Flashcards in Vertebrates 2 - Classification Deck (35)
Prokarya, Archaea, Eukarya
Kingdoms in Eukarya
Protists, Plantae, Fungi, Animalia
Phylum of vertebrates
Chordata (falls under Animalia Kingdom)
Breakdown of Chordata
Urochordata (tunicates), Cephalochordata (Amphioxus), Craniata (Hagfish, vertebrates)
5 synapomorphies of all chordates (p28)
Pharyngeal pouches, Notochord, Endostyle, Hollow Nerve chord, postanal muscular tail
Becomes parts of gills, or inner ear.
groove in pharynx. In some vertebrates it becomes part of thyroid; other just stays as a groove.
Fibrous tissue like cartilage that acts as a support for the body. Found on Dorsal side below the nerve chord. Sometimes found in adult.
Hollow Nerve chord
Anterior end may become brain in higher vertebrates
Muscular, past anal opening. Present at some point in development.
Sea squirts. Don’t move. Filter feed. Adult doesn’t look like vertebrate, but larva stage is mobile and has all the vertebrate characteristics.
Lives buried in sand, filter feeding. Possesses chordata characteristics.
Are Urochordata or Cephalochordata more closely related to Craniata?
Actually Urochordata (genomic comparison).
Has a cranium (brain case); Cephalization (specialized sensory structures at anterior end)
Hagfish and vertebrates.
Neural crest cells; brain case; complex sense organs; tripartite brain; complex endocrine system; muscularization of the gut tube; differentiation of digestive system; multichambered heart; type of hemoglobin
Neural Crest cells
Become part of peripheral nervous system. Develop during development
A true brain. Forebrain, midbrain, hindbrain.
How are vertebrates classified?
Generally by shared anatomical characteristics; in last 20 years we use molecular comparisons.
Examples of shared anatomical characteristics (p15)
Amniotic egg, hair, endothermy, viviparity, marsupium.
Closest living relative of whales and dolphins?
The hippo and other even-toed ungulates like deer (archyodactyls). Determined by molecular phylogeny.
Organism with a Jaw. Includes all vertebrates except agnathians (lampreys and hagfish)
Importance of Extinct Animals
Jawless fish, about 120 species. Hagfish and lampreys (closely related).
mixiniformes. Benthic, scavengers. Do not have vertebrae. Only a notochord to support the body which is not as specialized as a real vertebral column. Secrete lots of mucus as defense.
petromyzontiformes. Open ocean and benthic. Sometimes parasitic.
Cartilaginous fish. No bone, just calcified cartilage. Sharks and Rays (and Ratfish and chimeras). Large, diverse group, 1000 species.
Bony fish. Bone replaces cartilage. 29000 species. 3 main groups: Ray-finned fishes (majority). Coelacanths and Lungfishes (only 8 species), have fleshy fins with more bones (more similar to an arm).
Names for Ray-finned fish, Coelacanths and lungfishes
Actinopterygii, actinistia, dipnoi