It reminds me of Crataegus of some sort.

Are the leaf margins doubly serrated?

https://aggie-horticulture.tamu.edu/ornamentals/natives/CRATAEGUSCRUS-GALLI.HTM what do ya think?

Would be a cool find, but the leaves on Crataegus crus-galli are fully-serrated, while these only are at the ends? And Crataegus texana looks a little closer, but its leaves are also much larger and still far more serrated?

I get the impression this is evergreen. So not either of thos Crataegus. I'm not getting Crataegus vibes from this at all.

Compare with Spiny Hackberry, Celtis ehrenbergiana.