From Jasmin Fox Skelly at New Scientist:
A 520-million-year-old fossil shows an ancient shrimp-like creature caring for its four offspring. It is the oldest ever example of a parent actively looking after its young after they hatch. More. (paywall)
The arthropod may be the ancestor of insects and spiders (or maybe not). We have one “snapshot” and that’s from billions of lives.
What it mainly shows is that, contrary to what we might expect, there seems to have been little evolution of animal psychology since then.
See also: The cancer theory of the Cambrian explosion of life 541 million years ago