Evolution Diary

An ancient creature with bulging eyes and a “great appendage” could be a missing link in the evolution of grasping claws, according to a new study.

The new fossil species Schinderhannes bartelsi—seen above in fossil form and in an artist’s reconstruction—resembles an ancient group of animals that had pairs of large, interconnected limbs on their heads, a configuration known among paleontologists as the great appendage.

Modern scorpions and other arthropods often have a grasping claw that looks like it might have evolved from the great appendage. But until now the fossil record had suggested that animals with this distinctive limb had all gone extinct in the middle of the Cambrian period, creating an evolutionary dead end.

Schinderhannes was found in a German quarry within a slate deposit that dates to 390 million years ago—100 million years after the great-appendage group was supposedly wiped off the map.

Described in this week’s issue of the journal Science, the fossil could offer valuable clues to solving the long-standing dispute over how arthropods are related to one another.

“Sadly, the quarry from which this fabulous material comes has closed for economic reasons,” study co-author Derek Briggs, of Yale University’s Peabody Museum of Natural History, said in a statement.

“So the only additional specimens that are going to appear now are items that are already in collectors’ hands, and that may not have been fully prepared or realized for what they are.”

News from National Geographic