Deuterostomes and Chordates 1 BIOL 1407 Deuterostomes Phylum

Deuterostomes and Chordates 1 BIOL 1407

Deuterostomes • Phylum Echinodermata – Sea stars, sea urchins, sea cucumbers, crinoids • Phylum Chordata – Tunicates, lancelets, fishes, amphibians, reptiles, birds, mammals

Phylum Echinodermata

Phylum Echinodermata • Larvae: bilateral symmetry • Adults: pentaradial symmetry • • Photo credit of pluteus larva: NOAA, 2001 Photo credit of adult brittle star: Larry Zetwoch, 1989, Florida Keys National Marine Sanctuary, NOAA

Water Vascular System • Unique • Hydraulic system used for feeding and locomotion • Video of tube feet: http: //www. youtube. com/w atch? v=s. Mgf. Zj 3 Ds. XY&fea ture=related • Photo Credit: Dr. James P. Mc. Vey, NOAA Sea Grant Program

Phylum Chordata

Characteristics of Chordates • Bilateral symmetry • Triploblastic • Coelomate • Segmented

Other Chordate Characteristics • • • Complete Digestive System Closed Circulatory System Respiratory System: Gills or Lungs Excretory System: Kidneys Centralized Nervous System

Unique Chordate Characteristics

Phylum Cephalochordata: Lancelets

Phylum Urochordata: Tunicates

Major Chordate Clades • Craniates: Cranium – Vertebrates + Hagfishes • Vertebrates: Vertebral Column – Gnathostomes: Jaws & Paired Appendages – Osteichthyans: Lung/Lung Derivatives – Lobe-finned Fishes: Limb Bone Pattern – Tetrapods: Four Well-Developed Limbs – Amniotes: Amniotic Egg

Hagfishes • • Craniates Head Simple cranium Not vertebrates

Characteristics of Vertebrates • Vertebral Column • Welldeveloped skull • Photo Credit of Hippo skull: Raul 654, 2005, Wikimedia Commons

Photo Credit for Platypus Skeleton at Melbourne Museum: Peter Halasz, 2006, Wikimedia Commons

Lampreys • Vertebrates • No jaws or paired appendages

Evolution of Jaws

Chondrichthyes • Cartilaginous skeleton • Jaws Present • Paired Appendages

Osteichthyans • Bony Skeleton • Lung and Lung Derivatives • Two Main Groups: – Ray-finned – Lobe-finned

Ray-Finned Fishes • Fins are supported by fin rays • Swim bladders • Largest vertebrate group

Lobe-Finned Vertebrates • Fins and limbs supported by internal bones and muscles

Lobe-Fin Pattern Photo Credit: Courtesy of Dennis Murphy, Devonian Times, http: //www. devoniantimes. org/opportunity/tetrapods. Answer. html

• Video of Fish with Fingers: http: //www. pbs. org/wgbh/evolution/library/03/4/l_034_03. html

The End Unless otherwise specified, all images in this presentation came from: Campbell, et al. 2008. Biology, 8 th ed. Pearson Benjamin Cummings.