Based on the world record nomination from Australia Records Institute (AURI) and Decision No. WK/USA.INDIA/690/2021/No.146, World Records Union (WorldKings) officially declared Red Kangaroo as the world’s largest extant marsupial on May 06^th, 2021.

The red kangaroo (Macropus rufus or Osphranter rufus) is the largest of all kangaroos, the largest terrestrial mammal native to Australia, and the largest extant marsupial. It is found across mainland Australia, except for the more fertile areas, such as southern Western Australia, the eastern and southeastern coasts, and the rainforests along the northern coast.

The red kangaroo ranges encompasses scrubland, grassland, and desert habitats. It typically inhabits open habitats with some trees for shade. Red kangaroos are capable of conserving enough water and selecting enough fresh vegetation to survive in an arid environment. Red kangaroos are mostly crepuscular and nocturnal, resting in the shade during the day. However, they sometimes move about during the day.

This species is a very large kangaroo with long, pointed ears and a square-shaped muzzle (snout/nose). They are sexually dimorphic as the males have short, red-brown fur, fading to pale buff below and on the limbs. Females are smaller than males and are blue-grey with a brown tinge, pale grey below, although arid zone females are coloured more like males. It has two forelimbs with small claws, two muscular hind-limbs, which are used for jumping, and a strong tail which is often used to create a tripod when standing upright.

The red kangaroo's legs work much like a rubber band, with the Achilles tendon stretching as the animal comes down, then releasing its energy to propel the animal up and forward, enabling the characteristic bouncing locomotion. The males can cover 8–9 m in one leap while reaching heights of 1.8–3 m, though the average is 1.2–1.9 m.

Males grow up to a head-and-body length of 1.3–1.6 m with a tail that adds a further 1.2 m to the total length and is referred to by Australians as "Big Reds".  Females are considerably smaller, with a head-and-body length of 85–105 cm and tail length of 65–85 cm. Females can weigh from 18 to 40 kg, while males typically weigh about twice as much at 55 to 90kg. The average red kangaroo stands approximately 1.5 m tall to the top of the head in an upright posture. Large mature males can stand more than 1.8 m tall, with the largest confirmed one having been around 2.1 m tall and weighed 91 kg.

According to en.wikipedia