That always bother me too. Thanks for clarifying. Also it should be noted (I *think* I'm correct here) that our fossil lobe-fins are all shallow water species, whereas the living coelacanth is a deep water fish.
Lungfish are shallow-water, lobe-finned fish.
Bichirs are another shallow-water fish, though their disposition as lobe-finned or ray-finned has been up in the air.
The following article utilizes mitochondrial sequencing to propose the latter... Second, our markers demonstrate that the extant tetrapods are monophyletic and lungfishes are the closest living relatives of tetrapods as proposed in phylogenetic model 1a (Fig. 1). The extant tetrapods can be divided into two groups: amphibians and amniotes, with amphibians represented by three living orders, Anura (frogs), Caudata (salamanders), and Gymnophiona (caecilians), and the amniotes, including reptiles, birds, and mammals. Although a large number of morphological characters supports a monophyletic status of these tetrapods (1, 2), some systematists have argued a diphyletic origin of tetrapods, suggesting that salamanders and newts arose from a lobe-finned fish lineage different from that which led to frogs and other tetrapods (17, 18). Furthermore, it has not been possible so far to resolve the phylogenetic position of tetrapods in relation to the extant lobe-finned fishes, the lungfish and the coelacanth (3-6). Our synapomorphies confirm the monophyletic status of the living tetrapods and provide evidence for a sister-group relationship between the living lungfishes and tetrapods. Third, the markers cloned by us resolve the phylogenetic position of bichirs, a group of freshwater fishes endemic to Africa. The classification of bichirs has been problematic, as they display a mixture of ancestral and derived characters and share many characters with both lobe-finned fishes and ray-finned fishes (2). For example, they possess paired fins with fleshy bases and lungs that arise from the ventral side of the digestive tract, similar to the anatomy of lobe-finned fishes, but ganoid rhombic scales and a single elongated dorsal fin that is directly inserted into the body, as in ray-finned fishes (2). Phylogenetic analysis of the complete mitochondrial sequence of bichirs was also unable to determine whether they are ray-finned fishes or lobe-finned fishes (19). Based on the phylogenetic distribution of some nuclear introns, we had shown that bichirs lie outside the clade comprising (sturgeon + gar + bowfin + Teleostei) but did not resolve whether bichirs are within the ray-finned fish lineage or lobe-finned fish lineage (13). The additional data presented here clearly demonstrate that bichirs are in the ray-finned fish lineage basal to all other living ray-finned fishes. Thus bichirs occupy an important position in the ray-finned fish lineage and are a useful model for understanding the evolution, development, and physiology of the diverse ray-finned fishes.
Molecular synapomorphies resolve evolutionary relationships of extant jawed vertebrates
Byrappa Venkatesh, Mark V. Erdmann, and Sydney Brenner
Proceedings of the National Acadamy of Sciences - September 25th, 2001
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