Two questions please:
1) Rear Mount - crossed legs (not a figure 4 leg cross)
One of the first things you learn when you have rear mount is not to cross your legs (why not we all ask? - then the guy getting choked crosses his legs against yours and almost breaks your ankles by pressing down hard). Anyway in a lot of scrambles and positional moves you can sometimes see fighters crossing their legs in rear mount, but I've never actually seen someone submitted this way in grappling or MMA.
Are there any "real" fights or matches that have used this submission as a finish?
2) Rear Mount - figure 4 crossed legs
This is "realitively" new to MMA (yes catch wrestling has had it for 100 years or so and I'm sure other styles used it before too) but is there some kind of counter leg lock you can do when someone wraps a figure 4 leg cross from rear mount, or are you just basically screwed?
I catch people that body lock me fairly often with that submission. All you have to do is over hook the leg hanging from the body triangle, trap it against the mat and hip up hard. Puts a lot of pressure on the foot.
i've tapped to that and haven't crossed my feet ever since. that shit is Painful!
I HAVEN'T BEEN CAUGHT IN THAT SINCE THE 90'S LOL
Kid at my gym got caught with it in competition and was out for two to three months.
i ogt my firt grappling tournament win becasue my opponent crossed his ankles.....
seen in it in grappling severla times but not mma.
one time i had someones back in sparrring and he was tryin to cross me legs for me so he could get the leg lock. i fight it off and get over under with control of one wrist. mf'er then grabs my free hand and pushes it down for a wristlock. i had to tap shit was awesome and shitty at the same time.
strained my MCL 2 weeks ago because my hooks slipped (sweaty no-gi class) and crossed. it fuckin sucks.
body triangle is bullshit.
Saw it happen at NAGA a couple years back. Guy who got tapped was ahead on points and was on his way to the finals too. Intermediate division no less. 
there is a video somewhere from a bajillion years ago of eddie rolon geting the crodded ankle sub in an mma match......
holy balls i can;t belive i found it...
teh whole msnbc segment in question...
Nice Job, great find The Elastic Assassin!!!!!
that is from like 99-2000.....i think...lol @ the refs in that vid...my they look familiar...
K-Dub-"T" - Oh my....
yes i have gone old school....
LOL, great video.
Brad Burrick tapped Jason Davis a while back with that move.
Holt shit....Eddy Rolon!
Thats olde school right there!
BTW... the elastic assasin stole his whole 'signing every post' thing from Eddie.
Like a child touching a stove. I only did it once. in 99 hehe.
Now I either do body triangle or half backmount.
I used to know a guy (just grappling not mma) that was pretty slick at using his legs and one hand to actually cross his opponent's legs (opponent just had his hooks in and he would cross there feet by sort of shucking one hook downward), then he would throw on that submission.