/sci/ - Science & Math

>>11389265
I'm not an expert but can try to answer,

The point you refer to is called an internal node, which are more precisely hypothetical taxonomic unit. So no. We don't know what specie/common ancestor is there.
These threes are just to show the evolutionary relationship between species (sometimes higher taxa), if you look at my image I found, you can see the shared loci used to construct these trees.
Trees made with morphological traits explained here:
https://www.khanacademy.org/science/biology/her/tree-of-life/a/building-an-evolutionary-tree

Basilosaurus share a common ancestor with modern whales, that line is extinct so it never became modern whales.
https://en.wikipedia.org/wiki/Evolution_of_cetaceans#/media/File:Cladogram_of_Cetacea_within_Artiodactyla.png