Why not go for one of the extinct dragonflies: Meganisoptera had a wingspan of 71 cm (28") and was a predator just like today's...
All predators have more than moderate mental aptitude anyway, so pushing the limit a bit wouldn't be too hard...
[![enter image description here][1]][1]
Source: linked Wikipedia article.
Edit: An IQ of 90 or above would mean a lot of handwavium as a higher IQ needs both a larger energy intake and external stimuli:
- Higher oxygen content of the atmosphere
- Parallel evolution where they became an apex predator:
- they learnt how to capture small birds, flying fish, ...
- Learnt to live in social groups like bees
- ...
- And depending on your universe: Magic can do anything... [1]: https://i.sstatic.net/8h6Yg.jpg
