Module 11: Avian Osteology Flashcards
Neornithes
Only extant subclass of birds
Paleognathae
Old jaws-more primitive and reptile-like
Paleognathae families
• Struthioniformes: ostriches, emus, kiwis, and allies
• Tinamiformes: tinamous
Neognathae
more derived in bill, fee, function, and behavior
Neognathae families
• Anseriformes—waterfowl
• Galliformes—fowl
• Charadriiformes—gulls, button-quails, plovers and allies • Gaviiformes—loons
• Podicipediformes—grebes
• Procellariiformes—albatrosses, petrels, and allies
• Sphenisciformes—penguins
• Pelecaniformes—pelicans and allies
• Phaethontiformes—tropicbirds
• Ciconiiformes—storks and allies
• Cathartiformes—New World vultures
• Phoenicopteriformes—flamingos
• Falconiformes—falcons, eagles, hawks and
allies
• Gruiformes—cranes and allies
• Pteroclidiformes—sandgrouse
• Columbiformes—doves and pigeons
• Psittaciformes—parrots and allies
• Cuculiformes—cuckoos and turacos
• Opisthocomiformes—hoatzin
• Strigiformes—owls
• Caprimulgiformes—nightjars and allies • Apodiformes—swifts and hummingbirds • Coraciiformes—kingfishers and allies
• Piciformes—woodpeckers and allies
• Trogoniformes—trogons
• Coliiformes—mousebirds
• Passeriformes—passerines, the songbirds or
perching birds
Bone structure of birds
Light-weight
Highly pneumatized (esp. flight birds)
Thin cortical wall, little medullary bone
Non-compacted cancellous bone
Thin struts crossing throughout medullary cavity
Bird skull
Modified to reduce weight
Less than 1% of total weight
Bones fuse very early in life-hardly found separate
Largest bone-frontal (most of cranial vault)
Frontals-contain orbital structure with interorbital septum between eyes attached to ethmoid, small lachrymal bone on anterior margin of orbits
Parietals and occipital are caudal portion
Squamosal portion-much reduced temporal bone
Basitemporal plate-triangular bone on floor of skull
Basisphenoid-anterior to plate, pair of basipterygoid process project to articulate with quadrate
Maxilla has posterior and ventral projection-maxillopalatine process
Vomer, maxilla, nasals and premaxilla-beak
Maxilla, jugal, quadratojugal bone-zygomatic arch
Mandible-5 fused bones
Diagnostic features
Size, shape and location of nares or nasal aperture
Bill shape/size
Palate structure-3 groups
-schiognathous: bony palata with cleft down length separating maxillopalatines, small, pointy vomer
-aegithognathous: 2 pronged vomer anteriorly and separate maxillopalatines
-desmognathous: fused maxillopalatines, small/lacking vomer
Furcula
Clavicles fused-wishbone in chickens
Furcula float free in muscle, not supportive
V/U shaped, sometimes W
Sternum
Large keel to support pectorals
Articulates with coracoids at proximal end, ribs lateral margins
Size/shape highly diagnostic
Gruiformes-laryngeal box incorporated into sternum
Pelecaniformes-furcula articulates with sternum
Coracoid
Separate from scapula
Struct from sternum to humerus
Somewhat triangular
Articulates with sternum, humerus, furcula, & scapula
Scapula
Elongated and slender
Humerus
Proximal end-spatulate, small humeral head
Lateral condyle larger than medial
Some species have pneumatic fossa, others do not
Ulna
Dorsal surface tiny bony papillae for quill knobs & secondary feather attachment
Carpometacarpus
Fusion of most carpals and metacarpals. Cuneiform and scapholunate only carpals remaining
Like violin bow- MC 1 and carpals=grip, MC ii=bow, MC iii=strings
Distinct appearance
Fingers reduced to 3 w 1 or 2 phalanges
1st phalanx 2nd digit shaped like scapula
Pelvis
Several elements-normal 3 and fused vertebrae (synsacrum)
Flight birds-area cranial to acetabulum larger than caudal
Diving/terrestrial birds-more equal
Femur
Short in comp to other hindlimb elements
Sometimes greater trochanter above the head, level in others
Tibiotarsus
Like tibia on proximal end, like femur on distal with 2 condyles
Loons/grebes patella fuses to proximal end forming semilunar notch and structure like olecranon
Distal end tendinal groove or supracondylar fossa and supratendinal bridge
Fibula may be separate or fused
Tarsometatarsus
Fusion of tarsals and metatarsals
Proximal end condylar facets like tibia to accommodate condyles of tibiotarsus
Distal end trochlea
-typically 3, woodpeckers 4
Males may have spur
Feet retain reptilian phalange formula 2,3,4,5 for first 4 digits. Terminal phalanges are claws
Wild vs domestic turkey
Breast bone most diagnostic feature-significantly larger in domesticated turkeys
Wild turkeys more slender limb elements, particularly evident in tibiotarsus
Domestic birds harvested before mature-lack of full development of distal ends of long bones
