I don’t know why people are freaking out over this article. It’s pretty well known that lots of animals (especially within their own class) have eggs that can be fertilized by different species. It doesn’t matter like 99.99% of the time because the resulting cell is unviable and will not develop into anything because the merged DNA is incompatible and will fail to generate into a developed organism.

The exception to this are hybrids (like a mule), rare cases where similar enough species can actually create a viable fetus, but the resultant hybrid is usually sterile and unable to reproduce its own offspring: en.wikipedia.org/wiki/Hybrid_(biology)