01:119:116 Lecture Notes - Lecture 7: Water Vascular System, Agnatha, Acanthopterygii
Document Summary
Lecture 7: deuterostomia clade, shared derived traits. Clade shares a single ancestor that had deuterostome development. All chordates share a common ancestor: larvae vs adults, endoskeleton, water vascular system. Notochord: flexible rod that allows animals to wiggle back and forth movement. Characters of vertebrates (a clade of the phylum chordate) Backbone composed of vertebrae of bone or cartilage-replaces notochord. Basal vertebrates are hagfish and lampreys: basal vertebrates (jawless fish) Muscular limgs: for locomotion (sister group of tetrapods) Basal clade: first tetrapods-first on land: amniotes. Class reptilian: shelled eggs, scales: derived traits. Marsupials: nipples, live young, placenta but born early->maternal pouch. Eutherians: most mammals; nipples, live young, placenta, complex internal development. Opposable thumbs: shared derived traits of primates. Shared traits of primates: recent human evolutionary history. Today homo sapiens is the only living hominid but in the past many hominids lived at the same time early homo sapiens lived at same time as homo neanderthalensis likely bred together.