Why does catclaw claw?

[TooOld2Hike_EP]

First, I'm not sure if it's spelled catclaw or Cat's Claw. This page says the former.

(Scientific name Senegalia greggii?)

But after being snagged multiple times by catclaw during my recent hike in the Superstitions, I was wondering why catclaw claws the way it does? (Unlike thorns on rose bushes, catclaw pulls inward.)

It's not like a Venus Flytrap, where the plant is trying to entrap animals that pass by. And if you brush past without pushing into the branches, the catlcaw doesn't catch you.

I noticed that the "beak" of the claw would break off and remain in my sleeve if I tugged. Are those seeds? (I don't think so.)

Or maybe the claws are to grab and climb other things like vines? Although the page above calls it a shrub and I didn't notice any of the plants climbing anything.

[xsproutx]

There's thinking that it might be leftover from a previous time where megafauna existed that would walk past it, get caught up in it, and shake/mess up the shrub which would disturb the seeds and masticate them a bit, which those seeds need to germinate.