In what year was the younger of the two brother boxers, Lucas Martin Matthysse and Walter Dario Matthysse, born?
Walter Matthysse: Walter Dario Matthysse (born August 29, 1978) is an Argentine former professional boxer who competed from 2002 to 2009, and challenged once for the IBF welterweight title in 2007. Walter Matthysse:  He is the elder brother of professional boxer Lucas Matthysse.
i don't know