autapomorphies

Far less appreciated is that the Red-crested pochard is also odd, however, with more recognised autapomorphies than the Pink-headed duck.

Archive 2006-11-01 Darren Naish 2006

Of 108 named British dinosaur taxa (representing the valid species and the nomina dubia), over 50% are nomina dubia (that is, based on remains that lack autapomorphies [unique, diagnostic characters]).

Archive 2006-03-01 Darren Naish 2006

Then there are unnamed taxa: specimens that can be identified to a clade but remain unnamed because, like nomina dubia, they lack autapomorphies.

Archive 2006-03-01 Darren Naish 2006

Far less appreciated is that the Red-crested pochard is also odd, however, with more recognised autapomorphies than the Pink-headed duck.

The Madagascar pochard returns Darren Naish 2006

Consider that, rather than being useless, indeterminate objects that do not really reflect biological entities, some nomina dubia surely represent real taxa, it’s just that we lack the data to diagnose them by autapomorphies.

Archive 2006-03-01 Darren Naish 2006

There’s already a precedent for recognising taxa that lack autapomorphies: they’re called metataxa, and I think that at least some nomina dubia should be regarded as such.

Archive 2006-03-01 Darren Naish 2006

1974; Brauer, 1984a; Van Vark, 1995; ¨ its unique autapomorphies are not de fi ned.

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