scholarly journals Muscular reconstruction and functional morphology of the hind limb of santacrucian (Early Miocene) sloths (Xenarthra, Folivora) of Patagonia

2015 ◽  
Vol 298 (5) ◽  
pp. 842-864 ◽  
Author(s):  
Néstor Toledo ◽  
M. Susana Bargo ◽  
Sergio F. Vizcaíno
2014 ◽  
Vol 22 (3) ◽  
pp. 355-419 ◽  
Author(s):  
Eli Amson ◽  
Christine Argot ◽  
H. Gregory McDonald ◽  
Christian de Muizon

2012 ◽  
Vol 296 (2) ◽  
pp. 305-325 ◽  
Author(s):  
Néstor Toledo ◽  
M. Susana Bargo ◽  
Sergio F. Vizcaíno

2009 ◽  
Vol 215 (4) ◽  
pp. 383-400 ◽  
Author(s):  
Anthony J. Channon ◽  
Michael M. Günther ◽  
Robin H. Crompton ◽  
Evie E. Vereecke

Lethaia ◽  
2018 ◽  
Vol 52 (1) ◽  
pp. 91-106 ◽  
Author(s):  
Nahuel A. Muñoz ◽  
Néstor Toledo ◽  
Adriana M. Candela ◽  
Sergio F. Vizcaíno

1988 ◽  
Vol 62 (01) ◽  
pp. 83-87 ◽  
Author(s):  
Patricia H. Kelley ◽  
Charles T. Swann

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.


1977 ◽  
Vol 38 (04) ◽  
pp. 0850-0862 ◽  
Author(s):  
Robert G. Schaub ◽  
Ronald Sande ◽  
Kenneth M. Meyers

SummaryPermanent ligation of the feline aorta at the iliac bifurcation is followed by rapid opening of pre-existing collateral blood vessels. However, if ligation is combined with formation of a clot, these protective collateral vessels do not function. This study was undertaken to determine if drugs which alter serotonin function can improve collateral blood flow after arterial thrombosis. Permanent ligations were placed at the iliac bifurcation, circumflex iliac and sixth lumbar arteries in all cats. A clot was produced in the aorta of 27 cats by injection of 0.1 ml of thromboplastin. Ligated clot-occluded cats were untreated (10); had blood serotonin depleted using a single dose of reserpine (0.1 mg/kg i. m.) followed by para-chlorophenylanine (p-CPA) (100 mg/kg orally) every 3 days (9) ; or were treated prior to surgery with a serotonin antagonist cinanserin HC1 (4 mg/kg i. v.) (8). Control cats (18) were acutely ligated. 9 of these cats were untreated, 5 were cinanserin HC1-treated, and 4 were reserpine/p-CPA-treated. Extent of collateral development was assessed by aortograms 3 days after occlusion and by neurologic rating. Aortograms of acutely ligated cats indicated a significant collateral blood flow around the segment of ligated aorta, while ligated clot-occluded cats had a severely depressed hind-limb perfusion. Reserpine/p-CPA-treated ligation clot-occluded cats had aortograms similar to acutely ligated cats. The cinanserin HC1-treated ligation clot-occluded cats had aortograms which indicated hind-limb perfusion was not as adequate as the acutely ligated cats. However, the perfusion of these animals was improved over untreated ligation clot-occluded cats. Neurologic rating correlated with aortograms. These results suggest: 1) the clinical consequences of arterial thrombosis cannot be entirely attributed to mechanical occlusion of an artery, but may be due to depression of protective collateral blood flow induced by thrombosis, 2) serotonin is an important factor in this depression of collateral blood flow, and 3) isolation of the factors responsible for collateral inhibition could permit the development of therapeutic interventions.


2018 ◽  
Vol 52 (1-4) ◽  
pp. 1-9 ◽  
Author(s):  
MT Hussan ◽  
MS Islam ◽  
J Alam

The present study was carried out to determine the morphological structure and the branches of the lumbosacral plexus in the indigenous duck (Anas platyrhynchos domesticus). Six mature indigenous ducks were used in this study. After administering an anesthetic to the birds, the body cavities were opened. The nerves of the lumbosacral plexus were dissected separately and photographed. The lumbosacral plexus consisted of lumbar and sacral plexus innervated to the hind limb. The lumbar plexus was formed by the union of three roots of spinal nerves that included last two and first sacral spinal nerve. Among three roots, second (middle) root was the highest in diameter and the last root was least in diameter. We noticed five branches of the lumbar plexus which included obturator, cutaneous femoral, saphenus, cranial coxal, and the femoral nerve. The six roots of spinal nerves, which contributed to form three trunks, formed the sacral plexus of duck. The three trunks united medial to the acetabular foramen and formed a compact, cylindrical bundle, the ischiatic nerve. The principal branches of the sacral plexus were the tibial and fibular nerves that together made up the ischiatic nerve. Other branches were the caudal coxal nerve, the caudal femoral cutaneous nerve and the muscular branches. This study was the first work on the lumbosacral plexus of duck and its results may serve as a basis for further investigation on this subject.


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