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Body Plan
Transport within the Body
Closed (chambered heart pumps blood to capillaries)
Blood with a central heart to pump, nutrients and whatnot transferred
Gas Exchange
Method of Waste Disposal
Nervous System
Important Distinguishing Feature
  • Agnatha: gills used as major sites of gas exchange between blood and water
  • Placoderm: pharyngeal gill slits play major part in gas exchange
  • Chondrichthyes: swim continuously to move water to gills, where gas exchange occurs
  • Osteichthyes: draws water over pairs of gills with assistance of protective flap called Operculum
  • Amphibia: lateral line and gills, then develops into lungs; moist skin also needed to respiration to occur via the skin
  • Reptilia: dry skin is waterproof and restricts gas exchange with air via the skin; must obtain all oxygen with lungs
  • Mammalia: Lungs connect blood with the air, diffusing necessary gases across epithelial membrane
  • Digestive tube with a mouth and an anus
  • Chondrichthyes: sharp vision, smell, can detect electrical fields generated by muscle contractions of nearby animals, hear, and a Lateral Line System, or a row of microscopic organs to sense changes in surrounding water pressure
  • Osteichthyes: Lateral Line System
  • Amphibia: lateral line in development, nerve system matured
  • Reptilia: sensitive to ground vibrations, heat, and acute chemical sensors
  • Avian: complex brain, very developed eyes and motor skills
  • Mammalia: central nervous system with most complex brain
  • Male and female sexes
  • Reptilia, Ave, and Mammalia called Amniotes, or water-retaining wombs
  • Chondrichthyes: fertilized internally
  • Osteichthyes: various types, however, internal fertilization and birthing most common
  • Amphibia: external fertilization, with specialized egg shells for gas exchange
  • Reptilia: amniotic eggs, internally fertilized
  • Avian: internal fertilization, eggs
  • Mammalia: internal fertilization, birthed, (platypus and echidna lay eggs!)
  • Notochord, a longitudinal flexible rod structure located between gut and nerve cord
  • A dorsal, hollow nerve cord that develops into a central nervous system
  • Slits in the pharynx allow water to exit without going through whole digestive tract
  • A tail extending beyond the anus
  • Mammals have hair and produce milk