Mammals from the Upper Cretaceous Oldman Formation, Alberta. V. Eodelphis Matthew, and the evolution of the Stagodontidae (Marsupialia)

1981 ◽  
Vol 18 (2) ◽  
pp. 350-365 ◽  
Author(s):  
Richard C. Fox
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Related Species ◽  
Lower Cretaceous ◽  
Upper Cretaceous ◽  
Time Development ◽  
Special Relationship ◽  
Subsequent Increase ◽  
Closely Related Species ◽  
Primitive Species

The Judithian (Late Cretaceous) stagodontid marsupial Eodelphis Matthew is known from two closely related species, E. cutleri and E. browni, which differ in size and proportions of P3 and robustness of the molars. P1 is shown to be two-rooted in both species and not only in E. cutleri, as previously believed. Known upper molars of Eodelphis lack a stylar cusp D, indicating that neither E. cutleri nor E. browni can be a part of the direct (species) ancestry of the later Cretaceous stagodontid Didelphodon. Evolution of the Stagodontidae probably included derivation of an E. cutleri-like radicle having robust premolars and molars from E. browni-like ancestors, present in North America by Aquilan time; development by the Edmontonian of specialized crushing premolars in primitive species of Didelphodon, descended from ancestors that were similar to E. cutleri in size but had a prominent stylar cusp D on the upper molars; and subsequent increase in size leading to Lancian D. vorax and D. padanicus. Contrary to recent speculation, the Stagodontidae have no special relationship to the Lower Cretaceous Pappotheriidae, which are Eutheria.

Paleontological Evidence Against a Major Geographic Barrier at about the Paleolatitude of Colorado, USA, during the Late Campanian (Late Cretaceous): The Conspicuous Absence of Endemic Subclades of Chasmosaurine Ceratopsid (Horned) Dinosaurs and Its Significance

2018 ◽  
Vol 55 (1) ◽  
pp. 5-18
Author(s):  
Keith Berry
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Related Species ◽  
Western North America ◽  
Closely Related Species ◽  
Geographic Barrier

Several paleontologists have suggested that a major geographic barrier at about the paleolatitude of Colorado either prevented or severely restricted biogeographic exchange between the northern and southern regions of western North America during the Late Campanian. However, the origin and nature of this barrier remains enigmatic. In the present study, this hypothesis is tested by determining whether the diversification of Late Campanian chasmosaurine ceratopsid (horned) dinosaurs was affected by the presence of a barrier or, in other words, whether the biogeographic distribution of closely related species was nonrandom with respect to a line of paleolatitude drawn across Colorado. The results of this test indicate that there could not have been a major geographic barrier, which has implications for paleoclimatic and paleogeographic reconstructions of the Colorado region during its early Laramide history.

The Natural Groups of Species in the Genus Ips De Geer (Coleoptera: Scolytidae) in North America

1963 ◽  
Vol 95 (5) ◽  
pp. 508-516 ◽  
Author(s):  
G. R. Hopping
Keyword(s):  
North America ◽  
North American ◽  
Related Species ◽  
North American Species ◽  
Closely Related Species ◽  
The North ◽  
The World ◽  
Group Relationships ◽  
Natural Groups

AbstractThe genus Ips is one of four closely related genera in the tribe Ipini, sub-tribe Ipina (De Geer 1775, Balachowsky 1949, Nunberg 1954, Hopping 1963). There are now 32 species of Ips recognized in North America, with a few more as yet undescribed. This paper defines the groups of closely related species with observations on the group relationships of species from other parts of the world. Work is in progress to define the North American species in each group.

scholarly journals A new, transitional centrosaurine ceratopsid from the Upper Cretaceous Two Medicine Formation of Montana and the evolution of the ‘ Styracosaurus -line' dinosaurs

2020 ◽  
Vol 7 (4) ◽  
pp. 200284 ◽  
Author(s):  
John P. Wilson ◽  
Michael J. Ryan ◽  
David C. Evans
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Frames Of Reference ◽  
Unique Combination ◽  
Holotype Specimen ◽  
Intermediate Morphology ◽  
Northwestern Montana ◽  
Phylogenetic Framework ◽  
Stratigraphic Succession

Ceratopsids are among the most ubiquitous dinosaur taxa from the Late Cretaceous terrestrial formations of the Western Interior of North America, comprising two subfamilies, Chasmosaurinae and Centrosaurinae. The Two Medicine Formation of northwestern Montana has produced numerous remains of centrosaurine dinosaurs, which represent three taxa previously considered valid: Rubeosaurus ovatus , Einiosaurus procurvicornis and Achelousaurus horneri . Here, we reassess the previous referral of specimens to Rubeousaurus ovatus and demonstrate that this taxon is represented solely by its holotype specimen, which was first diagnosed as Styracosaurus ovatus . One of the specimens previously referred to ‘ Rubeosaurus ’ ovatus instead represents a new eucentrosauran centrosaurine taxon diagnosed here, Stellasaurus ancellae gen. et sp. nov. Stellasaurus expresses a unique combination of eucentrosauran centrosaurine characters, including an elongate nasal horncore, diminutive supraorbital horncores, and a parietal bearing straight, elongate P3 processes, semi-elongate P4 processes and non-elongate P5, P6 and P7 processes. Within the stratigraphic succession of Eucentrosaura, Stellasaurus occurs intermediate to Styracosaurus albertensis and Einiosaurus , and likewise reflects intermediate morphology. Assessed within the stratigraphic, geographical, taphonomic, ontogenetic and phylogenetic framework of Unified Frames of Reference, we fail to reject the hypothesis that Stellasaurus ancellae represents a transitional taxon within an anagenetic lineage of eucentrosauran centrosaurines.

A giant Permian fusulinid from east-central Alaska with comparisons of all giant fusulinids in western North America

1995 ◽  
Vol 69 (5) ◽  
pp. 805-812 ◽  
Author(s):  
Calvin H. Stevens
Keyword(s):  
North America ◽  
Related Species ◽  
The Other ◽  
Lower Permian ◽  
Early Permian ◽  
Western North America ◽  
Closely Related Species ◽  
East Central ◽  
West Texas ◽  
Species Groups

The discovery of a new locality yielding giant Guadalupian (Lower Permian) fusulinids in east-central Alaska extends the range of these forms much farther north than previously known, and into a tectonostratigraphic terrane from which they previously had not been reported. The number of areas from which giant parafusulinids are known in North America is thus raised to eight. Three of these localities are in rocks that previously had been referred to the allochthonous McCloud belt arc, and one, West Texas, is known to have been part of Paleozoic North America. Comparison of species from all areas suggests that there are two closely related species groups: one represented in Texas and Coahuila, and the other represented in Sonora, northern California, northeastern Washington, southern and northern British Columbia, Alaska, and apparently in Texas. These groups may differ because they are of slightly different ages or because interchange between the faunas of Texas–Coahuila area and the other regions was somewhat inhibited during the Early Permian.

Relocation of Alona manueli Sinev & Zawisza 2013 and a new closely related species from the Ecuadorian Andes to the new genus Alpinalona (Cladocera, Chydoridae, Aloninae)

Zootaxa ◽  
2017 ◽  
Vol 4350 (3) ◽  
pp. 563 ◽  
Author(s):  
MIGUEL ALONSO ◽  
ARTEM Y. SINEV
Keyword(s):  
North America ◽  
South America ◽  
High Altitude ◽  
Related Species ◽  
National Park ◽  
New Genus ◽  
Ventral Surface ◽  
Closely Related Species ◽  
Head Pores ◽  
Lateral Head

Alpinalona gen. nov. is described for two species found in high altitude localities of continental North America and South America: Alona manueli (Sinev & Zawisza, 2013) from the Neovolcanic Mexican Axis and Alpinalona cajasi gen. et sp. nov from El Cajas National Park (Ecuador). The new genus is separated from Hexalona and allies by the absence of limb VI and filter plate V;  from Anthalona, Coronatella and the elegans-group by having seven setae on exopodite III, and by the presence of a well-developed seta 1 on the IDL of limb III; from Alona s. str. (quadrangularis-group) and Ovalona, by two main head pores, lateral head pores located close to main pores, and by a bilobed exopodite V; from Ovalona by the presence of seta (i) and inner setae 2–3 on limb I, and setae 4–5 of exopodite III being of same size; and from Alona s. lato by weakly developed marginal denticles of postabdomen, clusters of thin setulae on ventral surface of limb I, and by plumose setae 5–6 of exopodite IV. Alpinalona cajasi sp. nov. can be easily distinguished from A. manueli by the following characteristics: prominent posterodorsal angle of carapace; broader headshield; longer PP distance; and postanal marginal denticles organized into groups.  

The Albian-Cenomanian (Lower Cretaceous-Upper Cretaceous) boundary in Texas and northern Mexico

1986 ◽  
Vol 60 (6) ◽  
pp. 1212-1219 ◽  
Author(s):  
Keith Young
Keyword(s):  
North America ◽  
North Africa ◽  
Lower Cretaceous ◽  
Upper Cretaceous ◽  
Northern Mexico

As first designated by Böse, the Albian-Cenomanian (Lower Cretaceous-Upper Cretaceous) boundary in northern Mexico and Texas is selected at the base of the ammonite zone ofPlesioturrilites brazoensis(Römer). This boundary seems to best agree with boundaries selected for North Africa and Europe, but in North America it may not be the optimum boundary for paleontologists working with foraminiferans.

SEX ATTRACTANT BLENDS FOR STRAWBERRY CUTWORM, AMPHIPOEA INTEROCEANICA (SMITH), AND A CLOSELY RELATED SPECIES, AMPHIPOEA AMERICANA (SPEYER) (LEPIDOPTERA: NOCTUIDAE)

1987 ◽  
Vol 119 (3) ◽  
pp. 301-303
Author(s):  
D.L. Struble ◽  
G.L. Ayre ◽  
J.R. Byers
Keyword(s):  
North America ◽  
Convenient Method ◽  
Related Species ◽  
Sex Pheromones ◽  
Sex Attractant ◽  
Similar Species ◽  
Closely Related Species ◽  
Tetradecenyl Acetate ◽  
Important Pest ◽  
Lepidoptera Noctuidae

The strawberry cutworm, Amphipoea interoceanica (Smith), has recently become an important pest of strawberry plants in Manitoba (Ayre 1980) and Quebec (Mailloux and Bostanian 1985). Larvae damage or kill the plants and commercial plantings are sometimes heavily damaged. Strawberry cutworm is widely distributed in North America and is broadly sympatric with a morphologically similar species, Amphipoea americana (Speyer) (Forbes 1954), which is occasionally a pest of corn (Gibson 1920). Sex pheromones of these species have not been reported, although Roelofs and Comeau (1971) found that males of strawberry cutworm were attracted to (Z)-9-tetradecenyl acetate (abbrev. Z9- 14:Ac). A sex attractant for strawberry cutworm would provide a convenient method for monitoring population levels in the vicinity of strawberry fields.

Two New Species of Ips De Geer (Coleoptera: Scolytidae) from Western Canada and Alaska

1963 ◽  
Vol 95 (2) ◽  
pp. 213-217 ◽  
Author(s):  
G. R. Hopping
Keyword(s):  
New Species ◽  
North America ◽  
Related Species ◽  
Western Canada ◽  
Closely Related Species ◽  
Two New Species

The two species described here were discovered during studies on a revision of the Ips of North America. They belong to a group of closely related species composed of Ips tridens (Mann.), I. engelmanni Sw., I. yoboensis Sw., I. pilifrons Sw. and I. sulcifrons Wood. The females in this group have the lower part of the front of the head slightly elevated as in I. yohoensis to very strongly protuberant as in I. tridens. All of them breed in species of spruce. The males of this group are difficult to determine from external characters alone. Descriptions were made under a magnification of 50X, using 100X occasionally.

Cytotaxonomic studies of Draba species of Canada and Alaska: D. ventosa, D. ruaxes, and D. paysonii

1971 ◽  
Vol 49 (8) ◽  
pp. 1455-1460 ◽  
Author(s):  
Gerald A. Mulligan
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Related Species ◽  
Basic Chromosome Number ◽  
Base Number ◽  
Western North America ◽  
Closely Related Species ◽  
Basic Chromosome ◽  
Hexaploid Species

The cytotaxonomy of three closely related species of Draba, of the mountains of western North America, is discussed and a key is given: D. ventosa A. Gray (2n = 36), D. ruaxes Payson & St. John (2n = ca. 72), and D. paysonii Macbride (2n = 42). Evidence is presented demonstrating that D. ventosa and D. paysonii are triploids reproducing by agamospermy whereas the hexaploid species D. ruaxes is a sexual outcrosser. The former two species produce seed apomictically without any pollen stimulation. Draba ventosa and D. ruaxes have the basic chromosome number x = 12 and D. paysonii has the base number x = 14.

scholarly journals Signatures of selection and genomic diversity of Muskellunge (Esox masquinongy) from two populations in North America.

2021 ◽  
Author(s):  
Josue Chinchilla-Vargas ◽  
Jonathan R. Meerbeek ◽  
Max F. Rothschild ◽  
Francesca Bertolini
Keyword(s):  
Genetic Diversity ◽  
North America ◽  
Related Species ◽  
Reference Genome ◽  
Genetic Differences ◽  
Genomic Diversity ◽  
Closely Related Species ◽  
Esox Masquinongy ◽  
Inbreeding Rate ◽  
Signatures Of Selection

Abstract Background Muskellunge (Esox masquinongy) is the largest and most prized game fish for anglers in North America. However, little is known about Muskellunge genetic diversity in Iowa’s propagation program. We used whole genome sequence from 12 brooding individuals from Iowa and publicly available RAD-seq of 625 individuals from Saint-Lawrence river in Canada to study the genetic differences between populations, analyze signatures of selection that might shed light on environmental adaptations, and evaluate the levels of genetic diversity in both populations. Given that there is no reference genome available for Muskellunge, reads were aligned to the genome of Pike (Esox lucius), a closely-related species.Results Variant calling produced 7,886,471 biallelic variants for the Iowa population and 16,867 high-quality SNPs that overlap with the Canadian samples. The Ti/Tv values were 1.09 and 1.29 for samples from Iowa and Canada, respectively. PCA and Admixture analyses showed a large genetic difference between Canadian and Iowan populations. Moreover, PCA showed clustering by sex in the Iowan population although widow-based Fst did not find outlier regions. Window-based pooled heterozygosity found 6 highly heterozygous windows containing 244 genes in the Iowa population and Fst comparing the Iowa and Canadian populations found 14 windows with Fst values larger than 0.9 containing 641 genes. One enriched GO term (sensory perception of pain) was found through pooled heterozygosity analyzes. Although not significant, several enriched GO terms associated to growth and development were found through Fst analyses.Inbreeding calculated as Froh was 0.03 on average for the Iowa population and 0.32 on average for the Canadian samples. The Canadian inbreeding rate appears to be higher, presumably due to isolation of subpopulations, than the inbreeding rate of the Iowa population.Conclusions This study was the first to document that brood stock Muskellunge from Iowa showed marked genetic differences with the Canadian population. Additionally, despite genetic differentiation based on sex has been observed, no major locus has been detected. Inbreeding does not seem to be an immediate concern for Muskellunge in Iowa, but apparent isolation of subpopulations has caused levels of homozygosity to increase in the Canadian Muskellunge population. Finally, these results prove the validity of using genomes of closely related species to perform genomic analyses when no reference genome assembly is available.

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