Going toe-to-toe, these fighting primates could give Floyd Mayweather a run for his money. The amazing images – captured by Australian tourist Julie Rathbone on the banks of the Zambezi river in Africa – show the pair engaging in a few fisticuffs. The Chacma baboons appeared to settle a disagreement by fighting – before a senior baboon plays referee and steps in to break it up. Nurse unit manager Julie Rathbone, 59, from New South Wales, was on a cruise down the river when she spotted the fracas unfolding. (Photo by Julie Rathbone/Caters News)

A handout photograph provided by Brian Kubicki of Costa Rican Amphibian Research Center on 26 April 2016 shows a “Crystal frog”, Hyalinobatrachium dianae (H. diane). This frog was discovered by US biologist Brian Kubicki and Costa Ricans Stanley Salazar and Robert Puschendorf in a rainy forest of Costa Rican caribbean after 40 years without notice of any new example of this kind. (Photo by Brian Kubicki/EPA/Costa Rican Amphibian Research Center)

The New World porcupine, family Erethizontidae, 1280 Gram born at 11 April 2015 Inventory in Zoo. Counting trade Fairs Weighing the Zoo is at 7 May 2015 too the 108 Birthday Zoo Hagenbeck Hamburg, Germany. (Photo by Imago/ZUMA Wire)

Female sea lion “Sarasa” holds a hose with her mouse to help a trainer clean her room at the Shinagawa Aqua Stadium aquarium in Tokyo on December 30, 2014. The aquarium is carrying out year-end general cleaning of their facilities. (Photo by Yoshikazu Tsuno/AFP Photo)

A woman cartwheels through the Coachella Valley Music and Arts Festival in Indio, California April 10, 2015. (Photo by Lucy Nicholson/Reuters)

A police officer removes a reveler from standing on a post as they guard and clear the street of revelers dressed in holiday themed costumes during SantaCon in New York Saturday, December 12, 2015. As thousands of Santa-suited merrymakers prepare to hit the city's streets and bars, organizers of the annual pub crawl say they're taking more steps than ever to deter naughty behavior. (Photo by Andres Kudacki/AP Photo)

A costumed guest attends WonderCon Anaheim 2015 at Anaheim Convention Center on April 4, 2015 in Anaheim, California. (Photo by Araya Diaz/WireImage)

NFL player Rob Gronkowski, of the New England Patriots, from second left, accepts the best comeback athlete award with his brothers, NFL free agent Chris Gronkowski and former NFL player Dan Gronkowski at the ESPY Awards at the Microsoft Theater on Wednesday, July 15, 2015, in Los Angeles. (Photo by Chris Pizzello/Invision/AP Photo)