scholarly journals Cranial morphometrics of the dire wolf, Canis dirus, at Rancho La Brea: temporal variability and its links to nutrient stress and climate

10.26879/437 ◽  
2014 ◽  
Author(s):  
FROBIN O'Keefe ◽  
WJ Binder ◽  
SR Frost ◽  
RW Sadleir ◽  
B Van Valkenburgh
Keyword(s):  
Temporal Variability ◽  
Nutrient Stress ◽  
Canis Dirus ◽  
Dire Wolf ◽  
Rancho La Brea

scholarly journals Parallels between playbacks and Pleistocene tar seeps suggest sociality in an extinct sabretooth cat, Smilodon

2008 ◽  
Vol 5 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Chris Carbone ◽  
Tom Maddox ◽  
Paul J Funston ◽  
Michael G.L Mills ◽  
Gregory F Grether ◽  
...  
Keyword(s):  
Fossil Record ◽  
Multiple Predators ◽  
Social Species ◽  
Novel Approach ◽  
Spotted Hyenas ◽  
Fossil Records ◽  
Canis Dirus ◽  
Dire Wolf ◽  
Rancho La Brea ◽  
Solitary Species

Inferences concerning the lives of extinct animals are difficult to obtain from the fossil record. Here we present a novel approach to the study of extinct carnivores, using a comparison between fossil records ( n =3324) found in Late Pleistocene tar seeps at Rancho La Brea in North America and counts ( n =4491) from playback experiments used to estimate carnivore abundance in Africa. Playbacks and tar seep deposits represent competitive, potentially dangerous encounters where multiple predators are lured by dying herbivores. Consequently, in both records predatory mammals and birds far outnumber herbivores. In playbacks, two large social species, lions, Panthera leo , and spotted hyenas, Crocuta crocuta , actively moved towards the sounds of distressed prey and made up 84 per cent of individuals attending. Small social species (jackals) were next most common and solitary species of all sizes were rare. In the La Brea record, two species dominated, the presumably social dire wolf Canis dirus (51%), and the sabretooth cat Smilodon fatalis (33%). As in the playbacks, a smaller social canid, the coyote Canis latrans , was third most common (8%), and known solitary species were rare (<4%). The predominance of Smilodon and other striking similarities between playbacks and the fossil record support the conclusion that Smilodon was social.

scholarly journals Hypercarnivorous teeth and healed injuries to Canis chihliensis from Early Pleistocene Nihewan beds, China, support social hunting for ancestral wolves

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9858
Author(s):  
Haowen Tong ◽  
Xi Chen ◽  
Bei Zhang ◽  
Bruce Rothschild ◽  
Stuart White ◽  
...  
Keyword(s):  
Large Body ◽  
Family Care ◽  
Northern China ◽  
Early Pleistocene ◽  
History Of ◽  
Behavioral Evidence ◽  
Displaced Fracture ◽  
Canis Dirus ◽  
Dire Wolf ◽  
Rancho La Brea

Collaborative hunting by complex social groups is a hallmark of large dogs (Mammalia: Carnivora: Canidae), whose teeth also tend to be hypercarnivorous, specialized toward increased cutting edges for meat consumption and robust p4-m1 complex for cracking bone. The deep history of canid pack hunting is, however, obscure because behavioral evidence is rarely preserved in fossils. Dated to the Early Pleistocene (>1.2 Ma), Canis chihliensis from the Nihewan Basin of northern China is one of the earliest canines to feature a large body size and hypercarnivorous dentition. We present the first known record of dental infection in C. chihliensis, likely inflicted by processing hard food, such as bone. Another individual also suffered a displaced fracture of its tibia and, despite such an incapacitating injury, survived the trauma to heal. The long period required for healing the compound fracture is consistent with social hunting and family care (food-sharing) although alternative explanations exist. Comparison with abundant paleopathological records of the putatively pack-hunting Late Pleistocene dire wolf, Canis dirus, at the Rancho La Brea asphalt seeps in southern California, U.S.A., suggests similarity in feeding behavior and sociality between Chinese and American Canis across space and time. Pack hunting in Canis may be traced back to the Early Pleistocene, well before the appearance of modern wolves, but additional evidence is needed for confirmation.

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.

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