scholarly journals Unusual pectoral apparatus in a predatory dinosaur resolves avian wishbone homology

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Cau ◽  
Vincent Beyrand ◽  
Rinchen Barsbold ◽  
Khishigjav Tsogtbaatar ◽  
Pascal Godefroit
Keyword(s):  
Pectoral Girdle ◽  
Articular Facet ◽  
Theropod Dinosaurs ◽  
Shoulder Region

AbstractThe furcula is a distinctive element of the pectoral skeleton in birds, which strengthens the shoulder region to withstand the rigor of flight. Although its origin among theropod dinosaurs is now well-supported, the homology of the furcula relative to the elements of the tetrapod pectoral girdle (i.e., interclavicle vs clavicles) remains controversial. Here, we report the identification of the furcula in the birdlike theropod Halszkaraptor escuilliei. The bone is unique among furculae in non-avian dinosaurs in bearing a visceral articular facet in the hypocleideal end firmly joined to and overlapped by the sternal plates, a topographical pattern that supports the primary homology of the furcula with the interclavicle. The transformation of the interclavicle into the furcula in early theropods is correlated to the loss of the clavicles, and reinforced the interconnection between the contralateral scapulocoracoids, while relaxing the bridge between the scapulocoracoids with the sternum. The function of the forelimbs in theropod ancestors shifted from being a component of the locomotory quadrupedal module to an independent module specialized to grasping. The later evolution of novel locomotory modules among maniraptoran theropods, involving the forelimbs, drove the re-acquisition of a tighter connection between the scapulocoracoids and the interclavicle with the sternal complex.

New information on the pectoral girdle and vertebral column in Lupeosaurus (Reptilia, Pelycosauria)

1989 ◽  
Vol 26 (7) ◽  
pp. 1343-1349 ◽  
Author(s):  
Stuart S. Sumida
Keyword(s):  
Cross Section ◽  
Vertebral Column ◽  
Cervical Vertebrae ◽  
Lower Permian ◽  
Pectoral Girdle ◽  
Postcranial Skeleton ◽  
Posterior Edge ◽  
Articular Facet ◽  
New Information

UCLA VP 1651, a new specimen from the Lower Permian Admiral Formation of Archer County, Texas, provides information on heretofore unknown portions of the postcranial skeleton of the large pelycosaur Lupeosaurus. Presacral neural spines are elongate and have a subcircular cross section. Laterally directed tubercles are not present on any of the neural spines. Cervical vertebrae appear to have elongate neural spines and sharply keeled centra. Transverse processes are positioned relatively high above the bases of the centra through the length of axial column. The pattern of tilting of the neural spines is similar to that in the primitive edaphosaur Ianthasaurus hardestii. The proximal end of the first sacral rib contributes significantly to the intervertebral articular facet usually formed by the centra. The sacral ribs do not appear to fuse with one another distally. The ventral clavicular plate is greatly expanded anteriorly. The posterior edge of the subcoracoscapular fossa is very well defined. The available morphological information does not warrant a separate familial designation for the genus Lupeosaurus. Despite the lack of laterally directed tubercles of the neural spines, Lupeosaurus appears to be referrable to the Edaphosauridae. However, in the absence of cranial materials, this association must remain tentative. Although this description adds new information for only a restricted portion of the skeleton, it does appear to confirm the existence of a distinct, albeit rare, pelycosaur from the extensively studied fauna of the Lower Permian.

The origin and early diversification of birds

Paleobiology ◽  
1986 ◽  
Vol 12 (4) ◽  
pp. 383-399 ◽  
Author(s):  
Joel Cracraft
Keyword(s):  
Phylogenetic Relationships ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Morphological Data ◽  
Phylogenetic Position ◽  
Pectoral Girdle ◽  
Avian Evolution ◽  
Theropod Dinosaurs ◽  
Early Diversification ◽  
Time Of Origin

Numerical cladistic analysis of 73 cranial and postcranial characters has resulted in a highly corroborated hypothesis describing the phylogenetic pattern of early avian evolution. Using “non-avian theropod” dinosaurs as a comparative outgroup and root for the tree, the analysis confirmed Archaeopteryx to be the sister-group of all remaining avian taxa, or Ornithurae. This latter taxon is subdivided into two lineages, the Hesperornithiformes and the Carinatae. The carinates, in turn, were also resolved into two sister-groups, the Ichthyornithiformes and the modern birds, or Neornithes. This paper provides morphological data corroborating the divergence of the two basal clades of the Neornithes: the Palaeognathae (tinamous and ratites) and Neognathae (all other modern birds). The phylogenetic relationships of four important Cretaceous taxa were also investigated, but these fossil taxa were too fragmentary to determine their phylogenetic position unambiguously. Alexornis and Ambiortus are both carinates, but their relationships cannot be resolved in greater detail. The relationships of the Enantiornithes may lie within the Carinatae or these two taxa may be sister-groups. Gobipteryx is a neornithine and possibly the sister-group of the Palaeognathae.This analysis indicates that major patterns of morphological change took place at the time of origin of the ancestors of the Ornithurae and the Carinatae. Ornithurine innovations included major changes throughout the skeleton, whereas those of the carinates, while substantial, were primarily restricted to the pectoral girdle and forelimb. The phylogenetic results, in conjunction with the known ages of fossil taxa, indicate that the early lineages of birds very likely arose in the Jurassic. The early cladistic events within the neornithine lineage are also more ancient than generally recognized, and may well extend back to the early Cretaceous.

scholarly journals The coracoscapular joint of neornithine birds—extensive homoplasy in a widely neglected articular surface of the avian pectoral girdle and its possible functional correlates

Zoomorphology ◽  
2021 ◽  
Author(s):  
Gerald Mayr
Keyword(s):  
Morphological Variation ◽  
Fossil Record ◽  
Articular Surface ◽  
Ancestral State Reconstruction ◽  
Pectoral Girdle ◽  
Ancestral State ◽  
State Reconstruction ◽  
Articular Facet ◽  
Stem Group ◽  
Large Crop

AbstractA survey is given of the morphological variation of the coracoscapular joint of neornithine birds. In Mesozoic stem group representatives, the coracoid exhibits a deeply concave cotyla scapularis, which articulates with a globose tuberculum coracoideum of the scapula. This morphology is likely to be functionally related to the development of a powerful supracoracoideus muscle and the formation of a triosseal canal as a pulley for the tendon of this muscle. In neornithine birds, the coracoid articulates with the scapula either via a concave cotyla or a flat facies articularis, with the latter largely restricting movements of the coracoid to the paramedian plane. Ancestral state reconstruction suggests that a cotyla scapularis is plesiomorphic for Neornithes and that a flat facies articularis scapularis evolved at least 13 times independently within the clade. For several lineages, the transition to a flat facies articularis scapularis can be traced in the fossil record, and the replacement of a cup-shaped cotyla by a flat articular facet seems to have been due to various functional demands. Often, a flat facies articularis scapularis is associated with reduced shafts of the furcula. A weakly developed furcula enables transverse movements of the coracoid and therefore enables a restriction of the mobility of the coracoscapular joint to the paramedian plane. In taxa with a large crop, a flat facies articularis scapularis is likely to be associated with a reorganization of the pectoral musculature, whereas in procellariiform birds, the transition from a cotyla to a facies articularis appears to have been correlated with the capacity for sustained soaring without wing flapping.

Sleep Impairment

2009 ◽  
Vol 14 (3) ◽  
pp. 7-10
Author(s):  
Craig Uejo ◽  
Stephen Demeter
Keyword(s):  
Rotator Cuff ◽  
Distal Clavicle ◽  
Rotator Cuff Disease ◽  
Degenerative Arthritis ◽  
Sixth Edition ◽  
Cuff Tear ◽  
Shoulder Region ◽  
Illness Causation ◽  
Traumatic Rotator Cuff Tear ◽  
Distal Clavicle Resection

Abstract In the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, distal clavicle resection (resection arthroplasty of the acromioclavicular joint [ACJ]) results in ratable impairment, but only a single diagnosis within a region may be rated. Therefore, if another impairing condition is present in the shoulder region (eg, impingement syndrome or rotator cuff disease) only that resulting in the greatest causally related impairment is rated. In the setting of an occupational or other compensable injury or illness, causation of the impairment often is a key issue because, typically, only impairment that is causally related to the injury can be rated. For example, assume that a lifting injury at work caused a tear in a rotator cuff tendon that was already attenuated by repetitive impingement on inferiorly projecting spurs from longstanding degenerative arthritis of the ACJ. If surgery was performed for a traumatic rotator cuff tear and the distal clavicle also was resected due to preexisting ACJ arthritis, the latter surgery is not considered to be related to the injury. In other words, because the ACJ arthritis was neither caused nor worsened by the injury, this condition is not rated. The distal clavicular resection may have been warranted to diminish pain due to ACJ arthritis and/or eliminate the distal clavicle as a source of impingement.

Arthroscintigraphy in Suspected Rotator Cuff Rupture

1998 ◽  
Vol 37 (08) ◽  
pp. 272-278 ◽  
Author(s):  
S. Gratz ◽  
G. Köster ◽  
T. Behr ◽  
R. Vosshenrich ◽  
E. Grabbe ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Shoulder Joint ◽  
Clinical Signs ◽  
Diagnostic Efficiency ◽  
Rotator Cuff Rupture ◽  
Lower Viscosity ◽  
Rotator Cuff Lesion ◽  
Shoulder Region ◽  
Degenerative Alterations ◽  
Additional Value

Summary Aim: In order to evaluate the diagnostic efficiency of arthroscintigraphy in suspected rotator cuff ruptures this new imaging procedure was performed 20 times in 17 patients with clinical signs of a rotator cuff lesion. The scintigraphic results were compared with sonography (n = 20), contrast arthrography (n = 20) and arthroscopy (n = 10) of the shoulder joint. Methods: After performing a standard bone scintigraphy with intravenous application of 300 MBq 99m-Tc-methylene diphosphonate (MDP) for landmarking of the shoulder region arthroscintigraphy was performed after an intraarticular injection of 99m-Tc microcolloid (ALBURES 400 μCi/5 ml). The application was performed either in direct combination with contrast arthrography (n = 10) or ultrasound conducted mixed with a local anesthetic (n = 10). Findings at arthroscopical surgery (n = 10) were used as the gold standard. Results: In case of complete rotator cuff rupture (n = 5), arthroscintigraphy and radiographic arthrography were identical in 5/5. In one patient with advanced degenerative alterations of the shoulder joint radiographic arthrography incorrectly showed a complete rupture which was not seen by arthroscintigraphy and endoscopy. In 3 patients with incomplete rupture, 2/3 results were consistant. A difference was seen in one patient with a rotator cuff, that has been already revised in the past and that suffered of capsulitis and calcification. Conclusion: Arthroscintigraphy is a sensitive technique for detection of rotator cuff ruptures. Because of the lower viscosity of the active compound, small ruptures can be easily detected, offering additional value over radiographic arthrography and ultrasound, especially for evaluation of incomplete cuff ruptures.

Reconstruction of the Distal Radius Articular Facet by a Free Vascularized Osteochondral Autograft: Anatomic Study and Report of Two Cases

2006 ◽  
Vol 22 (03) ◽  
Author(s):  
Francisco Piñal ◽  
F García-Bernal ◽  
Julio Delgado ◽  
Marcos Sanmartín ◽  
Javier Regalado ◽  
...  
Keyword(s):  
Distal Radius ◽  
Anatomic Study ◽  
Osteochondral Autograft ◽  
Articular Facet

SPINDLE CELL LIPOMA MASQUERADING AS MIXED PYOLARYNGOCELE : A RARE CASE REPORT

2020 ◽  
Vol VOLUME 8 (ISSUE 1) ◽  
pp. 47-51
Author(s):  
Vineet Narula
Keyword(s):  
Rare Case ◽  
Spindle Cell ◽  
Spindle Cell Lipoma ◽  
Computed Tomographic ◽  
Contrast Enhanced ◽  
Rare Case Report ◽  
Shoulder Region ◽  
Cervical Approach ◽  
Posterior Neck ◽  
Keywords Lipoma

ABSTRACT Spindle Cell Lipoma (SCL) is an uncommon benign tumor of adipose tissue that is usually super􀃶cially located in the posterior neck, back and shoulder region. We report a rare case of SCL in a 39 years old male presenting as neck swelling with c/o stridor and dysphagia. The contrast enhanced computed tomographic scan of neck showed an external and internal part of the swelling traversing through the thyrohyoid membrane suggestive of Mixed Pyolaryngocele. The tumor was excised by a trans-cervical approach but the post operative histopathology was found to be spindle cell Lipoma. We report this case due to its atypical presentation and location. Keywords: Lipoma, Spindle cell, Pyolaryngocele

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