On Monday, January 15, 2024 at 11:24:37 AM UTC-5, erik simpson wrote:
> On 1/13/24 7:48 PM, Popping Mad wrote:
> >>>
> >> You can't draw that conclusion from the study you cite. If you want, you
> >> could coin a term "reptile-like mammal", but that isn't any more use
> >> than the now-deprecated "mammal-like reptile". I'm surprised the nature
> >> article uses it at all.
"now-deprecated" is a highly subjective term that accepts Newspeak
from the dominant clique in taxonomy without murmur.
Popping Mad has the late Isaac Asimov on his side: he wanted desperately for
monotremes to be non-mammalian therapsids.
> >
> >
> > You know I am just armchair speculating, but the evidence shows that it
> > has broken from all mainstream mammals maybe even before the Placental
> > split? That is pretty amazing and puts the platapus into its own
> > classification.
> >
> > It would be like a last surviving non-Avian therapod making it to the
> > present?
> >
> >
> It definitely split off before placentals, the sister is theria
That's only among extant mammals. The sister group among
all mammals, extinct or extant, is very hard to pin down.
It's more fruitful to look for the sister group of therians,
the sister group of the clade the two determine, and repeat the process
an indeterminate number of times. Before you get close to monotremes,
you encounter multituberculates and, further away from therians,
a tantalizing Miocene mammal from Patagonia, *Necrolestes*.
I would be enthralled if it turned out that a descendant survived there.
Patagonia is sufficiently sparsely populated that a small burrowing
mammal might have escaped notice.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
https://people.math.sc.edu/nyikos