Macrauchenia patachonica Owen, 1838: limb bones morphology, locomotory biomechanics, and paleobiological inferences

Geobios ◽  
2021 ◽  
Author(s):  
R. Ernesto Blanco ◽  
Washington W. Jones ◽  
Lara Yorio ◽  
Andrés Rinderknecht
Keyword(s):  
2021 ◽  
Vol 49 (1) ◽  
pp. 39-52
Author(s):  
V. I. Molodin ◽  
M. S. Nesterova ◽  
L. S. Kobeleva

This article summarizes the findings relating to a spatially localized group of graves at the Andronovo (Fedorovka) cemetery Tartas-1 in the Baraba forest-steppe. Several rows of graves combine with ash pits suggestive of ritual activity. In the infill of graves, there were ash lenses with mammal and fish bones, and potsherds with traces showing the signs of applied heat. Ash had been taken from nearby ash pits with similar infill and artifacts. Faunal remains from graves and ash pits (limb bones of cattle, sheep/goat, and horse) indicate sacrificial offerings. In the ash layer of grave No. 282, there was an incomplete human burial, also believed to be a sacrifice. Features such as the orientation of the graves, their alignment, the position of human remains, and the grave goods in that area are similar to the Andronovo (Fedorovka) burial practice and do not differ from those in other parts of the cemetery. No complete parallels to this rite have been revealed. Some similarities, such as the use of ash, and the presence of animal bones, sacrificial pits, etc. at other sites are listed. A reconstruction of the funerary sequence and possible interpretations are considered. It is concluded that those graves were left by a group of Andronovo migrants who maintained close ties with the native population. Unusual features of the burial rite, therefore, can reflect an attempt to consolidate the immigrant groups on the basis of traditional ritual practices, where the major role was played by fire and its symbols.


Science ◽  
2018 ◽  
Vol 363 (6422) ◽  
pp. 78-80 ◽  
Author(s):  
Tomasz Sulej ◽  
Grzegorz Niedźwiedzki

Here, we describe the dicynodontLisowicia bojani, from the Late Triassic of Poland, a gigantic synapsid with seemingly upright subcursorial limbs that reached an estimated length of more than 4.5 meters, height of 2.6 meters, and body mass of 9 tons.Lisowiciais the youngest undisputed dicynodont and the largest nondinosaurian terrestrial tetrapod from the Triassic. The lack of lines of arrested growth and the highly remodeled cortex of its limb bones suggest permanently rapid growth and recalls that of dinosaurs and mammals. The discovery ofLisowiciaoverturns the established picture of the Triassic megaherbivore radiation as a phenomenon restricted to dinosaurs and shows that stem-group mammals were capable of reaching body sizes that were not attained again in mammalian evolution until the latest Eocene.


Paleobiology ◽  
2001 ◽  
Vol 27 (1) ◽  
pp. 14-38 ◽  
Author(s):  
Richard W. Blob

Analyses of limb joint morphology in nonmammalian therapsid “mammal-like reptiles” have suggested that among many lineages, individual animals were capable of shifting between sprawling and upright hindlimb postures, much like modern crocodilians. The ability to use multiple limb postures thus might have been ancestral to the generally more upright posture that evolved during the transition from “mammal-like reptiles” to mammals. Here I derive a biomechanical model to test this hypothesis through calculations of expected posture-related changes in femoral stress for therapsid taxa using different limb postures. The model incorporates morphological data from fossil specimens and experimental data from force platform experiments on iguanas and alligators.Experimental data suggest that the evolutionary transition from sprawling to nonsprawling posture was accompanied by a change in the predominant loading regime of the limb bones, from torsion to bending. Changes in the cross-sectional morphology of the hindlimb bones between sphenacodontid “pelycosaurs” and gorgonopsid therapsids are consistent with the hypothesis that bending loads increased in importance early in therapsid evolution; thus, bending stresses are an appropriate model for the maximal loads experienced by the limb bones of theriodont therapsids. Results from the model used to estimate stresses in these taxa do not refute the use of both sprawling and more upright stance among basal theriodont therapsids. Thus, the hypothesis that the use of multiple postures was ancestral to the more upright posture typical of most mammals is biomechanically plausible. Model calculations also indicate that the axial rotation of the femur typical in sprawling locomotion can reduce peak bending stresses. Therefore, as experimental data from alligators and iguanas suggest, the evolution of nonsprawling limb posture and kinematics in therapsids might have been accompanied by increased limb bone bending stress.


2013 ◽  
Vol 121 (1) ◽  
pp. 49-62 ◽  
Author(s):  
MASATOMI KUDAKA ◽  
HITOSHI FUKASE ◽  
RYOSUKE KIMURA ◽  
TSUNEHIKO HANIHARA ◽  
HIROFUMI MATSUMURA ◽  
...  
Keyword(s):  

1998 ◽  
Vol 193 (1) ◽  
pp. 61-72 ◽  
Author(s):  
BERNARD WOOD ◽  
LESLIE AIELLO ◽  
CHRISTOPHER WOOD ◽  
CATHY KEY
Keyword(s):  

1895 ◽  
Vol 2 (10) ◽  
pp. 441-443
Author(s):  
W. B. Scott

Hyænodon is one of the genera of fossil mammals which has been for a long time imperfectly known. Excellently preserved skulls have been described and figured by Leidy and Filhol, and some of the limb-bones and vertebræ by De Blainville and Schlosser. Material was, however, lacking for a satisfactory restoration of any of the species, and the specific refeŕence of the scattered bones found has always remained more or less uncertain. In the season of 1894 Mr. Hatcher had the good fortune to discover in the White River beds (Oligocene) of South Dakota a number of remarkably fine specimens pertaining to several species of Hyænodon, which at length enable us to gain an idea of the appearance of this most remarkable animal.


Author(s):  
Elena-Iulia HUZU ◽  
Ioana COFARU ◽  
Nicolae COFARU
Keyword(s):  

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