Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T05:54:03.992Z Has data issue: false hasContentIssue false

Biological Aspects of the Tongue and Oropharyngeal Cavity of the Eurasian Collared Dove (Streptopelia decaocto, Columbiformes, Columbidae): Anatomical, Histochemical, and Ultrastructure Study

Published online by Cambridge University Press:  08 July 2021

Ahmed A. El-Mansi*
Affiliation:
Department of Biology, Faculty of Science, King Khalid University, P.O. Box 641, Abha61421, Saudi Arabia Department of Zoology, Faculty of Science, Mansoura University, Mansoura, Egypt
Eman A. El-Bealy
Affiliation:
Department of Biology, Faculty of Science, King Khalid University, P.O. Box 641, Abha61421, Saudi Arabia
Mohamed A. Al-Kahtani
Affiliation:
Department of Biology, Faculty of Science, King Khalid University, P.O. Box 641, Abha61421, Saudi Arabia
Khalid A. Al-Zailaie
Affiliation:
Department of Biology, Faculty of Science, King Khalid University, P.O. Box 641, Abha61421, Saudi Arabia
Ahmed M. Rady
Affiliation:
Department of Biology, Faculty of Science, King Saud University, Riyadh, Saudi Arabia
Mohamed A. Abumandour
Affiliation:
Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Alexandria University, Behera, Egypt
Dina A. El-Badry
Affiliation:
Department of Zoology, Faculty of Science, Mansoura University, Mansoura, Egypt
*
*Corresponding author: Ahmed El-Mansi, E-mail: [email protected]; [email protected]
Get access

Abstract

We characterized the morphological and anatomical adaptations of the lingual microstructures of the Eurasian collared dove and discussed their implications for its dietary niche. We analyzed tongues of nine S. decaocto using histological, histochemical, stereomicroscopic, and scanning electron microscopic techniques. Our findings showed that the tongue is relatively short with a tapered apex that carries a terminal lingual nail. However, the lingual body has median scales and is bordered laterally by filiform papillae. Further, the tongue body bears a distinctive papillary crest. The tongue root is nonpapillate and infiltered with orifices of the posterior salivary glands. The bulky laryngeal mound has a circular glottic fissure, carrying a single row of papillae at the rear edge. Concurrently, our histological and histochemical findings demonstrate that the tongue has taste buds, anterior and posterior salivary glands, along with an elongated entoglossum that extends from lingual apex to root. Besides, ovoid and globular mucous glands displayed intense alcianophilic reactions. More substantially, the palate is made up of three palatine ridges with a caudal choanal cleft that was bounded by two rows of palatine papillae. Our data indicate multiple and novel structural variations for the lingual and palatal sculptures coopted for their feeding style.

Type
Micrographia
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press on behalf of the Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abumandour, MA (2018). Surface ultrastructural (SEM) characteristics of oropharyngeal cavity of house sparrow (Passer domesticus). Anat Sci Int 93, 384393.CrossRefGoogle Scholar
Abumandour, MA, Bassuoni, NF & Hanafy, BG (2019). Surface ultrastructural descriptions of the oropharyngeal cavity of Anas querquedula. Microsc Res Tech 82, 13591371.CrossRefGoogle ScholarPubMed
Abumandour, MA & El-Bakary, NER (2017 a). Morphological features of the tongue and laryngeal entrance in two predatory birds with similar feeding preferences: Common kestrel (Falco tinnunculus) and Hume's tawny owl (Strix butleri). Anat Sci Int 92, 352363.CrossRefGoogle Scholar
Abumandour, MA & El-Bakary, NER (2019). Anatomical investigations of the tongue and laryngeal entrance of the Egyptian laughing dove Spilopelia senegalensis aegyptiaca in Egypt. Anat Sci Int 94, 6774.CrossRefGoogle ScholarPubMed
Abumandour, MMA & El-Bakary, NER (2017 b). Morphological characteristics of the oropharyngeal cavity (tongue, palate and laryngeal entrance) in the Eurasian Coot (Fulica atra, Linnaeus, 1758). J Vet Med Series C: Anat Histol Embryol 46, 347358.Google Scholar
Abumandour, MMA & Gewaily, MS (2019). Gross morphological and ultrastructural characterization of the oropharyngeal cavity of the Eurasian hoopoe captured from Egypt. Anat Sci Int 94, 172179.CrossRefGoogle ScholarPubMed
Abumandour, MMA & Kandyel, RM (2020). Age-related ultrastructural features of the tongue of the rock pigeon Columba livia dakhlae in different three age stages (young, mature, and adult) captured from Egypt. Microsc Res Tech 83, 118132.CrossRefGoogle ScholarPubMed
Al-Ahmady Al-Zahaby, S (2016). Light and scanning electron microscopic features of the tongue in cattle egret. Microsc Res Tech 79, 595603.CrossRefGoogle ScholarPubMed
Al-Zahaby, SA & Elsheikh, EH (2014). Ultramorphological and histological studies on the tongue of the common kingfisher in relation to its feeding habit. J Basic Appl Zool 67, 9199.CrossRefGoogle Scholar
Amerongen, AVN, Bolscher, JGM & Veerman, ECI (1995). Salivary mucins: Protective functions in relation to their diversity. Glycobiology 5, 733740.CrossRefGoogle ScholarPubMed
Bagi, Z, Dimopoulos, EA, Loukovitis, D, Eraud, C & Kusza, S (2018). MtDNA genetic diversity and structure of Eurasian collared dove (Streptopelia decaocto). PLoS One 13, e0193935.CrossRefGoogle Scholar
Bancroft, D, Layton, C & Suvarna, SK (2012). Bancroft's Theory and Practice of Histological Techniques: Expert Consult: Online and Print, 7e.Google Scholar
Baumel, JJ, King, SA, Breazile, JE, Evans, HE & Berge, JCV (1993). Handbook of Avian Anatomy: Nomina Anatomica Avium. 2nd ed. 779. Nuttall Ornithological Club.Google Scholar
Bels, V & Baussart, S (2006). Feeding behaviour and mechanisms in domestic birds. In Feeding in Domestic Vertebrates: From Structure to Behavior, Bels, V (Ed.), pp. 3349. Oxfordshire, UK: CABI Publishing, CAB International, Wallingford.CrossRefGoogle Scholar
Bock, WJ (1978). Anatomy of the domestic birds. Anim Behav 26. doi:10.1016/0003-3472(78)90083-0.CrossRefGoogle Scholar
Bock, WJ (1999). Functional and evolutionary morphology of woodpeckers. Ostrich 70, 2331.CrossRefGoogle Scholar
Bonter, DN, Zuckerberg, B & Dickinson, JL (2010). Invasive birds in a novel landscape: Habitat associations and effects on established species. Ecography 33, 494502.Google Scholar
Camacho-Cervantes, M & Schondube, JE (2018). Habitat use by the invasive exotic Eurasian Collared-Dove (Streptopelia decaocto) and native dove species in the Chamela-Cuixmala region of West Mexico. Wilson J Ornithol 130, 902907.CrossRefGoogle Scholar
Carlesso Santos, T, Yuri Fukuda, K, Plácido Guimarães, J, Franco Oliveira, M, Angelica Miglino, M & Watanabe, L-S (2011). Light and scanning electron microcopy study of the tongue in Rhea americana. Zoolog Sci 28, 4146.CrossRefGoogle ScholarPubMed
Crole, MR & Soley, JT (2009). Morphology of the tongue of the emu (Dromaius novaehollandiae). II. Histological features. Onderstepoort J Vet Res 76, 347361.Google Scholar
Crole, MR & Soley, JT (2010 a). Gross morphology of the intra-oral rhamphotheca, oropharynx and proximal oesophagus of the Emu (Dromaius novaehollandiae). J Vet Med Series C: Anat Histol Embryol 39, 207218.Google Scholar
Crole, MR & Soley, JT (2010 b). Surface morphology of the Emu (Dromaius novaehollandiae) tongue. J Vet Med Series C: Anat Histol Embryol 39, 355365.Google Scholar
Dehkordi, RAF, Parchami, A & Bahadoran, S (2010). Light and scanning electron microscopic study of the tongue in the zebra finch Carduelis carduelis (Aves: Passeriformes: Fringillidae). Slovenian VetRes 47, 139144.Google Scholar
Duncan, CJ (1960). Preference tests and the sense of taste in the feral pigeon (Columba livia var gmelin). Anim Behav 8, 5460.CrossRefGoogle Scholar
El-Bakry, AM & Iwasaki, SI (2014). Ultrastructure and histochemical study of the lingual salivary glands of some bird species. Pak J Zool 46, 553559.Google Scholar
El-Mansi, A, Al-Kahtani, M, Abumandour, M, Ezzat, A & El-Badry, D (2020 b). Gross anatomical and ultrastructural characterization of the oropharyngeal cavity of the Egyptian Nightjar Caprimulgus aegyptius: Functional dietary implications. Ornithol Sci 19, 145158.CrossRefGoogle Scholar
El-Mansi, AA, Al-Kahtani, MA & Abumandour, MMA (2019). Comparative phenotypic and structural adaptations of tongue and gastrointestinal tract in two bats having different feeding habits captured from Saudi Arabia: Egyptian fruit bat (Rousettus aegyptiacus) and Egyptian tomb bat (Taphozous perforatus). Zool Anz 281, 2438.CrossRefGoogle Scholar
El-Mansi, AA, El-Mansi, AA, Al-Kahtani, MA, Abumandour, MMA, Ahmed, AE & Ahmed, AE (2020 a). Structural and functional characterization of the tongue and digestive tract of Psammophis sibilans (Squamata, lamprophiidae): Adaptive strategies for foraging and feeding behaviors. Microsc Microanal 26, 524541.CrossRefGoogle ScholarPubMed
Elsheikh, EH & Al-Zahaby, SA (2014). Light and scanning electron microscopical studies of the tongue in the hooded crow (Aves: Corvus corone cornix). J Basic Appl Zool 67, 8390.CrossRefGoogle Scholar
Emura, S & Chen, H (2008). Scanning electron microscopic study of the tongue in the owl (Strix uralensis). J Vet Medi Series C: Anat Histol Embryol 37, 475478.Google Scholar
Emura, S, Okumura, T & Chen, H (2008). Scanning electron microscopic study of the tongue in the peregrine falcon and common kestrel. Okajimas Folia Anat Jpn 85, 1115.CrossRefGoogle ScholarPubMed
Emura, S, Okumura, T & Chen, H (2009). Scanning electron microscopic study of the tongue in the oriental scops owl (Otus scops). Okajimas Folia Anat Jpn 86, 16.CrossRefGoogle Scholar
Erdoǧan, S & Alan, A (2012). Gross anatomical and scanning electron microscopic studies of the oropharyngeal cavity in the European magpie (Pica pica) and the common raven (Corvus corax). Microsc Res Tech 75, 379387.CrossRefGoogle Scholar
Erdoǧan, S & Iwasaki, S (2014). Function-related morphological characteristics and specialized structures of the avian tongue. Ann Anat 196, 7587.CrossRefGoogle ScholarPubMed
Erdoğan, S & Pérez, W (2015). Anatomical and scanning electron microscopic characteristics of the oropharyngeal cavity (tongue, palate and laryngeal entrance) in the southern lapwing (Charadriidae: Vanellus chilensis, Molina 1782). Acta Zool 96, 264272.CrossRefGoogle Scholar
Erdoǧan, S, Pèrez, W & Alan, A (2012 a). Anatomical and scanning electron microscopic investigations of the tongue and laryngeal entrance in the long-legged buzzard (Buteo rufinus, Cretzschmar, 1829). Microsc Res Tech 75, 12451252.CrossRefGoogle Scholar
Erdoǧan, S, Saǧsöz, H & Akbalik, ME (2012 b). Anatomical and histological structure of the tongue and histochemical characteristics of the lingual salivary glands in the Chukar partridge (Alectoris chukar, Gray 1830). Br Poult Sci 53, 307315.CrossRefGoogle Scholar
Farner, DS & Ziswiller, VM (1972). Digestion and digestive system. In Avian Biology, Farner, DS & King, JR (Eds.), pp. 343430. London, UK: Academic Press.Google Scholar
Gadel-Rab, AG, Shawki, NA & Saber, SA (2017). Morpho-functional adaptations of the lingual epithelium of two bird species which have different feeding habits. Egypt J Hosp Med 69, 21152127.CrossRefGoogle Scholar
Ganchrow, D, Ganchrow, JR & Goldstein, RS (1991). Ultrastructure of palatal taste buds in the perihatching chick. Am J Anat 192, 6978.CrossRefGoogle ScholarPubMed
Gargiulo, AM, Lorvik, S, Ceccarelli, P & Pedini, V (1991). Histological and histochemical studies on the chicken lingual glands. Br Poult Sci 32, 693702.CrossRefGoogle ScholarPubMed
Goodge, WR (1972). Anatomical evidence for phylogenetic relationships among woodpeckers. The Auk 89, 6585.CrossRefGoogle Scholar
Guimarães, JP, de Mari, RB, de Carvalho, HS & Watanabe, I (2009). Fine structure of the dorsal surface of ostrich's (Struthio camelus) tongue. Zool Sci 26, 153156.CrossRefGoogle ScholarPubMed
Gupta, V, Archana, P, Farooqui, M & Ajay, P (2018). Anatomy of the oro-pharyngeal cavity of Turkey (Meleagris gallopavo). Haryana Vet 57, 178182.Google Scholar
Gussekloo, SWS (2006). Feeding structures in birds. In Feeding in Domestic Vertebrates: From Structure to Behavior, Bels, V (Ed.), pp. 1432. Wallingford, UK: CABI Publishing.CrossRefGoogle Scholar
Harrison, JG (1964). Tongue. In A new Dictionary of Birds, Thomson, AL (Ed.), pp. 598618. London, UK: Nelson.Google Scholar
Hassan, SM, Moussa, EA & Cartwright, AL (2010). Variations by sex in anatomical and morphological features of the tongue of Egyptian goose (Alopochen aegyptiacus). Cells Tissues Organs 191, 161165.CrossRefGoogle Scholar
Hayslette, SE & Poling, TD (2006). Dietary overlap and foraging competition between mourning doves and Eurasian collared-doves. J Wildl Manage 70, 9981004.Google Scholar
Igwebuike, UM & Eze, UU (2010). Anatomy of the oropharynx and tongue of the African pied crow (Corvus albus). Veterinarski Arhiv 80, 523531.Google Scholar
Iwasaki, S & Kobayashi, K (1986). Scanning and transmission electron microscopy studies on the lingual dorsal epithelium of chickens. Kaibogaku Zasshi. J Anat 61, 8396.Google ScholarPubMed
Iwasaki, S-I (1992). Fine structure of the dorsal lingual epithelium of the little tern, Sterna albifrons pallas (Aves, Lari). J Morphol 212, 1326.CrossRefGoogle Scholar
Iwasaki, SI (2002). Evolution of the structure and function of the vertebrate tongue. J Anat 201, 113.CrossRefGoogle ScholarPubMed
Iwasaki, SI, Asami, T & Chiba, A (1997). Ultrastructural study of the keratinization of the dorsal epithelium of the tongue of Middendorff's bean goose, Anser fabalis middendorffii (Anseres, Antidae). Anat Rec 247, 149163.3.0.CO;2-T>CrossRefGoogle Scholar
Jackowiak, H, Andrzejewski, W & Godynicki, S (2006). Light and scanning electron microscopic study of the tongue in the cormorant Phalacrocorax carbo (Phalacrocoracidae, Aves). Zool Sci 23, 161167.CrossRefGoogle Scholar
Jackowiak, H & Godynicki, S (2005). Light and scanning electron microscopic study of the tongue in the white tailed eagle (Haliaeetus albicilla, Accipitridae, Aves). Ann Anat 187, 251259.CrossRefGoogle Scholar
Jackowiak, H & Ludwig, M (2008). Light and scanning electron microscopic study of the structure of the ostrich (Strutio camelus) tongue. Zool Sci 25, 188194.CrossRefGoogle ScholarPubMed
Jackowiak, H, Skieresz-Szewczyk, K, Godynicki, S, Iwasaki, Si & Meyer, W (2011). Functional morphology of the tongue in the domestic goose (Anser Anser f. Domestica). Anat Rec 294, 15741584.CrossRefGoogle Scholar
Jackowiak, H, Skieresz-Szewczyk, K, Kwieciński, Z, Godynicki, S, Jackowiak, K & Leszczyszyn, A (2015). Light microscopy and scanning electron microscopy studies on the reduction of the tongue microstructures in the white stork (Ciconia ciconia, Aves). Acta Zool 96, 436441.CrossRefGoogle Scholar
Jackowiak, H, Skieresz-Szewczyk, K, Kwieciński, Z, Trzcielińska-Lorych, J & Godynicki, S (2010). Functional morphology of the tongue in the Nutcracker (Nucifraga caryocatactes). Zool Sci 27, 589594.CrossRefGoogle Scholar
Kabak, M, Orhan, IO & Haziroglu, RM (2007). The gross anatomy of larynx, trachae and syrinx in the long-legged buzzard (Buteo rufinus). J Vet Med Series C: Anat Histol Embryol 36, 2732.Google Scholar
Kabir, MA (2014). Breeding biology of domesticated Eurasian collared dove (Columbidae) Streptopelia decaocto Frivaldszky 1838 in Saidpur, Bangladesh. Int J Environ 3, 4854.CrossRefGoogle Scholar
Kasner, AC & Pyeatt, DN (2016). Eurasian collared-dove (Streptopelia decaocto) usurps nest of American Robins (Turdus migratorius). Wilson J Ornithol 128, 198–100.CrossRefGoogle Scholar
King, AS & McLelland, J (1984). Birds. In Their Structure and Function, pp. 2nd ed. pp. 8590. London, UK: Bailliere Tindall.Google Scholar
Kobayashi, K, Kumakura, M, Yoshimura, K, Inatomi, M & Asami, T (1998). Fine structure of the tongue and lingual papillae of the penguin. Arch Histol Cytol 61, 3746.CrossRefGoogle ScholarPubMed
Kudo, KI, Nishimura, S & Tabata, S (2008). Distribution of taste buds in layer-type chickens: Scanning electron microscopic observations. Anim Sci J 79, 680685.CrossRefGoogle Scholar
Liman, N, Bayram, G & Koçak, M (2001). Histological and histochemical studies on the lingual, preglottal and laryngeal salivary glands of the Japanese quail (Coturnix coturnix japonica) at the post-hatching period. Anat, Histol, Embryol 30, 367373.CrossRefGoogle Scholar
Madkour, F (2018). Morphological studies of the oral roof of the Egyptian laughing dove (Streptopelia senegalensis aegyptiaca) and Japanese quail (Coturnix coturnix japonicum). J Vet Anat 11, 1739.CrossRefGoogle Scholar
Madkour, F, Abdalla, K & Mohamed, S (2019). Choana morphogenesis in developmental stages of muscovy ducks. SVU-Int J Vet Sci 2, 1326.Google Scholar
Mahdy, MAA (2020). Comparative gross and scanning electron microscopical study of the oropharyngeal roof of young and adult domestic pigeons (Columba livia domestica). Microsc Res Tech 83, 10451055.CrossRefGoogle Scholar
Mohamed, R (2019). Histomorphological study on the tongue of the duck in the Caribbean with relation to feeding habit. J Adv Ve Anim Res 6, 7481.CrossRefGoogle Scholar
Niknafs, S & Roura, E (2018). Nutrient sensing, taste and feed intake in avian species. Nutr Res Rev 31, 256266.CrossRefGoogle ScholarPubMed
Onuk, B, Tütüncü, S, Kabak, M & Alan, A (2015). Macroanatomic, light microscopic, and scanning electron microscopic studies of the tongue in the seagull (Larus fuscus) and common buzzard (Buteo buteo). Acta Zool 96, 6066.CrossRefGoogle Scholar
Parchami, A, Dehkordi, RAF & Bahadoran, S (2010). Fine structure of the dorsal lingual epithelium of the common quail (Coturnix coturnix). World Appl Sci J 10, 11851189.Google Scholar
Parchami, A & Fatahian Dehkordi, RA (2013). Light and electron microscopic study of the tongue in the White-eared bulbul (Pycnonotus leucotis). Iranian J Vet Res 14, 914.Google Scholar
Paton, DC & Collins, BG (1989). Bills and tongues of nectar-feeding birds: A review of morphology, function and performance, with intercontinental comparisons. Aust J Ecol 14, 473506.CrossRefGoogle Scholar
Rajapaksha, P, Wang, Z, Venkatesan, N, Tehrani, KF, Payne, J, Swetenburg, RL, Kawabata, F, Tabata, S, Mortensen, LJ, Stice, SL, Beckstead, R & Liu, HX (2016). Labeling and analysis of chicken taste buds using molecular markers in oral epithelial sheets. Sci Rep 6, 37247.CrossRefGoogle ScholarPubMed
Rico-Guevara, A & Rubega, MA (2011). The hummingbird tongue is a fluid trap, not a capillary tube. Proc Natl Acad Sci USA 108, 93569360.CrossRefGoogle Scholar
Rocha-Camarero, G & de Trucios, HJS (2002). The spread of the collared dove Streptopelia decaocto in Europe: Colonization patterns in the west of the Iberian Peninsula. Bird Study 49, 1116.CrossRefGoogle Scholar
Romagosa, CM (2020). Eurasian collared-dove (Streptopelia decaocto). In Birds of the World.CrossRefGoogle Scholar
Romagosa, CM & Labisky, RF (2000). The establishment and dispersal of the Eurasian collared dove (Streptopelia decaocto) in Florida. J Field Ornithol 71, 159166.CrossRefGoogle Scholar
Sağsöz, H, Erdoğan, S & Akbalik, ME (2013). Histomorphological structure of the palate and histochemical profiles of the salivary palatine glands in the Chukar partridge (Alectoris chukar, gray 1830). Acta Zool 94, 382391.Google Scholar
Samar, ME, Ávila, RE, Esteban, FJ, Olmedo, L, Dettin, L, Massone, A, Pedrosa, JA & Peinado, MA (2002). Histochemical and ultrastructural study of the chicken salivary palatine glands. Acta Histochem 104, 199207.CrossRefGoogle ScholarPubMed
Schumacher, U, Duku, M, Katoh, M, Jörns, J & Krause, WJ (2004). Histochemical similarities of mucins produced by Brunner's glands and pyloric glands: A comparative study. Anat Rec A Discov Mol, Cell, Evol Biol 278A, 540550.CrossRefGoogle Scholar
Skieresz-Szewczyk, K & Jackowiak, H (2016). Morphofunctional study of the tongue in the domestic duck (anas platyrhynchos f. domestica, Anatidae): LM and SEM study. Zoomorphology 135, 255268.CrossRefGoogle ScholarPubMed
Smith, DV & Margolskee, RF (2001). Making sense of taste. Sci Am 284, 3239.CrossRefGoogle ScholarPubMed
Tabak, L (1995). In defense of the oral cavity: Structure, biosynthesis, and function of salivary mucins. Annu Rev Physiol 57, 547564.CrossRefGoogle ScholarPubMed
Taha, AM & AL-Duleemy, AS (2020). Morphological description of the digestive canal in Taeniopygia guttata (zebra finch) and Sturnus vulgaris (starling). J Basic Appl Zool 81, 24.CrossRefGoogle Scholar
Tivane, C, Rodrigues, MN, Soley, JT & Groenwald, HB (2011). Gross anatomical features of the oropharyngeal cavity of the ostrich (Struthio camelus). Pesqui Vet Bras 31, 543550.CrossRefGoogle Scholar
Toyoshima, K, Seta, Y & Shimamura, A (1993). Fine structure of Merkel corpuscles in the lingual mucosa of Japanese quail, Coturnix coturnix japonica. Arch Oral Biol 38, 10091012.CrossRefGoogle ScholarPubMed
Trivedi, V (2020). A comparative anatomy of the lingual apparatus of Indian doves (genus: Streptopelia and Stigmatopelia), aves: Columbidae. J Basic Appl Zool 81, 37.CrossRefGoogle Scholar
Uppal, V, Bansal, N, Anuradha, , Pathak, D & Singh, A (2014). Light and scanning electron microscopy studies of quail tongues. Avian Biol Res 7, 167171.CrossRefGoogle Scholar
Yoshimura, K, Hama, N, Shindo, J, Kobayashi, K & Kageyama, I (2008). Light and scanning electron microscopic study on the lingual papillae and their connective tissue cores of the Cape hyrax Procavia capensis. J Anat 213, 573582.Google ScholarPubMed
Zusi, RL & Livezey, BC (2006). Variation in the os palatinum and its structural relation to the palatum osseum of birds (aves). Ann Carnegie Mus 75, 137180.CrossRefGoogle Scholar