The legendary dire wolf may not have been a wolf at all

Science ◽  
2021 ◽  
Author(s):  
David Grimm
Keyword(s):  
Dire Wolf

The mysterious extinction of the dire wolf

Nature ◽  
2021 ◽  
Author(s):  
Benjamin Thompson ◽  
Nick Howe ◽  
Noah Baker ◽  
Elie Dolgin
Keyword(s):  
Dire Wolf

Diet and habitat of mesomammals and megamammals from Cedral, San Luis Potosí, México

2016 ◽  
Vol 155 (3) ◽  
pp. 674-684 ◽  
Author(s):  
VÍCTOR ADRIÁN PÉREZ-CRESPO ◽  
JOAQUÍN ARROYO-CABRALES ◽  
PEDRO MORALES-PUENTE ◽  
EDITH CIENFUEGOS-ALVARADO ◽  
FRANCISCO J. OTERO
Keyword(s):  
Dental Enamel ◽  
Mixed Diet ◽  
North Central ◽  
San Luis ◽  
San Luis Potosi ◽  
Oxygen Isotopic ◽  
Tree Coverage ◽  
Ground Sloth ◽  
Dire Wolf ◽  
San Luis Potosí

AbstractUsing carbon and oxygen isotopic relationships from dental enamel, diet and habitat were inferred for both mesomammals and megamammals that lived in Cedral (San Luis Potosi, north-central México) during Late Pleistocene time. δ13C and δ18O values show that bison, some horses and mammoth were eating C4 plants and lived in open areas, while tapir, camel and some llamas ate C3 plants and inhabited closed areas. All other studied herbivores (pronghorn, glyptodont, mylodont ground sloth, javelina, mastodon, and other llamas, horses and mammoth) had a C3/C4 mixed diet, living in areas with some percentage of tree coverage. On the other hand, American lion and dire wolf ate either C4 or mixed-diet herbivores, and short-faced bear ate C3 herbivores. At Cedral, more humid conditions existed than presently, allowing the presence of a forested area near the grassland.

scholarly journals Shape Dimensionality Metrics for Landmark Data

2020 ◽  
Author(s):  
F. Robin O’Keefe
Keyword(s):  
Permutation Test ◽  
Data Sets ◽  
Data Set ◽  
Geometric Morphometric ◽  
Current Test ◽  
Landmark Data ◽  
Measures Of Dispersion ◽  
Effective Dimensionality ◽  
Dire Wolf ◽  
Rancho La Brea

AbstractThe study of modularity in geometric morphometric landmark data has focused attention on an underlying question, that of whole-shape modularity, or the pattern and strength of covariation among all landmarks. Measuring whole-shape modularity allows measurement of the dimensionality of the shape, but current methods used to measure this dimensionality are limited in application. This paper proposes a metric for measuring the “effective dimensionality”, De, of geometric morphometric landmark data based on the Shannon entropy of the eigenvalue vector of the covariance matrix of GPA landmark data. A permutation test to establish null rank deficiency is developed to allow standardization for comparing dimensionality metrics between data sets, and a bootstrap test is employed for measures of dispersion. These novel methods are applied to a data set of 14 landmarks taken from 119 dire wolf jaws from Rancho La Brea. Comparison with the current test based on eigenvalue dispersion demonstrates that the new metric is more sensitive to detecting population differences in whole-shape modularity. The effective dimensionality metric is extended, in the dense semilandmark case, to a measure of “latent dimensionality”, Dl. Latent dimensionality should be comparable among landmark spaces, whether they are homologous or not.

scholarly journals Differential taphonomic effects of petroleum seeps and karstic sinkholes on ancient dire wolf teeth: Hydrocarbon impregnation preserves fossils for chemical and histological analysis

2021 ◽  
Author(s):  
Sabrina B. Sholts ◽  
Leslea J. Hlusko ◽  
Joshua P. Carlson ◽  
Sebastian K. T. S. Wärmländer
Keyword(s):  
Histological Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Chemical Examination ◽  
Yield Information ◽  
Excellent Preservation ◽  
La Brea Tar Pits ◽  
Petroleum Seep ◽  
Dire Wolf

ABSTRACTHistological analysis of teeth can yield information on an organism’s growth and development, facilitating investigations of diet, health, environment, and long-term responses to selective pressures. In the Americas, an extraordinary abundance of Late Pleistocene fossils including teeth has been preserved in petroleum seeps, constituting a major source of information about biotic changes and adaptations at the end of the last glacial period. However, the usefulness of these fossils for histological studies is unclear, due to the unknown taphonomic effects of long-term deposition in petroleum. Here, we compare histological and chemical analyses on dire wolf (Canis dirus) teeth obtained from two different environments, i.e. a petroleum seep (Rancho La Brea tar pits, California) and a carstic sinkhole (Cutler Hammock sinkhole, Florida). Optical and scanning electron microscopy (SEM) together with X-ray diffraction (XRD) analysis revealed excellent preservation of dental microstructure in the seep sample, and the petroleum-induced discoloration was found not to interfere with the histological and chemical examination. By comparison, teeth from the sinkhole sample showed severe degradation and contamination of the dentine by exogenous substances. These results indicate that petroleum seep assemblages are useful, or even ideal, environments for preserving the integrity of fossil material for chemical and histological analysis.

Dire Wolf Systematics and Behavior

Wolf and Man ◽  
1978 ◽  
pp. 179-196
Author(s):  
Marc Stevenson
Keyword(s):  
And Behavior ◽  
Dire Wolf
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