Instead, they remain a key tool, allowing northern seals to exploit niches not – or perhaps no longer – available to most of their kin. The platypus is a duck-billed, beaver-tailed, otter-footed, egg-laying aquatic creature native to Australia. Cases like the grey seals also show that claws are not just an evolutionary hangover. Swimming appendages with the digits still apparent, as in the webbed forefeet of amphibious turtles and platypus, are considered paddles rather than flippers. Their claws connect northern seals with their ancient past, and help us understand how their ancestors conquered the ocean. Somewhat shockingly, they even fed on members of their own kind. Grey seals prey on other marine mammals, using their paws and claws in the process. The true nature and cause of these wounds was revealed only recently. Grey seals, in particular, have put this skill to deadly use.įor years, scientists have noted carcasses of harbour porpoises and various seals with peculiar spiral injuries. Mobile paws may give seals an advantage when handling large prey. Renae Sattler, Alaska SeaLife Centerīut there is also a more sinister part to this story. See how the claws dig deep into the salmon, helping the seal to keep a firm grip on its prey. Harbour seal stretching a fish between its teeth and strong claws during feeding experiments carried out at the Alaska SeaLife Center as part of this study. Their paws thus remained free to perform other tasks, and simply kept doing what they always had done. Unlike their close relatives, the fur seals and sea lions, northern seals primarily swim with their hind limbs. ![]() The answer, partly, is simply because they could. Given the importance of clawed forelimbs to ancient seals, why are northern true seals the only ones that still use them? Clawed forelimbs: a relic of the ancient past or useful modern adaptation? Rather than changing all at once, the behaviour and anatomy of early seals changed gradually, remaining effective at each step along the way. This gradual transition helped to smooth the switch from feeding on land to hunting underwater. Later seals lost the sharp cutting teeth of Enaliarctos, but retained its ability to grasp prey. But unlike modern seals, these ancestral species still had sharp cutting teeth that may have allowed them to chew their food while hauled out on the shore. Pity that those iconic scales can’t protect them humanity.Like the modern Northern seals, ancient species like Enaliarctos likely used their forelimbs to help process prey into pieces. Pangolins are the only mammals totally covered in scales, which they use for protection from predators in the wild. ![]() The eight species of the animal are bipedal and hounded for their scales and meat, which are hot-ticket items in the illicit wildlife trade. These Southeast Asian mammals are notoriously adorable - they look a bit like a small anteater made itself armour out of an artichoke. Perhaps you guessed the owner of these scales from their making headlines last year, but if not, meet the pangolin. That’s convergent evolution for you: Why should reptiles be the only ones to enjoy the protection of scales, or birds the benefits of webbed feet? This list is comprised of mammals who have clearly been taking pages from other playbooks. ![]() ( Yes, even dolphins.) But in the churn of natural selection, some mammals ended up with appendages that look like they should be found on a reptile, bird, or insect. Among other things, we give birth to live young, we’re warm-blooded, and, perhaps most obviously, we all have hair.
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