For headlines like the former, I usually assume its the publication making a correction to a previous article. Maybe some NG.com inadvertantly turned a joyous story of birth into one a tragedy ("Rare Zoo Cubs Killed!"), and then had to scramble to fixed the disgruntled, unpaid intern's mistake. Maybe Dewey defeated Truman. But it's also that split second between reading it and realizing that you were supposed to take as your basic assumption that zoo cubs are usually killed (right after they are born-- a failure on the part of succinctness in headlines) and ancient deformed children were also usually killed that makes them peculiar and sometimes funny, if morbid. The assumption that this rare zoo cub is brought into the world via murder rather than birth, or maybe the headline forces you to assume that they had once found a mass grave in the Netherlands full of little side show ice man babies, and that you should have known about it. Maybe what's funny is the heights people go to prove to even themselves that they are savvier than they believed.
As it turns out, those rare cubs are clouded leopard cubs, of a species that has a tendency towards violent captive behavior. Explains the article, "For reasons still unknown, breeding clouded leopards in captivity usually turns bloody. Males often kill their mates, and females tend to neglect their cubs or inadvertently kill them. " Likewise, ancient parents have always been assumed, like many mammals, to have killed their little freak babies. The 530,000 year old deformed skull of a ten year old recently discovered may prove otherwise. Again, I had no idea that this was a thing; I never assumed ancient peoples did that. Which just goes to show my ignorance. The only thing I can say to those who already knew that clouded leopard cubs are born, not killed, is that you sure are missing out on some interpretively wackadoo headlines that would have made you giggle. (And that's my defense for being a dummy.)
Also interesting is nature's tendency to cause NG to have theme headline groups. This time it was about homicidal parents. A few weeks ago, with all the crazy squid discovery and life in Antarctica stories as well as the rats are invading India thing, it was positively Lovecraftian.