A crab’s’eye view of the ancient world

The fossil crab Callichimaera perplexa. (Credit: Daniel Ocampo R. /Vencejo Films) Their legs may get more attention, but a new study says a crab's eyes have much to offer, too - at least scientifically. Writing in the journal iScience, paleontologists from Yale and Harvard have discovered new, unusually large optical features from a 95-million-year-old crab fossil, Callichimaera perplexa - a species first described in 2019 in a study led by former Yale paleontologist Javier Luque - which suggest that Callichimaera was a predator. Callichimaera , which was found in Boyacá, Colombia, and Wyoming, in the United States, was about the size of a quarter, featuring large compound eyes with no sockets, bent claws, leg-like mouth parts, an exposed tail, and a long body. Previous research indicated that it was the earliest example of a swimming arthropod with paddle-like legs since the extinction of sea scorpions more than 250 million years ago. " The specimens we have of the unusual Cretaceous crab Callichimaera perplexa preserve some very delicate eye tissues that don't normally preserve," said Kelsey Jenkins, a graduate student in Earth & planetary sciences at Yale and the new study's first author. "This includes things like facets and internal optical tissues.