Les relations phylogénétiques des Lutrinae (Mustelidae, mammalia)

Evolution of river dolphins

“…In both trees, Platanista gangetica and Platanista minor, representing Platanistidae, are sister to the remaining odontocetes, although bootstrap support for this node is low. The remaining river dolphin taxa (Lipotes, Inia and Pontoporia) are paraphyletically arranged at the base of a well-supported clade that also includes porpoises, monodontids and modern dolphins, essentially Muizon's concept of the Infraorder Delphinida (Muizon 1988a(Muizon , 1991. In both analyses, beaked whales compose the sister group to Delphinida (Heyning 1989).…”

“…Although several marine delphinids are commonly found in rivers quite far upstream, river dolphins are morphologically and phylogenetically distinct from marine dolphins and most are restricted to freshwater ecosystems. Since the ¢rst suggestions of their a¤nities were advanced in the 19th century (Gray 1863;Flower 1867), the evolutionary relationship of river dolphins to one another and to other odontocetes has remained controversial (Simpson 1945;Kasuya 1973;Zhou 1982;Muizon 1984Muizon , 1988aMessenger 1994;Rice 1998). Despite di¡ering in detail, recent morphological systematic studies of modern and fossil taxa (Muizon 1988a(Muizon ,c, 1994Heyning 1989;Messenger & McGuire 1998) largely corroborated earlier views that each extant lineage is relatively ancient and that river dolphins comprise an unnatural group.…”

“…Since the ¢rst suggestions of their a¤nities were advanced in the 19th century (Gray 1863;Flower 1867), the evolutionary relationship of river dolphins to one another and to other odontocetes has remained controversial (Simpson 1945;Kasuya 1973;Zhou 1982;Muizon 1984Muizon , 1988aMessenger 1994;Rice 1998). Despite di¡ering in detail, recent morphological systematic studies of modern and fossil taxa (Muizon 1988a(Muizon ,c, 1994Heyning 1989;Messenger & McGuire 1998) largely corroborated earlier views that each extant lineage is relatively ancient and that river dolphins comprise an unnatural group. Nonmonophyly of river dolphins is consistent with their highly disjunct geographical distributions (¢gure 1): the Amazon river dolphin, Inia geo¡rensis, and the La Plata river dolphin, Pontoporia blainvillei, are found in South America; the Yangtze river dolphin, Lipotes vexillifer, and Indian river dolphin, Platanista gangetica, inhabit rivers on opposite sides of continental Asia.…”

A new otter of giant size,Siamogale melilutrasp. nov. (Lutrinae: Mustelidae: Carnivora), from the latest Miocene Shuitangba site in north-eastern Yunnan, south-western China, and a total-evidence phylogeny of lutrines

“…Furthermore, the ictonychines are either sister to or close to the base of the lutrines and thus we used Galictis as a second outgroup. In this context, we did not use Potamotherium as an outgroup, as it has been postulated to be an ancestral lutrine by several early studies (Thenius 1949b;Savage 1957;Fahlbusch 1967;Sokolov 1973;Willemsen 1992) but not by others (Muizon 1982). Whether Potamotherium is a musteloid or related to the origin of the pinnipeds (Rybczynski et al 2009), its phylogenetic position is considered too doubtful to include in an otter phylogeny.…”

“…In an early attempt at reconstructing higher level relationships of lutrines, de Muizon (1982) envisioned otters as a paraphyletic grouping, but he included thenknown 'musteloid' taxa, such as phocids and mephitids, that are now known to belong to clades that have no close relationships to otters. A morphological phylogeny of living mustelids by Bryant et al (1993) placed Lutrinae at the terminal end of Mustelidae and as the sister clade to the Melinae (i.e.…”