It's about 6,500 times as heavy as a Tyrannosaurus rex.
In other words, the weight of a Tyrannosaurus rex is 0.00016 times 40,000 tonnes.(for FMNH PR2081, a.k.a. "Sue") (a.k.a. Tyrannosaurus, a.k.a. T-Rex) (estimated live weight)
The notable Tyrannosaurus specimen housed at the Field Museum of Natural History in Chicago, Illinois, "Sue," is estimated to have weighed about 6.4 tonnes while alive. A renowned predator in popular culture, the teeth of tyrannosaurus rex were up to 33.02 cm (13 in) long.
It's about 6,500 times as heavy as an Elephant.
In other words, the weight of an Elephant is 0.00015 times 40,000 tonnes.(for African bush elephant, Loxodonta africana) (Adult, bull)
A bull African bush elephant weighs about 6.10 tonnes. Among African elephants, both males and females have tusks (whereas female Asian elephants, Elephas maximus, do not have tusks) which can grow to 3 m (10 ft) and typically weigh about 4 tonnes
It's about 10,000 times as heavy as a Hippopotamus.
In other words, 40,000 tonnes is 10,700 times the weight of a Hippopotamus, and the weight of a Hippopotamus is 0.00009350 times that amount.(Hippopotamus amphibius) (adult, male)
The average weight of an adult male hippopotamus ranges from 3.750 tonnes. Appearances to the contrary, adult hippos cannot swim or float in water; they actually move by leaping and walking across lake bottoms at about 8 kph (5 mph).
It's about 15,000 times as heavy as The Tongue of a Blue Whale.
In other words, the weight of The Tongue of a Blue Whale is 0.0000670 times 40,000 tonnes.(Balaenoptera musculus) (adult)
The tongue of a Blue Whale can weigh up to 2.7 tonnes. Despite their tremendous size, blue whales feed almost exclusively on tiny crustaceans called krill and cannot swallow anything much larger than a beach ball.
It's about 20,000 times as heavy as a Rhinoceros.
In other words, 40,000 tonnes is 19,000 times the weight of a Rhinoceros, and the weight of a Rhinoceros is 0.0000530 times that amount.(for Black rhinoceros, Diceros bicornis) (Adult, male)
An adult black rhinoceros weighs between 2.10 tonnes. Rhinoceros are extremely aggressive — nearly one of every two males will die as a result of fighting with other rhinoceros.
It's about 20,000 times as heavy as a Giraffe.
In other words, 40,000 tonnes is 20,700 times the weight of a Giraffe, and the weight of a Giraffe is 0.00004830 times that amount.(Giraffa camelopardalis reticulata) (adult, male, maximum of range)
An adult, male giraffe can weigh up to 1.930 tonnes. Reaching 5.5 m (18 ft) in height by adulthood, giraffe calves can grow as much as 3 cm (1 in) per day.
It's about 25,000 times as heavy as a Car.
In other words, 40,000 tonnes is 24,210 times the weight of a Car, and the weight of a Car is 0.000041310 times that amount.(for 2009 Ford Taurus; automatic transmission; curb weight)
A 2009 Ford Taurus weighs 1.6520 tonnes. The first mass-produced car, the Curved Dash Oldsmobile — introduced in 1901 — weighed just 0.3860 tonnes.