Fossilized tissue reveals largest known T. rex died from broken rib - Popular Science

The sea cucumber study reveals an unusual form of tissue regrowth, with detached fragments continuing to heal, reorganize, and grow for more than three years in natural seawater. Credit: ShutterstockSea cucumber tissue kept growing for more than three years after removal, surviving in seawater teeming with microbes. Like Thing, the disembodied hand in The Addams Family, a severed piece of sea cucumber tissue kept living without the body it came from, prompting scientists to describe the animal as a “real-life zombie.” Weeks after being cut from a tube foot, the fragment appeared to be growing in seawater full of microbes, far from the sterile conditions usually needed to keep tissue cultures alive. Scientists at Memorial University of Newfoundland followed up by placing tissue removed from the feet, main body, and tentacles of three sea cucumbers in flowing seawater. The animals belonged to Psolus fabricii, a cold-water species. Working with collaborators including Rachel Sipler, a senior research scientist at Bigelow Laboratory for Ocean Sciences, the team documented what happened to those fragments in a study published in Science Advances.

October 7, 20263 min read Add Us On GoogleAdd SciAmThe oldest known land animal is 194. How did he get so ancient? The secret to Jonathan the tortoise’s extreme longevity may be in keeping genes tidyBy Jacek Krywko edited by Sarah Lewin FrasierJonathan the Aldabra giant tortoise is the oldest known land animal. Gianluigi Guercia/AFP/Getty ImagesJonathan, an Aldabra giant tortoise on the South Atlantic island of Saint Helena, appears fully grown in a photograph researchers say was taken around 1882. That means he’s survived to at least 194 years old, about a century past his species’ usual upper limit. In a new Science Advances study, scientists read his DNA to try and figure out why. To get the tortoise’s DNA material, Jonathan’s veterinarian Joe Hollins pretended to feed him, wedged his mouth open with a hard glove and scraped cells from inside his cheek. “It was quite tricky and dangerous,” says study co-author Stephen Clark, a researcher at the Kallel Foundation, a longevity nonprofit in Nashville. But it was worth the maneuver: the researchers found that, compared with other Aldabra tortoises, Jonathan has unique variants in 287 genes, some involved in DNA repair.