It may seem like a scene straight out of the first Jurassic Park movie, but a team of researchers have found a 100-million-year-old crab stuck in fossilized tree resin. The analysis of this marvellous finding was published in the Sciences Advances Journal on Wednesday. The team of eight researchers came from Harvard University, Yunnan University, University of Regina, Lynn University, Duke University, Yale University, and China University of Geosciences.
Their analysis of the crab stuck in the amber has shown that the ancient animal extracted from the jungles of Southeast Asia, holds what is believed to be the oldest modern-looking crab ever found. The latest discovery provides new insights into the evolution of marine animals and when and how they spread around the world. Measuring just 5-millimeter, the ancient crab is the “first-ever” found in amber from the dinosaur era. The researchers believe that it represents the oldest evidence of incursions into non-marine environments by the true crabs. What makes this discovery even more unique is the fact that the best-known fossils in amber are usually terrestrial arthropods, primarily insects, whereas aquatic organisms are rarely represented. https://www.eurekalert.org/news-releases/932085
The study mentions that it is the first record of true crabs, also known as Brachyura, in amber, from the Cretaceous period in Myanmar. The latest fossil has perfectly preserved the large compound eyes, delicate mouthparts, and even the gills of the crab. The modern-looking crab is nested within crown Eubrachyura, or “higher” true crabs, which includes the majority of brachyuran species living today.
Lead author of the study, Javier Luque, who is a postdoctoral researcher in the Department of Organismic and Evolutionary Biology at Harvard University, said in a news release, “If we were to reconstruct the crabtree of life, putting together a genealogical family tree, and do some molecular DNA analysis, the prediction is that nonmarine crabs split from their marine ancestors more than 125 million years ago.” But there’s a catch as Luque said that because the actual fossil record, the one that they can touch, is way younger at 75 to 50 million years old, this new fossil and its mid-Cretaceous age allows them to bridge the gap between the predicted molecular divergence and the actual fossil record of crabs.