Brasilitherium is a transitional taxon that sets the stage for development of different critical features.
Brasilitherium has specialized their basicranium which allows them to start specializing in the middle ear and hearing.
Brasilitherium has a stapedial process of the quadrate which is a derivation of the middle ear.

Paleontologists looked at endocasts in order to study the increase in size of olfactory bulbs.
Preservation of soft tissue is virtually impossible in fossils, therefore paleontologists rely on endocasts to study the brain.
Some skulls have the brain pressed up against them, leaving impressions that allow the paleontologists to see possible structures that are soft tissue that are harder to see such as blood vessels.
They found that the casts in Brasilitherium was larger than non mammaliaform cynodonts.
This led to the suggestion that Brasilitherium had early evolution of the mammalian brain.

Similar to mammaliaforms and not cynodonts, Brasilitherium is found to have grooves in their post canine teeth as well as a formation of a tongue.

Another similarity to mammalian taxon is that the intraorbital fenstra evolves under the orbit.
Brasilitherium is a transitional taxon that sets the stage for development of different critical features. Brasilitherium has specialized their basicranium which allows them to start specializing in the middle ear and hearing. Brasilitherium has a stapedial process of the quadrate which is a derivation of the middle ear.
Paleontologists looked at endocasts in order to study the increase in size of olfactory bulbs. Preservation of soft tissue is virtually impossible in fossils, therefore paleontologists rely on endocasts to study the brain. Some skulls have the brain pressed up against them, leaving impressions that allow the paleontologists to see possible structures that are soft tissue that are harder to see such as blood vessels. They found that the casts in Brasilitherium was larger than non mammaliaform cynodonts. This led to the suggestion that Brasilitherium had early evolution of the mammalian brain.
Similar to mammaliaforms and not cynodonts, Brasilitherium is found to have grooves in their post canine teeth as well as a formation of a tongue.
Another similarity to mammalian taxon is that the intraorbital fenstra evolves under the orbit.
Brasilitherium