Lobefin Fishes Lecture

Lobefin Fishes Lecture - Two major groups of living fishes...

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1 Lobefinned Fishes--Living Relicts Three groups (Infraclasses) placed in the “ Sarcopterygii ”to separate them from the Rayfinned Fishes 2 Two major groups of living fishes ± Not important in marine systems, only one living sp, Latimeria chalumnae ± Not important generally because of low diversity ± Very important in terms of vertebrate evolution--three independent lines ± Placed in Subclass Sarcopterygii to separate them from Subclass Actinopterygii (=rayfinned) 3 Primitive Features ± Spiral valve intestine ± Lobed fins (= Sarco-pterygii) ± Paired fins supported internally by skeletal elements which attach to pectoral and pelvic girdles Homologous to tetrapod limbs 4 Infraclass Dipnomorpha--Lungfishes ± Orders Ceratodontiformes (Aust.) and ± Three families of living species ± Freshwater species ± Newly hatched African and South American lungfishes resemble salamander tadpoles with external gills 5 Infraclass Actinista--Coelacanth
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This note was uploaded on 09/13/2010 for the course OCS 4012 taught by Professor Baltz,d during the Spring '08 term at LSU.

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Lobefin Fishes Lecture - Two major groups of living fishes...

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