A crab fossil could explain a “void” in evolution

Saturday, October 23, 2021 at 2:48 PM – A team of scientists have discovered what is believed to be the oldest aquatic animal preserved in amber.

It is a tiny crab locked in fossil resin and believed to be over 100 million years old according to a study published in the journal Science Advances. It is the most complete fossilized crab ever discovered. The animal is so well preserved that its eyes, claws, legs and gills are visible. This discovery will help researchers better understand the era when crustaceans began to migrate out of the sea.

fossil crab

Scientists are now able to reconstruct what life looked like millions of years ago from preserved specimens like amber fossils and bones. Insects, plants, feathers, and microorganisms are the most likely specimens to be found trapped in amber. However, finding an aquatic creature fossilized in resin is extremely rare.

The absence of sand in the fossil and the way the sap flowed over the crab suggests that the animal lived far from the beach and in fresh or brackish water. It is also possible that the crab migrated, as do the red crabs on Christmas Island, to release their offspring into the ocean and then return to land.

Evidence shows that crabs have adapted to habitat on land and in brackish, freshwater since the dinosaur era. It is for this reason that their gills have evolved to have a tissue similar to that of the lungs, allowing them to breathe in and out of the water. The uncovered crab had no lung tissue and had well-developed gills instead, suggesting that it did not live primarily on land.

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