Human pregnancy dependent on cells evolved in platypus-like animal 300 million years ago

Platelet cells, which prevent mammals from bleeding non-stop, first evolved around 300 million years ago in an egg-laying animal similar to the modern duck-billed platypus, finds joint research by UCL and Yale University.

source https://www.lifetechnology.com/blogs/life-technology-news-blog/human-pregnancy-dependent-on-cells-evolved-in-platypus-like-animal-300-million-years-ago