Wrangler transmission part fell out

Take a look at my profile picture. My girlfriend was driving her 2000 Wrangler and it sounded like she hit something, but the only thing in the road was this. She sprung a smoky leak of transmission fluid (I think) from what looks like a protective panel, maybe over a transaxle or something, just fore of the muffler. What is it, and what shape was it originally?

P.S. It’s an automatic.

A picture tells a thousand words…HINT>>>>>>>>>>>