Appendicular Skeleton - Limbs Origin of limbs Crawling Superorder Crossopterygii Subclass Labyrinthodontia

Transition to land (lobe fins)

Function and Trends Locomotion Support Functional diversification distally Decreased number of bones

Limb Structure Propodium – Humerus – pectoral appendage – Femur – pelvic appendage Epipodium – Radius & Ulna – pectoral appendage – Tibia & Fibula – pelvic appendage

Limb Structure Mesopodium – Carpals in pectoral appendage – Tarsals in pelvic appendage Metapodium – Metacarpals in pectoral appendage – Metatarsal in pelvic appendage Phalanges – Bones of the digits (fingers, toes, claws….)

Limbs Manus is forefoot or hand. It includes mesopodium, metapodium, phalanges Pes is hindfoot or foot. It includes mesopodium, metapodium, phalanges Epiphysis and Diaphysis are the Ends and Shaft of a long bone

Limbs - amphibians Bone marrow cavity makes blood in tetrapods

Limbs - Reptiles Stronger

Limbs in Bird Digit 2 is long digit of wing Phalangeal formula for foot is 2,3,4,5,0

Limbs - mammals Phalangeal formula of 2,3,3,3,3 on human hands and feet Very prominent olecranon process

Key Points The axial/appendicular (choose one) skeleton is more important for movement in fish. The axial/appendicular (choose one) skeleton is more important for movement in tetrapods.

Dermal or Replacement? Scapula Operculum Vertebrae Nasal Clavicle Rib Squamosal Femur Dentary Articular Stapes Posttemporal Splenial Radius