check this out: http://en.wikipedia.org/wiki/Diplomystidae
a few snippets:
a primitive family of catfishes (order Siluriformes). Diplomystes is particularly interesting as a basal group of catfishes.
Diplomystids retain more plesiomorphic characteristics than any other siluriforms, recent or fossil, including aspects of the maxillary bone, barbels, nares, otic capsule, anterior pterygoid bones, Weberian complex centra, caudal skeleton and fin rays, and pectoral girdle. Monophyly for Diplomystes is well supported by synapomorphies of the vomerine and palatine shapes, cranial articulation of the hyomandibula, and heavily papillose skin
unfortunately there's no part of the globve that vcannot be screwed up by man.....Diplomystes species are the only extant catfish family with teeth on a well-developed maxilla (although this is also true of the extinct genus Hypsidoris)

All diplomystids are considered to be potentially or actually threatened or endangered due to habitat deterioration and predation or competition by introduced trout, Oncorhynchus mykiss and Salmo trutta. D. chilensis may be extinct
