[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Phylogeny of South American Late Cretaceous mammals

Or rather, their phylogenetic position!

I'd never have guessed that they're "symmetrodonts".

a parsimony analysis of 137  morphological characters among 44 taxa.

*sigh* I don't doubt for a second that this analysis is bigger and better than any other on this topic before it. But. 137 is juuuust barely above 3 times 44. Experience strongly suggests that lots more parsimony-informative characters remain to be discovered, and that the number of characters is not even necessarily high enough to exclude problems from accidental sampling bias.

Meridiolestida survived until  the early Paleocene (Peligrotherium)
> and early Miocene (Necrolestes) in South America, and their
> extinction is probably linked to the increasing competition with
> metatherian and eutherian tribosphenic mammals.

It's really hard to imagine such competition taking 45 million years or more. I still don't understand why people keep putting such vague speculations into their abstracts.

The clade Meridiolestida plus  Spalacotheriidae is the sister taxon to
> Cladotheria and forms a new clade Alethinotheria.

True beasties? Like Alethinophidia?

(Therion is the diminutive of ther = "generic wild beast".)