Phylum Chordata - Chordates Internal skeleton with muscle ...

Hooves, Horns, and Antlersclaws, fingernails, hair, and hooves are made of keratinHooves cushion and protect toes in running mammalsHorns have a core of bone surrounded by keratin sheathnot shed, bony core is attached to skullOuter layer is compacted hair-like layersAntlers are made only of boneMale deer grow and shed a set of antlers each yearCovered by thin skin layer of velvet while growingVelvet dies and is scraped off when antlers are fully grownAntlers used to combat rival males in fall and winterShed in spring after breeding seasonRhinoceros horn composed of keratinized hairFlightBats are only mammals capable of powered flightWings are modified forelimbsleathery membrane of skin stretched over bones of four fingersedges attach to side of body and to hind legBats at rest hang upside down from legsHave sonar system tonavigate in dark andfind insectsHigh frequency pulsesemitted through mouthor noseSound waves reflect offobjects, captured bylarge ears