Mass extinction is a common subject on what we think will happen when the world ends.

Humas, animals and plants will simply cease to exist when mass extinction occurs. In short, no life-form will survive this apocalyptic event - or not.

Because as reported by Vice, after countless mass extinctions in the history of Earth, researchers from the University of Pennsylvania presented an evidence that smaller animals have a better chance to survive when mass extinction occurs.

According to head paleobiologist Lauren Sallan, they have compared the body sizez of 1,120 fish fossils that lived before and after the late Devonian extinction event, a glacial period that wiped out about 96 percent of vertebrate life some 359 million years ago.

Sallan and her team found out that the late Devonian waters were filled with giant sea creatures, like the ten-meter-long Dunkleosteus terrelli, as well as plentiful smaller species. And they found out that, in the wake of the extinction event, large vertebrates either shrank or died off.

 In a similar report by News Science Mag, the team found that the species that indeed survived, were much smaller on average, compared to those that lived beforehand. And right after the extinction, most surviving species measured less than 40 centimeters in length.

The researchers point that among today's creatures, small species tend to grow and reproduce faster, so that they can produce a new generation before they are killed by large predators.

Moreover, when animals breed more quickly, their populations adapt to changing conditions more rapidly. Previous studies have called this phenomenon the "Liliput effect," named for the island of tiny humans in "Gulliver's Travels." However, this theory has only been supported with just a handful number of species.

The Sallan and her team also explained that the change in size trend, has no association with either temperature or oxygen, which were assumed as factors previously.

Her findings have implications for the modern world, which some scientists propose that is currently experiencing a sixth mass extinction - especially in marine ecosystems where over fishing tends to occur.

According to the Daily Mail, palaeontologists and evolutionary biologists have long debated the reasons behind the changes in animal body sizes.

And one main theories is known as "Cope's Rule," which says that the body size of a particular group of species tend to increase over time because of evolutionary advantages of being big that includes avoiding predation and being able to catch prey better.

But again, with this latest findings from scientists, it seems that the smaller really is the better. So before you tease your small friends, just remember that when mass extinction occurs, they have a better chance to survive than you.