Re: [dinosaur] Party like it's 1758!

[Tim Williams <tijawi@gmail.com>]

I think Mike's idea has a lot of merit.  As I understand it, it
essentially means that although each genus+species would *look* like a
Linnaean-style binomial, each would effectively be a uninomial.  So it
wouldn't fundamentally change the system.  Rather, it would be a
convention (not a rule) that works within the existing system of
nomenclature.

Here's the issue:  If someone does refer a new species to an existing
genus, then there's a decent chance that someone else at a later date
will erect a new genus for that species.  As Peter Dodson succinctly
put it in 'The Horned Dinosaurs' (back in 1996); "The problem is that
when you show such restraint somebody else will very likely come along
and rename your dinosaur".   There's nothing wrong with that - it's
usually done for the best of reasons.  (Peter cited _Breviceratops
kozlowskii_ as an example, which began as a species of
_Protoceratops_.)   But I can see advantages for fossil taxa in simply
erecting a new genus from the get-go, whenever a new species is named.

As so often mentioned, there is no universal 'genus-o-meter' that
determines when a species should get its own genus and when it should
be referred to a pre-existing genus.  The decision is subjective.
Sometimes it's intuitively obvious that a new species cannot be
accommodated in a known genus; other times it's less clear-cut, and
open to debate (especially for sister species).

Ceratopsians are a fine example of how uneven the taxonomy is.  New
ceratopsid genera have exploded in recent years as new species get
described.  By contrast, almost all new psittacosaurids still get
lumped into an increasingly speciose _Psittacosaurus_.

Elsewhere in the Dinosauria, certain genera have become wastebasket
taxa, like _Mamenchisaurus_ and _Omeisaurus_ - as the recent study by
Moore et al. on _Klamelisaurus_ made clear(er).  Having monospecific
genera limited to their respective type species would prevent the
practice of using genera as wastebaskets.  Based on the type species,
_Mamenchisaurus_ is actually quite poorly known scientifically - but
the genus has been bloated by the proliferation of new
'_Mamenchisaurus_' species, many (most?) of which are likely not
congeneric with the type.




Paul P <turtlecroc@yahoo.com> wrote:

> It can be a bit confusing, but no more so than removing a taxon from one 
> clade to another. It might be helpful to think of genera as small clades, so 
> when
> "Diplodocus hayi" becomes "Galeamopus hayi", "hayi" is simply switching 
> clades. That's not quite correct, of course, since names are binomial (genus +
> species). Part of the confusion may be that duplicate species names are 
> allowed, e.g. Achelousaurus horneri, Oohkotokia horneri, and Daspletosaurus
> horneri. If we couldn't do that, we'd have to coin things like "Horneria" and 
> "Horneraptor" as genus names.
>
> So in that sense, Mike is right that the name really is being changed when a 
> species is moved to a different genus. Binomial names are, at least to some
> degree, single names. At the same time, two names (genus + species) implies a 
> hierarchy. Making any fundamental changes to that system at this point
> would cause far more confusion than it would eliminate.
>
>
>
> On Monday, June 22, 2020, 09:24:26 AM UTC, Mike Taylor <sauropoda@gmail.com> 
> wrote:
>
> Exactly. "Galeamopus hayi" is a different name from "Diplodocus hayi", but 
> they are both names for the same animal. This is unhelpful: ideal names are 
> bijective (i.e. each taxon has one name and each name refers to one taxon). 
> By having guessed that the species "hayi" belongs to the genus "Dipldocus", 
> Holland (1924) put us in a position where we would have the change the name 
> of his species. Now we needn't be too critical of what he did a century ago; 
> but we also needn't copy his mistake.