They do look close to
Mimosa Tenuiflora/Hostilis, but seeds of other species in the Mimosa or Desmanthus genera have little differences.
If it's Mimosa Tenuiflora, germination should be very easy, and once you have a seedling with the first pair of real leaves (the ones unfolding after the cotyledons) identification will be easier.
Nick a couple of them carefully in a side, and put them between two moist paper towels. Once the radicle emerges from the seed (1-2 days), you can move them to a little container with soil mix, half an inch deep. In a week or week and a half you'll have a closer ID.
Keep us posted

Mandrake