The first Mid-Blancan occurrence of Agriotherium (Ursidae) In North America: A record from Hagerman Fossil Beds National Monument, Idaho

2009 ◽  
Vol 83 (4) ◽  
pp. 597-603 ◽  
Author(s):  
Joshua X. Samuels ◽  
Julie A. Meachen-Samuels ◽  
Philip A. Gensler
Keyword(s):  
North America ◽  
National Monument ◽  
Extant Genus ◽  
A Site ◽  
Land Mammal

Members of the subfamily Ursinae dispersed into North America from Africa and Asia during the Miocene, with the appearance of Ursavus (Schlosser, 1899), Indarctos (Pilgrim, 1913), and Agriotherium (Wagner, 1837) (Dalquest, 1986; Miller and Carranza-Castañeda, 1996; Hunt, 1998). However, none of these genera were thought to have survived past the Hemphillian Land Mammal Age in North America. It is thought that these genera were replaced, and possibly out-competed, by members of the extant genus Ursus (Linnaeus, 1758), or Plionarctos (Frick, 1926), as suggested by several sources (Bjork, 1970; Dalquest, 1986; Bell et al., 2004). It has also been suggested that the Ursavini (Agriotherium and Indarctos) may have given rise to the extant ursids and the Tremarctinae (Harrison, 1983; Miller and Carranza-Castañeda, 1996). Of the Ursavini, Agriotherium is consistently found in the Hemphillian Land Mammal Age, and so is used as an index fossil in that its absence is assumed to indicate that a site is Blancan rather than Hemphillian (Lundelius et al., 1987; Bell et al., 2004; Hunt, 2004).

scholarly journals Additional records and stratigraphic distribution of the middle Eocene carettochelyid turtle Anosteira pulchra from the Uinta Formation of Utah, North America

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9775
Author(s):  
Brent Adrian ◽  
Patricia A. Holroyd ◽  
J. Howard Hutchison ◽  
KE Beth Townsend
Keyword(s):  
North America ◽  
New Records ◽  
Middle Eocene ◽  
Single Species ◽  
Uinta Basin ◽  
Stratigraphic Framework ◽  
Multiple Levels ◽  
Land Mammal ◽  
Anatomical Information ◽  
Insight Into

Background Anosteira pulchra is one of two species of the obligately-aquatic freshwater clade Carettochelyidae (pig-nosed turtles) from the Eocene of North America. Anosteira pulchra is typically rare in collections, and their distribution is poorly documented. The Uinta Formation [Fm.] contains a diverse assemblage of turtles from the Uintan North American Land Mammal Age. Whereas turtles are abundantly preserved in the Uinta Fm., A. pulchra has been reported only from a few specimens in the Uinta C Member. Methods We describe new records of Anosteira pulchra from the Uinta Basin and analyze the distribution of 95 specimens from multiple repositories in the previously published stratigraphic framework of the middle and upper Uinta Fm. Results Here we report the first records of the species from the Uinta B interval, document it from multiple levels within the stratigraphic section and examine its uncommon appearance in only approximately 5% of localities where turtles have been systematically collected. This study details and extends the range of A. pulchra in the Uinta Fm. and demonstrates the presence of the taxon in significantly lower stratigraphic layers. These newly described fossils include previously unknown elements and associated trace fossils, with new anatomical information presented. This study provides insight into the taxonomy of Anosteira spp. in the middle Eocene, and suggests the presence of a single species, though no synonymy is defined here due to limits in Bridger material.

Geographic Patterns of Interspecific Hybridization between Spotted Knapweed (Centaurea stoebe) and Diffuse Knapweed (C. diffusa)

2009 ◽  
Vol 2 (1) ◽  
pp. 55-69 ◽  
Author(s):  
Amy C. Blair ◽  
Ruth A. Hufbauer
Keyword(s):  
North America ◽  
North American ◽  
Management Strategies ◽  
Spotted Knapweed ◽  
The North ◽  
Hybrid Swarms ◽  
Hybrid Plants ◽  
Introduced Range ◽  
Diffuse Knapweed ◽  
A Site

AbstractHybridization between species has the potential to change invasion dynamics. Field observations suggest that spotted knapweed and diffuse knapweed, two ecologically and economically destructive invasive plants, hybridize in their introduced range. As a first step towards understanding whether hybridization has affected the dynamics of the invasion of these species, we conducted field surveys in the introduced (North American) and native (European) ranges to discern patterns of hybridization and measured fitness-related traits among field hybrids and parental species. In North America we detected plants with hybrid morphology in 97% of the diffuse knapweed sites (n= 40); such hybrid plants were taller and more often exhibited polycarpy than plants with typical diffuse knapweed morphology. Hybrids were not detected in North American spotted knapweed sites (n= 22). In most regions surveyed in Europe, diffuse knapweed and spotted knapweed were isolated from each other and existed as distinct, nonhybridizing species. However, in Ukraine, the two species frequently coexisted within a site, resulting in hybrid swarms. On average, the plants from the North American diffuse knapweed sites (including plants with both diffuse and hybrid morphology), were larger than the apparently pure diffuse knapweed in the native range. The cross-continental patterns of hybridization likely are explained by differences in cytology. It recently has been confirmed that the spotted knapweed in North America is tetraploid whereas the diffuse knapweed is diploid. Genetic incompatibilities associated with these two cytotypes likely prevent ongoing hybridization. We hypothesize that hybrid individuals were introduced to North America along with diffuse knapweed. Because plants with hybrid morphology are found in nearly all North American diffuse knapweed sites, the introduction of hybrids likely occurred early in the invasion of diffuse knapweed. Thus, although the presence of hybrids might facilitate the ongoing invasion of diffuse knapweed into North America, elevated concern regarding their presence might not be warranted. Because such individuals are not likely to represent a new hybridization event, currently effective management strategies used in diffuse knapweed sites should not need alteration.

WEATHERING PITS VERSUS TRAMPLE MARKS: A REINTERPRETATION OF THE “DINOSAUR DANCE FLOOR”: A JURASSIC NAVAJO SANDSTONE SURFACE IN THE VERMILION CLIFFS NATIONAL MONUMENT, ARIZONA

Palaios ◽  
2021 ◽  
Vol 36 (11) ◽  
pp. 331-338
Author(s):  
BRENT H. BREITHAUPT ◽  
MARJORIE A. CHAN ◽  
WINSTON M. SEILER ◽  
NEFFRA A. MATTHEWS
Keyword(s):  
Direct Evidence ◽  
Lower Jurassic ◽  
Dance Floor ◽  
Navajo Sandstone ◽  
National Monument ◽  
A Site

ABSTRACT Within the eolian Lower Jurassic Navajo Sandstone, exposed in the Coyote Buttes area of Vermilion Cliffs National Monument in Arizona, a site (informally known as the “Dinosaur Dance Floor”) is reinterpreted as an enigmatic, modified (possibly pedogenic) eolian surface that was exposed and further modified and accentuated by modern weathering and erosion. The resultant surface is covered with small, shallow potholes or weathering pits, with no direct evidence of dinosaur activity.

scholarly journals Tree-Ring Records of Near-Younger Dryas Time in Central North America—Preliminary Results from the Lincoln Quarry Site, Central Illinois, Usa

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 933-941 ◽  
Author(s):  
Irina P Panyushkina ◽  
Steven W Leavitt ◽  
Alex Wiedenhoeft ◽  
Sarah Noggle ◽  
Brandon Curry ◽  
...  
Keyword(s):  
North America ◽  
Tree Ring ◽  
Environmental Changes ◽  
Ring Width ◽  
Younger Dryas ◽  
Late Glacial ◽  
Radiocarbon Dates ◽  
Initial Sampling ◽  
Central Illinois ◽  
A Site

The abrupt millennial-scale changes associated with the Younger Dryas (YD) event (“chronozone”) near the dawn of the Holocene are at least hemispheric, if not global, in extent. Evidence for the YD cold excursion is abundant in Europe but fairly meager in central North America. We are engaged in an investigation of high-resolution environmental changes in mid-North America over several millennia (about 10,000 to 14,000 BP) during the Late Glacial–Early Holocene transition, including the YD interval. Several sites containing logs or stumps have been identified and we are in the process of initial sampling or re-sampling them for this project. Here, we report on a site in central Illinois containing a deposit of logs initially thought to be of YD age preserved in alluvial sands. The assemblage of wood represents hardwood (angiosperm) trees, and the ring-width characteristics are favorable to developing formal tree-ring chronologies. However, 4 new radiocarbon dates indicate deposition of wood may have taken place over at least 8000 14C yr (6000–14,000 BP). This complicates the effort to develop a single floating chronology of several hundred years at this site, but it may provide wood from a restricted region over a long period of time from which to develop a sequence of floating chronologies, the timing of deposition and preservation of which could be related to paleoclimatic events and conditions.

Ecogeography and the Great American Interchange

Paleobiology ◽  
1991 ◽  
Vol 17 (3) ◽  
pp. 266-280 ◽  
Author(s):  
S. David Webb
Keyword(s):  
North America ◽  
South America ◽  
North American ◽  
Mammalian Fauna ◽  
The South ◽  
Land Bridge ◽  
Southern Mexico ◽  
The North ◽  
Land Mammal ◽  
The Impact

When the isthmian land bridge triggered the Great American Interchange, a large majority of land-mammal families crossed reciprocally between North and South America at about 2.5 Ma (i.e., Late Pliocene). Initially land-mammal dynamics proceeded as predicted by equilibrium theory, with roughly equal reciprocal mingling on both continents. Also as predicted, the impact of the interchange faded in North America after about 1 m.y. In South America, contrary to such predictions, the interchange became decidedly unbalanced: during the Pleistocene, groups of North American origin continued to diversify at exponential rates. Whereas only about 10% of North American genera are derived from southern immigrants, more than half of the modern mammalian fauna of South America, measured at the generic level, stems from northern immigrants. In addition, extinctions more severely decimated interchange taxa in North America, where six families were lost, than in South America, where only two immigrant families became extinct.This paper presents a two-phase ecogeographic model to explain the asymmetrical results of the land-mammal interchange. During the humid interglacial phase, the tropics were dominated by rain forests, and the principal biotic movement was from Amazonia to Central America and southern Mexico. During the more arid glacial phase, savanna habitats extended broadly right through tropical latitudes. Because the source area in the temperate north was six times as large as that in the south, immigrants from the north outnumbered those from the south. One prediction of this hypothesis is that immigrants from the north generally should reach higher latitudes in South America than the opposing contingent of land-mammal taxa in North America. Another prediction is that successful interchange families from the north should experience much of their phylogenetic diversification in low latitudes of North America before the interchange. Insofar as these predictions can be tested, they appear to be upheld.

On a Pleistocene human occupation at Pedra Furada, Brazil

Antiquity ◽  
1994 ◽  
Vol 68 (261) ◽  
pp. 695-714 ◽  
Author(s):  
David J. Meltzer ◽  
James M. Adovasio ◽  
Tom D. Dillehay
Keyword(s):  
North America ◽  
Special Interest ◽  
Northeastern Brazil ◽  
South American ◽  
Archaeological Record ◽  
Human Occupation ◽  
Wide Range ◽  
Peopling Of The Americas ◽  
Monte Verde ◽  
A Site

The last decades of fieldwork have not decisively upset the long-held view that the settlement of the Americas occurred in the very latest Pleistocene, as marked in North America by the Clovis archaeological horizon at about 11,200 years ago, and by a variety of contemporaneous South American industries. Yet there are several sites that may prove to be older, among them Pedra Furada, in the thorn forest of northeastern Brazil, a large and remarkable rock-shelter, whose Pleistocene deposits have been interpreted as containing clear evidence of human occupation.This paper offers a considered view of Pedra Furada from three archaeologists with a wide range of experiences in sites of all ages in the Americas and elsewhere, but who also share a special interest and expertise in the issues Pedra Furada has raised: Meltzer from long study of the peopling of the Americas and the frame of thinking within which we address that issue (Meltzer 1993a; 1993b); Adovasio from his intensive excavations and analysis of the Meadowcroft Rockshelter in Pennsylvania, the prime North American pre-Clovis candidate (Adovasio et al. 1990; Donahue & Adovasio 1990); and Dillehay from his work at the Monte Verde site in Chile, a site in which extraordinary preservation has produced a rich archaeological record with radiocarbon ages in excess of 12,500 years b.p. (Dillehay 1989a; in press). At the invitation of the Pedra Furada team, the three travelled to Brazil last December to participate in an international conference on the peopling of the Americas, and see first-hand the evidence from Pedra Furada.

scholarly journals Maybe So, Maybe Not: Canis lepophagus at Hagerman Fossil Beds National Monument, Idaho, USA

2022 ◽  
Author(s):  
Kari A. Prassack ◽  
Laura C. Walkup
Keyword(s):  
North American ◽  
National Park ◽  
National Park Service ◽  
Geological Survey ◽  
National Monument ◽  
South Central ◽  
Park Service ◽  
Land Mammal ◽  
The U.S ◽  
Central Idaho

AbstractA canid dentary is described from the Pliocene Glenns Ferry Formation at Hagerman Fossil Beds National Monument, south-central Idaho, USA. The specimen possesses traits in alliance with and measurements falling within or exceeding those of Canis lepophagus. The dentary, along with a tarsal IV (cuboid) and an exploded canine come from the base of the fossiliferous Sahara complex within the monument. Improved geochronologic control provided by new tephrochronologic mapping by the U.S. Geological Survey-National Park Service Hagerman Paleontology, Environments, and Tephrochronology Project supports an interpolated age of approximately 3.9 Ma, placing it in the early Blancan North American Land Mammal Age. It is conservatively referred to herein as Canis aff. C. lepophagus with the caveat that it is an early and robust example of that species. A smaller canid, initially assigned to Canis lepophagus and then to Canis ferox, is also known from Hagerman. Most specimens of Canis ferox, including the holotype, were recently reassigned to Eucyon ferox, but specimens from the Hagerman and Rexroad faunas were left as Canis sp. and possibly attributed to C. lepophagus. We agree that these smaller canids belong in Canis and not Eucyon but reject placing them within C. lepophagus; we refer to them here as Hagerman-Rexroad Canis. This study confirms the presence of two approximately coyote-sized canids at Hagerman and adds to the growing list of carnivorans now known from these fossil beds.

scholarly journals Luminescence Dates from the Tuinier Farm Site (41HP237), Hopkins County, Texas

2011 ◽  
Author(s):  
Timothy K. Perttula ◽  
James K. Feathers
Keyword(s):  
North America ◽  
Small Sample ◽  
Luminescence Dating ◽  
East Texas ◽  
Target Event ◽  
Considerable Success ◽  
A Site

The luminescence dating of ceramics has been applied with some considerable success in a variety of settings—and on different ceramic wares—in North America, but since the days of Alpha Analytic (a subsidiary of Beta Analytic) in the early to mid-1980s, there have been no luminescence dating of Caddo ceramic wares in Northeast or East Texas. Given the abundance of ceramics of several different kinds and styles at all Caddo sites, the luminescence dating of both plain and decorated sherds recovered in situ from these many sites should be explored since it is a method “that dates the manufacture and use of…ceramic objects [that] provide a closer relationship between the target event [when a site is occupied] and the dated event [the age determined by the luminescence on a sherd]. Luminescence is particularly well suited for the dating of ceramics since the method measures the time elapsed since vessels were last heated, usually corresponding to manufacture or use." In this article, we discuss the results of recent luminescence dating on a small sample of Caddo ceramic sherds at the Tuinier Farm site (41HP237).

Bonhoeffer in North America

2019 ◽  
pp. 23-38
Author(s):  
Gary Dorrien
Keyword(s):  
New York ◽  
North America ◽  
Social Gospel ◽  
Theological Seminary ◽  
Dietrich Bonhoeffer ◽  
Negative Experience ◽  
American Pragmatism ◽  
Social Ministry ◽  
Church And Community ◽  
A Site

Dietrich Bonhoeffer studied at Union Theological Seminary in 1930/1. He had decided to go to Union because it specialized in social ministry, and by this time he had misgivings about his theory-laden Habilitation thesis. He was also interested in Union because it was in New York, a site of cultural adventure. While he thought he was open to being challenged and taught by Union faculty, he quickly concluded that Union did not teach ‘real theology’. Bonhoeffer’s mostly negative experience at Union was redeemed by his friendships with Union classmates, his participation in church and community courses, his study of American pragmatism, his introduction to black Social Gospel preaching and worship at Abyssinian Church, and his shift toward Christian pacifism, the latter notwithstanding his complaint that Union reduced Christianity to Social Gospel pacifism.

scholarly journals Interference to Hardwood Regeneration in Northeastern North America: The Effects of Raspberries (Rubus spp.) Following Clearcutting and Shelterwood Methods

2006 ◽  
Vol 23 (4) ◽  
pp. 288-296 ◽  
Author(s):  
Pablo J. Donoso ◽  
Ralph D. Nyland
Keyword(s):  
North America ◽  
Tree Regeneration ◽  
Rubus Idaeus ◽  
Tree Seedlings ◽  
Northeastern North America ◽  
Northern Hardwood ◽  
Hardwood Species ◽  
Closed Canopy ◽  
Shallow Soils ◽  
A Site

Abstract Rubus often becomes the most prominent vegetation within 2–3 years following heavy overstory disturbances at mesic sites within temperate forests of northeastern North America. This review draws together available literature about its dynamics and effects, focusing primarilyon raspberry (Rubus idaeus L.) and blackberry (Rubus allegheniensis Porter). It covers some key ecologic functions of raspberries related to nutrient leaching, microclimate near the ground, and organic matter decomposition. It also summarizes published information about the potentialinterference with desirable tree regeneration at northern hardwood sites within the region. The review concentrates on raspberry (Rubus spp.) dynamics and effects following clearcutting, shelterwood method, and other heavy overstory disturbances. Findings indicate that raspberries commonlydevelop into a dense cover after cutting and other overstory disturbances reduce the stocking of northern hardwood stands by 40% or more. Ecologically, they shade the ground, intercept and transpire water, and reduce the rate of litter decomposition and nutrient cycling, all of whichreduce leaching from a site. On poorly drained, droughty, and shallow soils, raspberries have reportedly delayed the development of hardwood regeneration. However, by 5–7 years, rapidly developing hardwood species have normally grown through the Rubus at most other sites, andthe emerging tree community has formed a closed canopy by 10–15 years. The presence of abundant, well-developed, and well-distributed advance tree regeneration ensures prompt restocking of new hardwoods, seems to minimize the potential for interference by raspberries, and precludes anyneed to release the tree seedlings from a raspberry cover. North. J. Appl. For. 23(4):288 –296.

Sign in / Sign up

Export Citation Format

Share Document