Search

Animal mind is tripping blind across the bush elastic; and the planetary sun, swept entirely upside down lingers on the ripples of the tide, flashes of colour. When last did [...]

The fossil record of the earliest primates, purgatoriid plesiadapiforms, has become increasingly well documented during the past two decades, but their dietary preferences remain poorly understood. While the available evidence, which consists mostly of isolated teeth and incomplete jaws with teeth, suggests that purgatoriids were insectivorous to omnivorous, we describe here a new species of Purgatorius, Purgatorius pinecreeensis sp. nov., that extends the range of purgatoriid dental disparity toward greater omnivory than had been known before. Purgatorius pinecreeensis sp. nov., from the early Paleocene (Puercan) Ravenscrag Formation of southwestern Saskatchewan, differs from other species of Purgatorius in having slightly lower crowned teeth with a lower trigonid relative to talonid, blunter and more swollen major cusps, more transverse lower molar paracristids, and m3 with a more robustly developed posterior lobe. Taken together, these specializations enhanced the capacity for crushing and grinding at the expense of orthal shear, and represent the first instance of a modest degree of bunodonty in the family. The discovery of P. pinecreeensis sp. nov., along with other recently reported basal plesiadapiforms from the Puercan and Torrejonian of the northern Western Interior, lends additional support to the notion of a significant primate radiation soon after the Cretaceous-Paleogene extinction event. Le registre fossile des premiers primates, des plesiadapiformes purgatoriides, est de mieux en mieux documente depuis les vingt dernieres annees, mais les preferences alimentaires de ces animaux demeurent mal comprises. Si les preuves disponibles, qui consistent principalement en des dents isolees et des machoires incompletes avec dents, donnent a penser que les purgatoriides etaient insectivores a omnivores, nous decrivons une nouvelle espece de Purgatorius, Purgatorius pinecreeensis sp. nov., qui elargit la repartition de la disparite dentaire des purgatoriides vers une plus grande omnivorie que ce qui etait connu auparavant. Purgatorius pinecreeensis sp. nov., de la Formation de Ravenscrag du Paleocene precoce (Puerceen) du sudouest de la Saskatchewan se distingue d'autres especes de Purgatorius par ses dents a couronnes legerement plus basses presentant un trigonide bas par rapport au talonide, des cuspides majeures plus enflees et moins acerees, des paracristides des molaires inferieures plus transversales et m3 presentant un lobe posterieur plus fortement developpe. Ensemble, ces specialisations ont accru la capacite d'ecrasage et de broyage aux depens du cisaillement orthal et representent le premier exemple d'un degre modeste de bunodontie dans cette famille. La decouverte de P. pinecreeensis sp. nov., combinee a d'autres plesiadapiformes basaux signales recemment du Puerceen et du Torrejonien du nord du Bassin interieur de l'Ouest, appuie la notion voulant qu'une importante radiation des primates ait eu lieu peu apres l'extinction du Cretace-Paleocene. [Traduit par la Redaction], Introduction Of the mammals that diversified immediately after the end-of-Mesozoic extinctions ca. 66 Ma, plesiadapiform primates rank among the least well known, with both their systematics and paleoecology poorly understood. [...]

Cimolestes Marsh is a North American eutherian mammal primarily known from latest Cretaceous deposits in Alberta, Wyoming, Saskatchewan, and Montana. At present, five species of Cimolestes are considered valid, all Lancian in age; they include one of the largest North American Late Cretaceous therian mammals as well as one of the smallest, a size range far exceeding that within other genera of tribosphenic therians contemporary with Cimolestes, such as the leptictoid eutherian Gypsonictops Simpson or genera of alphadontid or pediomyid marsupials. Moreover, the species of Cimolestes display a disparity of dental morphology in addition to size well in excess of interspecific differences within these genera. Given these considerations, Cimolestes is clearly a grade-taxon, uniting species sharing an adaptively subzalambdodont dentition, but showing divergent specializations within this pattern that are inconsistent with monophyly of its presently included species. To correct these imbalances, this paper limits Cimolestes to Cimolestes incisus Marsh and Cimolestes stirtoni Clemens; Cimolestes magnus Clemens and Russell, Cimolestes cerberoides Lillegraven, and Cimolestes propalaeoryctes Lillegraven are reclassified in the new genera Altacreodus, Ambilestes, and Scollardius, respectively. Altacreodus magnus, having a massive shearing dentition, is reconfirmed as showing a relationship to some Tertiary 'creodonts' not shared by other species of Lancian cimolestids; Ambilestes cerberoides exhibits a distinctive molar wear pattern that emphasized horizontal grinding, not orthal shear; Scollardius propalaeoryctes, the smallest species in this revision and having hyper-faunivorous molars, was not ancestral to Paleogene Palaeoryctidae, as indicated in part by contradictions in premolar number and morphology. Cimolestes Marsh est un mammifere eutherien nord-americain connu principalement de depots du Cretace terminal en Alberta, au Wyoming, en Saskatchewan et au Montana. Cinq especes de Cimolestes sont actuellement considerees comme valides, toutes d'age lancien. Elles comprennent un des plus grands mammiferes theriens nord-americains du Cretace tardif, ainsi qu'un des plus petits, une fourchette de tailles qui depasse de loin celles d'autres genres de theriens tribospheniques contemporains de Cimolestes, comme les eutheriens leptictoides Gypsonictops Simpson ou des genres de marsupiaux alphadontides ou pediomyides. En outre, les especes de Cimolestes presentent une disparite sur le plan de la morphologie dentaire, en plus de celle de la taille, beaucoup plus grande que les differences interspecifiques au sein de ces genres. Etant donne ces considerations, il est clair que Cimolestes est un taxon artificiel qui reunit des especes ayant en commun une dentition subzalambdodonte adaptative, mais qui presentent des specialisations divergentes a l'interieur de ce motif incompatibles avec la monophylie des especes qui font actuellement partie du genre. Pour corriger ces desequilibres, le present article restreint Cimolestes a Cimolestes incisus Marsh et Cimolestes stirtoni Clemens; Cimolestes magnus Clemens et Russell, Cimolestes cerberoides Lillegraven et Cimolestes propalaeoryctes Lillegraven sont reclasses dans les nouveaux genres Altacreodus, Ambilestes et Scollardius, respectivement. L'existence d'un lien entre Altacreodus magnus, avec sa dentition cisaillante, et certains <> tertiaires, que ne partagent pas d'autres especes de cimolestides lanciens, est confirme; Ambilestes cerberoides presente un motif d'usure des molaires distinctif qui reflete principalement un broyage horizontal, non un cisaillement orthal; Scollardius propalaeoryctes, la plus petite espece dans la presente revision, qui presente des molaires hyper-faunivores, n'etait pas ancestral aux paleoryctides du Paleogene, comme l'indiquent en partie des contradictions quant au nombre et a la morphologie des premolaires. [Traduit par la Redaction], Introduction Cimolestes Marsh, 1889 is a genus containing five species of small eutherian mammals primarily known from latest Cretaceous (Lancian NALMA) deposits of the North American Western Interior, especially the [...]

There are so many cats in Old Town Nicosia that they often swirl as smoke around your ankles, as cats are wont to do. And where you can't walk for [...]

How clean the picking clean of bones, how upright the righteous beams of homes. How straight and narrow our streets and the lamplight turned fluorescence turned neon turned carbon neutered [...]

draw a line cross it out catch a bird set it free burn the cage take the twisted metal spokes poke out both eyes these are not tears this is [...]

Although stagodontid marsupials are among the most distinctive mammals of Late Cretaceous age in North America, there remain significant gaps in knowledge of their dental anatomy, particularly that of the stratigraphically oldest genus, Eodelphis Matthew, 1916. We report here on stagodontid specimens from the Judithian Belly River Group of southeastern Alberta, Canada, that document what was until now previously unknown parts of the upper and lower premolar dentition of Eodelphis browni Matthew, 1916 and Eodelphis cutleri (Smith Woodward, 1916). The new information further confirms the distinctiveness of both nominal species of Eodelphis, and bolsters previous hypotheses suggesting a close phylogenetic relationship between E. cutleri and the advanced stagodontid Didelphodon Marsh, 1889. Although the new specimens from Alberta suggest that the problematic holotype of 'Boreodonmatutinus' Lambe, 1902 is an upper third premolar, a referral to Eodelphis cannot be made with confidence and the name should continue to be treated as a nomen dubium. Lastly, we report the first occurrence of Didelphodon in strata of the Belly River Group, extending the geological age of the genus into the Judithian, co-eval with species of Eodelphis, and suggesting a significant prior and as yet undiscovered evolutionary history. Si les marsupiaux stagodontides figurent parmi les mammiferes les plus distinctifs du Cretace tardif en Amerique du Nord, d'importantes lacunes persistent dans les connaissances sur leur anatomie dentaire, en particulier celle du plus vieux genre, d'un point de vue stratigraphique, Eodelphis Matthew, 1916. Nous rendons compte de specimens de stagodontides du Groupe de Belly River du Judithien du sud-est de l'Alberta (Canada), qui documentent des parties jusqu'ici inconnues de la dentition premolaire superieure et inferieure d'Eodelphis browni Matthew, 1916 et d'Eodelphis cutleri (Smith Woodward, 1916). Les nouvelles donnees confirment le caractere distinctif des deux especes nominales d'Eodelphis et appuient des hypotheses anterieures qui postulent un lien phylogenetique etroit entre E. cutleri et le stagodontide avance Didelphodon Marsh, 1889. Bien que les nouveaux specimens de l'Alberta indiquent que l'holotype problematique de 'Boreodon matutinus' Lambe, 1902 est une troisieme premolaire superieure, il n'est pas possible de l'affecter avec confiance a Eodelphis et le nom devrait continuer d'etre traite comme un nomen dubium. Enfin, nous signalons la premiere decouverte de Didelphodon dans des strates du Groupe de Belly River, ce qui etend l'age geologique du genre au Judithien, donc contemporain des especes d'Eodelphis, et indiquerait une importante evolution prealable non decouverte a ce jour. [Traduit par le Redaction], Introduction The fossil record of Late Cretaceous marsupials is almost entirely restricted to the Western Interior of North America, where several endemic families are represented, primarily by isolated teeth and [...]

A new tribotherian mammal, Tirotherium aptum gen. et sp. nov., is described from the late Santonian to early Campanian upper Milk River Formation of Verdigris Coulee, southern Alberta, Canada. The new mammal is known only from isolated teeth, five upper and three lower molars. The upper molars represent two or possibly three pre-ultimate loci and are marked by reduction and loss of the stylar shelf anteriorly, loss of the stylocone, a paracone that is larger than the metacone, weakly developed conules, a low, small protocone, and specialized postvallum single-rank shear. The lower molars probably represent two pre-ultimate loci and are characterized by an anteriorly positioned paraconid, trenchant paracristid, small, posterolingual metaconid, a distal metacristid, broadly open trigonid angle, and a short, basined talonid in which the hypoconulid is closer to the entoconid than to the hypoconid. The molars of Tirotherium most closely resemble those of Picopsis Fox, 1980, a tribotherian that also occurs in the upper Milk River Formation, but the molars of Tirotherium are significantly larger than those of Picopsis. Nonetheless, Tirotherium aptum is best classified in the Picopsidae, aboreosphenidan family of tiny mammalian faunivores of uncertain relationships to other tribotherians, and displaying a unique mosaic of primitive and derived characters. Un nouveau mammifere tribotherien, Tirotherium aptum gen. et sp. nov., est decrit de la partie superieure de la Formation de Milk River du Santonien tardif au Campanien precoce de Verdigris Coulee, dans le sud de l'Alberta (Canada). Le nouveau mammifere n'est connu que par des dents isolees, dont cinq molaires superieures et trois molaires inferieures. Les molaires superieures representent deux ou possiblement trois sites pre-ultimes et sont marquees par la reduction et la perte de la plateforme stylaire anterieurement, la perte du stylocone, un paracone plus grand que le metacone, des conules faiblement developpees, un petit protocone bas et un tranchant post-vallum specialise d'un seul rang. Les molaires inferieures representent probablement deux sites pre-ultimes et sont caracterisees par une position anterieure de la paraconide, une paracristide tranchee, une petite metaconide posterolinguale une metacristide distale, un angle trigonide largement ouvert et une courte talonide bassinee dans laquelle l'hypoconulide est plus pres de l'entoconide que de l'hypoconide. Si les molaires de Tirotherium s'apparentent le plus etroitement a celles de Picopsis Fox, 1980, un tribotherien aussi present dans la partie superieure de la Formation de Milk River, les molaires de Tirotherium sont significativement plus grandes que celles de Picopsis. Quoi qu'il en soit, la meilleure affection de Tirotherium aptum est aux Picopsides, une famille de boreosphenides de tout petits mammiferes faunivores dont les liens avec d'autres tribotheriens sont incertains et qui presentent une mosaique unique de caracteres primitifs et derives. [Traduit par le Redaction], Introduction Mammals having a tribosphenic molar dentition--one in which a neomorphic lingual protocone occludes with a lower molar basined talonid or heel--underwent a rapid, global diversification during the Cretaceous. The [...]

Pandemonium hibernalis sp. nov., from a middle? Puercan (earliest Paleocene) locality in the upper Scollard Formation, Wintering Hills, southern Alberta, represents the second discovered occurrence of the enigmatic plesiadapiform primate Pandemonium Van Valen and the first from Canada. The holotype of Pandemonium hibernalis is the only known specimen of Pandemonium documented by multiple teeth from a single individual. Pandemonium hibernalis closely resembles the type species Pandemonium dis from Purgatory Hill, middle-late Puercan, Tullock Formation, Montana, but differs in having wider, more bunodont lower molar crowns and a more expanded posterior talonid lobe of m3, specializations suggesting enhanced capacity for crushing and grinding of soft food materials during mastication. Pandemonium hibernalis joins other recent discoveries in Alberta and elsewhere in the North American Western Interior in documenting a moderate radiation of basal plesiadapiforms that evolved unexpectedly early during primate evolution. Pandemonium hibernalis sp. nov., d'une localite du Puerceen ?moyen (debut du Paleocene) dans la partie superieure de la Formation de Scollard, a Wintering Hills (sud de l'Alberta), represente le deuxieme cas decouvert de primate plesiadapiforme enigmatique Pandemonium Van Valen et le premier exemple au Canada. L'holotype de Pandemonium hibernalis est le seul specimen connu de Pandemonium documente par plusieurs dents d'un seul individu. Pandemonium hibernalis ressemble etroitement a l'espece type Pandemonium dis de Purgatory Hill, du Puerceen moyen a tardif, de la Formation de Tullock, au Montana, mais s'en distingue par des couronnes de molaires inferieures plus bunodontes et larges et un lobe talonide posterieur de m3 agrandi, des specialisations qui semblent indiquer une capacite accrue d'ecrasement et de broyage du bois tendre durant la mastication. Pandemonium hibernalis s'ajoute a d'autres decouvertes recentes en Alberta et ailleurs dans la partie interieure de l'Ouest nord-americain qui documentent un rayonnement modere des plesiadapiformes basaux s'etant produit etonnamment tot durant revolution des primates. [Traduit par le Redaction], Introduction The earliest history of Primates, the order that includes extant prosimians, monkeys, apes, and humans, is poorly known. It is presently limited to fossils from North America, initially from [...]