The American marsupials which have barely modified for the reason that time of the dinosaurs

When you purchase via hyperlinks on our articles, Future and its syndication companions could earn a fee.

QUICK FACTS

Name: Virginia opossum (Didelphis virginiana)

Where it lives: Central and North America

What it eats: Fruit, bugs, small animals and carrion

With their beady eyes, huge ears, hairless tails and brief, stocky legs, opossums are distinctive marsupials. Despite their odd look, these animals have a wealthy evolutionary historical past and have remained largely unchanged for hundreds of thousands of years. Their outstanding capability to adapt to completely different environments, meals sources and predators has helped them survive from the time of the dinosaurs to right this moment.

The Virginia opossum is the one opossum species discovered within the United States and Canada. Opossums have the smallest brain-to-weight ratio of any North American mammal.

The earliest identified family of recent opossums lived over 65 million years in the past, across the time dinosaurs went extinct. A 2009 study printed in PLOS ONE discovered that peradectids, a household of marsupials identified from fossils largely in North America and Eurasia, are the closest extinct family of residing opossums. Like fashionable opossums, peradectids had opposable thumbs on their hind ft and a equally formed cranium — options which have remained practically unchanged for hundreds of thousands of years. The earliest opossum fossils date again to the early Miocene epoch, roughly 20 million years in the past.

One key motive why opossums have survived for thus lengthy with few modifications is as a result of they’re adaptable. These marsupials eat virtually something, together with fruit, bugs, small animals and animal carcasses. They can reside anyplace from forests to city backyards. And, though they’re largely nocturnal, they’ll typically be seen in daylight if meals is scarce.

Opossums are additionally immune to snake venom, significantly that of rattlesnakes and different pit vipers. This resistance is because of a protein known as Lethal Toxin Neutralising Factor discovered of their blood, which may neutralize varied toxins in snake venom. This permits opossums to prey on venomous snakes that might in any other case be a menace.

Opossums give start to underdeveloped younger, which crawl right into a pouch and nurse for round eight weeks as they develop. Young opossums then experience on their mom’s again for a number of weeks till they turn out to be impartial at 12 weeks previous.

When threatened, opossums could growl, hiss, naked their tooth or climb a close-by tree to flee. If escape is not doable, they resort to “playing dead” — a protection mechanism generally known as thanatosis.

RELATED STORIES

—Pacific spiny lumpsucker: The cute little fish with a bizarre suction cup resembling human tooth

—Plains viscacha: A rodent that builds vast underground cities and ovulates more than any other mammal

—Wandering salamander: The tree‑climbing amphibian with a blood‑powered grip

This response is not a acutely aware determination however a physiological response to excessive stress. It causes the opossum to turn out to be utterly motionless and seem lifeless. This habits is commonly accompanied by a significant drop in heart and respiratory rates, a lower in physique temperature and the discharge of a foul-smelling fluid from the anal glands. Together, these cues sign to predators that the opossum is already useless, typically inflicting them to lose curiosity and transfer on. So involuntarily “playing possum” permits the animals to outlive the encounter.