On the left are shown two theories of the relationships amongst modern animals.
Some paleontologists relate many or most of these forms to modern animals.
They can't even make modern animals, with intact genomes, that way.
The researchers compare the calculated body temperature to several groups of modern animals.
Such behavior was speculation informed by modern animals and not based directly on fossil evidence.
In some cases, modern animals may be left unbranded for several reasons.
For example, many explanations combine animation with videos of modern animals.
This, of course, includes most modern animals, including humans.
Plenty of other modern animals make their living in conditions where seeing is difficult or impossible.
We also can find a plausible series of intermediates among modern animals.