scholarly journals Paleobiology of a large mammal community from the late Pleistocene of Sonora, Mexico

2021 ◽  
pp. 1-13
Author(s):  
Rachel A. Short ◽  
Laura G. Emmert ◽  
Nicholas A. Famoso ◽  
Jeff M. Martin ◽  
Jim I. Mead ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Biodiversity Loss ◽  
Lynx Rufus ◽  
Comprehensive Understanding ◽  
Large Mammal ◽  
Northern Mexico ◽  
The Past ◽  
Community Restructuring ◽  
Land Mammal ◽  
Canis Dirus

Abstract A paleontological deposit near San Clemente de Térapa represents one of the very few Rancholabrean North American Land Mammal Age sites within Sonora, Mexico. During that time, grasslands were common, and the climate included cooler and drier summers and wetter winters than currently experienced in northern Mexico. Here, we demonstrate restructuring in the mammalian community associated with environmental change over the past 40,000 years at Térapa. The fossil community has a similar number of carnivores and herbivores whereas the modern community consists mostly of carnivores. There was also a 97% decrease in mean body size (from 289 kg to 9 kg) because of the loss of megafauna. We further provide an updated review of ungulates and carnivores, recognizing two distinct morphotypes of Equus, including E. scotti and a slighter species; as well as Platygonus compressus; Camelops hesternus; Canis dirus; and Lynx rufus; and the first regional records of Palaeolama mirifica, Procyon lotor, and Smilodon cf. S. fatalis. The Térapa mammals presented here provide a more comprehensive understanding of the faunal community restructuring that occurred in northern Mexico from the late Pleistocene to present day, indicating further potential biodiversity loss with continued warming and drying of the region.

scholarly journals Calibration of Radiocarbon Dates for the Late Pleistocene Using U/Th Dates on Stalagmites

Radiocarbon ◽  
1997 ◽  
Vol 39 (1) ◽  
pp. 27-32 ◽  
Author(s):  
John C. Vogel ◽  
Joel Kronfeld
Keyword(s):  
South Africa ◽  
Magnetic Dipole ◽  
Satisfactory Agreement ◽  
Late Pleistocene ◽  
Calibration Curve ◽  
Dipole Field ◽  
Radiocarbon Dates ◽  
The Past ◽  
The Earth ◽  
Magnetic Dipole Field

Twenty paired 14C and U/Th dates covering most of the past 50,000 yr have been obtained on a stalagmite from the Cango Caves in South Africa as well as some additional age-pairs on two stalagmites from Tasmania that partially fill a gap between 7 ka and 17 ka ago. After allowance is made for the initial apparent 14C ages, the age-pairs between 7 ka and 20 ka show satisfactory agreement with the coral data of Bard et al. (1990, 1993). The results for the Cango stalagmite between 25 ka and 50 ka show the 14C dates to be substantially younger than the U/Th dates except at 49 ka and 29 ka, where near correspondence occurs. The discrepancies may be explained by variations in 14C production caused by changes in the magnetic dipole field of the Earth. A tentative calibration curve for this period is offered.

scholarly journals Didelphidae marsupials (Mammalia, Didelphimorphia) from the Late Pleistocene deposit of the Gruta dos Moura Cave, northern Brazil

2015 ◽  
Vol 87 (1) ◽  
pp. 193-208 ◽  
Author(s):  
Patricia Villa Nova ◽  
Leonardo S. Avilla ◽  
Édison V. Oliveira
Keyword(s):  
Late Pleistocene ◽  
Open Environment ◽  
The Past ◽  
Intimate Association ◽  
Actual Environment ◽  
Gallery Forests ◽  
Northern Brazil ◽  
Open Forests ◽  
Didelphis Albiventris ◽  
Pleistocene Deposit

The present study acknowledges the diversity of fossil marsupials from the Gruta dos Moura cave, as well as environmental and climatic aspects during the Quaternary. The results show that this is the largest diversity of Pleistocene marsupials recorded in a single cave: Didelphis albiventris, D. aurita, Gracilinanus agilis, G. microtarsus, Marmosa murina, Monodelphis brevicaudata, M. domesticaand Sairadelphys tocantinensis. Furthermore, the described specimens are also part of the only fossil assemblage unequivocally referable to the late Pleistocene. Paleontological studies suggest an intimate association with dry and open environments with high abundance of water sources. Since most of the identified taxa are characteristic of open forests and gallery forests, this could represent the actual environment around the Gruta dos Moura cave. Recent studies identified sympatric occurrences between species from open and dry environments and species from humid forests that were identified among our material and are characteristic of humid regions. Therefore, these species could inhabit gallery forests and capons, or even ecotones, inside a dry and open environment. Moreover, the extinction of Sairadelphyscould also indicate that the climatic and environmental conditions changed or that the past environment was more heterogeneous than the current environment of the region.

Clovis Hunting Strategies, or How to Make out on Plentiful Resources

2003 ◽  
Vol 68 (2) ◽  
pp. 333-352 ◽  
Author(s):  
Nicole M. Waguespack ◽  
Todd A. Surovell
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
Diet Breadth ◽  
Ecological Framework ◽  
Hunter Gatherers ◽  
Large Mammal ◽  
Small Game ◽  
Terrestrial Mammals ◽  
Hunting Strategies ◽  
Alternative Diet

Traditionally, hunter-gatherers of the Clovis period have been characterized as specialized hunters of large terrestrial mammals. Recent critiques have attempted to upend this position both empirically and theoretically, alternatively favoring a more generalized foraging economy. In this paper, the distinction between subsistence specialists and generalists is framed in terms of forager selectivity with regards to hunted prey, following a behavioral ecological framework. Faunal data are compiled from 33 Clovis sites and used to test the two alternative diet-breadth hypotheses. The data support the older “Clovis as specialist” model, although some use of small game is apparent. Furthermore, data from modern hunter-gatherers are marshaled to support the theoretical plausibility of specialized large-mammal hunting across North America during the Late Pleistocene.

Late Pleistocene and Holocene tephrostratigraphy of interior Alaska and Yukon: Key beds and chronologies over the past 30,000 years

2016 ◽  
Vol 146 ◽  
pp. 28-53 ◽  
Author(s):  
Lauren J. Davies ◽  
Britta J.L. Jensen ◽  
Duane G. Froese ◽  
Kristi L. Wallace
Keyword(s):  
Late Pleistocene ◽  
The Past ◽  
Interior Alaska

Relative Elevation of Late Pleistocene High Sea Level Stands: Barbados Uplift Rates and their Implications

1973 ◽  
Vol 3 (1) ◽  
pp. 147-153 ◽  
Author(s):  
R.K. Matthews
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Pollen Record ◽  
Sea Levels ◽  
The Past ◽  
Uplift Rates ◽  
Christ Church

AbstractCalculations confirm that the uplift of Barbados during the past 130,000 yr has been at nearly constant relative rates in the Clermont and Christ Church standard traverses, and that sea levels responsible for Barbados terraces I (82,000 yr B.P.) and II (105,000 yr B.P.) attained approximately the same level which was 20–25 m below the level represented by Barbados III (125,000 yr B.P.).Preference for the correlation of Barbados III with the prominent first interglacial 18O peak in stage 5 is stated once again. Further, correlation with Eemian and Pangaion of the European pollen record is suggested.

scholarly journals River of Change: a Model for the Development of Terraces Along the Bow River, Alberta

2004 ◽  
Vol 56 (2-3) ◽  
pp. 155-169 ◽  
Author(s):  
Gerald A. Oetelaar
Keyword(s):  
Late Pleistocene ◽  
Rocky Mountains ◽  
Sediment Load ◽  
Younger Dryas ◽  
Early Holocene ◽  
Stream Power ◽  
Independent Variables ◽  
The Past ◽  
Initial Episode ◽  
Alluvial Terraces

Abstract Researchers working in the Bow River valley have identified a minimum of four alluvial terraces, the upper two of which have been designated as paired terraces. Over the past 35 years, they have attempted to correlate these alluvial landforms and to generate models for the development of the terraces along the section of the Bow River between Calgary and the Rocky Mountains. In this study, Mazama ash and an early Holocene paleosol are used to correlate the terrace suites examined by previous researchers and to generate a model which accounts for the development of the upper two sets of paired terraces. These paired terraces reflect major episodes of aggradation and degradation that result from changes in independent variables such as climate and uplift. The initial episode of aggradation, dating from the late Pleistocene, is the result of paraglacial processes in a sparsely vegetated, yet saturated environment. Following a brief episode of degradation at the end of the Younger Dryas, the second episode of aggradation, dating from 9000 to 5000 BP, is caused by increased sediment load and lowered stream power during the Hypsithermal.

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