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El-Mansi AA, El-Bealy EA, Rady AM, Abumandour MA, El-Badry DA. Macro- and microstructures of the digestive tract in the Eurasian collared dove, Streptopelia decaocto (Frivaldszky 1838): Adaptive interplay between structure and dietary niche. Microsc Res Tech 2021; 84:2837-2856. [PMID: 34036668 DOI: 10.1002/jemt.23843] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/15/2021] [Accepted: 05/16/2021] [Indexed: 11/06/2022]
Abstract
We describe the functional morphology of the digestive tract of the Eurasian collared dove, Streptopelia decaocto using anatomical, morphometric, histological, histochemical, and ultrastructure techniques, and relate our findings to the species' dietary niche. Our results revealed that the esophagus is displaced on both sides of the neck and has highly folded tunica mucosa, which confer greater elasticity for efficient swallowing and passage of food to the crop. The proventriculus is delicate and its mucosal layer contains polymorphic glands with dense profound and superficial secretory units that open to the luminal surface by gastric pores. The ventriculus is biconvex and lined with a keratinized koilin membrane. The tubular glands within the mucosal lining include the isthmus, the neck, and the basal segment that comprise chief and basal cells with prominent nuclei. At the cuticle-mucosal interface, pyramidal vertical rodlets of the cuticle are secreted and superficially covered by a thin film of a horizontal matrix. The mucosa of the ileum form pyramidal villi that are oriented perpendicularly to the central lumen. Enterocytes infiltrated with goblet cells make up the epithelial lining of the villi. There are subtle differences in the thicknesses of corresponding tunics together with histochemical reactions of alcian blue (AB) and Masson-Goldner trichrome (MT) for their microstructures. Overall, our findings reveal remarkable convergence of both macro-and microstructures in S. decaocto to other granivorous species, and offer further evidence of the close association between functional morphology and feeding style relative to food swallowing, digestion, and absorption.
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Affiliation(s)
- Ahmed A El-Mansi
- Biology Department, Faculty of Science, King Khalid University, Abha, Saudi Arabia.,Zoology Department, Faculty of Science, Mansoura University, Mansoura, Egypt
| | - Eman A El-Bealy
- Biology Department, Faculty of Science, King Khalid University, Abha, Saudi Arabia
| | - Ahmed M Rady
- Biology Department, Faculty of Science, King Saud University, Riyadh, Saudi Arabia
| | - Mohamed A Abumandour
- Anatomy and Embryology Department, Faculty of Veterinary Medicine, Alexandria University, Behera, Egypt
| | - Dina A El-Badry
- Zoology Department, Faculty of Science, Mansoura University, Mansoura, Egypt
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Klingler JJ. The evolution of the pectoral extrinsic appendicular and infrahyoid musculature in theropods and its functional and behavioral importance. J Anat 2020; 237:870-889. [PMID: 32794182 DOI: 10.1111/joa.13256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/24/2020] [Accepted: 05/25/2020] [Indexed: 01/13/2023] Open
Abstract
Birds have lost and modified the musculature joining the pectoral girdle to the skull and hyoid, called the pectoral extrinsic appendicular and infrahyoid musculature. These muscles include the levator scapulae, sternomandibularis, sternohyoideus, episternocleidomastoideus, trapezius, and omohyoideus. As non-avian theropod dinosaurs are the closest relatives to birds, it is worth investigating what conditions they may have exhibited to learn when and how these muscles were lost or modified. Using extant phylogenetic bracketing, osteological correlates and non-osteological influences of these muscles are identified and discussed. Compsognathids and basal Maniraptoriformes were found to have been the likeliest transition points of a derived avian condition of losing or modifying these muscles. Increasing needs to control the feather tracts of the neck and shoulder, for insulation, display, or tightening/readjustment of the skin after dynamic neck movements may have been the selective force that drove some of these muscles to be modified into dermo-osseous muscles. The loss and modification of shoulder protractors created a more immobile girdle that would later be advantageous for flight in birds. The loss of the infrahyoid muscles freed the hyolarynx, trachea, and esophagus which may have aided in vocal tract filtering.
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Affiliation(s)
- Jeremy J Klingler
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
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Li Z, Clarke JA, Eliason CM, Stidham TA, Deng T, Zhou Z. Vocal specialization through tracheal elongation in an extinct Miocene pheasant from China. Sci Rep 2018; 8:8099. [PMID: 29802379 PMCID: PMC5970207 DOI: 10.1038/s41598-018-26178-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 05/02/2018] [Indexed: 11/29/2022] Open
Abstract
Modifications to the upper vocal tract involving hyper-elongated tracheae have evolved many times within crown birds, and their evolution has been linked to a ‘size exaggeration’ hypothesis in acoustic signaling and communication, whereby smaller-sized birds can produce louder sounds. A fossil skeleton of a new extinct species of wildfowl (Galliformes: Phasianidae) from the late Miocene of China, preserves an elongated, coiled trachea that represents the oldest fossil record of this vocal modification in birds and the first documentation of its evolution within pheasants. The phylogenetic position of this species within Phasianidae has not been fully resolved, but appears to document a separate independent origination of this vocal modification within Galliformes. The fossil preserves a coiled section of the trachea and other remains supporting a tracheal length longer than the bird’s body. This extinct species likely produced vocalizations with a lower fundamental frequency and reduced harmonics compared to similarly-sized pheasants. The independent evolution of this vocal feature in galliforms living in both open and closed habitats does not appear to be correlated with other factors of biology or its open savanna-like habitat. Features present in the fossil that are typically associated with sexual dimorphism suggest that sexual selection may have resulted in the evolution of both the morphology and vocalization mechanism in this extinct species.
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Affiliation(s)
- Zhiheng Li
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China. .,CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China.
| | - Julia A Clarke
- Department of Geological Sciences, University of Texas at Austin, Austin, Texas, 78712, United States
| | - Chad M Eliason
- Integrative Research Center, Field Museum of Natural History, Chicago, Illinois, 60605, United States
| | - Thomas A Stidham
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China
| | - Tao Deng
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China
| | - Zhonghe Zhou
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China
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