Pliny the Elder [1st century CE] (Natural History, Book 10, 56): There is a bird called the shoveller-duck [platea] which flies up to the sea-divers and seizes their heads in its bill till it wrings their catch from them. The same bird after filling itself by swallowing shells brings them up again when digested by the warmth of the belly and so picked out from them the edible parts, discarding the shells. - [Rackham translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Birds 5.102): The platea is a bird, as Pliny says. It flies to those birds which dive into the sea for prey, and bites their heads until it has wrested their catch from them. The same bird sometimes, if it fills itself with shells, vomits them up cooked in the heat of its stomach. Then it separates the shells and passes the selected and separated meat into its stomach. - [Badke translation/paraphrase]