Bloody photos show how a mysterious predator turned the toad inside out.

Jane Friedman, curator of natural history at Plymouth Museum, and his family were walking in Wenfu Reservoir in Dartmoor when his 8-year-old son found this bloody body. He told Life Science in an email.

In a photo of the body, Friedman shared this photo on Twitter on March 24, when toad's glassy intestine splashed to the ground and its lower skin (still attached to the jaw) extended to the back. Friedman said, "amazing feast: photos of animals and their prey."

"The head is the only part that hasn't turned out, so we can see that it is an ordinary toad." "We have seen many toads in Dartmoor's gardens and other places, but we have never seen anything like this." Friedman wrote on Twitter that he suspected it was the masterpiece of a carnivore-but what kind of carnivore was it?

Friedman hoped that biologists on Twitter could explain the interesting (and bloody) state of toads, but they were not disappointed. Jack Ashby, the museum manager of the Animal Museum of Cambridge University, initially thought that frogs were pulled apart by crows. "This is how Australian crows treat the invading poisonous cane toads." In Australia, crows learn to avoid the poisonous glands on the toad's head and back. Photographer Steve Wilson (2018) recorded the act of tearing toad head down into its stomach and then swallowing its internal organs. Ashby told Life Science in an email that European toads also have toxin glands on their skin, so it is not surprising that predators will remove them. In the picture of the inverted toad, it seems that its meat has been carefully removed. "Which one can be made more easily with a flexible beak?" He added that "KDSP", "KDSP" and "KDSP" are all clenching their teeth and grasping the claws of "KDSP", but there is another carnivore, because it has cleverly peeled off the poisonous toad skin-the European otter. (Rutera Rutera). Although these otters mainly eat fish, they are also famous for eating mammals, birds and amphibians. Amy Schwartz, a researcher and doctoral student at the School of Biological Sciences at Cardiff University, told Life Science in an email. "kdspe" and "kdsps" toads often appear on the otter menu in spring. When a large number of amphibians gathered in the pond to breed, Schwartz explained. She suspected that the otter had skinned the toad in the photo, because she had seen similar evidence before: in a pond in Pembrokeshire-"a place full of otters"-there were many toad skins floating on the water.

After carefully examining the image, Ashby also concluded that this predator may be an otter. He said that many muscles and bones in the leg and spine were missing, which indicated that the toad was attacked by mammals-"something that might crush the whole toad's leg."

The detail that Ashby tied it up was the empty skin that had grabbed toad's foot. It must have been torn from the skin by a carnivore strong enough to connect the whole leg "muscles, bones, tendons and ligaments".

"It takes a lot of power. It may be that this animal grabbed the body with its claws and tore its legs off the skin with its teeth, "Ashby said. Ashby said that otters can do this more easily than birds. Toad's skin is only loosely connected with the animal's body, so it is easy to be removed. He said, "Toad's skin sticks tightly to his hands and feet and to his skull." If you are not worried about maintaining the integrity of the skin, it can be cut at the "waist" like tights and tight shirts.

Exquisite corpse: biologists share the "best corpse photos", the top ten most deadly animals (photos) and seven terrible toad survival strategies, which were first published in Life Science magazine.