Elephants feel empathy. Sea lions keen over the bodies of their loved ones. And new research suggests that yet another species mourns its dead: the spotted dolphin.

Scientists have long observed dolphin rituals around death that suggest they don’t like to leave their dead companions behind, reports Mary Bates for Wired. Now, a new study adds the Atlantic spotted dolphin to that list.

A group of Portuguese marine biologists studied two separate instances in which adult dolphins were recorded using their heads and backs to buoy up a calf who had recently died. Upon examining carcasses from those events and those of two other recently-dead calves, the biologists concluded that spotted dolphin adults tend to hold on to their dead young for about 30 minutes before giving them up to the ocean.

That’s consistent with grieving, study lead Filipe Alves told Bates. He believes the behavior is tied to the complex generational connections that are common in ocean mammals:

Species that live in a matrilineal system, such as killer whales and elephants; species that live in pods of related individuals, such as pilot whales whose pods can comprise up to four generations of animals—when they spend a lifetime together, sometimes 60 years or more, yes, I believe they can grieve.

Alves and his colleagues stop short of using the word “grief” in their study, preferring to classify the dolphins’ ritual as “nurturant behavior.” The term covers a wide variety of animal activities such as social grooming, exchanging gifts, even adopting an animal from another species.

So do dolphins feel sad about their dead loved ones or not? While it’s not certain which feelings drive the spotted dolphin’s need to stay with its dead young, the ritual could be construed as mourning. And the existence of a post-mortem ritual is another item on a long list of things humans and dolphins share.