Geometridae

i was in the greenhouse a little while ago picking some cherry tomatoes for staal.  the plant is one i grew in the garden last summer and dug up and put into a pot to keep in the greenhouse over winter.  it's got some dead branches on it so i started snipping them off and i was surprised to meet this interesting little guy...

other than being a caterpillar of some species of moth in the family Geometridae i have no idea who he is.  some of the caterpillars of the geometer moths mimic twigs like the one i found today.  i'll probably have a better chance at identification if i'm lucky enough to see him after he's become a moth.  neat.