https://www.vice.com/en_us/article/pkedvy/strange-dark-matter-findings-could-rewrite-the-universes-history

In November, astronomers at the Chinese Academy of Sciences in Beijng published a paper identifying 19 galaxies which might violate the most fundamental theory of how the universe first formed.

They had been searching the sky for yet-undiscovered galaxies which seem to be lacking the usual dark matter component, aiming to add more evidence to a baffling phenomenon scientists had begun observing last year. And they claimed to have found a whole group of them.