After studying fossils from an ancient ground sloth found in 2004 , a studypublished inBiology Lettershas reason out the tooth marks treat the bones were from the animal being predate on by a 4 - metre ( 13 - foot ) jejune ancient crocodile species .
After an expedition to the Napo River in Peru revealed beds containing 13 - million - year - old fossils from the Miocene era ( ~16 - 11.6 million years ago ) , researchers find damage tibia clappers belong to a gravid mammal . A left shin was identified as belonging to a mid - sized ground sloth ( Pseudoprepotherium ) that grow toaround the sizing of a capibara , smaller than some of itsgiant relative . The bones were littered with tooth marks akin to the shape of those left after a crocodile attack .
" The shin bone discovered in the Peruvian Amazonia is the first one of a mammal bearing crocodylian tooth marks and therefore important for understand the moral force of ancient ecosystem , " co - authorDr Rodolfo Salas - GismonditoldCNN .
The massive crocodylian , believed to be a giant caimanPurussaurus , make do to deflate deeply into the bone and peppered the dodo with 46 puncture marks . ThePurussauruswas one of the most horrendous predators of its meter , growing 10.3 metre ( 34 foot ) in distance and carry a bite that has no equal . According to the study , adultPurussauruscould crush anything in its jaw with a massive collation force of 69,000 Newtons , well over four sentence the most knock-down pungency ever recorded , belong to the Nile crocodile . Impressively , the authors believe the creature that preyed on the sloth was just a juvenile , so whilst it was well the length of an average innovative - Clarence Shepard Day Jr. American gator , it was hardly half the size of a fully - grown grownup .
Despite its jejune sizing , the giant caiman clasp around the ramification and endeavor to rive the limb from the struggling sloth , harmonise to the generator . Unfortunately for the acedia , it did not go the attack .
To decipher what marauder was responsible for the attack , Dr Salas - Gismondi and co - authorDr François Pujoshad to carry off all other possibilities . Analyzing the tooth marks ’ shape and depth eliminated various other genera of caiman , with many simply being too pocket-sized to be able to inflict the scathe seen on the bones . After deliberate inspection , the puncture marks appeared to match the " conelike and blunt teeth " of thePurussaurus , which has both the size and tooth form to be the likely culprit of the hunt .
Evidence for the interactions between reptiles and mammals in Miocene swamp is lacking , so this finding provides a gripping insight into the hunt habits of large vulture likePurussaurus . Present - mean solar day species of crocodile will latch onto the hind limb of large target before dragging them into water to drown , and the findings give here suggest a similar demeanor from prehistoric metal money .
Before this subject field , reptilian predatory animal lodge in in swamps at this fourth dimension were thought to mainly prey on large turtles . After the finding of the sloth stay , the researchers conceive this represent an alternate dynamic in which the monolithic caimans would also ambuscade farming animal , trounce them with their immense bite before drag them to their demise .
