Vertebraes C34 Flashcards
What are the descendants of Deuterstomia to Amniotes?
Chordates, Vertebraes, Gnatosomes(jaw), Osteichthyans(lungs&bone structure), Lobe-fins, Tetrapods, Amniotes
Qualities of a Gnathosome?
Vertebraes with Jaws (gnaw)
enlargened forebrain
Lateral line system (sensitives to vibrations)
Genome duplication (4 Hox genes)
Oviparous vs. ovoviviparous vs. viviparous
Viviparous: the young are born alive after having been nourished in the uterus by blood from the placenta (NO EGG)
Oviparous: young hatch from eggs laid outside the mother’s body
Ovoviviparous: in which young hatch from eggs that are retained in the mother’s uterus (lay eggs and hatch inside mother’s body)
What does Chordates split up into?
Cephalochordata and (Vertebraes + Unichordata)
Qualities of Vertebraes?
2 sets of Hox genes
Neural crest
Vertebrae surrounding spinal chord
elaborate skull
fin rays (for aquatic forms)
What does vertebraes split up into
Gnatostomes and cyclostomes
Qualities of gnatostomes
have jaws
lateral line fish system
good sense of smell (enlargened forebrain)
What is an Osteichyans
class of gnatosomes
Qualities of Osteichyans
have lungs
bony osified skeleton
Qualities of Lobe-fins
rod-shaped bones surrounded by thick muscles in pector and pelvis fins
Tetrapods
4 limbs
feet with digits
neck
NO GILLS (except some marine animals,ex:tadpoles)
What classes are fish found in?
Dipnoi(lungfish), Actinistia(coelanths), Actinoptoygii(ray-fish)
What is the Tiktaalik?
fossil discoverd in Canada that had both fish and tetrapods characteristics
- had fins, gills, and lungs, and its body was covered in scales
-also had a NECK, ribs and shoulders
What are cyclostomes?
all vertebraes that DONT have jaws, has 2 classes
Classes of cyclostomes? What are organisms in those classes?
Myxini (hagfish) and Petromyzontida (lampreys)
