I've photographed this species elsewhere in Central and West Texas, but this was a new moth for me here at home. @aredoubles had a Travis County record a few years ago and @greglasley recorded the species in adjacent Hays County this past May and several times this Fall. Austin is just about at the northeast edge of the species range and the species may not be regular here.
Not confident on ID.
Macaria transitaria – Blurry Chocolate Angle Moth?
The Macariini are a tribe of geometer moths in the Ennominae subfamily. Though they share many traits with the Sterrhinae, this is probably plesiomorphic rather than indicative of a close relationship, and DNA sequence data points to the Boarmiini as particularly close relatives of the Macariini. All things considered, this tribe might still resemble the very first Ennominae more than any other living lineage in the subfamily.