain gatunek umieszczony został w nowym rdozaju Cedaromys jako C. bestia, obok C. parvus sp. n. Bryceomys reprezentowany jest w opisywanej faunie przez B. intermedius sp. n. Niejasne pozostają pokrewieństwa między grupą Paracimexomys a późniejszymi taksonami. Bryceomys i Cedaromys mają jednak wiele cech wspólnych z rodziną Cimolodontidae. Ze względu na owe podobieństwa, a także na zachowanie przez Cimolodontidae pewnych plezjomorfii (masywny dolny siekacz, gigantopryzmatczne szkliwo) nieobecnych u Ptilodontoidea (do których się je zwykle zalicza), sugerujemy, ze Cimolodontidae mogły się wyodrębnić z kladu w obrębie ,,grupy Paracimexomys", niezależnie od ptilodontoidów.
Źródło:
Acta Palaeontologica Polonica; 2001, 46, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Primitive boreosphenidan mammal [?Deltatheroida] from the Early Cretaceous of Oklahoma
Autorzy:
Kielan-Jaworowska, Z
Cifelli, R L
Powiązania:
https://bibliotekanauki.pl/articles/21171.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Oklahoma
Early Cretaceous
Boreosphenida
Cretaceous
Atokatheridium boreni
primitive mammal
Deltatheroida
boreosphenidan mammal
Aegialodontidae
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.
Źródło:
Acta Palaeontologica Polonica; 2001, 46, 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:
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:
Middle Miocene carnivorans from the Monarch Mill Formation, Nevada
Autorzy:
Smith, K.
Czaplewski, N.
Cifelli, R.L.
Powiązania:
https://bibliotekanauki.pl/articles/21605.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Middle Miocene
Miocene
carnivore
Mammalia
Mustelidae
Canidae
Ailuridae
Felidae
Monarch Mill Formation
Nevada
Opis:
The lowest part of the Monarch Mill Formation in the Middlegate basin, west-central Nevada, has yielded a middle Miocene (Barstovian Land Mammal Age) vertebrate assemblage, the Eastgate local fauna. Paleobotanical evidence from nearby, nearly contemporaneous fossil leaf assemblages indicates that the Middle Miocene vegetation in the area was mixed coniferous and hardwood forest and chaparral-sclerophyllous shrubland, and suggests that the area had been uplifted to 2700–2800 m paleoaltitude before dropping later to near its present elevation of 1600 m. Thus, the local fauna provides a rare glimpse at a medium- to high-altitude vertebrate community in the intermountain western interior of North America. The local fauna includes the remains of fish, amphibians, reptiles, birds, and 25 families of mammals. Carnivorans, the focus of this study, include six taxa (three of which are new) belonging to four families. Canidae are represented by the borophagine Tomarctus brevirostris and the canine Leptocyon sp. indet. The earliest record and second North American occurrence of the simocyonine ailurid Actiocyon is represented by A. parverratis sp. nov. Two new mustelids, Brevimalictis chikasha gen. et sp. nov. and Negodiaetictis rugatrulleum gen. et sp. nov., may represent Galictinae but are of uncertain subfamilial and tribal affinity. The fourth family is represented by the felid Pseudaelurus sp. indet. Tomarctus brevirostris is limited biochronologically to the Barstovian land mammal age and thus is consistent with the age indicated by other members of the Eastgate local fauna as well as by indirect tephrochronological dates previously associated with the Monarch Mill Formation. Actiocyon parverratis sp. nov. extends the temporal range of the genus Actiocyon from late Clarendonian back to the Barstovian. The Eastgate local fauna improves our understanding of mammalian successions and evolution, during and subsequent to the Mid-Miocene Climatic Optimum (~14–17 Ma).
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dentition and relationships of the Jurassic mammal Shuotherium
Autorzy:
Kielan-Jaworowska, Z
Cifelli, R.L.
Luo, Z.
Powiązania:
https://bibliotekanauki.pl/articles/23028.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
molar
mammal
dentition
China
Shuotherium
Australosphenida
Jurassic
paleontology
Opis:
The Middle Jurassic mammal Shuotherium has lower molars that possess a trigonid and talonid, but are unique in having the talonid situated in front of the trigonid, rather than behind it, as in molars of usual tribosphenic pattern. Shuotherium dongi Chow and Rich, 1982 was based on a dentary bearing seven teeth, originally interpreted as three premolars and four molars. Based on comparison with other groups of early mammals, we reinterpret the premolar–molar boundary in the holotype of S. dongi, and propose a dental formula of four (or more) premolars and three molars. The ultimate lower premolar (previously identified as the first molar) has a completely developed trigonid and no talonid or pseudo−talonid. We hypothesize that the mesial cingulid on molars of Australosphenida is a highly plausible structural antecedent to the pseudo−talonid of Shuotherium. This and other shared, derived features support a relationship of Shuotherium and Australosphenida as sister−taxa. We hypothesize that the common ancestor of Shuotherium + Australosphenida had a global distribution no younger than early Middle Jurassic, and that the respective clades diverged prior to full separation of Gondwanan and Laurasian landmasses.
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Earliest Cretaceous mammals from the western United States
Autorzy:
Cifelli, R.L.
Davis, B.M.
Sames, B.
Powiązania:
https://bibliotekanauki.pl/articles/23353.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Mammalian diversity in North America shifted significantly during the Early Cretaceous, from archaic groups dominant in the well-sampled faunas of the Late Jurassic to advanced forms (including early members of modern clades) by the Albian–Cenomanian. However, the dynamics of this transition are poorly understood, since faunas of earliest Cretaceous age are unknown. Here we describe the first fossil mammals from exposures of the Lakota Formation in the Black Hills of South Dakota, a unit correlated with the upper Berriasian–lower Barremian and positioned stratigraphically between the underlying Morrison Formation and Aptian–Albian units exposed elsewhere in North America. The mammalian fauna from the Lakota Formation is transitional with regard to the North American fossil record, representing a broad spectrum of both Jurassic and Cretaceous lineages: present are “plagiaulacidan” multituberculates allied with Late Jurassic Allodontoidea and Early Cretaceous Plagiaulacoidea; the geologically youngest dryolestoid(s) and “triconodontine” triconodontids (characteristic Late Jurassic taxa from the Morrison Formation); the oldest spalacotheriid “symmetrodont”; the first record of an amphitheriid-like stem zatherian from North America (abundant in the Middle Jurassic–earliest Cretaceous of Europe); and the oldest North American tribosphenic mammal (abundant and diverse on the continent by the end of the Early Cretaceous). Taxa making their first North American appearance in the Lakota Formation (Plagiaulacoidea, including a genus also known from the Purbeck of Britain; Spalacotheriidae, stem Zatheria, Tribosphenida) are also known from the Early Cretaceous of Western Europe, suggesting the possibility that they represent immigrants.
Źródło:
Acta Palaeontologica Polonica; 2014, 59, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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