BIOL 1111 Lecture Notes - Lecture 10: Neoproterozoic, Choanoflagellate, Protostome
21 Oct 2014
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Objectives: know the major groups of animals and what an animal is, know major characteristics for divisions of animals and the possible origins of modern phyla, know the different feeding, movement and sensory strategies of animals. Animals are: monophyletic: multicellular eukaryotes, most develop tissues from embryonic layers heterotrophic lack cell wall ingest their prey. Recent phylogenetic analyses show several major groups: non-bilaterian lineages two protostome groups deuterostomes (lophotrochozoa and ecdysozoa) Animal ancestor: resembled modern choanoflagellates, closest living eukaryote relatives of animals, arose during neoproterozoic. Ediacarian biota: ediacaran biota, early soft-bodied members of the animal fossil record, date from 565 to 544 mya - latest neoproterozoic, lacked skeletons, burrowed, floated, or sat on seafloor. 535 to 525 million years ago: earliest fossil appearance of many major groups of living animals. Period of greatest evolutionary change in the history of animal life. Burgess shale biota ii: burgess shale biota show, tremendous size increase, great morphological complexity, diversification of lifestyles.
