1 / 9

Notes 25.1

Notes 25.1. Vertebrate Origins. Chordates . Share four features at some stage of their development: 1. notochord - a flexible skeletal support rod embedded in the animal’s back (becomes part of the intervertebral discs)

ethel
Télécharger la présentation

Notes 25.1

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Notes 25.1 Vertebrate Origins

  2. Chordates Share four features at some stage of their development: 1. notochord- a flexible skeletal support rod embedded in the animal’s back (becomes part of the intervertebral discs) 2. hollow nerve cord- runs along the animal’s back (develops into the spinal cord and brain) 3. pharyngeal slits- slits through the body wall in the pharynx ( filter feeders, gills, only in embryonic stage for humans) 4. tail- extends beyond the anal opening, for movement

  3. Chordates

  4. Vertebrate Endoskeleton Braincase- cranium protects the brain Vertebrae- a series of short, stiff vertebrae that are separated by joints, protects the spinal cord Bones- support and protect the body’s soft tissues and provide points of attachments for muscles Gill arches- found in the pharynx of fish and some amphibians to support the gills

  5. Vertebrate Endoskeleton

  6. Vertebrate classes 1. agnatha- jawless, lampreys 2. chondrichthyes- cartilaginous fish, sharks 3. osteichthyes- bony fish, perch 4. amphibia- adapted to live in water and on land, frogs 5. reptilia- retain moisture to live on land, snakes 6. aves- birds, feathers 7. mammals- have hair, mammary glands, and three middle ear bones

  7. Vertebrate classes

  8. Early Vertebrates First recognizable vertebrate were fish Early fish were small, jawless bottom feeders Some had bony head shields, others covered with bony plates and scales Only two groups of jawless fish remain: 1. Lampreys- vertebrates, eel like, mouths surrounded by large sucker, tongues covered by toothlike projections 2. Hagfish- no vertebrae

  9. Early Vertebrates

More Related