Archosauria Form and Function Lab Quiz UF

Anisodactyly

Most common arrangement; digit 1 (hallux) is in back and digits 2-4 are in front

Zygodactyly

Digit 1 faces back, 2 and 3 are in front, and 4 is located laterally, but often faces back when the bird is perched on a branch

Syndactyly

Proximal phalanges of digits 2 and 3 are fused to some extent

Tridactyly

Digit 1 has been lost

Palmate

Webbing occurs between toes 2, 3, and 4, but excludes the hallux

Totipalmate

webbing occurs when all four digits are included in the webbing

Semipalmate

webbing occurs when a small web is present between toes 2, 3, and 4, but this web does not extend to the claw of each toe

Lobate

Lobate toes 2, 3, and 4 are edged with lobes of skin, but the skin does not connect individual toes to one another

Fruit eating

Short, thick, curved beaks

Insect eating

Short and pointed beaks

Grain and seed eating

Conical bills

Chiseling

triangular and sharp with unique cranial structures

Filterfeeding

beak is lined with comb like plates

Meat eating

Sharp, hooked beak

Tail feather (contour)

Flight feather (contour)

Semiplume feather

Down feather

Filoplume feather

Bristle feather

Furcula

Keel of sternum

Triosseal canal 

Tarsometatarsus

Coniferous-seed eating