Why do we need parents? Found the oldest evidence of care for the offspring

More than 300 million years ago in the Carboniferous period in Nova Scotia (one of the Eastern provinces of Canada, the Atlantic ocean) was one giant subtropical swamp, which was dominated by lycopsid ancient representatives paunovich plants.

In a hollow stump of one of them, on the ground at the roots, the adult vertebrate, like a lizard, took refuge with her cub, probably, waiting out a strong storm or flood.

Ancient beings in the end still died. But in our time, their remains became the earliest example of parental behavior.

the Discovery was made by a local enthusiast, who reported the discovery to a paleontologist Madden Hillary (Hillary Maddin) from Carleton University in Canada.

In an article published in the journal Nature Ecology & Evolution, team Maddin described in detail studied the remains of the age of 309 million years.

turns out they belong to individuals of previously unknown species. He was named Dendromaia unamakiensis – from the Greek words “tree” and “mother”, and the name of the tribe the mi’kmaq (indigenous people who lived in the area where the discovery was made).

According to the researchers, specimens of this species were representatives of varanopids, predatory vertebrates from the group amniote.

Experts note that although varanopidae in appearance were like lizards on evolutionary tree, they are located far from each other.

once terrestrial vertebrates had the opportunity to lay eggs, they split into two evolutionary branches: sauropsid, which include reptiles, dinosaurs and birds, and sinapticheskih, which classifies mammals and their extinct relatives. To the last (synapsida) apply varanopidae.

the Fossilized remains of a species Dendromaia unamakiensis.Photo Maddin et al, 2019.

a study of the remains showed that the adult members of the species D. unamakiensis at length reached no more than 20 centimeters.

But most interesting is that under the rear extremities of the adult, wrapped her tail was the skull of a baby of the same species. This arrangement, according to experts, is a sign of parental care.

Maintaining all the details and structures in the fossils indicates that both specimens were very quickly buried under a layer of sedimentary rocks. This means that the remains have been preserved in the position in which the parent and the baby were, immediately before the death.

the Authors were unable to determine the sex of an adult individual, but pretty sure it was female.

“This is the earliest evidence of prolonged post-Natal care [for offspring] in vertebrates, says Muddin. – An adult animal, apparently, hides and protects the baby in their shelter. This behavior is very common in mammals today. Interestingly, this is the animal that is on the evolutionary line leading to mammals, and demonstrates this behavior at such an early period.”

the Authors note that previous paleontological evidence of care for the offspring by 40 million years younger than new finds.

We tend to consider many of the ancient creatures as a primitive, say paleontologists. However, this petrified pair – a great Testament to the fact that hundreds of millions of years ago, long before dinosaurs, the behaviour of animals was largely similar to modern.

Today, many birds, mammals and reptiles have a lot of time and invest a lot of resources in defense of their offspring (sometimes to his own detriment). In some species, especially social, education of offspring can be incredibly complex: the parents feed the young, are taught to hunt and to defend themselves (and in rare cases, the care of the offspring show and grandmothers).

Commenting on this work in an interview with National Geographic, experts said, when parents and cubs start spending time together, it may be decisive evolutionary step to more complex forms of parental behavior.

If adults show concern for the offspring constantly, over time one or the other develop more complex forms of guardianship and care of the young.

to trace the development of such behaviour, evolutionary biologists it is important to know about the most early and primitive forms of parenthood.

the Authors hope that in the future new findings will allow us to understand whether evolved parental behavior repeatedly or appeared once in the common ancestor of D. unamakiensis and all the animals that continue to care for their children.

by the Way, the paleontologists found that the babies of the giant dinosaurs was surprisingly independent and did not need the protection of adult males or females.

Also “Conduct.Science” (nauka.vesti.ru) told me about the amazing parental behavior of female bonobos, bears, and jumping spiders.

Text: To.Science