Shortly after transitioning from sea to land, our egg-laying ancestors may have started parenting their young

Then Hebert spotted another set of bones that stopped him dead in his tracks: a tiny, inch-long skull, nestled into the space where a left femur met a pubic bone. This skull, Hebert realized, belonged to a juvenile, curled up against what was probably its mother.

Hebert didn’t know it at the time, but what he found would soon become the prime piece of evidence in a paper published today in the journal Nature Ecology & Evolution arguing that parental care—investing resources in offspring after birth—is at least 306 million years old.

Plenty of today’s amniotes, the group that includes mammals, birds and reptiles, fuss over their young. While the evolutionary strategy is costly, it increases the chances that an animal’s offspring will succeed, and parenting has often been considered by researchers to be a trait of more modern animals. But this ancient fossil duo, which dates back to the era before dinosaurs when our egg-laying predecessors first crawled ashore, suggests the origins of this nurturing behavior is much more deeply rooted in this branch of the tree of life.

“We tend to think of animals in the past as ‘primitive’ or ‘simple,’” says Jackie Lungmus, a vertebrate paleontologist at the University of Chicago who wasn’t involved in the study. “But they deserve more credit. Even back then … these animals were probably doing a lot of the things that animals still do today.”

https://www.smithsonianmag.com/science-nature/306-million-old-fossil-parental-care-180973833/

PermeateFree said:

Shortly after transitioning from sea to land, our egg-laying ancestors may have started parenting their young

Then Hebert spotted another set of bones that stopped him dead in his tracks: a tiny, inch-long skull, nestled into the space where a left femur met a pubic bone. This skull, Hebert realized, belonged to a juvenile, curled up against what was probably its mother.

Hebert didn’t know it at the time, but what he found would soon become the prime piece of evidence in a paper published today in the journal Nature Ecology & Evolution arguing that parental care—investing resources in offspring after birth—is at least 306 million years old.

Plenty of today’s amniotes, the group that includes mammals, birds and reptiles, fuss over their young. While the evolutionary strategy is costly, it increases the chances that an animal’s offspring will succeed, and parenting has often been considered by researchers to be a trait of more modern animals. But this ancient fossil duo, which dates back to the era before dinosaurs when our egg-laying predecessors first crawled ashore, suggests the origins of this nurturing behavior is much more deeply rooted in this branch of the tree of life.

“We tend to think of animals in the past as ‘primitive’ or ‘simple,’” says Jackie Lungmus, a vertebrate paleontologist at the University of Chicago who wasn’t involved in the study. “But they deserve more credit. Even back then … these animals were probably doing a lot of the things that animals still do today.”

https://www.smithsonianmag.com/science-nature/306-million-old-fossil-parental-care-180973833/

> And if Dendromaia and Heleosaurus were both precocious parents, “that tells us this behavior could have been present in a common ancestor of this group,”

306 million years ago – that’s old.

By way of comparison, the last common ancestor of crocodiles and dinosaurs was a mere 230 million years ago.