Autapomorphies

Far less appreciated is that the Red-crested pochard is also odd, however, with more recognised autapomorphies than the Pink-headed duck. ❋ 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]). ❋ 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. ❋ 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. ❋ 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. ❋ Darren Naish (2006)

1974; Brauer, 1984a; Van Vark, 1995; ¨ its unique autapomorphies are not de fi ned. ❋ Guestc2a28b (2009)