[Taxacom] What taxon corresponds to "birds'?

Francisco Welter-Schultes fwelter at gwdg.de
Tue Nov 29 15:08:12 CST 2016


"For thousands of years (or longer), there has long been a 
classificatory distinction between reptiles and birds" - this statement 
should not remain uncommented.

Linnaeus 1758 used the term Amphibia for three subgroups Reptiles, 
Serpentes and Nantes. Reptiles contained turtles, some squamates and 
frogs, but no snakes. Nantes contained some fishes. It took long until 
the differences between such groups were understood. The term Reptilium 
was introduced by Laurenti in 1768 (and still there it contained 
amphibians, and no turtles). Also Cuvier in the late 1700s did not 
distinguish between amphibians and reptiles.

Only a few decades before, European scientists had discovered that bats 
were no birds. So in Europe's 1600s the distinction between birds and 
reptiles could have been a distinction between bats and frogs. Others 
used terms such as flying animals and did not necessarily distiguish 
birds and flying insects. Prior to 1550 natural sciences in Europe were 
not in a good condition.

Aristotle (350 BC, Greece) presented several groups of vertebrates, 
birds was one of them. He recognised several partly mixed groups of 
reptiles and amphibians, and was probably not aware that his definition 
of mammals would also include some reptiles.

We would also have to consider attempts of animal classification in 
various cultures prior to global acceptance of standards developed in 
Europe.

Just some thoughts...

Francisco


Am 29.11.2016 um 05:44 schrieb Kenneth Kinman:
> Hi All,
>         For thousands of years (or longer), there has long been a classificatory distinction between reptiles and birds, although Archaeopteryx eventually showed that birds are clearly reptile descendants.  This was reflected in both informal and formal classifications as Classes Reptilia and Aves.  But the more recent discovery of fossil intermediates has blurred where to draw the line between reptiles and birds.  And around the same time we had adherents of phylogenetic nomenclature  concluding that both paraphyly and ranked classifications are somehow "unnatural".  And yet decades later the PhyloCode is still extremely controversial and perhaps not likely to be implemented anytime soon (if ever).
>         In the meantime, even among strict cladists, the meaning or definition of Class Aves has become increasingly muddled, between those who would make it a crown group (and thus a synonym of Neornithes) or alternately based on a group including Archaeopteryx, crown-group birds, and all of their descendants.
>         Given this muddled situation, I have long favored expanding that Class (for birds) to include avian dinosaurs that seem to have preceded the common ancestor of Archaeopteryx and modern birds.  Given the importance of flight in the concept of "birds", I have come to the conclusion that asymmetical flight feathers are a primary evolutionary development in what constitutes a "bird".
>         Therefore, given the muddled debate whether Aves is the crown group or anchored instead on Archaeopteryx, I would perhaps suggest that we recognize a Class Paraves for "birds" rather than a Class Aves.  The discovery of Archaeopteryx long before all the other intermediates between reptiles and modern birds long made it a convenient anchor for a very long time, but it no longer seems to be so important given all the other forms since discovered (some older) with adaptations for flight (the asymmetic flight feather being a primary synamorphy, although even though its gradual developmental can be problematic given problems inherent in fossil specimens).
>         Therefore, should we start calling it Class Paraves, or expand Class Aves to become a synonym of Paraves.  I'm not sure which would be the best choice.  However, I am convinced that we need to expand the concept of "birds" as a Class separate from Class Reptilia.  Whether we call that Class Paraves or an expanded Class Aves is the question.
>                                    ----------------------Ken
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